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2018
Arosio Paolo, Comito Giuseppina, Orsini Francesco, Lascialfari Alessandro, Chiarugi Paola, Ménard-Moyon Cécilia, Nativi Cristina, Richichi Barbara
Conjugation of a GM3 lactone mimetic on carbon nanotubes enhances the related inhibition of melanoma-associated metastatic events Journal Article
In: Organic & Biomolecular Chemistry, vol. 16, no. 33, pp. 6086–6095, 2018, ISSN: 1477-0539.
Abstract | Links | BibTeX | Tags: Antineoplastic Agents, Biomimetic Materials, carbon, Cell Line, G(M3) Ganglioside, Humans, I2CT, Melanoma, Models, Molecular, Molecular Conformation, Nanotubes, Neoplasm Metastasis, Team-Bianco, tumor
@article{arosio_conjugation_2018,
title = {Conjugation of a GM3 lactone mimetic on carbon nanotubes enhances the related inhibition of melanoma-associated metastatic events},
author = {Paolo Arosio and Giuseppina Comito and Francesco Orsini and Alessandro Lascialfari and Paola Chiarugi and Cécilia Ménard-Moyon and Cristina Nativi and Barbara Richichi},
doi = {10.1039/c8ob01817k},
issn = {1477-0539},
year = {2018},
date = {2018-01-01},
journal = {Organic & Biomolecular Chemistry},
volume = {16},
number = {33},
pages = {6086--6095},
abstract = {GM3-ganglioside is known to be involved in melanoma proliferation. In order to modulate metastatic-related events, we have functionalized multi-walled carbon nanotubes (MWCNTs) with multiple copies of a GM3-lactone mimetic. The MWCNTs proved to guarantee the appropriate spatial arrangement of the mimetic allowing a stronger inhibition of migration and invasiveness of human melanoma (A375) cells compared to other multivalent constructs reported before. In addition, the effect of the multivalent tubular conjugate on the inhibition of specific tyrosine kinases, which are associated with the ganglioside complexes within the membrane domains, was demonstrated. Finally, the short-term fate of the conjugate was assessed, for the first time, by means of the 1H NMR relaxometry technique by exploiting the signal arising from the CNTs.},
keywords = {Antineoplastic Agents, Biomimetic Materials, carbon, Cell Line, G(M3) Ganglioside, Humans, I2CT, Melanoma, Models, Molecular, Molecular Conformation, Nanotubes, Neoplasm Metastasis, Team-Bianco, tumor},
pubstate = {published},
tppubtype = {article}
}
GM3-ganglioside is known to be involved in melanoma proliferation. In order to modulate metastatic-related events, we have functionalized multi-walled carbon nanotubes (MWCNTs) with multiple copies of a GM3-lactone mimetic. The MWCNTs proved to guarantee the appropriate spatial arrangement of the mimetic allowing a stronger inhibition of migration and invasiveness of human melanoma (A375) cells compared to other multivalent constructs reported before. In addition, the effect of the multivalent tubular conjugate on the inhibition of specific tyrosine kinases, which are associated with the ganglioside complexes within the membrane domains, was demonstrated. Finally, the short-term fate of the conjugate was assessed, for the first time, by means of the 1H NMR relaxometry technique by exploiting the signal arising from the CNTs.
2013
Schaeffer Evelyne, Dehuyser Laure, Sigwalt David, Flacher Vincent, Bernacchi Serena, Chaloin Olivier, Remy Jean-Serge, Mueller Christopher G, Baati Rachid, Wagner Alain
Dynamic micelles of mannoside glycolipids are more efficient than polymers for inhibiting HIV-1 trans-infection Journal Article
In: Bioconjugate Chemistry, vol. 24, no. 11, pp. 1813–1823, 2013, ISSN: 1520-4812.
Abstract | Links | BibTeX | Tags: Anti-HIV Agents, Calcium, Cells, Chemistry, Cultured, Dendritic Cells, Dose-Response Relationship, Drug, Electron, fluorescence, Glycolipids, HIV, HIV Infections, HIV-1, Human, Humans, immunodeficiency, immunopathology, inhibition, LECTIN, Lectins, lipid, Mannosides, Micelles, Microbial Sensitivity Tests, Microscopy, Models, Molecular, Molecular Structure, Polymers, prophylaxis, Spectrometry, Structure-Activity Relationship, Surface Plasmon Resonance, target, Team-Mueller, Thermodynamics, Transmission, virus
@article{schaeffer_dynamic_2013,
title = {Dynamic micelles of mannoside glycolipids are more efficient than polymers for inhibiting HIV-1 trans-infection},
author = {Evelyne Schaeffer and Laure Dehuyser and David Sigwalt and Vincent Flacher and Serena Bernacchi and Olivier Chaloin and Jean-Serge Remy and Christopher G Mueller and Rachid Baati and Alain Wagner},
doi = {10.1021/bc4000806},
issn = {1520-4812},
year = {2013},
date = {2013-11-01},
journal = {Bioconjugate Chemistry},
volume = {24},
number = {11},
pages = {1813--1823},
abstract = {Mannoside glycolipid conjugates are able to inhibit human immunodeficiency virus type 1 (HIV-1) trans-infection mediated by human dendritic cells (DCs). The conjugates are formed by three building blocks: a linear or branched mannose head, a hydrophilic linker, and a 24-carbon lipid chain. We have shown that, even as single molecules, these compounds efficiently target mannose-binding lectins, such as DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN) important for HIV-1 transmission. With the goal to optimize their inhibitory activity by supramolecular structure formation, we have compared saturated and unsaturated conjugates, as single molecules, self-assemblies of dynamic micelles, and photopolymerized cross-linked polymers. Surface plasmon resonance showed that, unexpectedly, polymers of trivalent conjugates did not display a higher binding affinity for DC-SIGN than single molecules. Interactions on a chip or in solution were independent of calcium; however, binding to DCs was inhibited by a calcium chelator. Moreover, HIV-1 trans-infection was mostly inhibited by dynamic micelles and not by rigid polymers. The inhibition data revealed a clear correlation between the structure and molecular assembly of a conjugate and its biological antiviral activity. We present an interaction model between DC-SIGN and conjugates-either single molecules, micelles, or polymers-that highlights that the most effective interactions by dynamic micelles involve both mannose heads and lipid chains. Our data reveal that trivalent glycolipid conjugates display the highest microbicide potential for HIV prophylaxis, as dynamic micelles conjugates and not as rigid polymers.},
keywords = {Anti-HIV Agents, Calcium, Cells, Chemistry, Cultured, Dendritic Cells, Dose-Response Relationship, Drug, Electron, fluorescence, Glycolipids, HIV, HIV Infections, HIV-1, Human, Humans, immunodeficiency, immunopathology, inhibition, LECTIN, Lectins, lipid, Mannosides, Micelles, Microbial Sensitivity Tests, Microscopy, Models, Molecular, Molecular Structure, Polymers, prophylaxis, Spectrometry, Structure-Activity Relationship, Surface Plasmon Resonance, target, Team-Mueller, Thermodynamics, Transmission, virus},
pubstate = {published},
tppubtype = {article}
}
Mannoside glycolipid conjugates are able to inhibit human immunodeficiency virus type 1 (HIV-1) trans-infection mediated by human dendritic cells (DCs). The conjugates are formed by three building blocks: a linear or branched mannose head, a hydrophilic linker, and a 24-carbon lipid chain. We have shown that, even as single molecules, these compounds efficiently target mannose-binding lectins, such as DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN) important for HIV-1 transmission. With the goal to optimize their inhibitory activity by supramolecular structure formation, we have compared saturated and unsaturated conjugates, as single molecules, self-assemblies of dynamic micelles, and photopolymerized cross-linked polymers. Surface plasmon resonance showed that, unexpectedly, polymers of trivalent conjugates did not display a higher binding affinity for DC-SIGN than single molecules. Interactions on a chip or in solution were independent of calcium; however, binding to DCs was inhibited by a calcium chelator. Moreover, HIV-1 trans-infection was mostly inhibited by dynamic micelles and not by rigid polymers. The inhibition data revealed a clear correlation between the structure and molecular assembly of a conjugate and its biological antiviral activity. We present an interaction model between DC-SIGN and conjugates-either single molecules, micelles, or polymers-that highlights that the most effective interactions by dynamic micelles involve both mannose heads and lipid chains. Our data reveal that trivalent glycolipid conjugates display the highest microbicide potential for HIV prophylaxis, as dynamic micelles conjugates and not as rigid polymers.
Fukuyama Hidehiro, Verdier Yann, Guan Yongsheng, Makino-Okamura Chieko, Shilova Victoria, Liu Xi, Maksoud Elie, Matsubayashi Jun, Haddad Iman, Spirohn Kerstin, Ono Kenichiro, Hetru Charles, Rossier Jean, Ideker Trey, Boutros Michael, Vinh Joëlle, Hoffmann Jules A
Landscape of protein-protein interactions in Drosophila immune deficiency signaling during bacterial challenge Journal Article
In: Proc. Natl. Acad. Sci. U.S.A., vol. 110, no. 26, pp. 10717–10722, 2013, ISSN: 1091-6490.
Abstract | Links | BibTeX | Tags: Amino Acid, Animals, Chromatin Assembly and Disassembly, Escherichia coli, functional proteomics, Genes, Genetically Modified, Histone Acetyltransferases, hoffmann, Host-Pathogen Interactions, Humans, IMD interactome, Insect, M3i, Models, Molecular, Protein Interaction Maps, Sequence Homology, Signal Transduction, small ubiquitin-like modifier
@article{fukuyama_landscape_2013,
title = {Landscape of protein-protein interactions in Drosophila immune deficiency signaling during bacterial challenge},
author = {Hidehiro Fukuyama and Yann Verdier and Yongsheng Guan and Chieko Makino-Okamura and Victoria Shilova and Xi Liu and Elie Maksoud and Jun Matsubayashi and Iman Haddad and Kerstin Spirohn and Kenichiro Ono and Charles Hetru and Jean Rossier and Trey Ideker and Michael Boutros and Joëlle Vinh and Jules A Hoffmann},
doi = {10.1073/pnas.1304380110},
issn = {1091-6490},
year = {2013},
date = {2013-06-01},
journal = {Proc. Natl. Acad. Sci. U.S.A.},
volume = {110},
number = {26},
pages = {10717--10722},
abstract = {The Drosophila defense against pathogens largely relies on the activation of two signaling pathways: immune deficiency (IMD) and Toll. The IMD pathway is triggered mainly by Gram-negative bacteria, whereas the Toll pathway responds predominantly to Gram-positive bacteria and fungi. The activation of these pathways leads to the rapid induction of numerous NF-κB-induced immune response genes, including antimicrobial peptide genes. The IMD pathway shows significant similarities with the TNF receptor pathway. Recent evidence indicates that the IMD pathway is also activated in response to various noninfectious stimuli (i.e., inflammatory-like reactions). To gain a better understanding of the molecular machinery underlying the pleiotropic functions of this pathway, we first performed a comprehensive proteomics analysis to identify the proteins interacting with the 11 canonical members of the pathway initially identified by genetic studies. We identified 369 interacting proteins (corresponding to 291 genes) in heat-killed Escherichia coli-stimulated Drosophila S2 cells, 92% of which have human orthologs. A comparative analysis of gene ontology from fly or human gene annotation databases points to four significant common categories: (i) the NuA4, nucleosome acetyltransferase of H4, histone acetyltransferase complex, (ii) the switching defective/sucrose nonfermenting-type chromatin remodeling complex, (iii) transcription coactivator activity, and (iv) translation factor activity. Here we demonstrate that sumoylation of the IκB kinase homolog immune response-deficient 5 plays an important role in the induction of antimicrobial peptide genes through a highly conserved sumoylation consensus site during bacterial challenge. Taken together, the proteomics data presented here provide a unique avenue for a comparative functional analysis of proteins involved in innate immune reactions in flies and mammals.},
keywords = {Amino Acid, Animals, Chromatin Assembly and Disassembly, Escherichia coli, functional proteomics, Genes, Genetically Modified, Histone Acetyltransferases, hoffmann, Host-Pathogen Interactions, Humans, IMD interactome, Insect, M3i, Models, Molecular, Protein Interaction Maps, Sequence Homology, Signal Transduction, small ubiquitin-like modifier},
pubstate = {published},
tppubtype = {article}
}
The Drosophila defense against pathogens largely relies on the activation of two signaling pathways: immune deficiency (IMD) and Toll. The IMD pathway is triggered mainly by Gram-negative bacteria, whereas the Toll pathway responds predominantly to Gram-positive bacteria and fungi. The activation of these pathways leads to the rapid induction of numerous NF-κB-induced immune response genes, including antimicrobial peptide genes. The IMD pathway shows significant similarities with the TNF receptor pathway. Recent evidence indicates that the IMD pathway is also activated in response to various noninfectious stimuli (i.e., inflammatory-like reactions). To gain a better understanding of the molecular machinery underlying the pleiotropic functions of this pathway, we first performed a comprehensive proteomics analysis to identify the proteins interacting with the 11 canonical members of the pathway initially identified by genetic studies. We identified 369 interacting proteins (corresponding to 291 genes) in heat-killed Escherichia coli-stimulated Drosophila S2 cells, 92% of which have human orthologs. A comparative analysis of gene ontology from fly or human gene annotation databases points to four significant common categories: (i) the NuA4, nucleosome acetyltransferase of H4, histone acetyltransferase complex, (ii) the switching defective/sucrose nonfermenting-type chromatin remodeling complex, (iii) transcription coactivator activity, and (iv) translation factor activity. Here we demonstrate that sumoylation of the IκB kinase homolog immune response-deficient 5 plays an important role in the induction of antimicrobial peptide genes through a highly conserved sumoylation consensus site during bacterial challenge. Taken together, the proteomics data presented here provide a unique avenue for a comparative functional analysis of proteins involved in innate immune reactions in flies and mammals.
Baron Olga Lucia, van West Pieter, Industri Benoit, Ponchet Michel, Dubreuil Géraldine, Gourbal Benjamin, Reichhart Jean-Marc, Coustau Christine
Parental transfer of the antimicrobial protein LBP/BPI protects Biomphalaria glabrata eggs against oomycete infections Journal Article
In: PLoS Pathog., vol. 9, no. 12, pp. e1003792, 2013, ISSN: 1553-7374.
Abstract | Links | BibTeX | Tags: Acute-Phase Proteins, Animals, Antimicrobial Cationic Peptides, Biomphalaria, Blood Proteins, Carrier Proteins, Cell Membrane, Cell Membrane Permeability, Cloning, Escherichia coli, Female, Immunity, infection, M3i, Maternally-Acquired, Membrane Glycoproteins, Microbial Sensitivity Tests, Molecular, Oomycetes, Recombinant Proteins, reichhart, Zygote
@article{baron_parental_2013,
title = {Parental transfer of the antimicrobial protein LBP/BPI protects Biomphalaria glabrata eggs against oomycete infections},
author = {Olga Lucia Baron and Pieter van West and Benoit Industri and Michel Ponchet and Géraldine Dubreuil and Benjamin Gourbal and Jean-Marc Reichhart and Christine Coustau},
doi = {10.1371/journal.ppat.1003792},
issn = {1553-7374},
year = {2013},
date = {2013-01-01},
journal = {PLoS Pathog.},
volume = {9},
number = {12},
pages = {e1003792},
abstract = {Vertebrate females transfer antibodies via the placenta, colostrum and milk or via the egg yolk to protect their immunologically immature offspring against pathogens. This evolutionarily important transfer of immunity is poorly documented in invertebrates and basic questions remain regarding the nature and extent of parental protection of offspring. In this study, we show that a lipopolysaccharide binding protein/bactericidal permeability increasing protein family member from the invertebrate Biomphalaria glabrata (BgLBP/BPI1) is massively loaded into the eggs of this freshwater snail. Native and recombinant proteins displayed conserved LPS-binding, antibacterial and membrane permeabilizing activities. A broad screening of various pathogens revealed a previously unknown biocidal activity of the protein against pathogenic water molds (oomycetes), which is conserved in human BPI. RNAi-dependent silencing of LBP/BPI in the parent snails resulted in a significant reduction of reproductive success and extensive death of eggs through oomycete infections. This work provides the first functional evidence that a LBP/BPI is involved in the parental immune protection of invertebrate offspring and reveals a novel and conserved biocidal activity for LBP/BPI family members.},
keywords = {Acute-Phase Proteins, Animals, Antimicrobial Cationic Peptides, Biomphalaria, Blood Proteins, Carrier Proteins, Cell Membrane, Cell Membrane Permeability, Cloning, Escherichia coli, Female, Immunity, infection, M3i, Maternally-Acquired, Membrane Glycoproteins, Microbial Sensitivity Tests, Molecular, Oomycetes, Recombinant Proteins, reichhart, Zygote},
pubstate = {published},
tppubtype = {article}
}
Vertebrate females transfer antibodies via the placenta, colostrum and milk or via the egg yolk to protect their immunologically immature offspring against pathogens. This evolutionarily important transfer of immunity is poorly documented in invertebrates and basic questions remain regarding the nature and extent of parental protection of offspring. In this study, we show that a lipopolysaccharide binding protein/bactericidal permeability increasing protein family member from the invertebrate Biomphalaria glabrata (BgLBP/BPI1) is massively loaded into the eggs of this freshwater snail. Native and recombinant proteins displayed conserved LPS-binding, antibacterial and membrane permeabilizing activities. A broad screening of various pathogens revealed a previously unknown biocidal activity of the protein against pathogenic water molds (oomycetes), which is conserved in human BPI. RNAi-dependent silencing of LBP/BPI in the parent snails resulted in a significant reduction of reproductive success and extensive death of eggs through oomycete infections. This work provides the first functional evidence that a LBP/BPI is involved in the parental immune protection of invertebrate offspring and reveals a novel and conserved biocidal activity for LBP/BPI family members.
2011
Aoun Richard Bou, Hetru Charles, Troxler Laurent, Doucet Daniel, Ferrandon Dominique, Matt Nicolas
Analysis of thioester-containing proteins during the innate immune response of Drosophila melanogaster Journal Article
In: J Innate Immun, vol. 3, no. 1, pp. 52–64, 2011, ISSN: 1662-8128.
Abstract | Links | BibTeX | Tags: Animals, bioinformatic, DNA, Evolution, ferrandon, Gene Expression Regulation, Hemocytes, Immunity, In Situ Hybridization, Innate, M3i, matt, Molecular, Mutation, Phylogeny, Sequence Analysis
@article{bou_aoun_analysis_2011,
title = {Analysis of thioester-containing proteins during the innate immune response of Drosophila melanogaster},
author = {Richard Bou Aoun and Charles Hetru and Laurent Troxler and Daniel Doucet and Dominique Ferrandon and Nicolas Matt},
doi = {10.1159/000321554},
issn = {1662-8128},
year = {2011},
date = {2011-01-01},
journal = {J Innate Immun},
volume = {3},
number = {1},
pages = {52--64},
abstract = {Thioester-containing proteins (TEPs) are conserved proteins among insects that are thought to be involved in innate immunity. In Drosophila, the Tep family is composed of 6 genes named Tep1-Tep6. In this study, we investigated the phylogeny, expression pattern and roles of these genes in the host defense of Drosophila. Protostomian Tep genes are clustered in 3 distinct branches, 1 of which is specific to mosquitoes. Most D. melanogaster Tep genes are expressed in hemocytes, can be induced in the fat body, and are expressed in specific regions of the hypodermis. This expression pattern is consistent with a role in innate immunity. However, we find that TEP1, TEP2, and TEP4 are not strictly required in the body cavity to fight several bacterial and fungal infections. One possibility is that Drosophila TEPs act redundantly or that their absence can be compensated by other components of the immune response. TEPs may thus provide a subtle selective advantage during evolution. Alternatively, they may be required in host defense against specific as yet unidentified natural pathogens of Drosophila.},
keywords = {Animals, bioinformatic, DNA, Evolution, ferrandon, Gene Expression Regulation, Hemocytes, Immunity, In Situ Hybridization, Innate, M3i, matt, Molecular, Mutation, Phylogeny, Sequence Analysis},
pubstate = {published},
tppubtype = {article}
}
Thioester-containing proteins (TEPs) are conserved proteins among insects that are thought to be involved in innate immunity. In Drosophila, the Tep family is composed of 6 genes named Tep1-Tep6. In this study, we investigated the phylogeny, expression pattern and roles of these genes in the host defense of Drosophila. Protostomian Tep genes are clustered in 3 distinct branches, 1 of which is specific to mosquitoes. Most D. melanogaster Tep genes are expressed in hemocytes, can be induced in the fat body, and are expressed in specific regions of the hypodermis. This expression pattern is consistent with a role in innate immunity. However, we find that TEP1, TEP2, and TEP4 are not strictly required in the body cavity to fight several bacterial and fungal infections. One possibility is that Drosophila TEPs act redundantly or that their absence can be compensated by other components of the immune response. TEPs may thus provide a subtle selective advantage during evolution. Alternatively, they may be required in host defense against specific as yet unidentified natural pathogens of Drosophila.
2010
Al-Jamal Khuloud T, Toma Francesca M, Yilmazer Açelya, Ali-Boucetta Hanene, Nunes Antonio, Herrero Maria-Antonia, Tian Bowen, Eddaoudi Ayad, Eddaoui Ayad, Al-Jamal Wafa' T, Bianco Alberto, Prato Maurizio, Kostarelo Kostas
Enhanced cellular internalization and gene silencing with a series of cationic dendron-multiwalled carbon nanotube:siRNA complexes Journal Article
In: FASEB journal: official publication of the Federation of American Societies for Experimental Biology, vol. 24, no. 11, pp. 4354–4365, 2010, ISSN: 1530-6860.
Abstract | Links | BibTeX | Tags: Biological Transport, carbon, Cations, Cell Line, Cell Survival, Gene Silencing, HeLa Cells, Humans, I2CT, Models, Molecular, Nanotubes, RNA, Small Interfering, Team-Bianco, Transfection, tumor
@article{al-jamal_enhanced_2010,
title = {Enhanced cellular internalization and gene silencing with a series of cationic dendron-multiwalled carbon nanotube:siRNA complexes},
author = {Khuloud T Al-Jamal and Francesca M Toma and Açelya Yilmazer and Hanene Ali-Boucetta and Antonio Nunes and Maria-Antonia Herrero and Bowen Tian and Ayad Eddaoudi and Ayad Eddaoui and Wafa' T Al-Jamal and Alberto Bianco and Maurizio Prato and Kostas Kostarelo},
doi = {10.1096/fj.09-141036},
issn = {1530-6860},
year = {2010},
date = {2010-11-01},
journal = {FASEB journal: official publication of the Federation of American Societies for Experimental Biology},
volume = {24},
number = {11},
pages = {4354--4365},
abstract = {One of the major obstacles to the clinical development of gene silencing by small interfering RNA (siRNA) is its effective cytoplasmic delivery. Carbon nanotubes have been proposed as novel nanomaterials that can offer significant advantages for the intracellular delivery of nucleic acids, such as siRNA. We recently demonstrated in a proof-of-principle study that amino-functionalized multiwalled carbon nanotubes (f-MWNT) can effectively deliver in vivo an siRNA sequence, triggering cell apoptosis that results in human lung xenograft eradication and prolonged survival. In the present study, we demonstrate how a newly synthesized series of polycationic dendron-MWNT constructs with a precisely tailored number of amino functions (dendron generations) can complex and effectively deliver double-stranded siRNA to achieve gene silencing in vitro. A systematic comparison between the f-MWNT series in terms of cellular uptake, cytotoxicity, and siRNA complexation is offered. Significant improvement in siRNA delivery with the dendron-MWNT conjugates is shown, and gene silencing was obtained in 2 human cell lines using 2 different siRNA sequences. The study reveals that through f-MWNT structure-biological function analysis novel nanotube-based siRNA transfer vectors can be designed with minimal cytotoxicity and effective delivery and gene-silencing capabilities.},
keywords = {Biological Transport, carbon, Cations, Cell Line, Cell Survival, Gene Silencing, HeLa Cells, Humans, I2CT, Models, Molecular, Nanotubes, RNA, Small Interfering, Team-Bianco, Transfection, tumor},
pubstate = {published},
tppubtype = {article}
}
One of the major obstacles to the clinical development of gene silencing by small interfering RNA (siRNA) is its effective cytoplasmic delivery. Carbon nanotubes have been proposed as novel nanomaterials that can offer significant advantages for the intracellular delivery of nucleic acids, such as siRNA. We recently demonstrated in a proof-of-principle study that amino-functionalized multiwalled carbon nanotubes (f-MWNT) can effectively deliver in vivo an siRNA sequence, triggering cell apoptosis that results in human lung xenograft eradication and prolonged survival. In the present study, we demonstrate how a newly synthesized series of polycationic dendron-MWNT constructs with a precisely tailored number of amino functions (dendron generations) can complex and effectively deliver double-stranded siRNA to achieve gene silencing in vitro. A systematic comparison between the f-MWNT series in terms of cellular uptake, cytotoxicity, and siRNA complexation is offered. Significant improvement in siRNA delivery with the dendron-MWNT conjugates is shown, and gene silencing was obtained in 2 human cell lines using 2 different siRNA sequences. The study reveals that through f-MWNT structure-biological function analysis novel nanotube-based siRNA transfer vectors can be designed with minimal cytotoxicity and effective delivery and gene-silencing capabilities.
2009
Kemp Cordula, Imler Jean-Luc
Antiviral immunity in drosophila Journal Article
In: Current Opinion in Immunology, vol. 21, no. 1, pp. 3–9, 2009, ISSN: 1879-0372.
Abstract | Links | BibTeX | Tags: Animals, Argonaute Proteins, Caspases, DEAD-box RNA Helicases, Evolution, Gene Expression Regulation, Host-Pathogen Interactions, imler, M3i, Membrane Proteins, Molecular, Nuclear Proteins, Ribonuclease III, RNA, RNA Helicases, RNA Interference, RNA Virus Infections, RNA Viruses, RNA-Induced Silencing Complex, Viral, Virulence
@article{kemp_antiviral_2009,
title = {Antiviral immunity in drosophila},
author = {Cordula Kemp and Jean-Luc Imler},
doi = {10.1016/j.coi.2009.01.007},
issn = {1879-0372},
year = {2009},
date = {2009-02-01},
journal = {Current Opinion in Immunology},
volume = {21},
number = {1},
pages = {3--9},
abstract = {Genetic analysis of the drosophila antiviral response indicates that RNA interference plays a major role. This contrasts with the situation in mammals, where interferon-induced responses mediate innate antiviral host-defense. An inducible response also contributes to antiviral immunity in drosophila, and similarities in the sensing and signaling of viral infection are becoming apparent between drosophila and mammals. In particular, DExD/H box helicases appear to play a crucial role in the cytosolic detection of viral RNAs in flies and mammals.},
keywords = {Animals, Argonaute Proteins, Caspases, DEAD-box RNA Helicases, Evolution, Gene Expression Regulation, Host-Pathogen Interactions, imler, M3i, Membrane Proteins, Molecular, Nuclear Proteins, Ribonuclease III, RNA, RNA Helicases, RNA Interference, RNA Virus Infections, RNA Viruses, RNA-Induced Silencing Complex, Viral, Virulence},
pubstate = {published},
tppubtype = {article}
}
Genetic analysis of the drosophila antiviral response indicates that RNA interference plays a major role. This contrasts with the situation in mammals, where interferon-induced responses mediate innate antiviral host-defense. An inducible response also contributes to antiviral immunity in drosophila, and similarities in the sensing and signaling of viral infection are becoming apparent between drosophila and mammals. In particular, DExD/H box helicases appear to play a crucial role in the cytosolic detection of viral RNAs in flies and mammals.
Garrett Matthew, Fullaondo Ane, Troxler Laurent, Micklem Gos, Gubb David
Identification and analysis of serpin-family genes by homology and synteny across the 12 sequenced Drosophilid genomes Journal Article
In: BMC Genomics, vol. 10, pp. 489, 2009, ISSN: 1471-2164.
Abstract | Links | BibTeX | Tags: Animals, bioinformatic, Comparative Genomic Hybridization, Conserved Sequence, DNA, Drosophilidae, Evolution, Genome, Insect, Molecular, Multigene Family, Sequence Alignment, Sequence Analysis, Serpins, Synteny
@article{garrett_identification_2009,
title = {Identification and analysis of serpin-family genes by homology and synteny across the 12 sequenced Drosophilid genomes},
author = {Matthew Garrett and Ane Fullaondo and Laurent Troxler and Gos Micklem and David Gubb},
doi = {10.1186/1471-2164-10-489},
issn = {1471-2164},
year = {2009},
date = {2009-01-01},
journal = {BMC Genomics},
volume = {10},
pages = {489},
abstract = {BACKGROUND: The Drosophila melanogaster genome contains 29 serpin genes, 12 as single transcripts and 17 within 6 gene clusters. Many of these serpins have a conserved "hinge" motif characteristic of active proteinase inhibitors. However, a substantial proportion (42%) lacks this motif and represents non-inhibitory serpin-fold proteins of unknown function. Currently, it is not known whether orthologous, inhibitory serpin genes retain the same target proteinase specificity within the Drosophilid lineage, nor whether they give rise to non-inhibitory serpin-fold proteins or other, more diverged, proteins. RESULTS: We collated 188 orthologues to the D. melanogaster serpins from the other 11 Drosophilid genomes and used synteny to find further family members, raising the total to 226, or 71% of the number of orthologues expected assuming complete conservation across all 12 Drosophilid species. In general the sequence constraints on the serpin-fold itself are loose. The critical Reactive Centre Loop (RCL) sequence, including the target proteinase cleavage site, is strongly conserved in inhibitory serpins, although there are 3 exceptional sets of orthologues in which the evolutionary constraints are looser. Conversely, the RCL of non-inhibitory serpin orthologues is less conserved, with 3 exceptions that presumably bind to conserved partner molecules. We derive a consensus hinge motif, for Drosophilid inhibitory serpins, which differs somewhat from that of the vertebrate consensus. Three gene clusters appear to have originated in the melanogaster subgroup, Spn28D, Spn77B and Spn88E, each containing one inhibitory serpin orthologue that is present in all Drosophilids. In addition, the Spn100A transcript appears to represent a novel serpin-derived fold. CONCLUSION: In general, inhibitory serpins rarely change their range of proteinase targets, except by a duplication/divergence mechanism. Non-inhibitory serpins appear to derive from inhibitory serpins, but not the reverse. The conservation of different family members varied widely across the 12 sequenced Drosophilid genomes. An approach considering synteny as well as homology was important to find the largest set of orthologues.},
keywords = {Animals, bioinformatic, Comparative Genomic Hybridization, Conserved Sequence, DNA, Drosophilidae, Evolution, Genome, Insect, Molecular, Multigene Family, Sequence Alignment, Sequence Analysis, Serpins, Synteny},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: The Drosophila melanogaster genome contains 29 serpin genes, 12 as single transcripts and 17 within 6 gene clusters. Many of these serpins have a conserved "hinge" motif characteristic of active proteinase inhibitors. However, a substantial proportion (42%) lacks this motif and represents non-inhibitory serpin-fold proteins of unknown function. Currently, it is not known whether orthologous, inhibitory serpin genes retain the same target proteinase specificity within the Drosophilid lineage, nor whether they give rise to non-inhibitory serpin-fold proteins or other, more diverged, proteins. RESULTS: We collated 188 orthologues to the D. melanogaster serpins from the other 11 Drosophilid genomes and used synteny to find further family members, raising the total to 226, or 71% of the number of orthologues expected assuming complete conservation across all 12 Drosophilid species. In general the sequence constraints on the serpin-fold itself are loose. The critical Reactive Centre Loop (RCL) sequence, including the target proteinase cleavage site, is strongly conserved in inhibitory serpins, although there are 3 exceptional sets of orthologues in which the evolutionary constraints are looser. Conversely, the RCL of non-inhibitory serpin orthologues is less conserved, with 3 exceptions that presumably bind to conserved partner molecules. We derive a consensus hinge motif, for Drosophilid inhibitory serpins, which differs somewhat from that of the vertebrate consensus. Three gene clusters appear to have originated in the melanogaster subgroup, Spn28D, Spn77B and Spn88E, each containing one inhibitory serpin orthologue that is present in all Drosophilids. In addition, the Spn100A transcript appears to represent a novel serpin-derived fold. CONCLUSION: In general, inhibitory serpins rarely change their range of proteinase targets, except by a duplication/divergence mechanism. Non-inhibitory serpins appear to derive from inhibitory serpins, but not the reverse. The conservation of different family members varied widely across the 12 sequenced Drosophilid genomes. An approach considering synteny as well as homology was important to find the largest set of orthologues.
Guichard Gilles, Trouche Nathalie, Wieckowski Sébastien, Sun Weimin, Chaloin Olivier, Bianco Alberto, Hoebeke Johan, Schneider Pascal, Fournel Sylvie
Rationally-designed multivalent architectures for mimicking homotrimers of CD40L, a member of the TNF superfamily Journal Article
In: Advances in Experimental Medicine and Biology, vol. 611, pp. 355–357, 2009, ISSN: 0065-2598.
Links | BibTeX | Tags: Biopolymers, CD40 Ligand, I2CT, Models, Molecular, Molecular Mimicry, Team-Bianco, X-Ray Diffraction
@article{guichard_rationally-designed_2009,
title = {Rationally-designed multivalent architectures for mimicking homotrimers of CD40L, a member of the TNF superfamily},
author = {Gilles Guichard and Nathalie Trouche and Sébastien Wieckowski and Weimin Sun and Olivier Chaloin and Alberto Bianco and Johan Hoebeke and Pascal Schneider and Sylvie Fournel},
doi = {10.1007/978-0-387-73657-0_157},
issn = {0065-2598},
year = {2009},
date = {2009-01-01},
journal = {Advances in Experimental Medicine and Biology},
volume = {611},
pages = {355--357},
keywords = {Biopolymers, CD40 Ligand, I2CT, Models, Molecular, Molecular Mimicry, Team-Bianco, X-Ray Diffraction},
pubstate = {published},
tppubtype = {article}
}
Geotti-Bianchini Piero, Crisma Marco, Peggion Cristina, Bianco Alberto, Formaggio Fernando
Synthesis and 3D-structure of conformationally controlled nucleo-peptides Journal Article
In: Advances in Experimental Medicine and Biology, vol. 611, pp. 37–38, 2009, ISSN: 0065-2598.
Links | BibTeX | Tags: I2CT, Models, Molecular, Nucleoproteins, Peptides, Protein Conformation, Team-Bianco
@article{geotti-bianchini_synthesis_2009,
title = {Synthesis and 3D-structure of conformationally controlled nucleo-peptides},
author = {Piero Geotti-Bianchini and Marco Crisma and Cristina Peggion and Alberto Bianco and Fernando Formaggio},
doi = {10.1007/978-0-387-73657-0_16},
issn = {0065-2598},
year = {2009},
date = {2009-01-01},
journal = {Advances in Experimental Medicine and Biology},
volume = {611},
pages = {37--38},
keywords = {I2CT, Models, Molecular, Nucleoproteins, Peptides, Protein Conformation, Team-Bianco},
pubstate = {published},
tppubtype = {article}
}
2008
Geary C., Baudrey S., Jaeger L.
Comprehensive features of natural and in vitro selected GNRA tetraloop-binding receptors Journal Article
In: Nucleic Acids Res, vol. 36, no. 4, pp. 1138-52, 2008, (1362-4962 (Electronic) Journal Article Research Support, N.I.H., Extramural Research Support, U.S. Gov't, Non-P.H.S.).
Abstract | BibTeX | Tags: Acid, Adenine/chemistry, Analysis, Base, Conformation, Data, dimerization, directed, Evolution, KROL, Models, Molecular, Nucleic, RNA, RNA/*chemistry/classification, Sequence, Thermodynamics
@article{,
title = {Comprehensive features of natural and in vitro selected GNRA tetraloop-binding receptors},
author = { C. Geary and S. Baudrey and L. Jaeger},
year = {2008},
date = {2008-01-01},
journal = {Nucleic Acids Res},
volume = {36},
number = {4},
pages = {1138-52},
abstract = {Specific recognitions of GNRA tetraloops by small helical receptors are among the most widespread long-range packing interactions in large ribozymes. However, in contrast to GYRA and GAAA tetraloops, very few GNRA/receptor interactions have yet been identified to involve GGAA tetraloops in nature. A novel in vitro selection scheme based on a rigid self-assembling tectoRNA scaffold designed for isolation of intermolecular interactions with A-minor motifs has yielded new GGAA tetraloop-binding receptors with affinity in the nanomolar range. One of the selected receptors is a novel 12 nt RNA motif, (CCUGUG. AUCUGG), that recognizes GGAA tetraloop hairpin with a remarkable specificity and affinity. Its physical and chemical characteristics are comparable to those of the well-studied '11nt' GAAA tetraloop receptor motif. A second less specific motif (CCCAGCCC. GAUAGGG) binds GGRA tetraloops and appears to be related to group IC3 tetraloop receptors. Mutational, thermodynamic and comparative structural analysis suggests that natural and in vitro selected GNRA receptors can essentially be grouped in two major classes of GNRA binders. New insights about the evolution, recognition and structural modularity of GNRA and A-minor RNA-RNA interactions are proposed.},
note = {1362-4962 (Electronic)
Journal Article
Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.},
keywords = {Acid, Adenine/chemistry, Analysis, Base, Conformation, Data, dimerization, directed, Evolution, KROL, Models, Molecular, Nucleic, RNA, RNA/*chemistry/classification, Sequence, Thermodynamics},
pubstate = {published},
tppubtype = {article}
}
Specific recognitions of GNRA tetraloops by small helical receptors are among the most widespread long-range packing interactions in large ribozymes. However, in contrast to GYRA and GAAA tetraloops, very few GNRA/receptor interactions have yet been identified to involve GGAA tetraloops in nature. A novel in vitro selection scheme based on a rigid self-assembling tectoRNA scaffold designed for isolation of intermolecular interactions with A-minor motifs has yielded new GGAA tetraloop-binding receptors with affinity in the nanomolar range. One of the selected receptors is a novel 12 nt RNA motif, (CCUGUG. AUCUGG), that recognizes GGAA tetraloop hairpin with a remarkable specificity and affinity. Its physical and chemical characteristics are comparable to those of the well-studied '11nt' GAAA tetraloop receptor motif. A second less specific motif (CCCAGCCC. GAUAGGG) binds GGRA tetraloops and appears to be related to group IC3 tetraloop receptors. Mutational, thermodynamic and comparative structural analysis suggests that natural and in vitro selected GNRA receptors can essentially be grouped in two major classes of GNRA binders. New insights about the evolution, recognition and structural modularity of GNRA and A-minor RNA-RNA interactions are proposed.
2007
Mandin P., Repoila F., Vergassola M., Geissmann T., Cossart P.
Identification of new noncoding RNAs in Listeria monocytogenes and prediction of mRNA targets Journal Article
In: Nucleic Acids Res, vol. 35, no. 3, pp. 962-74, 2007, (1362-4962 (Electronic) Journal Article Research Support, Non-U.S. Gov't).
Abstract | BibTeX | Tags: 5', Assay, Bacterial, Base, Biology, Computational, Data, DNA, Electrophoretic, Flanking, Genes, Genomics, Intergenic/chemistry, Listeria, Messenger/chemistry/*metabolism, Mobility, Molecular, monocytogenes/*genetics/metabolism, Region, RNA, ROMBY, Sequence, Shift, Untranslated/analysis/*genetics/metabolism
@article{,
title = {Identification of new noncoding RNAs in Listeria monocytogenes and prediction of mRNA targets},
author = { P. Mandin and F. Repoila and M. Vergassola and T. Geissmann and P. Cossart},
year = {2007},
date = {2007-01-01},
journal = {Nucleic Acids Res},
volume = {35},
number = {3},
pages = {962-74},
abstract = {To identify noncoding RNAs (ncRNAs) in the pathogenic bacterium Listeria monocytogenes, we analyzed the intergenic regions (IGRs) of strain EGD-e by in silico-based approaches. Among the twelve ncRNAs found, nine are novel and specific to the Listeria genus, and two of these ncRNAs are expressed in a growth-dependent manner. Three of the ncRNAs are transcribed in opposite direction to overlapping open reading frames (ORFs), suggesting that they act as antisense on the corresponding mRNAs. The other ncRNA genes appear as single transcription units. One of them displays five repeats of 29 nucleotides. Five of these new ncRNAs are absent from the non-pathogenic species L. innocua, raising the possibility that they might be involved in virulence. To predict mRNA targets of the ncRNAs, we developed a computational method based on thermodynamic pairing energies and known ncRNA-mRNA hybrids. Three ncRNAs, including one of the putative antisense ncRNAs, were predicted to have more than one mRNA targets. Several of them were shown to bind efficiently to the ncRNAs suggesting that our in silico approach could be used as a general tool to search for mRNA targets of ncRNAs.},
note = {1362-4962 (Electronic)
Journal Article
Research Support, Non-U.S. Gov't},
keywords = {5', Assay, Bacterial, Base, Biology, Computational, Data, DNA, Electrophoretic, Flanking, Genes, Genomics, Intergenic/chemistry, Listeria, Messenger/chemistry/*metabolism, Mobility, Molecular, monocytogenes/*genetics/metabolism, Region, RNA, ROMBY, Sequence, Shift, Untranslated/analysis/*genetics/metabolism},
pubstate = {published},
tppubtype = {article}
}
To identify noncoding RNAs (ncRNAs) in the pathogenic bacterium Listeria monocytogenes, we analyzed the intergenic regions (IGRs) of strain EGD-e by in silico-based approaches. Among the twelve ncRNAs found, nine are novel and specific to the Listeria genus, and two of these ncRNAs are expressed in a growth-dependent manner. Three of the ncRNAs are transcribed in opposite direction to overlapping open reading frames (ORFs), suggesting that they act as antisense on the corresponding mRNAs. The other ncRNA genes appear as single transcription units. One of them displays five repeats of 29 nucleotides. Five of these new ncRNAs are absent from the non-pathogenic species L. innocua, raising the possibility that they might be involved in virulence. To predict mRNA targets of the ncRNAs, we developed a computational method based on thermodynamic pairing energies and known ncRNA-mRNA hybrids. Three ncRNAs, including one of the putative antisense ncRNAs, were predicted to have more than one mRNA targets. Several of them were shown to bind efficiently to the ncRNAs suggesting that our in silico approach could be used as a general tool to search for mRNA targets of ncRNAs.
Croker Ben, Crozat Karine, Berger Michael, Xia Yu, Sovath Sosathya, Schaffer Lana, Eleftherianos Ioannis, Imler Jean-Luc, Beutler Bruce
ATP-sensitive potassium channels mediate survival during infection in mammals and insects Journal Article
In: Nature Genetics, vol. 39, no. 12, pp. 1453–1460, 2007, ISSN: 1546-1718.
Abstract | Links | BibTeX | Tags: Animals, ATP-Binding Cassette Transporters, Cloning, Coronary Vessels, Crosses, Ethylnitrosourea, Genetic, Homozygote, imler, infection, Inwardly Rectifying, KATP Channels, Lipopolysaccharides, M3i, Mice, Molecular, Mutagenesis, Potassium Channels, Sulfonylurea Receptors
@article{croker_atp-sensitive_2007,
title = {ATP-sensitive potassium channels mediate survival during infection in mammals and insects},
author = {Ben Croker and Karine Crozat and Michael Berger and Yu Xia and Sosathya Sovath and Lana Schaffer and Ioannis Eleftherianos and Jean-Luc Imler and Bruce Beutler},
doi = {10.1038/ng.2007.25},
issn = {1546-1718},
year = {2007},
date = {2007-01-01},
journal = {Nature Genetics},
volume = {39},
number = {12},
pages = {1453--1460},
abstract = {Specific homeostatic mechanisms confer stability in innate immune responses, preventing injury or death from infection. Here we identify, from a screen of N-ethyl-N-nitrosourea-mutagenized mice, a mutation causing both profound susceptibility to infection by mouse cytomegalovirus and approximately 20,000-fold sensitization to lipopolysaccharide (LPS), poly(I.C) and immunostimulatory (CpG) DNA. The LPS hypersensitivity phenotype is not suppressed by mutations in Myd88, Trif, Tnf, Tnfrsf1a, Ifnb, Ifng or Stat1, genes contributing to LPS responses, and results from an abnormality extrinsic to hematopoietic cells. The phenotype is due to a null allele of Kcnj8, encoding Kir6.1, a protein that combines with SUR2 to form an ATP-sensitive potassium channel (K(ATP)) expressed in coronary artery smooth muscle and endothelial cells. In Drosophila melanogaster, suppression of dSUR by RNA interference similarly causes hypersensitivity to infection by flock house virus. Thus, K(ATP) evolved to serve a homeostatic function during infection, and in mammals it prevents coronary artery vasoconstriction induced by cytokines dependent on TLR and/or MDA5 immunoreceptors.},
keywords = {Animals, ATP-Binding Cassette Transporters, Cloning, Coronary Vessels, Crosses, Ethylnitrosourea, Genetic, Homozygote, imler, infection, Inwardly Rectifying, KATP Channels, Lipopolysaccharides, M3i, Mice, Molecular, Mutagenesis, Potassium Channels, Sulfonylurea Receptors},
pubstate = {published},
tppubtype = {article}
}
Specific homeostatic mechanisms confer stability in innate immune responses, preventing injury or death from infection. Here we identify, from a screen of N-ethyl-N-nitrosourea-mutagenized mice, a mutation causing both profound susceptibility to infection by mouse cytomegalovirus and approximately 20,000-fold sensitization to lipopolysaccharide (LPS), poly(I.C) and immunostimulatory (CpG) DNA. The LPS hypersensitivity phenotype is not suppressed by mutations in Myd88, Trif, Tnf, Tnfrsf1a, Ifnb, Ifng or Stat1, genes contributing to LPS responses, and results from an abnormality extrinsic to hematopoietic cells. The phenotype is due to a null allele of Kcnj8, encoding Kir6.1, a protein that combines with SUR2 to form an ATP-sensitive potassium channel (K(ATP)) expressed in coronary artery smooth muscle and endothelial cells. In Drosophila melanogaster, suppression of dSUR by RNA interference similarly causes hypersensitivity to infection by flock house virus. Thus, K(ATP) evolved to serve a homeostatic function during infection, and in mammals it prevents coronary artery vasoconstriction induced by cytokines dependent on TLR and/or MDA5 immunoreceptors.
2006
Pastorin Giorgia, Marchesan Silvia, Hoebeke Johan, Ros Tatiana Da, Ehret-Sabatier Laurence, Briand Jean-Paul, Prato Maurizio, Bianco Alberto
Design and activity of cationic fullerene derivatives as inhibitors of acetylcholinesterase Journal Article
In: Organic & Biomolecular Chemistry, vol. 4, no. 13, pp. 2556–2562, 2006, ISSN: 1477-0520.
Abstract | Links | BibTeX | Tags: Acetylcholinesterase, Binding Sites, Cations, Cholinesterase Inhibitors, Drug Design, Fullerenes, I2CT, Models, Molecular, Team-Bianco
@article{pastorin_design_2006,
title = {Design and activity of cationic fullerene derivatives as inhibitors of acetylcholinesterase},
author = {Giorgia Pastorin and Silvia Marchesan and Johan Hoebeke and Tatiana Da Ros and Laurence Ehret-Sabatier and Jean-Paul Briand and Maurizio Prato and Alberto Bianco},
doi = {10.1039/b604361e},
issn = {1477-0520},
year = {2006},
date = {2006-07-01},
journal = {Organic & Biomolecular Chemistry},
volume = {4},
number = {13},
pages = {2556--2562},
abstract = {Four different regioisomers of cationic bis-N,N-dimethylfulleropyrrolidinium salts have been prepared and evaluated as inhibitors of the enzymatic activity of acetylcholinesterase. These fullerene-based derivatives were found to be noncompetitive inhibitors of acetylthiocholine hydrolysis. Molecular modelling was used to describe the possible interactions between the fullerene cage and the amino acids surrounding the cavity of the enzyme. The cationic C(60) derivatives used in this study represent a new class of molecules potentially able to modulate the enzymatic activity of acetylcholinesterase.},
keywords = {Acetylcholinesterase, Binding Sites, Cations, Cholinesterase Inhibitors, Drug Design, Fullerenes, I2CT, Models, Molecular, Team-Bianco},
pubstate = {published},
tppubtype = {article}
}
Four different regioisomers of cationic bis-N,N-dimethylfulleropyrrolidinium salts have been prepared and evaluated as inhibitors of the enzymatic activity of acetylcholinesterase. These fullerene-based derivatives were found to be noncompetitive inhibitors of acetylthiocholine hydrolysis. Molecular modelling was used to describe the possible interactions between the fullerene cage and the amino acids surrounding the cavity of the enzyme. The cationic C(60) derivatives used in this study represent a new class of molecules potentially able to modulate the enzymatic activity of acetylcholinesterase.
2004
Burnouf D. Y., Olieric V., Wagner J., Fujii S., Reinbolt J., Fuchs R. P., Dumas P.
Structural and biochemical analysis of sliding clamp/ligand interactions suggest a competition between replicative and translesion DNA polymerases Journal Article
In: J Mol Biol, vol. 335, no. 5, pp. 1187-97, 2004, (0022-2836 Journal Article).
Abstract | BibTeX | Tags: *Binding, Antigen/metabolism, Bacterial/genetics, beta/*chemistry/genetics/*metabolism, Binding, Cell, coli/*enzymology, Competitive, Crystallization, DNA, DUMAS, Escherichia, Fragments/*metabolism, I/metabolism, III/metabolism, Kinetics, ligands, Models, Molecular, Nuclear, Peptide, Polymerase, Proliferating, Protein, Proteins/chemistry/metabolism, Recombinant, Replication/*genetics, Subunits
@article{,
title = {Structural and biochemical analysis of sliding clamp/ligand interactions suggest a competition between replicative and translesion DNA polymerases},
author = { D. Y. Burnouf and V. Olieric and J. Wagner and S. Fujii and J. Reinbolt and R. P. Fuchs and P. Dumas},
year = {2004},
date = {2004-01-01},
journal = {J Mol Biol},
volume = {335},
number = {5},
pages = {1187-97},
abstract = {Most DNA polymerases interact with their cognate processive replication factor through a small peptide, this interaction being absolutely required for their function in vivo. We have solved the crystal structure of a complex between the beta sliding clamp of Escherichia coli and the 16 residue C-terminal peptide of Pol IV (P16). The seven C-terminal residues bind to a pocket located at the surface of one beta monomer. This region was previously identified as the binding site of another beta clamp binding protein, the delta subunit of the gamma complex. We show that peptide P16 competitively prevents beta-clamp-mediated stimulation of both Pol IV and alpha subunit DNA polymerase activities, suggesting that the site of interaction of the alpha subunit with beta is identical with, or overlaps that of Pol IV. This common binding site for delta, Pol IV and alpha subunit is shown to be formed by residues that are highly conserved among many bacterial beta homologs, thus defining an evolutionarily conserved hydrophobic crevice for sliding clamp ligands and a new target for antibiotic drug design.},
note = {0022-2836
Journal Article},
keywords = {*Binding, Antigen/metabolism, Bacterial/genetics, beta/*chemistry/genetics/*metabolism, Binding, Cell, coli/*enzymology, Competitive, Crystallization, DNA, DUMAS, Escherichia, Fragments/*metabolism, I/metabolism, III/metabolism, Kinetics, ligands, Models, Molecular, Nuclear, Peptide, Polymerase, Proliferating, Protein, Proteins/chemistry/metabolism, Recombinant, Replication/*genetics, Subunits},
pubstate = {published},
tppubtype = {article}
}
Most DNA polymerases interact with their cognate processive replication factor through a small peptide, this interaction being absolutely required for their function in vivo. We have solved the crystal structure of a complex between the beta sliding clamp of Escherichia coli and the 16 residue C-terminal peptide of Pol IV (P16). The seven C-terminal residues bind to a pocket located at the surface of one beta monomer. This region was previously identified as the binding site of another beta clamp binding protein, the delta subunit of the gamma complex. We show that peptide P16 competitively prevents beta-clamp-mediated stimulation of both Pol IV and alpha subunit DNA polymerase activities, suggesting that the site of interaction of the alpha subunit with beta is identical with, or overlaps that of Pol IV. This common binding site for delta, Pol IV and alpha subunit is shown to be formed by residues that are highly conserved among many bacterial beta homologs, thus defining an evolutionarily conserved hydrophobic crevice for sliding clamp ligands and a new target for antibiotic drug design.
Delarue M., Dumas P.
On the use of low-frequency normal modes to enforce collective movements in refining macromolecular structural models Journal Article
In: Proc Natl Acad Sci U S A, vol. 101, no. 18, pp. 6957-62, 2004, (0027-8424 Journal Article).
Abstract | BibTeX | Tags: *Models, Carrier, coli, Computer, Diffraction, DUMAS, Escherichia, Gov't, Molecular, Non-U.S., Proteins/*chemistry, Proteins/chemistry, Simulation, Support, X-Ray
@article{,
title = {On the use of low-frequency normal modes to enforce collective movements in refining macromolecular structural models},
author = { M. Delarue and P. Dumas},
year = {2004},
date = {2004-01-01},
journal = {Proc Natl Acad Sci U S A},
volume = {101},
number = {18},
pages = {6957-62},
abstract = {As more and more structures of macromolecular complexes get solved in different conditions, it has become apparent that flexibility is an inherent part of their biological function. Normal mode analysis using simplified models of proteins such as the elastic network model has proved very effective in showing that many of the structural transitions derived from a survey of the Protein Data Bank can be explained by just a few of the lowest-frequency normal modes. In this work, normal modes are used to carry out medium- or low-resolution structural refinement, enforcing collective and large-amplitude movements that are beyond the reach of existing methods. Refinement is carried out in reciprocal space with respect to the normal mode amplitudes, by using standard conjugate-gradient minimization. Several tests on synthetic diffraction data whose mode concentration follows the one of real movements observed in the Protein Data Bank have shown that the radius of convergence is larger than the one of rigid-body refinement. Tests with experimental diffraction data for the same protein in different environments also led to refined structural models showing drastic reduction of the rms deviation with the target model. Because the structural transition is described by very few parameters, over-fitting of real experimental data is easily detected by using a cross-validation test. The method has also been applied to the refinement of atomic models into molecular envelopes and could readily be used to fit large macromolecular complex rearrangements into cryo-electron microscopy-reconstructed images as well as small-angle x-ray scattering-derived envelopes.},
note = {0027-8424
Journal Article},
keywords = {*Models, Carrier, coli, Computer, Diffraction, DUMAS, Escherichia, Gov't, Molecular, Non-U.S., Proteins/*chemistry, Proteins/chemistry, Simulation, Support, X-Ray},
pubstate = {published},
tppubtype = {article}
}
As more and more structures of macromolecular complexes get solved in different conditions, it has become apparent that flexibility is an inherent part of their biological function. Normal mode analysis using simplified models of proteins such as the elastic network model has proved very effective in showing that many of the structural transitions derived from a survey of the Protein Data Bank can be explained by just a few of the lowest-frequency normal modes. In this work, normal modes are used to carry out medium- or low-resolution structural refinement, enforcing collective and large-amplitude movements that are beyond the reach of existing methods. Refinement is carried out in reciprocal space with respect to the normal mode amplitudes, by using standard conjugate-gradient minimization. Several tests on synthetic diffraction data whose mode concentration follows the one of real movements observed in the Protein Data Bank have shown that the radius of convergence is larger than the one of rigid-body refinement. Tests with experimental diffraction data for the same protein in different environments also led to refined structural models showing drastic reduction of the rms deviation with the target model. Because the structural transition is described by very few parameters, over-fitting of real experimental data is easily detected by using a cross-validation test. The method has also been applied to the refinement of atomic models into molecular envelopes and could readily be used to fit large macromolecular complex rearrangements into cryo-electron microscopy-reconstructed images as well as small-angle x-ray scattering-derived envelopes.
Martineau Y., Bec C. Le, Monbrun L., Allo V., Chiu I. M., Danos O., Moine H., Prats H., Prats A. C.
Internal ribosome entry site structural motifs conserved among mammalian fibroblast growth factor 1 alternatively spliced mRNAs Journal Article
In: Mol Cell Biol, vol. 24, no. 17, pp. 7622-35, 2004, (0270-7306 Journal Article).
Abstract | BibTeX | Tags: (Genetics), *5', *Alternative, *Nucleic, *Promoter, 1/*genetics, Acid, Alignment, Animals, Base, Cell, Conformation, Data, EHRESMANN, Factor, Fibroblast, Gene, Genes, Genetic, Gov't, Growth, Human, Line, Messenger/chemistry/*genetics/metabolism, Mice, Molecular, Muscle, Mutagenesis, Non-U.S., Regions, Ribosomes/*metabolism, RNA, Sequence, Site-Directed, Skeletal/cytology/physiology, Splicing, Structural/genetics, Support, Techniques, Transfer, Untranslated, Vectors
@article{,
title = {Internal ribosome entry site structural motifs conserved among mammalian fibroblast growth factor 1 alternatively spliced mRNAs},
author = { Y. Martineau and C. Le Bec and L. Monbrun and V. Allo and I. M. Chiu and O. Danos and H. Moine and H. Prats and A. C. Prats},
year = {2004},
date = {2004-01-01},
journal = {Mol Cell Biol},
volume = {24},
number = {17},
pages = {7622-35},
abstract = {Fibroblast growth factor 1 (FGF-1) is a powerful angiogenic factor whose gene structure contains four promoters, giving rise to a process of alternative splicing resulting in four mRNAs with alternative 5' untranslated regions (5' UTRs). Here we have identified, by using double luciferase bicistronic vectors, the presence of internal ribosome entry sites (IRESs) in the human FGF-1 5' UTRs, particularly in leaders A and C, with distinct activities in mammalian cells. DNA electrotransfer in mouse muscle revealed that the IRES present in the FGF-1 leader A has a high activity in vivo. We have developed a new regulatable TET OFF bicistronic system, which allowed us to rule out the possibility of any cryptic promoter in the FGF-1 leaders. FGF-1 IRESs A and C, which were mapped in fragments of 118 and 103 nucleotides, respectively, are flexible in regard to the position of the initiation codon, making them interesting from a biotechnological point of view. Furthermore, we show that FGF-1 IRESs A of murine and human origins show similar IRES activity profiles. Enzymatic and chemical probing of the FGF-1 IRES A RNA revealed a structural domain conserved among mammals at both the nucleotide sequence and RNA structure levels. The functional role of this structural motif has been demonstrated by point mutagenesis, including compensatory mutations. These data favor an important role of IRESs in the control of FGF-1 expression and provide a new IRES structural motif that could help IRES prediction in 5' UTR databases.},
note = {0270-7306
Journal Article},
keywords = {(Genetics), *5', *Alternative, *Nucleic, *Promoter, 1/*genetics, Acid, Alignment, Animals, Base, Cell, Conformation, Data, EHRESMANN, Factor, Fibroblast, Gene, Genes, Genetic, Gov't, Growth, Human, Line, Messenger/chemistry/*genetics/metabolism, Mice, Molecular, Muscle, Mutagenesis, Non-U.S., Regions, Ribosomes/*metabolism, RNA, Sequence, Site-Directed, Skeletal/cytology/physiology, Splicing, Structural/genetics, Support, Techniques, Transfer, Untranslated, Vectors},
pubstate = {published},
tppubtype = {article}
}
Fibroblast growth factor 1 (FGF-1) is a powerful angiogenic factor whose gene structure contains four promoters, giving rise to a process of alternative splicing resulting in four mRNAs with alternative 5' untranslated regions (5' UTRs). Here we have identified, by using double luciferase bicistronic vectors, the presence of internal ribosome entry sites (IRESs) in the human FGF-1 5' UTRs, particularly in leaders A and C, with distinct activities in mammalian cells. DNA electrotransfer in mouse muscle revealed that the IRES present in the FGF-1 leader A has a high activity in vivo. We have developed a new regulatable TET OFF bicistronic system, which allowed us to rule out the possibility of any cryptic promoter in the FGF-1 leaders. FGF-1 IRESs A and C, which were mapped in fragments of 118 and 103 nucleotides, respectively, are flexible in regard to the position of the initiation codon, making them interesting from a biotechnological point of view. Furthermore, we show that FGF-1 IRESs A of murine and human origins show similar IRES activity profiles. Enzymatic and chemical probing of the FGF-1 IRES A RNA revealed a structural domain conserved among mammals at both the nucleotide sequence and RNA structure levels. The functional role of this structural motif has been demonstrated by point mutagenesis, including compensatory mutations. These data favor an important role of IRESs in the control of FGF-1 expression and provide a new IRES structural motif that could help IRES prediction in 5' UTR databases.
Blandin Stephanie A, Shiao Shin-Hong, Moita Luis F, Janse Chris J, Waters Andrew P, Kafatos Fotis C, Levashina Elena A
Complement-like protein TEP1 is a determinant of vectorial capacity in the malaria vector Anopheles gambiae Journal Article
In: Cell, vol. 116, no. 5, pp. 661–670, 2004, ISSN: 0092-8674.
Abstract | BibTeX | Tags: Animals, Anopheles, blandin, Female, Genetic, Humans, Insect Proteins, Insect Vectors, M3i, Malaria, Models, Molecular, Plasmodium berghei, Polymorphism, Protein Structure, RNA, Sequence Alignment, Tertiary
@article{blandin_complement-like_2004,
title = {Complement-like protein TEP1 is a determinant of vectorial capacity in the malaria vector Anopheles gambiae},
author = {Stephanie A Blandin and Shin-Hong Shiao and Luis F Moita and Chris J Janse and Andrew P Waters and Fotis C Kafatos and Elena A Levashina},
issn = {0092-8674},
year = {2004},
date = {2004-01-01},
journal = {Cell},
volume = {116},
number = {5},
pages = {661--670},
abstract = {Anopheles mosquitoes are major vectors of human malaria in Africa. Large variation exists in the ability of mosquitoes to serve as vectors and to transmit malaria parasites, but the molecular mechanisms that determine vectorial capacity remain poorly understood. We report that the hemocyte-specific complement-like protein TEP1 from the mosquito Anopheles gambiae binds to and mediates killing of midgut stages of the rodent malaria parasite Plasmodium berghei. The dsRNA knockdown of TEP1 in adults completely abolishes melanotic refractoriness in a genetically selected refractory strain. Moreover, in susceptible mosquitoes this knockdown increases the number of developing parasites. Our results suggest that the TEP1-dependent parasite killing is followed by a TEP1-independent clearance of dead parasites by lysis and/or melanization. Further elucidation of the molecular mechanisms of TEP1-mediated parasite killing will be of great importance for our understanding of the principles of vectorial capacity in insects.},
keywords = {Animals, Anopheles, blandin, Female, Genetic, Humans, Insect Proteins, Insect Vectors, M3i, Malaria, Models, Molecular, Plasmodium berghei, Polymorphism, Protein Structure, RNA, Sequence Alignment, Tertiary},
pubstate = {published},
tppubtype = {article}
}
Anopheles mosquitoes are major vectors of human malaria in Africa. Large variation exists in the ability of mosquitoes to serve as vectors and to transmit malaria parasites, but the molecular mechanisms that determine vectorial capacity remain poorly understood. We report that the hemocyte-specific complement-like protein TEP1 from the mosquito Anopheles gambiae binds to and mediates killing of midgut stages of the rodent malaria parasite Plasmodium berghei. The dsRNA knockdown of TEP1 in adults completely abolishes melanotic refractoriness in a genetically selected refractory strain. Moreover, in susceptible mosquitoes this knockdown increases the number of developing parasites. Our results suggest that the TEP1-dependent parasite killing is followed by a TEP1-independent clearance of dead parasites by lysis and/or melanization. Further elucidation of the molecular mechanisms of TEP1-mediated parasite killing will be of great importance for our understanding of the principles of vectorial capacity in insects.
2003
Bianco Alberto, Pantarotto Davide, Hoebeke Johan, Briand Jean-Paul, Prato Maurizio
Solid-phase synthesis and characterization of a novel fullerene-peptide derived from histone H3 Journal Article
In: Organic & Biomolecular Chemistry, vol. 1, no. 23, pp. 4141–4143, 2003, ISSN: 1477-0520.
Abstract | Links | BibTeX | Tags: Chromatography, Epitopes, Fullerenes, Glutamic Acid, High Pressure Liquid, Histones, I2CT, Models, Molecular, Molecular Structure, Peptides, Protein Structure, Team-Bianco, Tertiary
@article{bianco_solid-phase_2003,
title = {Solid-phase synthesis and characterization of a novel fullerene-peptide derived from histone H3},
author = {Alberto Bianco and Davide Pantarotto and Johan Hoebeke and Jean-Paul Briand and Maurizio Prato},
doi = {10.1039/b311505d},
issn = {1477-0520},
year = {2003},
date = {2003-12-01},
journal = {Organic & Biomolecular Chemistry},
volume = {1},
number = {23},
pages = {4141--4143},
abstract = {A peptide analogue from a histone H3 protein containing the L-fulleropyrrolidino-glutamic acid has been prepared by a solid-phase approach and has been fully characterized. By molecular modelling it was verified that this peptide derivative is able to retain a binding capacity to the MHC (major histocompatibility complex) molecule similar to that of the cognate epitope.},
keywords = {Chromatography, Epitopes, Fullerenes, Glutamic Acid, High Pressure Liquid, Histones, I2CT, Models, Molecular, Molecular Structure, Peptides, Protein Structure, Team-Bianco, Tertiary},
pubstate = {published},
tppubtype = {article}
}
A peptide analogue from a histone H3 protein containing the L-fulleropyrrolidino-glutamic acid has been prepared by a solid-phase approach and has been fully characterized. By molecular modelling it was verified that this peptide derivative is able to retain a binding capacity to the MHC (major histocompatibility complex) molecule similar to that of the cognate epitope.
Luna C, Hoa N T, Zhang J, Kanzok S M, Brown S E, Imler Jean-Luc, Knudson D L, Zheng L
Characterization of three Toll-like genes from mosquito Aedes aegypti Journal Article
In: Insect Molecular Biology, vol. 12, no. 1, pp. 67–74, 2003, ISSN: 0962-1075.
Abstract | BibTeX | Tags: Aedes, Animals, Base Sequence, Cell Surface, Chimera, Cloning, Developmental, Female, Gene Expression Regulation, Genetic, imler, Insect Proteins, M3i, Male, messenger, Models, Molecular, Mutagenesis, Promoter Regions, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Sequence Alignment, Signal Transduction, Site-Directed, Transfection
@article{luna_characterization_2003,
title = {Characterization of three Toll-like genes from mosquito Aedes aegypti},
author = {C Luna and N T Hoa and J Zhang and S M Kanzok and S E Brown and Jean-Luc Imler and D L Knudson and L Zheng},
issn = {0962-1075},
year = {2003},
date = {2003-02-01},
journal = {Insect Molecular Biology},
volume = {12},
number = {1},
pages = {67--74},
abstract = {Three Toll-related genes (AeToll1A, AeToll1B and AeToll5) were cloned and characterized from the yellow fever vector mosquito, Aedes aegypti. All three genes exhibited high levels of amino acid sequence similarity with Drosophila melanogaster (Dm)Toll1 and DmTehao (Toll5). AeToll1A and AeToll1B are 1124 and 1076 amino acid residues long, respectively. Both contain a carboxyl extension downstream of the Toll/interleukin-1 receptor (TIR) domain. AeToll5 is 1007 residues long and, like DmTehao, lacks the carboxyl terminal extension. Expression of these three genes was examined throughout development and after immune challenge. Both AeToll1A and AeToll5, like their Drosophila counterparts, activate transcription of drosomycin promoter in both Aedes and Drosophila cell lines. Deletion of the carboxyl extension of AeToll1A did not result in a further elevated level of the antifungal response. The intracellular signalling process appears to be species specific based on two observations. (1) DmToll is completely inactive in an Aedes cell line, suggesting a higher specificity requirement for DmToll in the intracellular signalling process. (2) Only one of three amino acid residues essential for DmToll function is required for AeToll1A function.},
keywords = {Aedes, Animals, Base Sequence, Cell Surface, Chimera, Cloning, Developmental, Female, Gene Expression Regulation, Genetic, imler, Insect Proteins, M3i, Male, messenger, Models, Molecular, Mutagenesis, Promoter Regions, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Sequence Alignment, Signal Transduction, Site-Directed, Transfection},
pubstate = {published},
tppubtype = {article}
}
Three Toll-related genes (AeToll1A, AeToll1B and AeToll5) were cloned and characterized from the yellow fever vector mosquito, Aedes aegypti. All three genes exhibited high levels of amino acid sequence similarity with Drosophila melanogaster (Dm)Toll1 and DmTehao (Toll5). AeToll1A and AeToll1B are 1124 and 1076 amino acid residues long, respectively. Both contain a carboxyl extension downstream of the Toll/interleukin-1 receptor (TIR) domain. AeToll5 is 1007 residues long and, like DmTehao, lacks the carboxyl terminal extension. Expression of these three genes was examined throughout development and after immune challenge. Both AeToll1A and AeToll5, like their Drosophila counterparts, activate transcription of drosomycin promoter in both Aedes and Drosophila cell lines. Deletion of the carboxyl extension of AeToll1A did not result in a further elevated level of the antifungal response. The intracellular signalling process appears to be species specific based on two observations. (1) DmToll is completely inactive in an Aedes cell line, suggesting a higher specificity requirement for DmToll in the intracellular signalling process. (2) Only one of three amino acid residues essential for DmToll function is required for AeToll1A function.
Salah R. Ben, Zouari N., Reinbolt J., Mejdoub H.
Purification of turkey pancreatic phospholipase A2 Journal Article
In: Biosci Biotechnol Biochem, vol. 67, no. 10, pp. 2139-44, 2003, (0916-8451 Journal Article).
Abstract | BibTeX | Tags: *Turkeys, &, A/*isolation, Acid, acids, Amino, Ammonium, and, Animals, Bile, Calcium, Chromatography, Concentration, Data, Hydrogen-Ion, Molecular, Pancreas/*enzymology, Phospholipases, purification, Salts, Sequence, Sulfate, Temperature, Weight
@article{,
title = {Purification of turkey pancreatic phospholipase A2},
author = { R. Ben Salah and N. Zouari and J. Reinbolt and H. Mejdoub},
year = {2003},
date = {2003-01-01},
journal = {Biosci Biotechnol Biochem},
volume = {67},
number = {10},
pages = {2139-44},
abstract = {Turkey pancreatic phospholipase (TPP) has been purified from delipidated pancreases. The purification included ammonium sulfate fractionation, acidic (pH 5) treatment, followed by sequencial column chromatographies on DEAE-cellulose, Sephadex G-75, and reverse phase high pressure liquid chromatography. The purified enzyme was found to be a monomeric protein with molecular mass of 14 kDa. The optimal activity was measured at pH 8 and 37 degrees C using egg yolk emulsion as substrate. Our results show that the enzyme (TPP) was not stable for 1 h at 60 degrees C, and that bile salt and Ca2+ were required for the expression of the purified enzyme. The sequence of the N-terminal amino acids of the purified enzyme shows a very close similarity between TPP and all other known pancreatic phospholipases.},
note = {0916-8451
Journal Article},
keywords = {*Turkeys, &, A/*isolation, Acid, acids, Amino, Ammonium, and, Animals, Bile, Calcium, Chromatography, Concentration, Data, Hydrogen-Ion, Molecular, Pancreas/*enzymology, Phospholipases, purification, Salts, Sequence, Sulfate, Temperature, Weight},
pubstate = {published},
tppubtype = {article}
}
Turkey pancreatic phospholipase (TPP) has been purified from delipidated pancreases. The purification included ammonium sulfate fractionation, acidic (pH 5) treatment, followed by sequencial column chromatographies on DEAE-cellulose, Sephadex G-75, and reverse phase high pressure liquid chromatography. The purified enzyme was found to be a monomeric protein with molecular mass of 14 kDa. The optimal activity was measured at pH 8 and 37 degrees C using egg yolk emulsion as substrate. Our results show that the enzyme (TPP) was not stable for 1 h at 60 degrees C, and that bile salt and Ca2+ were required for the expression of the purified enzyme. The sequence of the N-terminal amino acids of the purified enzyme shows a very close similarity between TPP and all other known pancreatic phospholipases.
Bonnal S., Schaeffer C., Creancier L., Clamens S., Moine H., Prats A. C., Vagner S.
A single internal ribosome entry site containing a G quartet RNA structure drives fibroblast growth factor 2 gene expression at four alternative translation initiation codons Journal Article
In: J Biol Chem, vol. 278, no. 41, pp. 39330-6, 2003, (0021-9258 Journal Article).
Abstract | BibTeX | Tags: 2/*genetics, Acid, Alternative, Base, Cell, Chain, Codon, Complementary/genetics, Conformation, Data, Deletion, DNA, Expression, Factor, Fibroblast, Gene, Gov't, Growth, Human, initiation, Initiator/genetics, Line, Messenger/*chemistry/*genetics, Molecular, Non-U.S., Nucleic, Peptide, Ribosomes/*metabolism, RNA, Sequence, Splicing, Support, Transfection
@article{,
title = {A single internal ribosome entry site containing a G quartet RNA structure drives fibroblast growth factor 2 gene expression at four alternative translation initiation codons},
author = { S. Bonnal and C. Schaeffer and L. Creancier and S. Clamens and H. Moine and A. C. Prats and S. Vagner},
year = {2003},
date = {2003-01-01},
journal = {J Biol Chem},
volume = {278},
number = {41},
pages = {39330-6},
abstract = {The 484-nucleotide (nt) alternatively translated region (ATR) of the human fibroblast growth factor 2 (FGF-2) mRNA contains four CUG and one AUG translation initiation codons. Although the 5'-end proximal CUG codon is initiated by a cap-dependent translation process, the other four initiation codons are initiated by a mechanism of internal entry of ribosomes. We undertook here a detailed analysis of the cis-acting elements defining the FGF-2 internal ribosome entry site (IRES). A thorough deletion analysis study within the 5'-ATR led us to define a 176-nt region as being necessary and sufficient for IRES function at four codons present in a downstream 308-nt RNA segment. Unexpectedly, a single IRES module is therefore responsible for translation initiation at four distantly localized codons. The determination of the FGF-2 5'-ATR RNA secondary structure by enzymatic and chemical probing experiments showed that the FGF-2 IRES contained two stem-loop regions and a G quartet motif that constitute novel structural determinants of IRES function.},
note = {0021-9258
Journal Article},
keywords = {2/*genetics, Acid, Alternative, Base, Cell, Chain, Codon, Complementary/genetics, Conformation, Data, Deletion, DNA, Expression, Factor, Fibroblast, Gene, Gov't, Growth, Human, initiation, Initiator/genetics, Line, Messenger/*chemistry/*genetics, Molecular, Non-U.S., Nucleic, Peptide, Ribosomes/*metabolism, RNA, Sequence, Splicing, Support, Transfection},
pubstate = {published},
tppubtype = {article}
}
The 484-nucleotide (nt) alternatively translated region (ATR) of the human fibroblast growth factor 2 (FGF-2) mRNA contains four CUG and one AUG translation initiation codons. Although the 5'-end proximal CUG codon is initiated by a cap-dependent translation process, the other four initiation codons are initiated by a mechanism of internal entry of ribosomes. We undertook here a detailed analysis of the cis-acting elements defining the FGF-2 internal ribosome entry site (IRES). A thorough deletion analysis study within the 5'-ATR led us to define a 176-nt region as being necessary and sufficient for IRES function at four codons present in a downstream 308-nt RNA segment. Unexpectedly, a single IRES module is therefore responsible for translation initiation at four distantly localized codons. The determination of the FGF-2 5'-ATR RNA secondary structure by enzymatic and chemical probing experiments showed that the FGF-2 IRES contained two stem-loop regions and a G quartet motif that constitute novel structural determinants of IRES function.
Heyman T., Wilhelm M., Wilhelm F. X.
The central PPT of the yeast retrotransposon Ty1 is not essential for transposition Journal Article
In: J Mol Biol, vol. 331, no. 2, pp. 315-20, 2003, (0022-2836 Journal Article).
Abstract | BibTeX | Tags: Base, cerevisiae/genetics, Data, DNA/*biosynthesis, Genetic, Gov't, Models, Molecular, Mutation, Non-U.S., Purines/*chemistry, Retroelements/*genetics, Saccharomyces, Sequence, Support
@article{,
title = {The central PPT of the yeast retrotransposon Ty1 is not essential for transposition},
author = { T. Heyman and M. Wilhelm and F. X. Wilhelm},
year = {2003},
date = {2003-01-01},
journal = {J Mol Biol},
volume = {331},
number = {2},
pages = {315-20},
abstract = {The yeast retrotransposon Ty1 has structural and functional similarities to retroviruses. We report here that, as in retroviruses, the plus-strand DNA of Ty1 is synthesized as two segments. A central DNA flap is formed during reverse transcription consecutive to elongation (with strand displacement) of the upstream segment beyond the central polypurine tract (cPPT) until the replication machinery is stopped at the central termination sequence. Comparison of wild-type and cPPT-mutant Ty1 elements shows that the mutant element lacking the central DNA flap is only twofold defective in transposition.},
note = {0022-2836
Journal Article},
keywords = {Base, cerevisiae/genetics, Data, DNA/*biosynthesis, Genetic, Gov't, Models, Molecular, Mutation, Non-U.S., Purines/*chemistry, Retroelements/*genetics, Saccharomyces, Sequence, Support},
pubstate = {published},
tppubtype = {article}
}
The yeast retrotransposon Ty1 has structural and functional similarities to retroviruses. We report here that, as in retroviruses, the plus-strand DNA of Ty1 is synthesized as two segments. A central DNA flap is formed during reverse transcription consecutive to elongation (with strand displacement) of the upstream segment beyond the central polypurine tract (cPPT) until the replication machinery is stopped at the central termination sequence. Comparison of wild-type and cPPT-mutant Ty1 elements shows that the mutant element lacking the central DNA flap is only twofold defective in transposition.
Wilhelm F. X., Wilhelm M., Gabriel A.
Extension and cleavage of the polypurine tract plus-strand primer by Ty1 reverse transcriptase Journal Article
In: J Biol Chem, vol. 278, no. 48, pp. 47678-84, 2003, (0021-9258 Journal Article).
Abstract | BibTeX | Tags: Base, Calf, Data, DNA, DNA/chemistry, Genetic, Gov't, H, Messenger/metabolism, Models, Molecular, Non-U.S., P.H.S., Polymerase/*chemistry, Primers, Proteins/chemistry, Purines/*chemistry, Recombinant, Replication, Retroelements/*genetics, Ribonuclease, RNA, RNA-Directed, RNA/chemistry, Sequence, Support, Templates, Thymus/chemistry, U.S., Viral
@article{,
title = {Extension and cleavage of the polypurine tract plus-strand primer by Ty1 reverse transcriptase},
author = { F. X. Wilhelm and M. Wilhelm and A. Gabriel},
year = {2003},
date = {2003-01-01},
journal = {J Biol Chem},
volume = {278},
number = {48},
pages = {47678-84},
abstract = {Using hybrid RNA/DNA substrates containing the polypurine tract (PPT) plus-strand primer, we have examined the interaction between the Ty1 reverse transcriptase (RT) and the plus-strand initiation complex. We show here that, although the PPT sequence is relatively resistant to RNase H cleavage, it can be cleaved internally by the polymerase-independent RNase H activity of Ty1 RT. Alternatively, this PPT can be used to initiate plus-strand DNA synthesis. We demonstrate that cleavage at the PPT/DNA junction occurs only after at least 9 nucleotides are extended. Cleavage leaves a nick between the RNA primer and the nascent plus-strand DNA. We show that Ty1 RT has a strand displacement activity beyond a gap but that the PPT is not efficiently re-utilized in vitro for another round of DNA synthesis after a first plus-strand DNA has been synthesized and cleaved at the PPT/U3 junction.},
note = {0021-9258
Journal Article},
keywords = {Base, Calf, Data, DNA, DNA/chemistry, Genetic, Gov't, H, Messenger/metabolism, Models, Molecular, Non-U.S., P.H.S., Polymerase/*chemistry, Primers, Proteins/chemistry, Purines/*chemistry, Recombinant, Replication, Retroelements/*genetics, Ribonuclease, RNA, RNA-Directed, RNA/chemistry, Sequence, Support, Templates, Thymus/chemistry, U.S., Viral},
pubstate = {published},
tppubtype = {article}
}
Using hybrid RNA/DNA substrates containing the polypurine tract (PPT) plus-strand primer, we have examined the interaction between the Ty1 reverse transcriptase (RT) and the plus-strand initiation complex. We show here that, although the PPT sequence is relatively resistant to RNase H cleavage, it can be cleaved internally by the polymerase-independent RNase H activity of Ty1 RT. Alternatively, this PPT can be used to initiate plus-strand DNA synthesis. We demonstrate that cleavage at the PPT/DNA junction occurs only after at least 9 nucleotides are extended. Cleavage leaves a nick between the RNA primer and the nascent plus-strand DNA. We show that Ty1 RT has a strand displacement activity beyond a gap but that the PPT is not efficiently re-utilized in vitro for another round of DNA synthesis after a first plus-strand DNA has been synthesized and cleaved at the PPT/U3 junction.
2002
Bates Elizabeth E M, Fridman Wolf H, Mueller Chris G F
The ADAMDEC1 (decysin) gene structure: evolution by duplication in a metalloprotease gene cluster on chromosome 8p12 Journal Article
In: Immunogenetics, vol. 54, no. 2, pp. 96–105, 2002, ISSN: 0093-7711.
Abstract | Links | BibTeX | Tags: ADAM Proteins, Amino Acid Sequence, Animals, Base Sequence, Chromosomes, Evolution, Gene Dosage, Gene Duplication, Genetic, Human, Humans, Inbred BALB C, Macaca mulatta, Membrane Glycoproteins, Metalloendopeptidases, Mice, Molecular, Molecular Sequence Data, Multigene Family, Pair 8, Promoter Regions, Sequence Alignment, Team-Mueller
@article{bates_adamdec1_2002,
title = {The ADAMDEC1 (decysin) gene structure: evolution by duplication in a metalloprotease gene cluster on chromosome 8p12},
author = {Elizabeth E M Bates and Wolf H Fridman and Chris G F Mueller},
doi = {10.1007/s00251-002-0430-3},
issn = {0093-7711},
year = {2002},
date = {2002-05-01},
journal = {Immunogenetics},
volume = {54},
number = {2},
pages = {96--105},
abstract = {Members of the ADAM superfamily of metalloprotease genes are involved in a number of biological processes, including fertilization, neurogenesis, muscle development, and the immune response. These proteins have been classified into several groups. The prototypic ADAM family is comprised of a pro-domain, a metalloprotease domain, a disintegrin domain, a cysteine-rich region, a transmembrane domain, and a variable cytoplasmic tail. We recently identified a novel member of this superfamily, ADAMDEC1 (decysin). Due to the partial lack of a disintegrin domain and the total lack of a cysteine-rich domain, this protein has been placed in a novel subclass of the ADAM gene family. We have investigated the gene structure of the human and mouse ADAMDEC1 and have revealed a metalloprotease gene cluster on human Chromosome 8p12 comprising ADAMDEC1, ADAM7, and ADAM28. Our results suggest that ADAMDEC1 has arisen by partial gene duplication from an ancestral gene at this locus and has acquired a novel function. ADAMDEC1 is expressed in the immune system, by dendritic cells and macrophages. The relatedness of ADAMDEC1, ADAM7, and ADAM28 suggests that these proteases share a similar function.},
keywords = {ADAM Proteins, Amino Acid Sequence, Animals, Base Sequence, Chromosomes, Evolution, Gene Dosage, Gene Duplication, Genetic, Human, Humans, Inbred BALB C, Macaca mulatta, Membrane Glycoproteins, Metalloendopeptidases, Mice, Molecular, Molecular Sequence Data, Multigene Family, Pair 8, Promoter Regions, Sequence Alignment, Team-Mueller},
pubstate = {published},
tppubtype = {article}
}
Members of the ADAM superfamily of metalloprotease genes are involved in a number of biological processes, including fertilization, neurogenesis, muscle development, and the immune response. These proteins have been classified into several groups. The prototypic ADAM family is comprised of a pro-domain, a metalloprotease domain, a disintegrin domain, a cysteine-rich region, a transmembrane domain, and a variable cytoplasmic tail. We recently identified a novel member of this superfamily, ADAMDEC1 (decysin). Due to the partial lack of a disintegrin domain and the total lack of a cysteine-rich domain, this protein has been placed in a novel subclass of the ADAM gene family. We have investigated the gene structure of the human and mouse ADAMDEC1 and have revealed a metalloprotease gene cluster on human Chromosome 8p12 comprising ADAMDEC1, ADAM7, and ADAM28. Our results suggest that ADAMDEC1 has arisen by partial gene duplication from an ancestral gene at this locus and has acquired a novel function. ADAMDEC1 is expressed in the immune system, by dendritic cells and macrophages. The relatedness of ADAMDEC1, ADAM7, and ADAM28 suggests that these proteases share a similar function.
Perederina A., Nevskaya N., Nikonov O., Nikulin A., Dumas P., Yao M., Tanaka I., Garber M., Gongadze G., Nikonov S.
Detailed analysis of RNA-protein interactions within the bacterial ribosomal protein L5/5S rRNA complex Journal Article
In: RNA, vol. 8, no. 12, pp. 1548-57, 2002, (1355-8382 Journal Article).
Abstract | BibTeX | Tags: 5S/*chemistry/*metabolism, Acid, Amino, Bacterial, Base, Binding, Bonding, coli/genetics, Conformation, Data, Escherichia, Fragments/chemistry/metabolism, Gov't, Hydrogen, Models, Molecular, Non-U.S., Nucleic, Peptide, Protein, Proteins/*chemistry/*metabolism, Proteins/chemistry/metabolism, Ribosomal, RNA, Sequence, Sites, Support
@article{,
title = {Detailed analysis of RNA-protein interactions within the bacterial ribosomal protein L5/5S rRNA complex},
author = { A. Perederina and N. Nevskaya and O. Nikonov and A. Nikulin and P. Dumas and M. Yao and I. Tanaka and M. Garber and G. Gongadze and S. Nikonov},
year = {2002},
date = {2002-01-01},
journal = {RNA},
volume = {8},
number = {12},
pages = {1548-57},
abstract = {The crystal structure of ribosomal protein L5 from Thermus thermophilus complexed with a 34-nt fragment comprising helix III and loop C of Escherichia coli 5S rRNA has been determined at 2.5 A resolution. The protein specifically interacts with the bulged nucleotides at the top of loop C of 5S rRNA. The rRNA and protein contact surfaces are strongly stabilized by intramolecular interactions. Charged and polar atoms forming the network of conserved intermolecular hydrogen bonds are located in two narrow planar parallel layers belonging to the protein and rRNA, respectively. The regions, including these atoms conserved in Bacteria and Archaea, can be considered an RNA-protein recognition module. Comparison of the T. thermophilus L5 structure in the RNA-bound form with the isolated Bacillus stearothermophilus L5 structure shows that the RNA-recognition module on the protein surface does not undergo significant changes upon RNA binding. In the crystal of the complex, the protein interacts with another RNA molecule in the asymmetric unit through the beta-sheet concave surface. This protein/RNA interface simulates the interaction of L5 with 23S rRNA observed in the Haloarcula marismortui 50S ribosomal subunit.},
note = {1355-8382
Journal Article},
keywords = {5S/*chemistry/*metabolism, Acid, Amino, Bacterial, Base, Binding, Bonding, coli/genetics, Conformation, Data, Escherichia, Fragments/chemistry/metabolism, Gov't, Hydrogen, Models, Molecular, Non-U.S., Nucleic, Peptide, Protein, Proteins/*chemistry/*metabolism, Proteins/chemistry/metabolism, Ribosomal, RNA, Sequence, Sites, Support},
pubstate = {published},
tppubtype = {article}
}
The crystal structure of ribosomal protein L5 from Thermus thermophilus complexed with a 34-nt fragment comprising helix III and loop C of Escherichia coli 5S rRNA has been determined at 2.5 A resolution. The protein specifically interacts with the bulged nucleotides at the top of loop C of 5S rRNA. The rRNA and protein contact surfaces are strongly stabilized by intramolecular interactions. Charged and polar atoms forming the network of conserved intermolecular hydrogen bonds are located in two narrow planar parallel layers belonging to the protein and rRNA, respectively. The regions, including these atoms conserved in Bacteria and Archaea, can be considered an RNA-protein recognition module. Comparison of the T. thermophilus L5 structure in the RNA-bound form with the isolated Bacillus stearothermophilus L5 structure shows that the RNA-recognition module on the protein surface does not undergo significant changes upon RNA binding. In the crystal of the complex, the protein interacts with another RNA molecule in the asymmetric unit through the beta-sheet concave surface. This protein/RNA interface simulates the interaction of L5 with 23S rRNA observed in the Haloarcula marismortui 50S ribosomal subunit.
Wilhelm M., Fishman J. A., Pontikis R., Aubertin A. M., Wilhelm F. X.
Susceptibility of recombinant porcine endogenous retrovirus reverse transcriptase to nucleoside and non-nucleoside inhibitors Journal Article
In: Cell Mol Life Sci, vol. 59, no. 12, pp. 2184-90, 2002, (1420-682x Journal Article).
Abstract | BibTeX | Tags: Acid, Amino, Animals, Calf, Chloride/metabolism, Chlorides/metabolism, Cloning, Compounds/metabolism, Data, DNA, DNA-Directed, endogenous, Gov't, H, Human, Inhibitors/*pharmacology, Magnesium, Manganese, Molecular, Non-U.S., Nucleosides/chemistry/*metabolism, P.H.S., Polymerase/chemistry/genetics/*metabolism, Polymerase/metabolism, Proteins/metabolism, Recombinant, Retroviruses/*enzymology, Reverse, Ribonuclease, RNA-Directed, Sequence, Sodium, structure, Support, Swine, Thymus/metabolism, Transcriptase, U.S.
@article{,
title = {Susceptibility of recombinant porcine endogenous retrovirus reverse transcriptase to nucleoside and non-nucleoside inhibitors},
author = { M. Wilhelm and J. A. Fishman and R. Pontikis and A. M. Aubertin and F. X. Wilhelm},
year = {2002},
date = {2002-01-01},
journal = {Cell Mol Life Sci},
volume = {59},
number = {12},
pages = {2184-90},
abstract = {Transplantation of organs, tissues or cells from pigs to humans could be a potential solution to the shortage of human organs for transplantation. Porcine endogenous retroviruses (PERVs) remain a major safety concern for porcine xenotransplantation. Thus, finding drugs that could be used as virological prophylaxis (or therapy) against PERV replication would be desirable. One of the most effective ways to block retroviral multiplication is to inhibit the enzyme reverse transcriptase (RT) which catalyzes the reverse transcription of viral RNA to proviral double-stranded DNA. We report here the cloning and expression of PERV RT and its susceptibility to several inhibitors. Our data demonstrate PERV susceptibility in vitro to the triphosphorylated nucleoside analog of zidovudine (AZT) and to ddGTP and to a lesser extent to ddTTP but almost no susceptibility to the non-nucleoside RT inhibitors tested.},
note = {1420-682x
Journal Article},
keywords = {Acid, Amino, Animals, Calf, Chloride/metabolism, Chlorides/metabolism, Cloning, Compounds/metabolism, Data, DNA, DNA-Directed, endogenous, Gov't, H, Human, Inhibitors/*pharmacology, Magnesium, Manganese, Molecular, Non-U.S., Nucleosides/chemistry/*metabolism, P.H.S., Polymerase/chemistry/genetics/*metabolism, Polymerase/metabolism, Proteins/metabolism, Recombinant, Retroviruses/*enzymology, Reverse, Ribonuclease, RNA-Directed, Sequence, Sodium, structure, Support, Swine, Thymus/metabolism, Transcriptase, U.S.},
pubstate = {published},
tppubtype = {article}
}
Transplantation of organs, tissues or cells from pigs to humans could be a potential solution to the shortage of human organs for transplantation. Porcine endogenous retroviruses (PERVs) remain a major safety concern for porcine xenotransplantation. Thus, finding drugs that could be used as virological prophylaxis (or therapy) against PERV replication would be desirable. One of the most effective ways to block retroviral multiplication is to inhibit the enzyme reverse transcriptase (RT) which catalyzes the reverse transcription of viral RNA to proviral double-stranded DNA. We report here the cloning and expression of PERV RT and its susceptibility to several inhibitors. Our data demonstrate PERV susceptibility in vitro to the triphosphorylated nucleoside analog of zidovudine (AZT) and to ddGTP and to a lesser extent to ddTTP but almost no susceptibility to the non-nucleoside RT inhibitors tested.
2001
Mueller C G, Cremer I, Paulet P E, Niida S, Maeda N, Lebeque S, Fridman W H, Sautès-Fridman C
Mannose receptor ligand-positive cells express the metalloprotease decysin in the B cell follicle Journal Article
In: Journal of Immunology (Baltimore