Intranet
Acces
Contact
Publications
2001
Monneaux F, Dumortier H, Steiner G, Briand J P, Muller S
Murine models of systemic lupus erythematosus: B and Ŧ cell responses to spliceosomal ribonucleoproteins in MRL/Fas(lpr) and (NZB x NZW)F(1) lupus mice Article de journal
Dans: International Immunology, vol. 13, no. 9, p. 1155–1163, 2001, ISSN: 0953-8178.
Résumé | Liens | BibTeX | Étiquettes: Animals, Antibody Specificity, B-Lymphocytes, Crosses, Dumortier, fas Receptor, Female, Genetic, Heterogeneous-Nuclear Ribonucleoprotein Group A-B, Heterogeneous-Nuclear Ribonucleoproteins, Histocompatibility Antigens Class II, I2CT, Immunoglobulin G, Inbred MRL lpr, Inbred NZB, Lupus Erythematosus, Mice, Monneaux, Peptide Fragments, Ribonucleoprotein, Ribonucleoproteins, Small Nuclear, Species Specificity, Spliceosomes, Systemic, T-Lymphocytes, Team-Dumortier, U1 Small Nuclear
@article{monneaux_murine_2001,
title = {Murine models of systemic lupus erythematosus: B and Ŧ cell responses to spliceosomal ribonucleoproteins in MRL/Fas(lpr) and (NZB x NZW)F(1) lupus mice},
author = {F Monneaux and H Dumortier and G Steiner and J P Briand and S Muller},
doi = {10.1093/intimm/13.9.1155},
issn = {0953-8178},
year = {2001},
date = {2001-01-01},
journal = {International Immunology},
volume = {13},
number = {9},
pages = {1155--1163},
abstract = {(NZB x NZW)F(1) and MRL/Fas(lpr) lupus mice present a similar phenotype with a spectrum of autoantibodies associated with very severe nephritis. It is thought, however, that in contrast to other lupus-prone mice such as MRL/Fas(lpr) mice, (NZB x NZW)F(1) mice do not generate autoantibodies to ribonucleoproteins (RNP) Sm/RNP. In this study, we demonstrate that contrary to previous reports, the autoimmune response directed against Sm/RNP antigens also occurs in NZB x NZW mice. CD4(+) T cells from unprimed 10-week-old NZB x NZW mice proliferate and secrete IL-2 in response to peptide 131-151 of the U1-70K protein, which is known to contain a T(h) epitope recognized by CD4(+) T cells from MRL/Fas(lpr) mice. Peptide 131-151, which was found to bind I-A(k) and I-E(k) class II MHC molecules, also bound both I-A(d) and I-E(d) molecules. This result led us to also re-evaluate longitudinally the anti-Sm/RNP antibody response in NZB x NZW mice. We found that 25-week-old mice do produce antibodies reacting with several small nuclear and heterogeneous nuclear (hn) RNP proteins, such as SmD1, U1-70K and hnRNP A2/B1 proteins. The fine specificity of these antibodies was studied with overlapping synthetic peptides. The same antigenically positive and negative peptides were characterized in MRL/Fas(lpr) and NZB x NZW mice in the three proteins. This new finding can help to understand the mechanisms involved in the development of the anti-Sm/RNP antibody response and, particularly, the role played by non-MHC genes in this autoimmune response.},
keywords = {Animals, Antibody Specificity, B-Lymphocytes, Crosses, Dumortier, fas Receptor, Female, Genetic, Heterogeneous-Nuclear Ribonucleoprotein Group A-B, Heterogeneous-Nuclear Ribonucleoproteins, Histocompatibility Antigens Class II, I2CT, Immunoglobulin G, Inbred MRL lpr, Inbred NZB, Lupus Erythematosus, Mice, Monneaux, Peptide Fragments, Ribonucleoprotein, Ribonucleoproteins, Small Nuclear, Species Specificity, Spliceosomes, Systemic, T-Lymphocytes, Team-Dumortier, U1 Small Nuclear},
pubstate = {published},
tppubtype = {article}
}
(NZB x NZW)F(1) and MRL/Fas(lpr) lupus mice present a similar phenotype with a spectrum of autoantibodies associated with very severe nephritis. It is thought, however, that in contrast to other lupus-prone mice such as MRL/Fas(lpr) mice, (NZB x NZW)F(1) mice do not generate autoantibodies to ribonucleoproteins (RNP) Sm/RNP. In this study, we demonstrate that contrary to previous reports, the autoimmune response directed against Sm/RNP antigens also occurs in NZB x NZW mice. CD4(+) T cells from unprimed 10-week-old NZB x NZW mice proliferate and secrete IL-2 in response to peptide 131-151 of the U1-70K protein, which is known to contain a T(h) epitope recognized by CD4(+) T cells from MRL/Fas(lpr) mice. Peptide 131-151, which was found to bind I-A(k) and I-E(k) class II MHC molecules, also bound both I-A(d) and I-E(d) molecules. This result led us to also re-evaluate longitudinally the anti-Sm/RNP antibody response in NZB x NZW mice. We found that 25-week-old mice do produce antibodies reacting with several small nuclear and heterogeneous nuclear (hn) RNP proteins, such as SmD1, U1-70K and hnRNP A2/B1 proteins. The fine specificity of these antibodies was studied with overlapping synthetic peptides. The same antigenically positive and negative peptides were characterized in MRL/Fas(lpr) and NZB x NZW mice in the three proteins. This new finding can help to understand the mechanisms involved in the development of the anti-Sm/RNP antibody response and, particularly, the role played by non-MHC genes in this autoimmune response.
2000
Monneaux F, Muller S
Laboratory protocols for the identification of Th cell epitopes on self-antigens in mice with systemic autoimmune diseases Article de journal
Dans: Journal of Immunological Methods, vol. 244, no. 1-2, p. 195–204, 2000, ISSN: 0022-1759.
Résumé | Liens | BibTeX | Étiquettes: Animals, Antigen Presentation, Antigen-Presenting Cells, Autoantigens, B-Lymphocytes, Coculture Techniques, Epitopes, Female, Flow Cytometry, I2CT, Inbred MRL lpr, Inbred NZB, Lupus Erythematosus, Lymphocyte Activation, Mice, Monneaux, Ribonucleoproteins, Small Nuclear, Systemic, T-Lymphocyte, Team-Dumortier, Th1 Cells, Th2 Cells
@article{monneaux_laboratory_2000,
title = {Laboratory protocols for the identification of Th cell epitopes on self-antigens in mice with systemic autoimmune diseases},
author = {F Monneaux and S Muller},
doi = {10.1016/s0022-1759(00)00256-8},
issn = {0022-1759},
year = {2000},
date = {2000-10-01},
journal = {Journal of Immunological Methods},
volume = {244},
number = {1-2},
pages = {195--204},
abstract = {T cells play a critical role in both the immunological and clinical manifestations of systemic autoimmune diseases such as systemic lupus erythematosus (SLE). Although in normal mice multiple T cell epitopes have been characterized in several self-proteins, there is little information on the fine specificity of autoreactive T cells in lupus model mice and humans. In SLE-prone mice and humans, the only Th cell epitopes identified at the molecular level in self-antigens concern histones and nucleosomes, and the 70-kD U1-snRNP protein. T cell characterization in certain autoimmune mice such as MRL lpr/lpr and NZB/NZW mice has been largely impaired by their hyporesponsiveness in response to mitogen and minimal IL-2 secretion. In addition, MRL lpr/lpr mice also develop lymphadenopathy characterized by the progressive accumulation of functionally immature CD4(-) CD8(-) T cells. It is therefore important to optimize the methods used to measure T cell proliferation and cytokine production ex vivo in order to identify minimal activation in the presence of appropriate antigen. The protocol described in this article has been used for identifying in young MRL lpr/lpr and NZB/NZW mice a CD4(+) T cell epitope in the murine 70-kD U1-RNP protein.},
keywords = {Animals, Antigen Presentation, Antigen-Presenting Cells, Autoantigens, B-Lymphocytes, Coculture Techniques, Epitopes, Female, Flow Cytometry, I2CT, Inbred MRL lpr, Inbred NZB, Lupus Erythematosus, Lymphocyte Activation, Mice, Monneaux, Ribonucleoproteins, Small Nuclear, Systemic, T-Lymphocyte, Team-Dumortier, Th1 Cells, Th2 Cells},
pubstate = {published},
tppubtype = {article}
}
T cells play a critical role in both the immunological and clinical manifestations of systemic autoimmune diseases such as systemic lupus erythematosus (SLE). Although in normal mice multiple T cell epitopes have been characterized in several self-proteins, there is little information on the fine specificity of autoreactive T cells in lupus model mice and humans. In SLE-prone mice and humans, the only Th cell epitopes identified at the molecular level in self-antigens concern histones and nucleosomes, and the 70-kD U1-snRNP protein. T cell characterization in certain autoimmune mice such as MRL lpr/lpr and NZB/NZW mice has been largely impaired by their hyporesponsiveness in response to mitogen and minimal IL-2 secretion. In addition, MRL lpr/lpr mice also develop lymphadenopathy characterized by the progressive accumulation of functionally immature CD4(-) CD8(-) T cells. It is therefore important to optimize the methods used to measure T cell proliferation and cytokine production ex vivo in order to identify minimal activation in the presence of appropriate antigen. The protocol described in this article has been used for identifying in young MRL lpr/lpr and NZB/NZW mice a CD4(+) T cell epitope in the murine 70-kD U1-RNP protein.
1999
Dumortier H, Abbal M, Fort M, Briand J P, Cantagrel A, Muller S
MHC class II gene associations with autoantibodies to U1A and SmD1 proteins Article de journal
Dans: International Immunology, vol. 11, no. 2, p. 249–257, 1999, ISSN: 0953-8178.
Résumé | Liens | BibTeX | Étiquettes: Alleles, Antibody Specificity, Autoantibodies, Autoantigens, Autoimmune Diseases, Blotting, Dumortier, Enzyme-Linked Immunosorbent Assay, Genes, HLA-DP Antigens, HLA-DP beta-Chains, HLA-DQ Antigens, HLA-DQ beta-Chains, HLA-DR Antigens, HLA-DRB1 Chains, Humans, I2CT, MHC Class II, Peptides, Rheumatic Diseases, Ribonucleoprotein, Ribonucleoproteins, RNA-Binding Proteins, Small Nuclear, snRNP Core Proteins, Team-Dumortier, U1 Small Nuclear, Western
@article{dumortier_mhc_1999,
title = {MHC class II gene associations with autoantibodies to U1A and SmD1 proteins},
author = {H Dumortier and M Abbal and M Fort and J P Briand and A Cantagrel and S Muller},
doi = {10.1093/intimm/11.2.249},
issn = {0953-8178},
year = {1999},
date = {1999-01-01},
journal = {International Immunology},
volume = {11},
number = {2},
pages = {249--257},
abstract = {Autoantibodies against U small nuclear ribonucleoproteins (snRNP) are frequently present in the serum of patients with systemic rheumatic diseases, and have been reported to be associated with HLA-DR and -DQ genes. To better define the role of HLA genes in the production of such antibodies, we studied immunogenetic associations with autoantibodies reacting with U1 RNP, U1A and SmD1 proteins, and synthetic peptides containing immunodominant linear epitopes of these proteins. Only two out of the 15 overlapping peptides of U1A (i.e. peptides 35-58 and 257-282) and three of 11 peptides of SmD1 (i.e. peptides 1-20, 44-67 and 97-119) were significantly recognized by patients' sera selected on the basis of their antibody positivity with RNP in immunodiffusion. The distribution of DRB1, DQB1 and DPB1 alleles among the anti-RNP antibody-positive patients (n = 28) and healthy control subjects was similar. Antibodies against U1A (tested in Western immunoblotting with HeLa cell extracts) were positively associated to DRB1*06 allele; antibodies reacting with SmD1 peptide 44-67 were negatively associated to DRB1*02 and DQB1*0602 alleles. No association was found between DPB1 alleles and antibodies reacting with U1A and SmD1 antigens. This first study reporting an association between autoantibodies reacting with U1A and SmD1 proteins (and peptides of these proteins), and immunogenetic markers suggest that the production of antibody subsets directed against different components (or regions of these proteins) bound to the same snRNP particle is associated with distinct MHC class II alleles.},
keywords = {Alleles, Antibody Specificity, Autoantibodies, Autoantigens, Autoimmune Diseases, Blotting, Dumortier, Enzyme-Linked Immunosorbent Assay, Genes, HLA-DP Antigens, HLA-DP beta-Chains, HLA-DQ Antigens, HLA-DQ beta-Chains, HLA-DR Antigens, HLA-DRB1 Chains, Humans, I2CT, MHC Class II, Peptides, Rheumatic Diseases, Ribonucleoprotein, Ribonucleoproteins, RNA-Binding Proteins, Small Nuclear, snRNP Core Proteins, Team-Dumortier, U1 Small Nuclear, Western},
pubstate = {published},
tppubtype = {article}
}
Autoantibodies against U small nuclear ribonucleoproteins (snRNP) are frequently present in the serum of patients with systemic rheumatic diseases, and have been reported to be associated with HLA-DR and -DQ genes. To better define the role of HLA genes in the production of such antibodies, we studied immunogenetic associations with autoantibodies reacting with U1 RNP, U1A and SmD1 proteins, and synthetic peptides containing immunodominant linear epitopes of these proteins. Only two out of the 15 overlapping peptides of U1A (i.e. peptides 35-58 and 257-282) and three of 11 peptides of SmD1 (i.e. peptides 1-20, 44-67 and 97-119) were significantly recognized by patients' sera selected on the basis of their antibody positivity with RNP in immunodiffusion. The distribution of DRB1, DQB1 and DPB1 alleles among the anti-RNP antibody-positive patients (n = 28) and healthy control subjects was similar. Antibodies against U1A (tested in Western immunoblotting with HeLa cell extracts) were positively associated to DRB1*06 allele; antibodies reacting with SmD1 peptide 44-67 were negatively associated to DRB1*02 and DQB1*0602 alleles. No association was found between DPB1 alleles and antibodies reacting with U1A and SmD1 antigens. This first study reporting an association between autoantibodies reacting with U1A and SmD1 proteins (and peptides of these proteins), and immunogenetic markers suggest that the production of antibody subsets directed against different components (or regions of these proteins) bound to the same snRNP particle is associated with distinct MHC class II alleles.
1998
Dumortier H, Gunnewiek J Klein, Roussel J P, van Aarssen Y, Briand J P, van Venrooij W J, Muller S
Dans: Nucleic Acids Research, vol. 26, no. 23, p. 5486–5491, 1998, ISSN: 0305-1048.
Résumé | Liens | BibTeX | Étiquettes: Amino Acid Sequence, Animals, Dumortier, HeLa Cells, Humans, I2CT, Molecular Sequence Data, Peptide Fragments, Protein Binding, Rabbits, Ribonucleoprotein, Ribonucleoproteins, Small Nuclear, Solutions, Spliceosomes, Team-Dumortier, U1 Small Nuclear, Zinc, Zinc Fingers
@article{dumortier_at_1998,
title = {At least three linear regions but not the zinc-finger domain of U1C protein are exposed at the surface of the protein in solution and on the human spliceosomal U1 snRNP particle},
author = {H Dumortier and J Klein Gunnewiek and J P Roussel and Y van Aarssen and J P Briand and W J van Venrooij and S Muller},
doi = {10.1093/nar/26.23.5486},
issn = {0305-1048},
year = {1998},
date = {1998-12-01},
journal = {Nucleic Acids Research},
volume = {26},
number = {23},
pages = {5486--5491},
abstract = {No structural information on U1C protein either in its free state or bound to the spliceosomal U1 small nuclear ribonucleoprotein (snRNP) particle is currently available. Using rabbit antibodies raised against a complete set of 15 U1C overlapping synthetic peptides (16-30 residues long) in different immunochemical tests, linear regions exposed at the surface of free and U1 snRNP-bound U1C were identified. Epitopes within at least three regions spanning residues 31-62, 85-103 and 116-159 were recognized on free and plastic-immobilized recombinant human U1C expressed in Escherichia coli, on in vitro translated U1C protein and on U1C bound to the U1 snRNP particle present in HeLa S100 extract. Using a zinc affinity labeling method, we further showed that the N-terminal U1C peptide containing a zinc-finger motif (peptide 5-34) effectively binds65Zn2+. The N-terminal region of U1C, which is functional in U1 snRNP assembly, is apparently not located at the surface of the U1 snRNP particle.},
keywords = {Amino Acid Sequence, Animals, Dumortier, HeLa Cells, Humans, I2CT, Molecular Sequence Data, Peptide Fragments, Protein Binding, Rabbits, Ribonucleoprotein, Ribonucleoproteins, Small Nuclear, Solutions, Spliceosomes, Team-Dumortier, U1 Small Nuclear, Zinc, Zinc Fingers},
pubstate = {published},
tppubtype = {article}
}
No structural information on U1C protein either in its free state or bound to the spliceosomal U1 small nuclear ribonucleoprotein (snRNP) particle is currently available. Using rabbit antibodies raised against a complete set of 15 U1C overlapping synthetic peptides (16-30 residues long) in different immunochemical tests, linear regions exposed at the surface of free and U1 snRNP-bound U1C were identified. Epitopes within at least three regions spanning residues 31-62, 85-103 and 116-159 were recognized on free and plastic-immobilized recombinant human U1C expressed in Escherichia coli, on in vitro translated U1C protein and on U1C bound to the U1 snRNP particle present in HeLa S100 extract. Using a zinc affinity labeling method, we further showed that the N-terminal U1C peptide containing a zinc-finger motif (peptide 5-34) effectively binds65Zn2+. The N-terminal region of U1C, which is functional in U1 snRNP assembly, is apparently not located at the surface of the U1 snRNP particle.
Hoet R M, Raats J M, de Wildt R, Dumortier H, Muller S, van den Hoogen F, van Venrooij W J
Dans: Molecular Immunology, vol. 35, no. 16, p. 1045–1055, 1998, ISSN: 0161-5890.
Résumé | Liens | BibTeX | Étiquettes: Amino Acid Sequence, Antibodies, Autoantibodies, Cross Reactions, Dumortier, Epitope Mapping, Genes, HeLa Cells, Humans, I2CT, Immunoglobulin, Immunoglobulin Fragments, Immunoglobulin Variable Region, Immunohistochemistry, Lupus Erythematosus, Monoclonal, Ribonucleoprotein, Ribonucleoproteins, Small Nuclear, Systemic, Team-Dumortier, U1 Small Nuclear
@article{hoet_human_1998,
title = {Human monoclonal autoantibody fragments from combinatorial antibody libraries directed to the U1snRNP associated U1C protein; epitope mapping, immunolocalization and V-gene usage},
author = {R M Hoet and J M Raats and R de Wildt and H Dumortier and S Muller and F van den Hoogen and W J van Venrooij},
doi = {10.1016/s0161-5890(98)00093-5},
issn = {0161-5890},
year = {1998},
date = {1998-11-01},
journal = {Molecular Immunology},
volume = {35},
number = {16},
pages = {1045--1055},
abstract = {To study the localization and function of the U1snRNP associated U1C protein, so far only human sera from systemic lupus erythematosus (SLE) overlap syndrome patients have been used. Here we report for the first time the isolation of human monoclonal anti-UIC autoantibody fragments from IgG derived combinatorial and semi-synthetic human antibody libraries. Two classes of human monoclonal anti-UIC (auto)antibodies were found: specific anti-U1C autoantibodies, recognizing U1C only, and cross-reactive antibodies which also react with U1A and Sm-B/B'proteins. The heavy chains (V(H)genes) of all five antibodies from the semi-synthetic libraries and two of the three U1C-specific patient derived autoantibody fragments are encoded by V(H)3 genes, in which V(H) 3-30 (DP-49) was overrepresented. The heavy chain of the two cross-reactive autoantibodies are derived from the 3-07 (DP-54) gene. Three epitope regions on the U1C protein are targeted by these antibodies. (1) Four U1C specific antibodies recognize an N-terminal region of U1C in which amino acids 30-63 are essential for recognition, (2) two antibodies recognize only the complete U1C protein, and (3) two cross-reactive and one U1C specific antibody recognize the C-terminal domain in which amino acids 98-126 are critical for recognition. The two cross-reactive antibodies (K 11 and K 15) recognize the proline-rich region of the U1C protein (amino acids 98 126) and cross-react with proline-rich regions in Sm-B/B' (amino acids 163-184) and U1A (amino acids 187-204). All 10 antibody fragments are able to immunoprecipitate the native U1snRNP particle. The two cross-reactive antibodies immunoprecipitate the other Sm containing snRNPs as well. Using confocal immunofluorescence microscopy we could show that the major part of the U1C protein is localized within the coiled body structure.},
keywords = {Amino Acid Sequence, Antibodies, Autoantibodies, Cross Reactions, Dumortier, Epitope Mapping, Genes, HeLa Cells, Humans, I2CT, Immunoglobulin, Immunoglobulin Fragments, Immunoglobulin Variable Region, Immunohistochemistry, Lupus Erythematosus, Monoclonal, Ribonucleoprotein, Ribonucleoproteins, Small Nuclear, Systemic, Team-Dumortier, U1 Small Nuclear},
pubstate = {published},
tppubtype = {article}
}
To study the localization and function of the U1snRNP associated U1C protein, so far only human sera from systemic lupus erythematosus (SLE) overlap syndrome patients have been used. Here we report for the first time the isolation of human monoclonal anti-UIC autoantibody fragments from IgG derived combinatorial and semi-synthetic human antibody libraries. Two classes of human monoclonal anti-UIC (auto)antibodies were found: specific anti-U1C autoantibodies, recognizing U1C only, and cross-reactive antibodies which also react with U1A and Sm-B/B'proteins. The heavy chains (V(H)genes) of all five antibodies from the semi-synthetic libraries and two of the three U1C-specific patient derived autoantibody fragments are encoded by V(H)3 genes, in which V(H) 3-30 (DP-49) was overrepresented. The heavy chain of the two cross-reactive autoantibodies are derived from the 3-07 (DP-54) gene. Three epitope regions on the U1C protein are targeted by these antibodies. (1) Four U1C specific antibodies recognize an N-terminal region of U1C in which amino acids 30-63 are essential for recognition, (2) two antibodies recognize only the complete U1C protein, and (3) two cross-reactive and one U1C specific antibody recognize the C-terminal domain in which amino acids 98-126 are critical for recognition. The two cross-reactive antibodies (K 11 and K 15) recognize the proline-rich region of the U1C protein (amino acids 98 126) and cross-react with proline-rich regions in Sm-B/B' (amino acids 163-184) and U1A (amino acids 187-204). All 10 antibody fragments are able to immunoprecipitate the native U1snRNP particle. The two cross-reactive antibodies immunoprecipitate the other Sm containing snRNPs as well. Using confocal immunofluorescence microscopy we could show that the major part of the U1C protein is localized within the coiled body structure.
1992
Sturchler C, Carbon P, Krol A
An additional long-range interaction in human U1 snRNA Article de journal
Dans: Nucleic Acids Res, vol. 20, no. 6, p. 1215-1221, 1992, ISBN: 1532853, (0305-1048 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Base Sequence Binding Sites Hela Cells Human Molecular Sequence Data Mutagenesis, Site-Directed Nucleic Acid Conformation RNA, Small Nuclear, Small Nuclear/*chemistry/metabolism Ribonucleases/metabolism Ribonucleoproteins/metabolism Ribonucleoproteins, Unité ARN
@article{,
title = {An additional long-range interaction in human U1 snRNA},
author = {C Sturchler and P Carbon and A Krol},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1532853},
isbn = {1532853},
year = {1992},
date = {1992-01-01},
journal = {Nucleic Acids Res},
volume = {20},
number = {6},
pages = {1215-1221},
abstract = {We present evidence for the existence of an additional long-range interaction in vertebrate U1 snRNAs. By submitting human U1 snRNP, HeLa nuclear extracts, authentic human or X. laevis in vitro transcribed U1 snRNAs to RNase V1, a nuclease specific for double-stranded regions, cleavages occurred in the sequence psi psi ACC (positions 5-9) residing in the 5' terminal region of the RNA. The RNase V1 sensitive region is insensitive to single-stranded probes, something unexpected knowing that it was considered single-stranded in order to base-pair to pre-mRNA 5' splice site. We have identified the sequence GGUAG (positions 132-136) as the only possible 3' partner. Mutants, either abolishing or restoring the interaction between the partners, coupled to an RNase V1 assay, served to substantiate this base-pairing model. The presence of this additional helix, even detected in nuclear extracts under in vitro splicing conditions, implies that a conformational change must occur to release a free U1 snRNA 5' end.},
note = {0305-1048
Journal Article},
keywords = {Base Sequence Binding Sites Hela Cells Human Molecular Sequence Data Mutagenesis, Site-Directed Nucleic Acid Conformation RNA, Small Nuclear, Small Nuclear/*chemistry/metabolism Ribonucleases/metabolism Ribonucleoproteins/metabolism Ribonucleoproteins, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
We present evidence for the existence of an additional long-range interaction in vertebrate U1 snRNAs. By submitting human U1 snRNP, HeLa nuclear extracts, authentic human or X. laevis in vitro transcribed U1 snRNAs to RNase V1, a nuclease specific for double-stranded regions, cleavages occurred in the sequence psi psi ACC (positions 5-9) residing in the 5' terminal region of the RNA. The RNase V1 sensitive region is insensitive to single-stranded probes, something unexpected knowing that it was considered single-stranded in order to base-pair to pre-mRNA 5' splice site. We have identified the sequence GGUAG (positions 132-136) as the only possible 3' partner. Mutants, either abolishing or restoring the interaction between the partners, coupled to an RNase V1 assay, served to substantiate this base-pairing model. The presence of this additional helix, even detected in nuclear extracts under in vitro splicing conditions, implies that a conformational change must occur to release a free U1 snRNA 5' end.
