Structural insertion/deletion variation in IRF5 is associated with a risk haplotype and defines the precise IRF5 isoforms expressed in systemic lupus erythematosus
Autor: | Kozyrev, Sergey V, Lewén, Susanna, Reddy, Prasad M V Linga, Pons-Estel, Bernardo, Collaborative Group, Argentine, Witte, Torsten, Collaborative Group, German, Junker, Peter, Laustrup, Helle, Gutiérrez, Carmen, Suárez, Ana, Francisca González-Escribano, Maria, Martín, Javier, Collaborative Group, Spanish, Alarcón-Riquelme, Marta E |
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Rok vydání: | 2007 |
Předmět: |
Male
Sequence analysis RNA Splicing Molecular Sequence Data Immunology Biology Polymorphism Single Nucleotide Nuclear Family Exon Rheumatology Risk Factors Genotype medicine Humans Lupus Erythematosus Systemic Protein Isoforms Immunology and Allergy SNP Pharmacology (medical) Allele Genotyping Sequence Deletion Family Health Genetics Lupus erythematosus Base Sequence Reverse Transcriptase Polymerase Chain Reaction Haplotype Reverse Transcription Sequence Analysis DNA medicine.disease Mutagenesis Insertional Gene Expression Regulation Haplotypes Interferon Regulatory Factors Leukocytes Mononuclear Female 5' Untranslated Regions |
Zdroj: | Kozyrev, S V, Lewén, S, Reddy, P M V L, Pons-Estel, B, Collaborative Group, A, Witte, T, Collaborative Group, G, Junker, P, Laustrup, H, Gutiérrez, C, Suárez, A, Francisca González-Escribano, M, Martín, J, Collaborative Group, S & Alarcón-Riquelme, M E 2007, ' Structural insertion/deletion variation in IRF5 is associated with a risk haplotype and defines the precise IRF5 isoforms expressed in systemic lupus erythematosus ', Arthritis & Rheumatism, vol. 56, no. 4, pp. 1234-41 . https://doi.org/10.1002/art.22497 |
ISSN: | 1529-0131 0004-3591 |
Popis: | Objective To determine whether specific isoforms of IRF5 are transcribed in patients with systemic lupus erythematosus (SLE) who have risk genotypes in the exon 1B donor splice site at single-nucleotide polymorphism (SNP) no. rs2004640. Methods Peripheral blood mononuclear cells were obtained from SLE patients and healthy controls from Argentina, Spain, and Germany and from trio families from Spain and Denmark. A reporter assay was used to investigate the role of SNP no. rs2004640. IRF5 expression in relation to the genotypes of functional SNPs was analyzed using quantitative polymerase chain reaction. Sequencing and genotyping of the IRF5 gene was performed. Results Sequencing of complementary DNA from individuals with different genotypes showed 4 basic isoforms transcribed from all 5′-untranslated regions (5′-UTRs), suggesting no preferential isoform transcription based on rs2004640 genotypes. Analysis of translation efficiency showed that exon 1A was the most efficient in initiating protein synthesis. We identified a novel polymorphic insertion/deletion that defines the pattern of expression of isoforms of IRF5. The insertion consists of 4 repeats in exon 6 affecting the protein interaction domain. The insertion segregates in the risk haplotype with the high expression allele of a poly(A) site SNP no. rs10954213 and the exon 1B donor splice allele of the 5′-UTR SNP no. rs2004640. The poly(A) polymorphism correlated with levels of IRF5 in cells stimulated with interferon-α. The SNP most strongly associated with SLE was SNP no. rs2070197 (P = 5.2 × 10−11), which is a proxy of the risk haplotype, but does not appear to be functional. Conclusion None of the functional variants investigated in this study is strongly associated with SLE, with the exception of the exon 1B donor splice site, and its functional importance appears to be small. Our results suggest that there may be other functional polymorphisms, yet to be identified, in IRF5. We did not observe evidence of epistatic interaction between the functional SNPs. |
Databáze: | OpenAIRE |
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