Common variations in the IL4R gene affect splicing and influence natural expression of the soluble isoform.
We previously found the soluble interleukin 4 receptor (sIL4R) to be differently expressed in allergic asthma patients compared to healthy individuals. Here we present data demonstrating the involvement of the sequence variations, c.912-1003A > G, c.912-833T > C, c. 912-630A > G, and c.912-577A > G, in the expressional regulation of IL4R splice variants. By using an IL4R minigene construct, genomic DNA and mRNA from asthma patients and nonasthmatic individuals, we analyzed the function of four highly-linked SNPs, flanking the alternatively-spliced exon in the IL4R gene. Results from the minigene assay showed that the form containing the minor alleles significantly decreased the expression of the soluble IL4R (exon 8+) variant, a decrease that could only be seen in the major construct after increasing amounts of either the splicing factor SRp20, or YT521-B. Analysis of mRNA expression in our human material confirmed the results, demonstrating lower expression of the sIL4R in patients and controls carrying the minor alleles. Together these results show sequence variations as a possible way of altering alternative splicing selection of IL4R in vivo.
Bergin
Ann-Marie
AM
Department of Clinical Immunology, Sahlgrenska University Hospital, Göteborg University, Göteborg, Sweden. h.bergin@qmul.ac.uk
Balder
Barbro
B
Kishore
Shivendra
S
Swärd
Kajsa
K
Hahn-Zoric
Mirjana
M
Löwhagen
Olle
O
Hanson
Lars A
LA
Padyukov
Leonid
L
D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D005260:Female; D015870:Gene Expression / Q000235:genetics*; D006801:Humans; D047468:Immunoprecipitation / Q000379:methods; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012326:RNA Splicing / Q000235:genetics*; D000072260:RNA Splicing Factors; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D019948:Receptors, Interleukin-4 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000068103:Serine-Arginine Splicing Factors; D012995:Solubility
D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D000072260:RNA Splicing Factors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D019948:Receptors, Interleukin-4; C491388:SRSF3 protein, human; C490769:YTHDC1 protein, human; D000068103:Serine-Arginine Splicing Factors