title: Modeling SNP mediated differential targeting of homologous 3'UTR by microRNA.
abstract: We had previously proposed that the post-transcriptional regulation through microRNA as a mechanism for incomplete penetrance and variable expressivity, leads to lack of correlation between genotype and phenotype. Here we report the validation of miRNA-target interactions we predicted earlier and demonstrate the regulation of endogenous JAG1 by hsa-miR-214 and hsa-miR-124, and TGFBR2 by hsa-miR-34b*, through luciferase activity of reporter constructs and also the expression levels of the endogenous genes. Using these targets, we have modeled the diploid state for miRNA target site with heterozygosity for the SNP and demonstrate the differential targeting of an otherwise identical 3'UTR. We show that SNP rs8708 (A > G) at the target site of hsa-miR-214 can relieve the repression while an SNP rs11466532 (C > T) enhances the repression of reporter expression by hsa-miR-34b*. We discuss the results in the light of its implications in the context of penetrance of dominant mutations in miRNA targeted genes, using JAG1 as an example. These observations imply that disease causing mutations in JAG1 linked to the SNP rs8708G will be poorly targeted by hsa-miR-214 when present against a normal allele of JAG1 with rs8708A and will show penetrance of JAG1 mutations as Alagille syndrome, while mutant JAG1 linked to rs8708A against rs8708G on the normal allele will show either no disease or much attenuated symptoms and hence exhibit incomplete penetrance.
authors.affiliation: Dr. B.R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India.
authors.forename: Jasmine Kaur
authors.initials: JK
authors.lastname: Ahluwalia
authors.forename: Kartik
authors.initials: K
authors.lastname: Soni
authors.forename: Sridhar
authors.initials: S
authors.lastname: Sivasubbu
authors.forename: Vani
authors.initials: V
authors.lastname: Brahmachari
mesh_terms: D020413:3' Untranslated Regions; D000483:Alleles; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000235:genetics; D002460:Cell Line; D005786:Gene Expression Regulation; D023061:Gene Order; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics; D000072100:Jagged-1 Protein; D008565:Membrane Proteins / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D008954:Models, Biological; D020641:Polymorphism, Single Nucleotide; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics; D000072099:Serrate-Jagged Proteins
chemical_list: D020413:3' Untranslated Regions; D002135:Calcium-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; C000606273:JAG1 protein, human; D000072100:Jagged-1 Protein; C509207:MIRN124 microRNA, human; C547397:MIRN214 microRNA, human; D008565:Membrane Proteins; D035683:MicroRNAs; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D000072099:Serrate-Jagged Proteins; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II