A Polymorphism in the 3′ Untranslated Region of the Gene for Tumor Necrosis Factor Receptor 2 Modulates Reporter Gene Expression

Abstract

The gene encoding the human TNF alpha receptor (TNFR) 2 contains polymorphisms in the 3' untranslated region (UTR). Previous studies have shown that some variant alleles in this region are associated with obesity and insulin resistance. However, the effect of these polymorphisms on the expression of TNFR2 has not been studied to date. To examine the role played by different haplotypes in the control of TNFR2 expression (haplotypes A1-A5, referring to nucleotides 1663 G/A, 1668 T/G, and 1690 T/C), we introduced these sequences into the 3'-UTR of a heterologous reporter gene and expressed the corresponding constructs in a human T-cell line. We demonstrate that a 485-nt fragment of the TNFR2 3'-UTR that contains a U-rich region decreases reporter expression and that haplotypes A1-A4 exert a stronger effect than A5. Furthermore, time-course assays of mRNA stability using actinomycin D revealed that haplotypes A1-A4 destabilize the mRNA. The proximal TNFR2 3'-UTR, independently of haplotype differences, responded to T-cell activation by increasing mRNA decay. Electromobility shift analysis demonstrated that protein(s) found in T-cell extracts bind to the 485-nt fragment. We suggest that an increased rate of TNFR2 mRNA decay protects cells from unrestrained TNF alpha effects and that this protection is weakened in A5 subjects. These findings may explain the association of this haplotype with obesity and increased leptin levels.

A Functional Haplotype in the 3′Untranslated Region ofTNFRSF1BIs Associated with Tuberculosis in Two African Populations

“…Interestingly, these regulatory elements are located in close proximity to the polymorphic region in the TNFR2 mRNA and thus might easily be affected by allelic variations. The regulatory capacity of this region is underscored by the finding that 39UTR-haplotype GTC results in significantly decreased mRNA decay rates compared with the other haplotypes, as shown by luciferase-based-reporter gene studies in Jurkat T cell line (21). Nevertheless, the GTC haplotype itself has never been shown to contribute to disease susceptibility in any study including the one presented here.…”

“…Genetic variants in the 39UTR of TNFRSF1B are important for a number of pathologies including obesity and insulin resistance (31) and Crohn's disease (32), a chronic inflammatory disorder of the bowels. Interestingly, a recent study showed that this region affects TNFR2 expression by influencing mRNA stability (21). According to this report, a U-rich region within the 39UTR increases the decay rate of the TNFR2 mRNA following T cell activation, and thus is predicted to protect cells from exaggerated TNFR2 effects.…”

“…We previously showed that a nonsynonymous coding SNP, rs1061622 (Met196Arg), significantly alters TNFR2-mediated NF-kB activation and target gene expression (20). Moreover, haplotypes in the 39untranslated region (UTR) have been reported to affect TNFR2 expression by influencing messenger ribonucleic acid (mRNA) decay rate (21). Given the pivotal role of TNFR2 in antimycobacterial immune responses, we investigated functional TNFRSF1B polymorphisms for association with TB susceptibility.…”

“…The functionally relevant TNFRSF1B polymorphisms rs1061622, rs1061624, rs5030792, and rs3397 (20,21,28) were genotyped in the SAC population. All markers were in Hardy-Weinberg equilibrium in the control group.…”

Association analysis of TNFRSF1B polymorphisms with type 2 diabetes and its related traits in North India

“…M196R is postulated to affect the proteolytic cleavage of the membrane bound TNFR2 to soluble form, TNF binding and/or TNF induced apoptosis by impaired NF-jB signaling (Stark et al 2003;Till et al 2005). Also, a haplotype including rs3397 in 3 0 UTR which alters TNFR2 stability and activity is associated with insulin resistance in young diabetic subjects (Puga et al 2005;Fernandez-Real et al 2000).…”