Activation of alpha-tropomyosin exon 2 is regulated by the SR protein 9G8 and heterogeneous nuclear ribonucleoproteins H and F.

ABSTRACT: The inclusion of exons 2 and 3 of alpha-tropomyosin is governed through tissue-specific alternative splicing. These exons are mutually exclusive, with exon 2 included in smooth muscle cells and exon 3 included in nearly all other cell types. Several cis-acting sequences contribute to this splicing decision: the branchpoints and pyrimidine tracts upstream of both exons, UGC-repeat elements flanking exon 3, and a series of purine-rich enhancers in exon 2. Previous work showed that proteins rich in serine-arginine (SR) dipeptides act through the exon 2 enhancers, but the specific proteins responsible for such activation remained unknown. Here we show that a 35-kDa member of the SR protein family, 9G8, can activate the splicing of alpha-tropomyosin exon 2. Using RNA affinity chromatography and

SUBMITTER: Crawford JB 

PROVIDER: S-EPMC1636816 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature