title: Functional inactivation of the SR family of splicing factors during a vaccinia virus infection.
abstract: SR proteins are essential splicing factors required for constitutive splicing and function as key regulators of alternative RNA splicing. We have shown that SR proteins purified from late adenovirus-infected cells (SR-Ad) are functionally inactivated as splicing enhancer or splicing repressor proteins by a virus-induced partial de-phosphorylation. Here, we show that SR proteins purified from late vaccinia-virus-infected cells (SR-VV) are also hypo-phosphorylated and functionally inactivated as splicing regulatory proteins. We further show that incubating SR-Ad proteins under conditions that restore the phospho-epitopes to the SR proteins results in the restoration of their activity as splicing enhancer and splicing repressor proteins. Interestingly, re-phosphorylation of SR-VV proteins only partially restored the splicing enhancer or splicing repressor phenotype to the SR proteins. Collectively, our results suggest that viral control of SR protein activity may be a common strategy used by DNA viruses to take control of the host cell RNA splicing machinery.
authors.affiliation: Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, 751 23 Uppsala, Sweden.
authors.forename: Tien-sheng
authors.initials: TS
authors.lastname: Huang
authors.forename: Camilla Estmer
authors.initials: CE
authors.lastname: Nilsson
authors.forename: Tanel
authors.initials: T
authors.lastname: Punga
authors.forename: Goran
authors.initials: G
authors.lastname: Akusjarvi
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015967:Gene Expression Regulation, Viral; D006367:HeLa Cells; D006801:Humans; D010641:Phenotype; D010766:Phosphorylation; D012326:RNA Splicing; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism; D014616:Vaccinia virus / Q000235:genetics / Q000378:metabolism*
chemical_list: D016601:RNA-Binding Proteins; D012097:Repressor Proteins