title: SF2/ASF binds the human papillomavirus type 16 late RNA control element and is regulated during differentiation of virus-infected epithelial cells.
abstract: Pre-mRNA splicing occurs in the spliceosome, which is composed of small ribonucleoprotein particles (snRNPs) and many non-snRNP components. SR proteins, so called because of their C-terminal arginine- and serine-rich domains (RS domains), are essential members of this class. Recruitment of snRNPs to 5' and 3' splice sites is mediated and promoted by SR proteins. SR proteins also bridge splicing factors across exons to help to define these units and have a central role in alternative and enhancer-dependent splicing. Here, we show that the SR protein SF2/ASF is part of a complex that forms upon the 79-nucleotide negative regulatory element (NRE) that is thought to be pivotal in posttranscriptional regulation of late gene expression in human papillomavirus type 16 (HPV-16). However, the NRE does not contain any active splice sites, is located in the viral late 3' untranslated region, and regulates RNA-processing events other than splicing. The level of expression and extent of phosphorylation of SF2/ASF are upregulated with epithelial differentiation, as is subcellular distribution, specifically in HPV-16-infected epithelial cells, and expression levels are controlled, at least in part, by the virus transcription regulator E2.
authors.affiliation: Institute of Biomedical and Life Sciences, Division of Virology, University of Glasgow, Church Street, Glasgow G11 5JR, Scotland, United Kingdom.
authors.forename: Maria G
authors.initials: MG
authors.lastname: McPhillips
authors.forename: Thanaporn
authors.initials: T
authors.lastname: Veerapraditsin
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Cumming
authors.forename: Dimitra
authors.initials: D
authors.lastname: Karali
authors.forename: Steven G
authors.initials: SG
authors.lastname: Milligan
authors.forename: Winifred
authors.initials: W
authors.lastname: Boner
authors.forename: Iain M
authors.initials: IM
authors.lastname: Morgan
authors.forename: Sheila V
authors.initials: SV
authors.lastname: Graham
mesh_terms: D020413:3' Untranslated Regions; D002454:Cell Differentiation; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000502:physiology; D004847:Epithelial Cells / Q000166:cytology / Q000821:virology*; D015967:Gene Expression Regulation, Viral; D006801:Humans; D009687:Nuclear Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D009856:Oncogene Proteins, Viral / Q000502:physiology; D027383:Papillomaviridae / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D010766:Phosphorylation; D011485:Protein Binding; D012322:RNA Precursors / Q000378:metabolism; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism*; D016601:RNA-Binding Proteins; D012045:Regulatory Sequences, Nucleic Acid; D012261:Ribonucleoproteins / Q000032:analysis / Q000378:metabolism; D000068103:Serine-Arginine Splicing Factors; D000072668:Splicing Factor U2AF
chemical_list: D020413:3' Untranslated Regions; D004268:DNA-Binding Proteins; C054855:E2 protein, Human papillomavirus type 16; D009687:Nuclear Proteins; D009856:Oncogene Proteins, Viral; D012322:RNA Precursors; D012333:RNA, Messenger; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D000072668:Splicing Factor U2AF; C000607494:U2AF2 protein, human; D000068103:Serine-Arginine Splicing Factors