title: Differential localization of HPV16 E6 splice products with E6-associated protein.
abstract: High-risk Human Papillomavirus (HPV) is the etiological agent associated with the majority of anogenital cancers. The primary HPV oncogenes, E6 and E7, undergo a complex splicing program resulting in protein products whose purpose is not fully understood. Previous mouse studies have confirmed the existence of a translated product corresponding to the E6*I splice product. In terms of function, the translated E6*I protein has been shown to bind to E6 protein and to E6 associated protein (E6AP). E6*I has an inhibitory effect on E6-mediated p53 degradation in E6 expressing cells. In order to analyze the relationship between E6*I and full-length E6 in relation to localization, we created a series of green fluorescent protein (GFP) fusion products. The localization of these proteins with reference to E6AP in vivo remains unclear. Therefore, we investigated the cellular distribution of different forms of E6 with reference to E6AP. E6 and E6*I proteins, expressed from a wild type E6 gene cassette, were dispersed in the nucleus and the cytoplasm. Whereas, the E6 splice donor mutant (E6MT) was primarily localized to the nucleus. E6*I protein and E6AP were found to co-localize mainly to the cytoplasm, whereas the co-localization of full-length E6 protein and E6AP, if at all, was found mainly at the perinuclear region. These results suggest a functional relationship between the E6*I and full-length E6 protein which correlates with their localization and likely is important in regulation of the E6-E6AP complex.
authors.affiliation: Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand. g4238029@student.mahidol.ac.th
authors.forename: Kulthida
authors.initials: K
authors.lastname: Vaeteewoottacharn
authors.forename: Siriphatr
authors.initials: S
authors.lastname: Chamutpong
authors.forename: Mathurose
authors.initials: M
authors.lastname: Ponglikitmongkol
authors.forename: Peter C
authors.initials: PC
authors.lastname: Angeletti
mesh_terms: D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm; D052162:Human papillomavirus 16 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009856:Oncogene Proteins, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030361:Papillomavirus Infections / Q000378:metabolism*; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D019154:Protein Splicing; D017433:Protein Structure, Secondary; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*
chemical_list: C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D012097:Repressor Proteins; C471639:UBE3A protein, human; D044767:Ubiquitin-Protein Ligases; D017346:Protein Serine-Threonine Kinases