title: A truncated T antigen expressed from an alternatively spliced BK virus early mRNA.
abstract: The early region of BK virus (BKV) is known to encode two well-characterized tumour (T) antigens, large T antigen (TAg) and small T antigen (tAg). In this study, we provide evidence of a third early BKV mRNA that codes for an additional early region product with an apparent molecular mass of 17-20 kDa. This truncated form of TAg (truncTAg) is expressed from an alternatively spliced mRNA that is derived from the excision of a second intron from the mRNA encoding TAg. The first 133 aa of truncTAg are identical to those of TAg but the additional splice results in translation from a different reading frame, adding three new amino acids before reaching a stop codon. TruncTAg is expressed in both BKV-transformed and lytically infected cells and it is found to be primarily localized to the nucleus. The function of BKV truncTAg is likely to be relevant to transformation, similar to the additional T antigens of simian virus 40, JC virus and mouse polyomavirus.
authors.affiliation: Department of Microbiology and Immunology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109-5942, USA.
authors.forename: Johanna R
authors.initials: JR
authors.lastname: Abend
authors.affiliation: Department of Microbiology and Immunology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109-5942, USA.
authors.forename: Amy E
authors.initials: AE
authors.lastname: Joseph
authors.affiliation: Department of Microbiology and Immunology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109-5942, USA.
authors.forename: Dweepanita
authors.initials: D
authors.lastname: Das
authors.affiliation: Department of Microbiology and Immunology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109-5942, USA.
authors.forename: Deniz B
authors.initials: DB
authors.lastname: Campbell-Cecen
authors.affiliation: Department of Microbiology and Immunology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109-5942, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Imperiale
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D000957:Antigens, Viral, Tumor / Q000235:genetics / Q000378:metabolism*; D001739:BK Virus / Q000235:genetics* / Q000378:metabolism*; D002460:Cell Line; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D006801:Humans; D021381:Protein Transport / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*
chemical_list: D000957:Antigens, Viral, Tumor; D012333:RNA, Messenger; D012367:RNA, Viral