title: Identification and functional characterization of Bet protein as a negative regulator of BFV3026 replication.
abstract: Foamy virus (FV) establishes persistent infection in the host without causing apparent disease. Besides the transactivator Tas protein, another auxiliary protein--Bet--has been reported in prototype foamy virus, equine foamy virus, and feline foamy virus. Here, we found the putative bbet gene in clone C74 from a cDNA library of bovine foamy virus strain 3026 (BFV3026) by comparison of gene localization, composition, and splicing features with other known bet genes. Subsequently, BBet protein was detected in BFV3026-infected cells by Western blot and immunofluorescence analyses. Analysis of the BBet mutant infectious clone (pBS-BFVdelBBet) revealed that BBet could inhibit BFV3026 replication. Consistent with this result, overexpression of BBet in Cf2Th cells reduced BFV replication by approximately threefold. Furthermore, virus replication levels similarly were reduced by approximately threefold in pBS-BFV-transfected and BFV3026-infected Cf2Th cells stably expressing BBet compared with control cells. After three passages, BFV3026 replicated more slowly in BBet-expressing cells. This study implicates BBet as a negative regulator of BFV replication and provides a resource for future studies on the function of this protein in the virus lifecycle.
authors.affiliation: Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin, 300071, China.
authors.forename: Tiejun
authors.initials: T
authors.lastname: Bing
authors.forename: Kai
authors.initials: K
authors.lastname: Wu
authors.forename: Xiaoxu
authors.initials: X
authors.lastname: Cui
authors.forename: Peng
authors.initials: P
authors.lastname: Shao
authors.forename: Qicheng
authors.initials: Q
authors.lastname: Zhang
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Bai
authors.forename: Juan
authors.initials: J
authors.lastname: Tan
authors.forename: Wentao
authors.initials: W
authors.lastname: Qiao
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000821:virology*; D002460:Cell Line; D015536:Down-Regulation; D005260:Female; D015967:Gene Expression Regulation, Viral; D051379:Mice; D008807:Mice, Inbred BALB C; D012192:Retroviridae Infections / Q000662:veterinary* / Q000821:virology; D016092:Spumavirus / Q000235:genetics / Q000502:physiology*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D014764:Viral Proteins