Identification and functional characterization of BTas transactivator as a DNA-binding protein.
The genome of bovine foamy virus (BFV) encodes a transcriptional transactivator, namely BTas, that remarkably enhances gene expression by binding to the viral long-terminal repeat promoter (LTR) and internal promoter (IP). In this report, we characterized the functional domains of BFV BTas. BTas contains two major functional domains: the N-terminal DNA-binding domain (residues 1-133) and the C-terminal activation domain (residues 198-249). The complete BTas responsive regions were mapped to the positions -380/-140 of LTR and 9205/9276 of IP. Four BTas responsive elements were identified at the positions -368/-346, -327/-307, -306/-285 and -186/-165 of the BFV LTR, and one element was identified at the position 9243/9264 of the BFV IP. Unlike other foamy viruses, the five BTas responsive elements in BFV shared obvious sequence homology. These data suggest that among the complex retroviruses, BFV appears to have a unique transactivation mechanism.
Tan
Juan
J
State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, Nankai University, Tianjin 300071, China.
Hao
Peng
P
Jia
Rui
R
Yang
Wei
W
Liu
Ruichang
R
Wang
Jinzhong
J
Xi
Zhen
Z
Geng
Yunqi
Y
Qiao
Wentao
W
D000818:Animals; D002417:Cattle; D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D015967:Gene Expression Regulation, Viral; D006801:Humans; D011401:Promoter Regions, Genetic / Q000235:genetics; D020218:Response Elements / Q000235:genetics; D016092:Spumavirus / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D020079:Terminal Repeat Sequences / Q000235:genetics; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D014162:Transfection; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D015534:Trans-Activators; D014764:Viral Proteins