Characterization of the promoter region of the viral interferon regulatory factor encoded by Kaposi's sarcoma-associated herpesvirus.
Viral interferon regulatory factor (vIRF) encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) inhibits the expression of interferon-responsive genes, causes cellular transformation and transactivates KSHV genes. In the present study, we characterized the mRNA expression pattern of the vIRF gene and its promoter. A vIRF transcript of 1.7 kb in size was detected in low level in uninduced KSHV-infected cells and its expression was inducible by 12-O-tetradecanoylphorbol-13-acetate (TPA), sensitive to cycloheximide and resistant to phosphonoacetic acid. The transcription start site was mapped to 79 nt upstream of the ATG initiation site by 5'-RACE. Mutagenesis analysis identified a region between -56 and the transcription start site (+1) as the minimal promoter region that contains a functional TATA box at -27. A region between -337 and -125 contains a repressor domain negated by sequence from -991 to -499 in BCBL-1 cells, a region which was also identified to be responsive to TPA induction. These results demonstrate vIRF as a KSHV early gene, identify its promoter and define the promoter regions that contain regulatory elements controlling vIRF transcription.
Wang
X P
XP
Department of Pediatrics, The University of Texas Health Science Center at San Antonio, San Antonio, Texas TX 78229, USA.
Zhang
Y J
YJ
Deng
J H
JH
Pan
H Y
HY
Zhou
F C
FC
Montalvo
E A
EA
Gao
S J
SJ
D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics*; D019288:Herpesvirus 8, Human / Q000235:genetics*; D050835:Interferon Regulatory Factors; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012367:RNA, Viral / Q000235:genetics*; D016385:TATA Box; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics*
D004268:DNA-Binding Proteins; D050835:Interferon Regulatory Factors; D012367:RNA, Viral; D014157:Transcription Factors; D014764:Viral Proteins; C413486:viral interferon regulatory factors; D013755:Tetradecanoylphorbol Acetate