USF-related transcription factor, HIV-TF1, stimulates transcription of human immunodeficiency virus-1.
The transcription factor HIV-TF1, which binds to a region about 60 bp upstream from the enhancer of the human immunodeficiency virus-1 (HIV-1), was purified from human B cells. HIV-TF1 had a molecular weight of 39,000. Binding of HIV-TF1 to the HIV long terminal repeat (LTR) activated transcription from the HIV promoter in vitro. The HIV-TF1-binding site in HIV LTR was similar to the site recognized by upstream stimulatory factor (USF) in the adenovirus major late promoter. DNA-binding properties of HIV-TF1 suggested that HIV-TF1 might be identical or related to USF. Interestingly, treatment of purified HIV-TF1 by phosphatase greatly reduced its DNA-binding activity, suggesting that phosphorylation of HIV-TF1 was essential for DNA binding. The disruption of HIV-TF1-binding site induced a 60% decrease in the level of transcription from the HIV promoter in vivo. These results suggest that HIV-TF1 is involved in transcriptional regulation of HIV-1.
Maekawa
T
T
Laboratory of Molecular Genetics, RIKEN, Ibaraki, Japan.
Sudo
T
T
Kurimoto
M
M
Ishii
S
S
D001402:B-Lymphocytes; D001483:Base Sequence; D002460:Cell Line; D004268:DNA-Binding Proteins; D004742:Enhancer Elements, Genetic / Q000502:physiology*; D015967:Gene Expression Regulation, Viral; D016325:HIV Long Terminal Repeat / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; C070853:HIV-TF1 protein, human; D014157:Transcription Factors; D010744:Phosphoric Monoester Hydrolases