Tat mediates transcriptional activation of HIV-1 gene in vitro.
Gene expression of human immunodeficiency virus (HIV-1) is greatly enhanced by a viral transactivator, the Tat protein, which interacts with R region sequences of the HIV-1 long terminal repeat (LTR). There is no direct evidence to indicate transcriptional activation of HIV-1 by Tat. Using an in vitro transcription system, we demonstrate that an established mouse cell line, which constitutively expresses Tat protein, selectively stimulates the steady state levels of the transcripts directed from the long terminal repeat (LTR) sequences of HIV-1. The gel binding retardation assays further demonstrate a stable activated complex, formed due to direct binding of Tat to DNA elements of the HIV-1 LTR. These data implicate transcription as the site of Tat action in trans-activation and could play an essential role in human immunodeficiency virus replication, similar to the nuclear trans-activators of other viruses.
West
M
M
Biological Carcinogenesis and Development Program, Program Resources Inc./DynCorp, National Cancer Institute, Frederick, MD 21702, USA.
Hoover
T
T
Kung
H
H
Raziuddin
D000818:Animals; D002460:Cell Line; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D015696:Gene Products, tat / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics*; D051379:Mice; D015533:Transcriptional Activation; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D054322:tat Gene Products, Human Immunodeficiency Virus