Trans-activation by human immunodeficiency virus Tat protein requires the C-terminal domain of RNA polymerase II.
Human immunodeficiency virus (HIV)-encoded trans-activator (Tat) acts through the trans-activation response element RNA stem-loop to increase greatly the processivity of RNA polymerase II. Without Tat, transcription originating from the HIV promoter is attenuated. In this study, we demonstrate that transcriptional activation by Tat in vivo and in vitro requires the C-terminal domain (CTD) of RNA polymerase II. In contrast, the CTD is not required for basal transcription and for the formation of short, attenuated transcripts. Thus, trans-activation by Tat resembles enhancer-dependent activation of transcription. These results suggest that effects of Tat on the processivity of RNA polymerase II require proteins that are associated with the CTD and may result in the phosphorylation of the CTD.
Okamoto
H
H
Howard Hughes Medical Institute, Department of Medicine, University of California, San Francisco 94143-0724, USA.
Sheline
C T
CT
Corden
J L
JL
Jones
K A
KA
Peterlin
B M
BM
D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D015696:Gene Products, tat / Q000096:biosynthesis / Q000378:metabolism*; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D011994:Recombinant Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus; D012319:RNA Polymerase II