Acetylation of Tat defines a cyclinT1-independent step in HIV transactivation.
The HIV transcriptional activator Tat is acetylated by p300 at a single lysine residue in the TAR RNA binding domain. We have generated monoclonal and polyclonal antibodies specific for the acetylated form of Tat (AcTat). Microinjection of anti-AcTat antibodies inhibited Tat-mediated transactivation in cells. Similarly, the p300 inhibitor Lys-CoA and ... siRNA specific for p300 suppressed Tat transcriptional activity. Full-length synthetic AcTat bound to TAR RNA with the same affinity as unacetylated Tat, but formation of a Tat-TAR-CyclinT1 ternary complex was completely inhibited in the presence of AcTat. We propose that Tat acetylation may help in dissociating the Tat cofactor CyclinT1 from TAR RNA and serve to transfer Tat onto the elongating RNA polymerase II.
Mesh Terms:
Acetylation, Acetyltransferases, Antibodies, Cell Cycle Proteins, Cyclin T, Cyclins, Gene Products, tat, HIV Long Terminal Repeat, HIV-1, HeLa Cells, Histone Acetyltransferases, Humans, Jurkat Cells, Macromolecular Substances, Models, Molecular, RNA Polymerase II, RNA, Small Interfering, Transcription Factors, Transcriptional Activation, p300-CBP Transcription Factors, tat Gene Products, Human Immunodeficiency Virus
Acetylation, Acetyltransferases, Antibodies, Cell Cycle Proteins, Cyclin T, Cyclins, Gene Products, tat, HIV Long Terminal Repeat, HIV-1, HeLa Cells, Histone Acetyltransferases, Humans, Jurkat Cells, Macromolecular Substances, Models, Molecular, RNA Polymerase II, RNA, Small Interfering, Transcription Factors, Transcriptional Activation, p300-CBP Transcription Factors, tat Gene Products, Human Immunodeficiency Virus
Mol. Cell
Date: Jul. 01, 2003
PubMed ID: 12887902
View in: Pubmed Google Scholar
Download Curated Data For This Publication
170947
Switch View:
- Interactions 2