Acetylation of Tat defines a cyclinT1-independent step in HIV transactivation
Autor: | Philip A. Cole, Peter Henklein, Erwann Loret, Martina Schnoelzer, Alexander Dorr, Eric Verdin, Katrin Kaehlcke, Melanie Ott, Veronique Kiermer, Claudia Hetzer-Egger |
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Rok vydání: | 2003 |
Předmět: |
Models
Molecular Transcriptional Activation Macromolecular Substances RNA polymerase II Cell Cycle Proteins P300-CBP Transcription Factors complex mixtures Antibodies Transactivation Jurkat Cells Acetyltransferases Cyclins Humans p300-CBP Transcription Factors RNA Small Interfering Ternary complex Transcription factor Molecular Biology HIV Long Terminal Repeat Histone Acetyltransferases biology Cyclin T RNA Acetylation Cell Biology Molecular biology Gene Products tat biology.protein HIV-1 tat Gene Products Human Immunodeficiency Virus RNA Polymerase II Binding domain HeLa Cells Transcription Factors |
Zdroj: | Molecular cell. 12(1) |
ISSN: | 1097-2765 |
Popis: | 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. |
Databáze: | OpenAIRE |
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