Flores O, Lee G, Kessler J, Miller M, Schlief W, Tomassini J, Hazuda D. Host-cell positive transcription elongation factor b kinase activity is essential and limiting for HIV type 1 replication.
Proc Natl Acad Sci U S A 1999;
96:7208-13. [PMID:
10377393 PMCID:
PMC22054 DOI:
10.1073/pnas.96.13.7208]
[Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
HIV-1 gene expression and viral replication require the viral transactivator protein Tat. The RNA polymerase II transcriptional elongation factor P-TEFb (cyclin-dependent kinase 9/cyclin T) is a cellular protein kinase that has recently been shown to be a key component of the Tat-transactivation process. For this report, we studied the requirement for P-TEFb in HIV-1 infection, and we now show that P-TEFb is both essential and limiting for HIV-1 replication. Attenuation of P-TEFb kinase activity either by expression of a dominant-negative cyclin-dependent kinase 9 transgene or through the use of small-molecule inhibitors suppresses HIV-1 gene expression and HIV-1 replication. Inhibition of HIV-1 replication is affected in a manner consistent with a direct and specific effect on P-TEFb and the known functional role of P-TEFb in Tat-activated transcription. Tat-activated expression of HIV-1 genes seems uniquely dependent on P-TEFb, as inhibition of P-TEFb activity and HIV-1 replication can be achieved without compromising cell viability or RNA polymerase II-dependent cellular gene transcription. Selective inhibition of the P-TEFb kinase may therefore provide a novel approach for developing chemotherapeutic agents against HIV-1.
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