HIV-1 Tat complexes reveal subunit composition of active P-TEFb and stable association with 7SKsnRNP
© Sobhian et al; licensee BioMed Central Ltd. 2010
Published: 04 November 2010
HIV-infected individuals harbour a latent reservoir, which is not accessible to current treatments and constitutes a major obstacle for virus eradication. Post-integration latency could result from transcriptional inhibition of the provirus. Efficient transcription of the viral genome requires recruitment of the positive transcription elongation factor b (P-TEFb) to the long terminal repeat by the viral protein, Tat. To better understand the regulation of viral transcription, we aimed at characterizing nuclear Tat-associated protein complexes.
HeLa-S3 cells were stably transduced with C-terminally TAP-tagged Tat. Tat-associated complexes were purified from Dignam nuclear extracts by tandem affinity chromatography and interactors identified by tandem mass spectrometry. Biochemical and functional analysis using the siRNA approach were applied to understand the role of the newly identified Tat cofactors.
We identified new factors required for Tat transactivation and important for P-TEFb function. Given the involvement of P-TEFb in HIV-1 transcriptional latency, they may represent new potential targets against HIV.
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