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SKIP interacts with c-Myc and Menin to promote HIV-1 Tat transactivation.

ABSTRACT: The Ski-interacting protein SKIP/SNW1 associates with the P-TEFb/CDK9 elongation factor and coactivates inducible genes, including HIV-1. We show here that SKIP also associates with c-Myc and Menin, a subunit of the MLL1 histone methyltransferase (H3K4me3) complex and that HIV-1 Tat transactivation requires c-Myc and Menin, but not MLL1 or H3K4me3. RNAi-ChIP experiments reveal that SKIP acts downstream of Tat:P-TEFb to recruit c-Myc and its partner TRRAP, a scaffold for histone acetyltransferases, to the HIV-1 promoter. By contrast, SKIP is recruited by the RNF20 H2B ubiquitin ligase to the basal HIV-1 promoter in a step that is bypassed by Tat and downregulated by c-Myc. Of interest, we find that SKIP and P-TEFb are dispensable for UV stress-induced HIV-1 transcription, which is strongly upregulated by treating cells with the CDK9 inhibitor flavopiridol. Thus, SKIP acts with c-Myc and Menin to promote HIV-1 Tat:P-TEFb transcription at an elongation step that is bypassed under stress.

SUBMITTER: Bres V

PROVIDER: S-EPMC2766281 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature

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SKIP interacts with c-Myc and Menin to promote HIV-1 Tat transactivation.

Brès Vanessa V Yoshida Tomonori T Pickle Loni L Jones Katherine A KA

Molecular cell 20091001 1

The Ski-interacting protein SKIP/SNW1 associates with the P-TEFb/CDK9 elongation factor and coactivates inducible genes, including HIV-1. We show here that SKIP also associates with c-Myc and Menin, a subunit of the MLL1 histone methyltransferase (H3K4me3) complex and that HIV-1 Tat transactivation requires c-Myc and Menin, but not MLL1 or H3K4me3. RNAi-ChIP experiments reveal that SKIP acts downstream of Tat:P-TEFb to recruit c-Myc and its partner TRRAP, a scaffold for histone acetyltransferase ...[more]

PMID: 19818711

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