The BioGRID | PUBLICATION VIEW

	EMBO J. Mar (2001); 20(6):1353-62
Acetylation of TAF(I)68, a subunit of TIF-IB/SL1, activates RNA polymerase I transcription.
Muth V, Nadaud S, Grummt I, Voit R
Division of Molecular Biology of the Cell II, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany.
Abstract: Mammalian rRNA genes are preceded by a terminator element that is recognized by the transcription termination factor TTF-I. In exploring the functional significance of the promoter-proximal terminator, we found that TTF-I associates with the p300/CBP-associated factor PCAF, suggesting that TTF-I may target histone acetyltransferase to the rDNA promoter. We demonstrate that PCAF acetylates TAF(I)68, the second largest subunit of the TATA box-binding protein (TBP)-containing factor TIF-IB/SL1, and acetylation enhances binding of TAF(I)68 to the rDNA promoter. Moreover, PCAF stimulates RNA polymerase I (Pol I) transcription in a reconstituted in vitro system. Consistent with acetylation of TIF-IB/SL1 being required for rDNA transcription, the NAD(+)-dependent histone deacetylase mSir2a deacetylates TAF(I)68 and represses Pol I transcription. The results demonstrate that acetylation of the basal Pol I transcription machinery has functional consequences and suggest that reversible acetylation of TIF-IB/SL1 may be an effective means to regulate rDNA transcription in response to external signals.
[PUBMED: 11250901]