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Acetylation of TAF I 68, a subunit of TIF‐IB/SL1, activates RNA polymerase I transcription
Author(s) -
Muth Viola,
Nadaud Sophie,
Grummt Ingrid,
Voit Renate
Publication year - 2001
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/20.6.1353
Subject(s) - pcaf , biology , general transcription factor , microbiology and biotechnology , rna polymerase ii , transcription factor ii d , terminator (solar) , transcription (linguistics) , transcription factor ii f , rna polymerase iii , rna polymerase i , histone acetyltransferase , acetylation , transcription factor ii b , promoter , transcription factor , rna polymerase , transcriptional regulation , genetics , rna , gene , gene expression , linguistics , philosophy , ionosphere , physics , astronomy
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 deacetyl ates 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.