Acetyl coenzyme A stimulates RNA polymerase II transcription and promoter binding by transcription factor IID in the absence of histones

Protein acetylation has emerged as a means of controlling levels of mRNA sy nthesis in eukaryotic cells. Here we report that acetyl coenzyme A (acetyl- CoA) stimulates RNA polymerase II, transcription in vitro in the absence of histones. The effect of acetyl-CoA on basal and activated transcription wa s studied in a human RNA polymerase II transcription system reconstituted f rom recombinant and highly purified transcription factors. Both basal and a ctivated transcription were stimulated by the addition of acetyl-CoA to tra nscription reaction mixtures. By varying the concentrations of general tran scription factors in the reaction mixtures, we found that acetyl-CoA decrea sed the concentration of TFIID required to observe transcription. Electroph oretic mobility shift assays and DNase I footprinting revealed that acetyl- CoA increased the affinity of the general transcription factor TFIID for pr omoter DNA in a TBP-associated factor (TAF)-dependent manner. Interestingly , acetyl-CoA also caused a conformational change in the TFIID-TFIIA-promote r complex as assessed by DNase I footprinting. These results show that acet yl-CoA alters the DNA binding activity of TFIID and indicate that this biol ogically important cofactor functions at multiple levels to control gene ex pression.