Acetylation is not mere a consequence of transcription: histones are acetylated without ongoing transcription [ChIP-seq]

In all eukaryotes, acetylation of histones lysine residues correlates with transcription activation. Whether histone acetylation is a cause or consequence of transcription is debated. One model suggests that transcription promotes the recruitment and/or activation of acetyltransferases and histone acetylation occurs as a consequence of ongoing transcription. However, the extent to which transcription shapes the global acetylation landscapes is not known. Here we show that global protein acetylation remains virtually unaltered after acute transcription inhibition. Transcription inhibition ablates the co-transcriptionally occurring ubiquitylation of H2BK120 but does not reduce histone acetylation. The combined inhibition of transcription and CBP/p300 further demonstrates that acetyltransferases remain active and continue to acetylate histones independently of transcription. Together, these results show that histone acetylation is not a mere consequence of transcription; acetyltransferase recruitment and activation is uncoupled from the act of transcription and histone and non-histone protein acetylation are sustained in the absence of ongoing transcription.