Histone acetylation and methylation: combinatorial players for transcriptional regulation.

Post-synthetic modification of histone proteins in chromatin architecture plays a central role in the epigenetic regulation of transcription. Histone acetylation and methylation are the two major modifications that function as a specific transcription regulator in response to various cellular signals. Albeit the mechanism of action of these modifications in transcription is not well understood, recent discovery of histone acetyltransferase (HAT) and methyltransferase (HMT) activities within transcriptional regulators has an important implication for histone modification to be a key player for the precise regulation of transcription processes. Here, we discuss recent advances made on histone acetylation and methylation as a fundamental process to modulate gene transcription, with a particular emphasis on their combinatorial effects in transcriptional control.