PMID: 26416878

Authors:

Chatterjee N, North JA, Dechassa ML, Manohar M, Prasad R, Luger K, Ottesen JJ, Poirier MG, Bartholomew B

Title:

Histone acetylation near the nucleosome dyad axis enhances nucleosome disassembly by RSC and SWI/SNF.

Journal:

Mol Cell Biol. 2015 Sep 28. pii: MCB.00441-15.

Abstract:

Signaling associated with transcription activation occurs through post-translational modification of histones and is best exemplified by lysine acetylation. Lysines are acetylated in histone tails and the core domain / lateral surface of histone octamers. While acetylated lysines in histone tails are frequently recognized by other factors referred to as "readers" that promote transcription, the mechanistic role of the modifications in the lateral surface of the histone octamer remain unclear. Using x-ray crystallography, we show that acetylated lysines 115 and 122 in histone H3 are solvent-accessible, but in biochemical assays appear not to interact with the bromodomains of SWI/SNF and RSC to enhance recruitment or nucleosome mobilization as was previously shown for acetylated lysines in H3 histone tails. Instead we find that acetylation of lysines 115 and 122 increases the predisposition of nucleosomes for disassembly by SWI/SNF and RSC up to seven-fold, independent of bromodomains, and only in conjunction with contiguous nucleosomes. Thus, in combination with SWI/SNF and RSC, acetylation of lateral surface lysines in the histone octamer serve as crucial regulators of nucleosomal dynamics distinct from the histone code readers and writers.