Acetylated histone H3K56 interacts with Oct4 to promote mouse embryonic stem cell pluripotency

The presence of acetylated histone H3K56 (H3K56ac) in human ES cells (ESCs) correlates positively with the binding of Nanog, Sox2, and Oct4 (NSO) transcription factors at their target gene promoters. However, the function of H3K56ac there has been unclear. We now report that Oct4 interacts with H3K56ac in mouse ESC nuclear extracts and that perturbing H3K56 acetylation decreases Oct4-H3 binding. This interaction is likely to be direct because it can be recapitulated in vitro in an H3K56ac-dependent manner and is functionally important because H3K56ac combines with NSO factors in chromatin immunoprecipitation sequencing to mark the regions associated with pluripotency better than NSO alone. Moreover, reducing H3K56ac by short hairpin Asf1a decreases expression of pluripotency-related markers and increases expression of differentiation-related ones. Therefore, our data suggest that H3K56ac plays a central role in binding to Oct4 to promote the pluripotency of ESCs.