A conserved BAH module within mammalian BAHD1 connects H3K27me3 to Polycomb gene silencing

ABSTRACT: Trimethylation of histone H3 lysine 27 (H3K27me3) is important for gene silencing, (epi)genome organization and organismal development. In a prevalent model, the functional “readout” of H3K27me3 in mammalian cells is achieved through the H3K27me3-recognizing chromodomain harbored within the chromobox (CBX) component of canonical Polycomb repressive complex 1 (cPRC1), which induces chromatin compaction and gene repression. Here, we report that binding of H3K27me3 by a Bromo Adjacent Homology (BAH) domain harbored within BAH domain-containing protein 1 (BAHD1) is required for overall BAHD1 targeting to chromatin and for optimal repression of the H3K27me3-demarcated genes in mammalian cells. Disruption of direct interaction between BAHD1-BAH and H3K27me3 by point mutagenesis leads to chromatin remodeling, notably, increased histone acetylation, at its Polycomb gene targets. Mice carrying an H3K27me3-interaction-defective mutation of Bahd1BAH causes marked embryonic lethality, showing a requirement of this pathway for normal development. Altogether, this work demonstrates an H3K27me3-initiated signaling cascade that operates through a conserved BAH “reader” module within BAHD1 in mammals.

ORGANISM(S): Mus musculus

PROVIDER: GSE167079 | GEO | 2021/03/16

REPOSITORIES: GEO