Mus musculus musculus ChIP-seq. Mus musculus musculus strain:B6

Chromodomain Helicase DNA-binding protein 5 (CHD5) is a tumor suppressor mapping to 1p36—a genomic region frequently deleted in human cancer. Although CHD5 belongs to the CHD family of chromatin remodeling proteins, whether its tumor suppressive role involves an interaction with chromatin is unknown. Here we report that Chd5 binds the unmodified N-terminus of H3 through its tandem plant homeodomains (PHDs). Genome-wide ChIP studies reveal preferential binding of Chd5 to loci lacking the active mark H3K4me3, and also identify novel Chd5-targets implicated in cancer. Chd5 mutations abrogating H3 binding are unable to inhibit proliferation or to transcriptionally modulate target genes, leading to tumorigenesis in vivo. Unlike wild-type Chd5, the Chd5-PHD mutants are unable to induce differentiation or to efficiently suppress growth of human neuroblastoma in vivo. Our work defines Chd5 as an N-terminally unmodified H3-binding protein and provides functional evidence that this interaction orchestrates chromatin-mediated transcriptional programs critical for tumor suppression.