CpG islands recruit a histone H3 lysine 36 demethylase [Agilent data]

ABSTRACT: Transcription factors that bind small DNA motifs embedded in promoters play a central role in controlling gene expression. However, in addition to these elements, up to 70% of genes in higher eukaryotes also have high levels of non-methylated cytosine/guanine base pairs (CpGs) surrounding promoters and gene regulatory units. These features, called CpG islands, were identified over twenty years ago but there remains little mechanistic evidence to suggest how these enigmatic elements contribute to promoter function, with the exception that they are refractory to epigenetic silencing by DNA methylation. Here we show that CpG islands directly recruit the H3K36 specific lysine demethylase enzyme KDM2A. Genome wide analyses by ChIP-seq demonstrated a striking global association of KDM2A with CpG islands. Nucleation of KDM2A at these elements resulted in removal of H3K36 methylation creating CpG island chromatin that is uniquely depleted of this modification. KDM2A utilizes a zinc finger CxxC (ZF-CxxC) domain that specifically recognizes non-methylated CpG DNA and binding is blocked when the CpG DNA is methylated, thus constraining KDM2A to nonmethylated CpG islands. These data expose a remarkably straightforward mechanism through which KDM2A delineates a unique architecture that differentiates CpG island chromatin from bulk chromatin. Two cell lines were used in this study: a control line (LMP) with wildtype levels of KDM2A, and a KDM2A knockdown line (RNAi) in which KDM2A levels were depleted by approximately 60% using an shRNA-based approach. For each cell line, RNA was extracted from cells collected on two different dates (rep1 and rep2).

ORGANISM(S): Homo sapiens

SUBMITTER: Peter Park 

PROVIDER: E-GEOD-21201 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress