An RNAi Screen of Chromatin Proteins Identifies Tip60-p400 as a Regulator of Embryonic Stem Cell Identity, Experiment B

ABSTRACT: Proper regulation of chromatin structure is necessary for the maintenance of cell type-specific gene expression patterns. The embryonic stem cell (ESC) expression pattern governs self-renewal and pluripotency. Here, we present an RNAi screen in mouse ESCs of 1008 loci encoding chromatin proteins. We identified 68 proteins that exhibit diverse phenotypes upon knockdown (KD), including seven subunits of the Tip60-p400 complex. Phenotypic analyses revealed that Tip60-p400 is necessary to maintain characteristic features of ESCs. We show that p400 localization to the promoters of both silent and active genes is dependent upon histone H3 lysine 4 trimethylation (H3K4me3). Furthermore, the Tip60-p400 KD gene expression profile is enriched for developmental regulators and significantly overlaps with that of the transcription factor Nanog. Depletion of Nanog reduces p400 binding to target promoters without affecting H3K4me3 levels. Together, these data indicate that Tip60-p400 integrates signals from Nanog and H3K4me3 to regulate gene expression in ESCs. Keywords: ChIP-chip We identified genes encoding subunits of the Tip60-p400 complex in an RNAi screen of chromatin proteins in mouse embryonic stem cells (ESCs), which upon depletion resulted in a dramatic phenotype. To investigate the role of this complex in gene expression in ESCs, we performed ChIP-chip location analysis using genome-wide promoter tiling arrays. We immunoprecipitated chromatin with an antibody to p400 and competitively hybridized it to input material on two arrays with probes interrogating essentially all mouse promoters with 100 bp tiling of -3250 bp to +750 bp around the transcription start sites.

ORGANISM(S): Mus musculus

SUBMITTER: Jason Huff 

PROVIDER: E-GEOD-11241 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress