title: An RNAi screen of chromatin proteins identifies Tip60-p400 as a regulator of embryonic stem cell identity.
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.
authors.affiliation: Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA. thomas.fazzio@ucsf.edu
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Fazzio
authors.forename: Jason T
authors.initials: JT
authors.lastname: Huff
authors.forename: Barbara
authors.initials: B
authors.lastname: Panning
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000378:metabolism*; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D051548:Histone Acetyltransferases / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors; D000074443:Lysine Acetyltransferase 5; D051379:Mice; D000071317:Nanog Homeobox Protein; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D015534:Trans-Activators; D014158:Transcription, Genetic
chemical_list: D015220:Calcium Channels; D006657:Histones; D018398:Homeodomain Proteins; D053496:Inositol 1,4,5-Trisphosphate Receptors; C025389:Itpr1 protein, mouse; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D018160:Receptors, Cytoplasmic and Nuclear; D015534:Trans-Activators; D051548:Histone Acetyltransferases; C523065:Kat5 protein, mouse; D000074443:Lysine Acetyltransferase 5