title: Critical components of the pluripotency network are targets for the p300/CBP interacting protein (p/CIP) in embryonic stem cells.
abstract: p/CIP, also known as steroid receptor coactivator 3 (SRC-3)/Nuclear Receptor Coactivator 3 (NCoA3), is a transcriptional coactivator that binds liganded nuclear hormone receptors, as well as other transcription factors, and facilitates transcription through direct recruitment of accessory factors. We have found that p/CIP is highly expressed in undifferentiated mouse embryonic stem cells (mESCs) and is downregulated during differentiation. siRNA-mediated knockdown of p/CIP decreased transcript levels of Nanog, but not Oct4 or Sox2. Microarray expression analysis showed that Klf4, Tbx3, and Dax-1 are significantly downregulated in mESCs when p/CIP is knocked down. Subsequent chromatin immunoprecipitation (ChIP) analysis demonstrated that Tbx3, Klf4, and Dax-1 are direct transcriptional targets of p/CIP. Using the piggyBac transposition system, a mouse ESC line that expresses Flag-p/CIP in a doxycycline-dependent manner was generated. p/CIP overexpression increased the level of target genes and promoted the formation of undifferentiated colonies. Collectively, these results indicate that p/CIP contributes to the maintenance of ESC pluripotency through direct regulation of essential pluripotency genes. To better understand the mechanism by which p/CIP functions in ESC pluripotency, we integrated our ChIP and transcriptome data with published protein-protein interaction and promoter occupancy data to draft a p/CIP gene regulatory network. The p/CIP gene regulatory network identifies various feed-forward modules including one in which p/CIP activates members of the extended pluripotency network, demonstrating that p/CIP is a component of this extended network.
authors.affiliation: Department of Oncology, The London Regional Cancer Program and the Lawson Health Research Institute, London, Ontario, Canada; Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada.
authors.forename: J M
authors.initials: JM
authors.lastname: Chitilian
authors.forename: G
authors.initials: G
authors.lastname: Thillainadesan
authors.forename: J L
authors.initials: JL
authors.lastname: Manias
authors.forename: W Y
authors.initials: WY
authors.lastname: Chang
authors.forename: E
authors.initials: E
authors.lastname: Walker
authors.forename: M
authors.initials: M
authors.lastname: Isovic
authors.forename: W L
authors.initials: WL
authors.lastname: Stanford
authors.forename: J
authors.initials: J
authors.lastname: Torchia
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D015536:Down-Regulation / Q000187:drug effects; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D000090062:Kruppel-Like Factor 4; D051379:Mice; D056921:Nuclear Receptor Coactivator 3 / Q000378:metabolism*; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism*; D014162:Transfection
chemical_list: C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; C538867:Ncoa3 protein, mouse; D056921:Nuclear Receptor Coactivator 3
keywords: Coactivator; Embryonic stem cells; Gene expression; Pluripotent stem cells; Transcription factors