title: p53 induces differentiation of mouse embryonic stem cells by suppressing Nanog expression.
abstract: The tumour suppressor p53 becomes activated in response to upstream stress signals, such as DNA damage, and causes cell-cycle arrest or apoptosis. Here we report a novel role for p53 in the differentiation of mouse embryonic stem cells (ESCs). p53 binds to the promoter of Nanog, a gene required for ESC self-renewal, and suppresses Nanog expression after DNA damage. The rapid down-regulation of Nanog mRNA during ESC differentiation correlates with the induction of p53 transcriptional activity and Ser 315 phosphorylation. The importance of Ser 315 phosphorylation was revealed by the finding that induction of p53 activity is impaired in p53(S315A) knock-in ESCs during differentiation, leading to inefficient suppression of Nanog expression. The decreased inhibition of Nanog expression in p53(S315A) ESCs during differentiation is due to an impaired recruitment of the co-repressor mSin3a to the Nanog promoter. These findings indicate an alternative mechanism for p53 to maintain genetic stability in ESCs, by inducing the differentiation of ESCs into other cell types that undergo efficient p53-dependent cell-cycle arrest and apoptosis.
authors.affiliation: Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0322, USA.
authors.forename: Tongxiang
authors.initials: T
authors.lastname: Lin
authors.forename: Connie
authors.initials: C
authors.lastname: Chao
authors.forename: Shin'ichi
authors.initials: S
authors.lastname: Saito
authors.forename: Sharlyn J
authors.initials: SJ
authors.lastname: Mazur
authors.forename: Maureen E
authors.initials: ME
authors.lastname: Murphy
authors.forename: Ettore
authors.initials: E
authors.lastname: Appella
authors.forename: Yang
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015536:Down-Regulation; D004622:Embryo, Mammalian / Q000166:cytology; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000378:metabolism*; D051379:Mice; D000071317:Nanog Homeobox Protein; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D013234:Stem Cells / Q000166:cytology*; D014212:Tretinoin; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*
chemical_list: D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D016159:Tumor Suppressor Protein p53; D014212:Tretinoin