OCT4/SOX2-independent Nanog autorepression modulates heterogeneous Nanog gene expression in mouse ES cells

• Published in: The EMBO journal Vol. 31; no. 24; pp. 4547 - 4562
• Main Authors: Navarro, Pablo, Festuccia, Nicola, Colby, Douglas, Gagliardi, Alessia, Mullin, Nicholas P, Zhang, Wensheng, Karwacki-Neisius, Violetta, Osorno, Rodrigo, Kelly, David, Robertson, Morag, Chambers, Ian
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 12.12.2012; Nature Publishing Group UK; Blackwell Publishing Ltd; EMBO Press; Nature Publishing Group
• Subjects: Animals; Biochemistry, Molecular Biology; Cell Differentiation - genetics; Cell Differentiation - physiology; Cellular Biology; Chromatin Immunoprecipitation; EMBO09; EMBO11; Embryonic Stem Cells - metabolism; Feedback, Physiological; Flow Cytometry; Gene expression; Gene Expression Regulation - genetics; Gene Expression Regulation - physiology; Gene Regulatory Networks - genetics; Genomics; Green Fluorescent Proteins; Heterogeneity; Homeodomain Proteins - metabolism; In Situ Hybridization, Fluorescence; Life Sciences; Mice; Molecular biology; nanog; Nanog Homeobox Protein; network; pluripotency; Pluripotent Stem Cells - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Rodents; self-renewal; Signal transduction; Stem cells; Transcription Factors - metabolism; self‐renewal; nanog; pluripotency; heterogeneity; network
• ISSN: 0261-4189; 1460-2075
• DOI: 10.1038/emboj.2012.321

NANOG, OCT4 and SOX2 form the core network of transcription factors supporting embryonic stem (ES) cell self‐renewal. While OCT4 and SOX2 expression is relatively uniform, ES cells fluctuate between states of high NANOG expression possessing high self‐renewal efficiency, and low NANOG expression exhibiting increased differentiation propensity. NANOG, OCT4 and SOX2 are currently considered to activate transcription of each of the three genes, an architecture that cannot readily account for NANOG heterogeneity. Here, we examine the architecture of the Nanog ‐centred network using inducible NANOG gain‐ and loss‐of‐function approaches. Rather than activating itself, Nanog activity is autorepressive and OCT4/SOX2‐independent. Moreover, the influence of Nanog on Oct4 and Sox2 expression is minimal. Using Nanog :GFP reporters, we show that Nanog autorepression is a major regulator of Nanog transcription switching. We conclude that the architecture of the pluripotency gene regulatory network encodes the capacity to generate reversible states of Nanog transcription via a Nanog ‐centred autorepressive loop. Therefore, cellular variability in self‐renewal efficiency is an emergent property of the pluripotency gene regulatory network. The discovery of Nanog autorepression offers a new perspective on the transcriptional networks that govern Nanog's heterogeneous expression in ES cells.