title: Functional expression cloning of Nanog, a pluripotency sustaining factor in embryonic stem cells.
abstract: Embryonic stem (ES) cells undergo extended proliferation while remaining poised for multilineage differentiation. A unique network of transcription factors may characterize self-renewal and simultaneously suppress differentiation. We applied expression cloning in mouse ES cells to isolate a self-renewal determinant. Nanog is a divergent homeodomain protein that directs propagation of undifferentiated ES cells. Nanog mRNA is present in pluripotent mouse and human cell lines, and absent from differentiated cells. In preimplantation embryos, Nanog is restricted to founder cells from which ES cells can be derived. Endogenous Nanog acts in parallel with cytokine stimulation of Stat3 to drive ES cell self-renewal. Elevated Nanog expression from transgene constructs is sufficient for clonal expansion of ES cells, bypassing Stat3 and maintaining Oct4 levels. Cytokine dependence, multilineage differentiation, and embryo colonization capacity are fully restored upon transgene excision. These findings establish a central role for Nanog in the transcription factor hierarchy that defines ES cell identity.
authors.affiliation: Institute for Stem Cell Research, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh EH9 3JQ, Scotland. ichambers@ed.ac.uk
authors.forename: Ian
authors.initials: I
authors.lastname: Chambers
authors.forename: Douglas
authors.initials: D
authors.lastname: Colby
authors.forename: Morag
authors.initials: M
authors.lastname: Robertson
authors.forename: Jennifer
authors.initials: J
authors.lastname: Nichols
authors.forename: Sonia
authors.initials: S
authors.lastname: Lee
authors.forename: Susan
authors.initials: S
authors.lastname: Tweedie
authors.forename: Austin
authors.initials: A
authors.lastname: Smith
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics*; D002455:Cell Division / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics / Q000302:isolation & purification*; D051379:Mice / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D050796:STAT3 Transcription Factor; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors