title: Requirement of Nanog dimerization for stem cell self-renewal and pluripotency.
abstract: Pluripotency of embryonic stem (ES) cells is maintained by transcription factors that form a highly interconnected protein interaction network surrounding the homeobox protein Nanog. Enforced expression of Nanog in mouse ES (mES) cells promotes self-renewal and alleviates their requirement for leukemia inhibitory factor (LIF). Understanding molecular mechanisms by which Nanog functions should illuminate fundamental properties of stem cells and the process of cellular reprogramming. Previously, we showed that Nanog forms multiple protein complexes in mES cells. Here, we demonstrate that Nanog dimerizes through its C-terminal domain rather than the homeodomain. Dimerization is required for interaction with other pluripotency network proteins. We also show that enforced expression of the Nanog dimer, but not the monomer, functionally replaces wild-type Nanog to sustain LIF-independent self-renewal of ES cells. Our results demonstrate that Nanog-Nanog homodimerization is a critical aspect of its function promoting stem cell pluripotency.
authors.affiliation: Division of Hematology-Oncology, Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Harvard Stem Cell Institute, and Howard Hughes Medical Institute, Boston, MA 02115, USA.
authors.forename: Jianlong
authors.initials: J
authors.lastname: Wang
authors.forename: Dana N
authors.initials: DN
authors.lastname: Levasseur
authors.forename: Stuart H
authors.initials: SH
authors.lastname: Orkin
mesh_terms: D000818:Animals; D019556:COS Cells; D049109:Cell Proliferation; D002522:Chlorocebus aethiops; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D019281:Dimerization; D053595:Embryonic Stem Cells / Q000378:metabolism; D018398:Homeodomain Proteins / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D053605:Leukemia Inhibitory Factor / Q000378:metabolism; D051379:Mice; D050505:Mutant Proteins / Q000378:metabolism; D000071317:Nanog Homeobox Protein; D039904:Pluripotent Stem Cells / Q000166:cytology*; D011485:Protein Binding; D017434:Protein Structure, Tertiary
chemical_list: D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D053605:Leukemia Inhibitory Factor; C507838:Lif protein, mouse; D050505:Mutant Proteins; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D004247:DNA