Leading science, pioneering therapies
CRM Publications

The pluripotency rheostat Nanog functions as a dimer.

TitleThe pluripotency rheostat Nanog functions as a dimer.
Publication TypeJournal Article
Year of Publication2008
AuthorsMullin NP, Yates A, Rowe AJ, Nijmeijer B, Colby D, Barlow PN, Walkinshaw MD, Chambers I
JournalBiochem J
Date Published2008 Apr 15
KeywordsAnimals, Cytokines, Dimerization, DNA-Binding Proteins, Gene Expression Regulation, Homeodomain Proteins, Mice, Protein Binding, Recombinant Proteins

The defining activity of the homeodomain protein Nanog is the ability to confer cytokine-independent self-renewal upon ES (embryonic stem) cells in which it is overexpressed. However, the biochemical basis by which Nanog achieves this function remains unknown. In the present study, we show that Nanog dimerizes through a functionally critical domain. Co-immunoprecipitation of Nanog molecules tagged with distinct epitopes demonstrates that Nanog self-associates through a region in which every fifth residue is tryptophan. In vitro binding experiments establish that this region participates directly in self-association. Moreover, analytical ultracentrifugation indicates that, in solution, Nanog is in equilibrium between monomeric and dimeric forms with a K(d) of 3 muM. The functional importance of Nanog dimerization is established by ES cell colony-forming assays in which deletion of the tryptophan-repeat region eliminates the capacity of Nanog to direct LIF (leukaemia inhibitory factor)-independent self-renewal.

Alternate JournalBiochem. J.
PubMed ID18290762
Grant ListG19/38 / / Medical Research Council / United Kingdom