Determination of the protein interactome of the transcription factor Sox2 in embryonic stem cells engineered for inducible expression of four reprogramming factors

Coordinate expression of the somatic cell reprogramming factors Oct4, Sox2, Klf4 and c-Myc within embryonic stem cells preserves the self-renewal of these cells, while allowing for the expression epitope tagged Sox2. Taking advantage of this observation, we engineered embryonic stem cells (i-OSKM-ESC) to inducibly express Oct4, Klf4, c-Myc and an epitope tagged form of Sox2 from a polycistronic element, in the presence of doxycycline. We isolated Sox2 and its associated protein complexes by co-immunoprecipitation. Subsequently, we identified the Sox2-protein interactome in self-renewing embryonic stem cells using an unbiased proteomic screen (Multidimensional Protein Identification Technology [MudPIT]).

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Gao Z, Cox JL, Gilmore JM, Ormsbee BD, Mallanna SK, Washburn MP, Rizzino A