Derivation and Characterization of Pcbp1-Deficient Mouse Embryonic Stem Cells

KH-domain PolyC-binding proteins perform many functions ranging from transcription regulation to alternative splicing. There are several evidences of their important role in embryogenesis and in embryonic stem cells (ESCs). ESCs are cultured counterparts of epiblast cells before implantation, and both cell types are in naive state of pluripotency. We have previously shown that members of the KH-domain family—hnRNP-K, Pcbp1 and Pcbp2 proteins—are able to bind to the PolyC-sites within regulatory elements of the Pou5f1 gene that encodes the key pluripotency gatekeeper Oct4. In addition, early lethal phenotype of Pcbp1–/– mouse embryos has been described in literature. In this study, we set to assess role of Pcbp1 in ESCs. To this end, we have obtained null-Pcbp1 ESCs. Contrary to previously observed by us lethal phenotype of hnRNP-K in ESCs, Pcbp1–/– ESCs were viable, continued to express Oct4 and retained overall pluripotent properties. Therefore, the obtained data reveal no critical role of Pcbp1 in self-renewal of naive pluripotent stem cells. Further studies should address whether this is the case during the transition of these cells to the primed state of pluripotency, as well as during the exit from this state due course of differentiation into the three germ layers.