PRC2 Complexes with JARID2, MTF2, and esPRC2p48 in ES Cells to Modulate ES Cell Pluripotency and Somatic Cell Reprograming§

Authors


  • Author contributions: H.W., T.T.: experimental strategy designing, manuscript writing; H.J., Z.Z.: contributing for purification; Z.Z.: determining the expression of PRC2 subunits in MEFs and ES cells, during ES cell differentiation with help from A.J., W.Y.; Z.Z.: designing and performing the knockdown experiments in ES cells and somatic cell reprograming experiments with help from C.S., C.L., C.C., L.W., K.P.; A.J.: performing the immunoprecipitation, histone methylation, and demethylation assays; C.S., L.W., K.L.: contributing teratoma assays and OSK lentivirus production; Q.D.: analyzing teratomas; Y.G., J.M.: performing the peptide array binding assay; M.M., Y. L.: deriving MEF from JARID2 knockout mice and wild-type littermates; H.E.-B., P.T.: performing mass spectrometric analysis.

  • Disclosure of potential conflicts of interest is found at the end of this article.

  • §

    First published online in STEM CELLSEXPRESS December 23, 2010.

Abstract

Polycomb repressive complex two (PRC2) has been implicated in embryonic stem (ES) cell pluripotency; however, the mechanistic roles of this complex are unclear. It was assumed that ES cells contain PRC2 with the same subunit composition as that identified in HeLa cells and Drosophila embryos. Here, we report that PRC2 in mouse ES cells contains at least three additional subunits: JARID2, MTF2, and a novel protein denoted esPRC2p48. JARID2, MTF2, and esPRC2p48 are highly expressed in mouse ES cells compared to differentiated cells. Importantly, knockdowns of JARID2, MTF2, or esPRC2p48 alter the level of PRC2-mediated H3K27 methylation and result in the expression of differentiation-associated genes in ES cells. Interestingly, expression of JARID2, MTF2, and esPRC2p48 together, but not individually, enhances Oct4/Sox2/Klf4-mediated reprograming of mouse embryonic fibroblasts (MEFs) into induced pluripotent stem cells, whereas knockdown or knockout of JARID2, MTF2, or esPRC2p48 significantly inhibits reprograming. JARID2, MTF2, and esPRC2p48 modulate H3K27 methylation and facilitate repression of lineage-associated gene expression when transduced into MEFs, and synergistically stimulate the histone methyltransferase activity of PRC2 in vitro. Therefore, these studies identify JARID2, MTF2, and esPRC2p48 as important regulatory subunits of PRC2 in ES cells and reveal critical functions of these subunits in modulating PRC2's activity and gene expression both in ES cells and during somatic cell reprograming. STEM CELLS 2011;29:229–240

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