title: Dynamic Protein Interactions of the Polycomb Repressive Complex 2 during Differentiation of Pluripotent Cells.
abstract: Polycomb proteins assemble to form complexes with important roles in epigenetic regulation. The Polycomb Repressive Complex 2 (PRC2) modulates the di- and tri-methylation of lysine 27 on histone H3, each of which are associated with gene repression. Although three subunits, EZH1/2, SUZ12, and EED, form the catalytic core of PRC2, a wider group of proteins associate with low stoichiometry. This raises the question of whether dynamic variation of the PRC2 interactome results in alternative forms of the complex during differentiation. Here we compared the physical interactions of PRC2 in undifferentiated and differentiated states of NTERA2 pluripotent embryonic carcinoma cells. Label-free quantitative proteomics was used to assess endogenous immunoprecipitation of the EZH2 and SUZ12 subunits of PRC2. A high stringency data set reflecting the endogenous state of PRC2 was produced that included all previously reported core and associated PRC2 components, and several novel interacting proteins. Comparison of the interactomes obtained in undifferentiated and differentiated cells revealed candidate proteins that were enriched in complexes isolated from one of the two states. For example, SALL4 and ZNF281 associate with PRC2 in pluripotent cells, whereas PCL1 and SMAD3 preferentially associate with PRC2 in differentiating cells. Analysis of the mRNA and protein levels of these factors revealed that their association with PRC2 correlated with their cell state-specific expression. Taken together, we propose that dynamic changes to the PRC2 interactome during differentiation may contribute to directing its activity during cell fate transitions.
authors.affiliation: From the ‡School of Biomolecular and Biomedical Science and Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Oliviero
authors.affiliation: §Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215 and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115.|¶Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Gerard L
authors.initials: GL
authors.lastname: Brien
authors.affiliation: From the ‡School of Biomolecular and Biomedical Science and Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Ariane
authors.initials: A
authors.lastname: Waston
authors.affiliation: ¶Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Gundula
authors.initials: G
authors.lastname: Streubel
authors.affiliation: ¶Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Emilia
authors.initials: E
authors.lastname: Jerman
authors.affiliation: From the ‡School of Biomolecular and Biomedical Science and Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Darrell
authors.initials: D
authors.lastname: Andrews
authors.affiliation: From the ‡School of Biomolecular and Biomedical Science and Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Doyle
authors.affiliation: From the ‡School of Biomolecular and Biomedical Science and Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Nayla
authors.initials: N
authors.lastname: Munawar
authors.affiliation: From the ‡School of Biomolecular and Biomedical Science and Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Kieran
authors.initials: K
authors.lastname: Wynne
authors.affiliation: From the ‡School of Biomolecular and Biomedical Science and Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: John
authors.initials: J
authors.lastname: Crean
authors.affiliation: ¶Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Bracken
authors.affiliation: From the ‡School of Biomolecular and Biomedical Science and Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland; gerard.cagney@ucd.ie.
authors.forename: Gerard
authors.identifier: 0000-0001-7189-9496
authors.initials: G
authors.lastname: Cagney
mesh_terms: D002454:Cell Differentiation; D045744:Cell Line, Tumor; D054278:Embryonal Carcinoma Stem Cells / Q000166:cytology* / Q000378:metabolism; D000071221:Enhancer of Zeste Homolog 2 Protein / Q000378:metabolism; D044127:Epigenesis, Genetic; D006657:Histones / Q000378:metabolism; D006801:Humans; D009363:Neoplasm Proteins; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D063151:Polycomb Repressive Complex 2 / Q000378:metabolism*; D060066:Protein Interaction Maps; D040901:Proteomics / Q000379:methods*; D014157:Transcription Factors
chemical_list: D006657:Histones; D009363:Neoplasm Proteins; C430461:SUZ12 protein, human; D014157:Transcription Factors; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D063151:Polycomb Repressive Complex 2