title: Association of Rex-1 to target genes supports its interaction with Polycomb function.
abstract: Rex-1/Zfp42 displays a remarkably restricted pattern of expression in preimplantation embryos, primary spermatocytes, and undifferentiated mouse embryonic stem (ES) cells and is frequently used as a marker gene for pluripotent stem cells. To understand the role of Rex-1 in selfrenewal and pluripotency, we used Rex-1 association as a measure to identify potential target genes, and carried out chromatin-immunoprecipitation assays in combination with gene specific primers to identify genomic targets Rex-1 associates with. We find association of Rex-1 to several genes described previously as bivalently marked regulators of differentiation and development, whose repression in mouse embryonic stem (ES) cells is Polycomb Group-mediated, and controlled directly by Ring1A/B. To substantiate the hypothesis that Rex-1 contributes to gene regulation by PcG, we demonstrate interactions of Rex-1 and YY2 (a close relative of YY1) with Ring1 proteins and the PcG-associated proteins RYBP and YAF2, in line with interactions reported previously for YY1. We also demonstrate the presence of Rex-1 protein in both trophectoderm and Inner Cell Mass of the mouse blastocyst and in both ES and in trophectoderm stem (TS) cells. In TS cells, we were unable to demonstrate association of Rex-1 to the genes it associates with in ES cells, suggesting that association may be cell-type specific. Rex-1 might fine-tune pluripotency in ES cells by modulating Polycomb-mediated gene regulation.
authors.affiliation: Regenerative Medicine Programme, IIS Aragón, Instituto Aragonés de Ciencias de la Salud, Zaragoza, Avda. Gómez Laguna, 25, Pl. 11, 50009 Zaragoza, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Garcia-Tuñon
authors.forename: D
authors.initials: D
authors.lastname: Guallar
authors.forename: S
authors.initials: S
authors.lastname: Alonso-Martin
authors.forename: A A
authors.initials: AA
authors.lastname: Benito
authors.forename: A
authors.initials: A
authors.lastname: Benítez-Lázaro
authors.forename: R
authors.initials: R
authors.lastname: Pérez-Palacios
authors.forename: P
authors.initials: P
authors.lastname: Muniesa
authors.forename: M
authors.initials: M
authors.lastname: Climent
authors.forename: M
authors.initials: M
authors.lastname: Sánchez
authors.forename: M
authors.initials: M
authors.lastname: Vidal
authors.forename: J
authors.initials: J
authors.lastname: Schoorlemmer
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D053595:Embryonic Stem Cells / Q000378:metabolism / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D063146:Polycomb-Group Proteins; D011247:Pregnancy; D011817:Rabbits; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D051741:Kruppel-Like Transcription Factors; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins; C507976:ZFP42 protein, human