title: Subcellular localization of ENS-1/ERNI in chick embryonic stem cells.
abstract: The protein of retroviral origin ENS-1/ERNI plays a major role during neural plate development in chick embryos by controlling the activity of the epigenetic regulator HP1γ, but its function in the earlier developmental stages is still unknown. ENS-1/ERNI promoter activity is down-regulated upon differentiation but the resulting protein expression has never been examined. In this study, we present the results obtained with custom-made antibodies to gain further insights into ENS-1 protein expression in Chicken embryonic stem cells (CES) and during their differentiation. First, we show that ENS-1 controls the activity of HP1γ in CES and we examined the context of its interaction with HP1γ. By combining immunofluorescence and western blot analysis we show that ENS-1 is localized in the cytoplasm and in the nucleus, in agreement with its role on gene's promoter activity. During differentiation, ENS-1 decreases in the cytoplasm but not in the nucleus. More precisely, three distinct forms of the ENS-1 protein co-exist in the nucleus and are differently regulated during differentiation, revealing a new level of control of the protein ENS-1. In silico analysis of the Ens-1 gene copies and the sequence of their corresponding proteins indicate that this pattern is compatible with at least three potential regulation mechanisms, each accounting only partially. The results obtained with the anti-ENS-1 antibodies presented here reveal that the regulation of ENS-1 expression in CES is more complex than expected, providing new tracks to explore the integration of ENS-1 in CES cells regulatory networks.
authors.affiliation: Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS UMR 5242, INRA USC 1370, Ecole Normale Supérieure de Lyon, Lyon, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Blanc
authors.affiliation: Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS UMR 5242, INRA USC 1370, Ecole Normale Supérieure de Lyon, Lyon, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Ruggiero
authors.affiliation: Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS UMR 5242, INRA USC 1370, Ecole Normale Supérieure de Lyon, Lyon, France.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Birot
authors.affiliation: Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS UMR 5242, INRA USC 1370, Ecole Normale Supérieure de Lyon, Lyon, France; Laboratoire de Génétique Cellulaire-INRA, ENVT, Castanet Tolosan, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Acloque
authors.affiliation: CIRI, International Center for Infectiology Research, Université de Lyon, INSERM U1111, Ecole Normale Supérieure de Lyon, Lyon, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Décimo
authors.affiliation: Université de Lyon, Lyon, France; Université Lyon 1, Villeurbanne, France; CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Villeurbanne, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Lerat
authors.affiliation: CIRI, International Center for Infectiology Research, Université de Lyon, INSERM U1111, Ecole Normale Supérieure de Lyon, Lyon, France.
authors.forename: Théophile
authors.initials: T
authors.lastname: Ohlmann
authors.affiliation: Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS UMR 5242, INRA USC 1370, Ecole Normale Supérieure de Lyon, Lyon, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Samarut
authors.affiliation: Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS UMR 5242, INRA USC 1370, Ecole Normale Supérieure de Lyon, Lyon, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Mey
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D058846:Antibodies, Monoclonal, Murine-Derived / Q000096:biosynthesis / Q000737:chemistry; D030161:Avian Proteins / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D002642:Chick Embryo; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D047108:Embryonic Development; D053595:Embryonic Stem Cells / Q000378:metabolism* / Q000648:ultrastructure; D044127:Epigenesis, Genetic; D005326:Fetal Proteins / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D053263:Gene Regulatory Networks; D051379:Mice; D008969:Molecular Sequence Data; D054258:Neural Plate / Q000196:embryology / Q000378:metabolism / Q000648:ultrastructure; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D030161:Avian Proteins; D002868:Chromosomal Proteins, Non-Histone; C432147:ENS-1 protein, chicken; D005326:Fetal Proteins; D020033:Protein Isoforms