title: The actin family member Arp6 and the histone variant H2A.Z are required for spatial positioning of chromatin in chicken cell nuclei.
abstract: The spatial organization of chromatin in the nucleus contributes to genome function and is altered during the differentiation of normal and tumorigenic cells. Although nuclear actin-related proteins (Arps) have roles in the local alteration of chromatin structure, it is unclear whether they are involved in the spatial positioning of chromatin. In the interphase nucleus of vertebrate cells, gene-dense and gene-poor chromosome territories (CTs) are located in the center and periphery, respectively. We analyzed chicken DT40 cells in which Arp6 had been knocked out conditionally, and showed that the radial distribution of CTs was impaired in these knockout cells. Arp6 is an essential component of the SRCAP chromatin remodeling complex, which deposits the histone variant H2A.Z into chromatin. The redistribution of CTs was also observed in H2A.Z-deficient cells for gene-rich microchromosomes, but to lesser extent for gene-poor macrochromosomes. These results indicate that Arp6 and H2A.Z contribute to the radial distribution of CTs through different mechanisms. Microarray analysis suggested that the localization of chromatin to the nuclear periphery per se is insufficient for the repression of most genes.
authors.affiliation: Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiyamachi 1-1, Aoba-ku, Sendai 981-8555,  Japan.
authors.forename: Eri Ohfuchi
authors.initials: EO
authors.lastname: Maruyama
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hori
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tanabe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitamura
authors.forename: Ryo
authors.initials: R
authors.lastname: Matsuda
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Tone
authors.forename: Pavel
authors.initials: P
authors.lastname: Hozak
authors.forename: Felix A
authors.initials: FA
authors.lastname: Habermann
authors.forename: Johann
authors.initials: J
authors.lastname: von Hase
authors.forename: Christoph
authors.initials: C
authors.lastname: Cremer
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Fukagawa
authors.forename: Masahiko
authors.initials: M
authors.lastname: Harata
mesh_terms: D000199:Actins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D002645:Chickens; D002843:Chromatin / Q000235:genetics / Q000378:metabolism*; D002875:Chromosomes / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D055786:Gene Knockout Techniques; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D000199:Actins; D002843:Chromatin; D006657:Histones; D008840:Microfilament Proteins; C077020:histone H2A.F-Z