title: The actin family protein ARP6 contributes to the structure and the function of the nucleolus.
abstract: The actin family members, consisting of actin and actin-related proteins (ARPs), are essential components of chromatin remodeling complexes. ARP6, one of the nuclear ARPs, is part of the Snf-2-related CREB-binding protein activator protein (SRCAP) chromatin remodeling complex, which promotes the deposition of the histone variant H2A.Z into the chromatin. In this study, we showed that ARP6 influences the structure and the function of the nucleolus. ARP6 is localized in the central region of the nucleolus, and its knockdown induced a morphological change in the nucleolus. We also found that in the presence of high concentrations of glucose ARP6 contributed to the maintenance of active ribosomal DNA (rDNA) transcription by placing H2A.Z into the chromatin. In contrast, under starvation, ARP6 was required for cell survival through the repression of rDNA transcription independently of H2A.Z. These findings reveal novel pleiotropic roles for the actin family in nuclear organization and metabolic homeostasis.
authors.affiliation: Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiyamachi 1-1, Aoka-ku, Sendai 981-8555, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitamura
authors.affiliation: Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Matsumori
authors.affiliation: Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic, v.v.i., Vídeňská 1083, 142 20 Prague, Czech Republic.
authors.forename: Alzbeta
authors.initials: A
authors.lastname: Kalendova
authors.affiliation: Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic, v.v.i., Vídeňská 1083, 142 20 Prague, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Hozak
authors.affiliation: Image Informatics and Computational Biology Unit, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, Baltimore, MD 21224, USA.
authors.forename: Ilya G
authors.initials: IG
authors.lastname: Goldberg
authors.affiliation: Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Tokyo 102-0076, Japan.
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Nakao
authors.affiliation: Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Saitoh
authors.affiliation: Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiyamachi 1-1, Aoka-ku, Sendai 981-8555, Japan. Electronic address: mharata@biochem.tohoku.ac.jp.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Harata
mesh_terms: D000199:Actins / Q000378:metabolism / Q000502:physiology*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D002466:Cell Nucleolus / Q000378:metabolism / Q000502:physiology*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism / Q000502:physiology*; D004275:DNA, Ribosomal / Q000235:genetics; D005947:Glucose / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D014158:Transcription, Genetic / Q000502:physiology
chemical_list: C431141:ACTR6 protein, human; D000199:Actins; D002868:Chromosomal Proteins, Non-Histone; D004275:DNA, Ribosomal; D000251:Adenosine Triphosphatases; C119652:SRCAP protein, human; D005947:Glucose
keywords: ARP6; Actin-related protein; Histone H2A.Z; Nucleolus; Wndchrm