title: The protein phosphatase 1 regulator PNUTS is a new component of the DNA damage response.
abstract: The function of protein phosphatase 1 nuclear-targeting subunit (PNUTS)--one of the most abundant nuclear-targeting subunits of protein phosphatase 1 (PP1c)--remains largely uncharacterized. We show that PNUTS depletion by small interfering RNA activates a G2 checkpoint in unperturbed cells and prolongs G2 checkpoint and Chk1 activation after ionizing-radiation-induced DNA damage. Overexpression of PNUTS-enhanced green fluorescent protein (EGFP)--which is rapidly and transiently recruited at DNA damage sites--inhibits G2 arrest. Finally, γH2AX, p53-binding protein 1, replication protein A and Rad51 foci are present for a prolonged period and clonogenic survival is decreased in PNUTS-depleted cells after ionizing radiation treatment. We identify the PP1c regulatory subunit PNUTS as a new and integral component of the DNA damage response involved in DNA repair.
authors.affiliation: Department of Biochemistry, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
authors.forename: Helga B
authors.initials: HB
authors.lastname: Landsverk
authors.forename: Felipe
authors.initials: F
authors.lastname: Mora-Bermúdez
authors.forename: Ole J B
authors.initials: OJ
authors.lastname: Landsverk
authors.forename: Grete
authors.initials: G
authors.lastname: Hasvold
authors.forename: Soheil
authors.initials: S
authors.lastname: Naderi
authors.forename: Oddmund
authors.initials: O
authors.lastname: Bakke
authors.forename: Jan
authors.initials: J
authors.lastname: Ellenberg
authors.forename: Philippe
authors.initials: P
authors.lastname: Collas
authors.forename: Randi G
authors.initials: RG
authors.lastname: Syljuåsen
authors.forename: Thomas
authors.initials: T
authors.lastname: Küntziger
mesh_terms: D002467:Cell Nucleus / Q000201:enzymology / Q000528:radiation effects; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000378:metabolism*; D036681:Fluorescence Recovery After Photobleaching; D016195:G2 Phase / Q000528:radiation effects; D055785:Gene Knockdown Techniques; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis / Q000528:radiation effects; D009687:Nuclear Proteins / Q000172:deficiency / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D011839:Radiation, Ionizing; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C110225:PPP1R10 protein, human; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins