title: Dynamic relocation of poly(ADP-ribose) glycohydrolase isoforms during radiation-induced DNA damage.
abstract: Poly(ADP-ribosyl)ation is a very early cellular response to DNA damage. Poly(ADP-ribose) (PAR) accumulation is transient since PAR is rapidly hydrolyzed by poly(ADP-ribose) glycohydrolase (PARG). PARG may play a prominent role in DNA damage response and repair by removing PAR from modified proteins including PARP-1. Using living cells, we provide evidence that in response to DNA damage induced by gamma-irradiation the cytoplasmic 103 kDa PARG isoform translocates into the nucleus. We further observed that the nuclear GFP-hPARG110 enzyme relocalizes to the cytoplasm in response to DNA damage. Using different GFP-PARG fusion proteins specific for the nuclear and cytoplasmic forms, we demonstrate their dynamic distribution between cytoplasm and nucleoplasm and a high mobility of major PARG isoforms by fluorescence recovery after photobleaching (FRAP). The dynamic relocation of all PARG isoforms presented in this report reveals a novel biological mechanism by which PARG could be involved in DNA damage response.
authors.affiliation: Health and Environment Unit, Laval University Hospital Research Center, CHUQ, Faculty of Medicine, Laval University, Room RC-9700, 2705 Laurier blvd., Ste-Foy, Québec, Canada G1V 4G2.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Haince
authors.forename: Marie-Eve
authors.initials: ME
authors.lastname: Ouellet
authors.forename: Darin
authors.initials: D
authors.lastname: McDonald
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hendzel
authors.forename: Guy G
authors.initials: GG
authors.lastname: Poirier
mesh_terms: D015153:Blotting, Western; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004247:DNA / Q000528:radiation effects; D004249:DNA Damage; D004058:Diffusion; D004591:Electrophoresis, Polyacrylamide Gel; D036681:Fluorescence Recovery After Photobleaching; D019084:Fluorescent Antibody Technique, Indirect; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008856:Microscopy, Fluorescence; D009447:Neuroblastoma / Q000473:pathology; D011064:Poly Adenosine Diphosphate Ribose / Q000235:genetics / Q000378:metabolism*; D011839:Radiation, Ionizing; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D011064:Poly Adenosine Diphosphate Ribose; D004247:DNA; D006026:Glycoside Hydrolases