title: Specific recruitment of human cohesin to laser-induced DNA damage.
abstract: Cohesin is a conserved multiprotein complex that plays an essential role in sister chromatid cohesion. During interphase, cohesin is required for the establishment of cohesion following DNA replication. Because cohesin mutants resulted in increased sensitivity to DNA damage, a role for cohesin in DNA repair was also suggested. However, it was unclear whether this was due to general perturbation of cohesion or whether cohesin has a specialized role at the damage site. We therefore used a laser microbeam to create DNA damage at discrete sites in the cell nucleus and observed specific in vivo assembly of proteins at these sites by immunofluorescent detection. We observed that human cohesin is recruited to the damage site immediately after damage induction. Analysis of mutant cells revealed that cohesin recruitment to the damage site is dependent on the DNA double-strand break repair factor Mre11/Rad50 but not ATM or Nbs1. Consistently, Mre11/Rad50 and cohesin interact with each other in an interphase-specific manner. This interaction peaks in S/G(2) phase, during which cohesin is recruited to the DNA damage. Our results demonstrate the S/G(2)-specific and Mre11/Rad50-dependent recruitment of human cohesin to DNA damage, suggesting a specialized subfunction for cohesin in cell cycle-specific DNA double strand break repair.
authors.affiliation: Department of Biological Chemistry, College of Medicine, University of California, Irvine, California 92697-1700, USA.
authors.forename: Jong-Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Tatiana B
authors.initials: TB
authors.lastname: Krasieva
authors.forename: Vickie
authors.initials: V
authors.lastname: LaMorte
authors.forename: A Malcolm R
authors.initials: AM
authors.lastname: Taylor
authors.forename: Kyoko
authors.initials: K
authors.lastname: Yokomori
mesh_terms: D017766:Acid Anhydride Hydrolases; D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins; D002467:Cell Nucleus / Q000378:metabolism / Q000528:radiation effects; D002868:Chromosomal Proteins, Non-Histone; D004247:DNA / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D004249:DNA Damage; D004260:DNA Repair; D045643:DNA Repair Enzymes; D004268:DNA-Binding Proteins / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism / Q000528:radiation effects; D005656:Fungal Proteins; D006367:HeLa Cells; D006801:Humans; D007834:Lasers / Q000009:adverse effects; D000076228:MRE11 Homologue Protein; D046911:Macromolecular Substances; D008957:Models, Genetic; D046912:Multiprotein Complexes; D009687:Nuclear Proteins / Q000378:metabolism*; D000097722:Cohesins
chemical_list: D017766:Acid Anhydride Hydrolases; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D004247:DNA; D045643:DNA Repair Enzymes; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D000076228:MRE11 Homologue Protein; D046911:Macromolecular Substances; D046912:Multiprotein Complexes; D009687:Nuclear Proteins; D000097722:Cohesins; C121766:MRE11 protein, human; C112158:RAD50 protein, human