title: Recruitment of DNA methyltransferase I to DNA repair sites.
abstract: In mammalian cells, the replication of genetic and epigenetic information is directly coupled; however, little is known about the maintenance of epigenetic information in DNA repair. Using a laser microirradiation system to introduce DNA lesions at defined subnuclear sites, we tested whether the major DNA methyltransferase (Dnmt1) or one of the two de novo methyltransferases (Dnmt3a, Dnmt3b) are recruited to sites of DNA repair in vivo. Time lapse microscopy of microirradiated mammalian cells expressing GFP-tagged Dnmt1, Dnmt3a, or Dnmt3b1 together with red fluorescent protein-tagged proliferating cell nuclear antigen (PCNA) revealed that Dnmt1 and PCNA accumulate at DNA damage sites as early as 1 min after irradiation in S and non-S phase cells, whereas recruitment of Dnmt3a and Dnmt3b was not observed. Deletion analysis showed that Dnmt1 recruitment was mediated by the PCNA-binding domain. These data point to a direct role of Dnmt1 in the restoration of epigenetic information during DNA repair.
authors.affiliation: Department of Biology II, Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Mortusewicz
authors.forename: Lothar
authors.initials: L
authors.lastname: Schermelleh
authors.forename: Joachim
authors.initials: J
authors.lastname: Walter
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Cardoso
authors.forename: Heinrich
authors.initials: H
authors.lastname: Leonhardt
mesh_terms: D000818:Animals; D004260:DNA Repair; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D007834:Lasers; D051379:Mice; D032446:Myoblasts / Q000201:enzymology; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: C411744:DMAP1 protein, human; C485852:Dmap1 protein, mouse; D018809:Proliferating Cell Nuclear Antigen; D012097:Repressor Proteins