title: The tumor suppressor PML specifically accumulates at RPA/Rad51-containing DNA damage repair foci but is nonessential for DNA damage-induced fibroblast senescence.
abstract: The PML tumor suppressor has been functionally implicated in DNA damage response and cellular senescence. Direct evidence for such a role based on PML knockdown or knockout approaches is still lacking. We have therefore analyzed the irradiation-induced DNA damage response and cellular senescence in human and mouse fibroblasts lacking PML. Our data show that PML nuclear bodies (NBs) nonrandomly associate with persistent DNA damage foci in unperturbed human skin and in high-dose-irradiated cell culture systems. PML bodies do not associate with transient γH2AX foci after low-dose gamma irradiation. Superresolution microscopy reveals that all PML bodies within a nucleus are engaged at Rad51- and RPA-containing repair foci during ongoing DNA repair. The lack of PML (i) does not majorly affect the DNA damage response, (ii) does not alter the efficiency of senescence induction after DNA damage, and (iii) does not affect the proliferative potential of primary mouse embryonic fibroblasts during serial passaging. Thus, while PML NBs specifically accumulate at Rad51/RPA-containing lesions and senescence-derived persistent DNA damage foci, they are not essential for DNA damage-induced and replicative senescence of human and murine fibroblasts.
authors.affiliation: Leibniz Institute for Age Research, Jena, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Münch
authors.forename: Stefanie
authors.initials: S
authors.lastname: Weidtkamp-Peters
authors.forename: Karolin
authors.initials: K
authors.lastname: Klement
authors.forename: Paulius
authors.initials: P
authors.lastname: Grigaravicius
authors.forename: Shamci
authors.initials: S
authors.lastname: Monajembashi
authors.forename: Paolo
authors.initials: P
authors.lastname: Salomoni
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Pandolfi
authors.forename: Klaus
authors.initials: K
authors.lastname: Weißhart
authors.forename: Peter
authors.initials: P
authors.lastname: Hemmerich
mesh_terms: D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D049109:Cell Proliferation; D016922:Cellular Senescence; D004249:DNA Damage; D004260:DNA Repair; D005347:Fibroblasts / Q000502:physiology*; D006657:Histones / Q000378:metabolism; D006801:Humans; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism*; D000071156:Promyelocytic Leukemia Protein; D021381:Protein Transport; D051135:Rad51 Recombinase / Q000378:metabolism*; D051716:Replication Protein A / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
chemical_list: C468783:H2AX protein, human; D006657:Histones; D009687:Nuclear Proteins; D000071156:Promyelocytic Leukemia Protein; C497167:RPA1 protein, human; D051716:Replication Protein A; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C070576:PML protein, human; C495153:RAD51 protein, human; D051135:Rad51 Recombinase