title: The SUMO (Small Ubiquitin-like Modifier) Ligase PIAS3 Primes ATR for Checkpoint Activation.
abstract: The maintenance of genomic stability relies on the concerted action of DNA repair and DNA damage signaling pathways. The PIAS (protein inhibitor of activated STAT) family of SUMO (small ubiquitin-like modifier) ligases has been implicated in DNA repair, but whether it plays a role in DNA damage signaling is still unclear. Here, we show that the PIAS3 SUMO ligase is important for activation of the ATR (ataxia telangiectasia and Rad3 related)-regulated DNA damage signaling pathway. PIAS3 is the only member of the PIAS family that is indispensable for ATR activation. In response to different types of DNA damage and replication stress, PIAS3 plays multiple roles in ATR activation. In cells treated with camptothecin (CPT), PIAS3 contributes to formation of DNA double-stranded breaks. In UV (ultraviolet light)- or HU (hydroxyurea)-treated cells, PIAS3 is required for efficient ATR autophosphorylation, one of the earliest events during ATR activation. Although PIAS3 is dispensable for ATRIP (ATR-interacting protein) SUMOylation and the ATR-ATRIP interaction, it is required for maintaining the basal kinase activity of ATR prior to DNA damage. In the absence of PIAS3, ATR fails to display normal kinase activity after DNA damage, which accompanies with reduced phosphorylation of ATR substrates. Together, these results suggest that PIAS3 primes ATR for checkpoint activation by sustaining its basal kinase activity, revealing a new function of the PIAS family in DNA damage signaling.
authors.affiliation: From the Massachusetts General Hospital (MGH) Cancer Center, Harvard Medical School, Charlestown, Massachusetts 02129 and.
authors.forename: Ching-Shyi
authors.initials: CS
authors.lastname: Wu
authors.affiliation: From the Massachusetts General Hospital (MGH) Cancer Center, Harvard Medical School, Charlestown, Massachusetts 02129 and Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02115 zou.lee@mgh.harvard.edu.
authors.forename: Lee
authors.identifier: http://orcid.org/0000-0003-3094-1058
authors.initials: L
authors.lastname: Zou
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D064007:Ataxia Telangiectasia Mutated Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D002166:Camptothecin / Q000494:pharmacology; D059447:Cell Cycle Checkpoints / Q000187:drug effects / Q000528:radiation effects; D002460:Cell Line; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects / Q000528:radiation effects; D004249:DNA Damage; D004261:DNA Replication / Q000187:drug effects / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects / Q000528:radiation effects; D055785:Gene Knockdown Techniques; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D018832:Molecular Chaperones / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects / Q000528:radiation effects; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects / Q000528:radiation effects; D050828:Protein Inhibitors of Activated STAT / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D058207:Sumoylation / Q000187:drug effects / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: C521194:ATRIP protein, human; D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; D018832:Molecular Chaperones; C484745:PIAS3 protein, human; D050828:Protein Inhibitors of Activated STAT; D034741:RNA, Small Interfering; D011065:Poly(ADP-ribose) Polymerases; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D006918:Hydroxyurea; D002166:Camptothecin
keywords: DNA damage response; DNA repair; DNA replication; checkpoint control; small ubiquitin-like modifier (SUMO)