title: Cep164 is a mediator protein required for the maintenance of genomic stability through modulation of MDC1, RPA, and CHK1.
abstract: The activation of the ataxia telangiectasia mutated (ATM) and ATM/Rad3-related (ATR) kinases triggers a diverse cellular response including the initiation of DNA damage-induced cell cycle checkpoints. Mediator of DNA Damage Checkpoint protein, MDC1, and H2AX are chromatin remodeling factors required for the recruitment of DNA repair proteins to the DNA damage sites. We identified a novel mediator protein, Cep164 (KIAA1052), that interacts with both ATR and ATM. Cep164 is phosphorylated upon replication stress, ultraviolet radiation (UV), and ionizing radiation (IR). Ser186 of Cep164 is phosphorylated by ATR/ATM in vitro and in vivo. The phosphorylation of Ser186 is not affected by RPA knockdown but is severely hampered by MDC1 knockdown. siRNA-mediated silencing of Cep164 significantly reduces DNA damage-induced phosphorylation of RPA, H2AX, MDC1, CHK2, and CHK1, but not NBS1. Analyses of Cep164 knockdown cells demonstrate a critical role of Cep164 in G2/M checkpoint and nuclear divisions. These findings reveal that Cep164 is a key player in the DNA damage-activated signaling cascade.
authors.affiliation: Department of Biological Chemistry and Department of Developmental and Biology, University of California, Irvine, CA 92697, USA.
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Sivasubramaniam
authors.forename: Xuemin
authors.initials: X
authors.lastname: Sun
authors.forename: Yen-Ru
authors.initials: YR
authors.lastname: Pan
authors.forename: Shaohui
authors.initials: S
authors.lastname: Wang
authors.forename: Eva Y-H P
authors.initials: EY
authors.lastname: Lee
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D064007:Ataxia Telangiectasia Mutated Proteins; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000378:metabolism; D002460:Cell Line; D000071877:Checkpoint Kinase 1; D004249:DNA Damage / Q000235:genetics; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D042822:Genomic Instability / Q000235:genetics; D006801:Humans; D008868:Microtubule Proteins; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000494:pharmacology; D051716:Replication Protein A / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C524694:CEP164 protein, human; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C413163:MDC1 protein, human; D008868:Microtubule Proteins; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; C497167:RPA1 protein, human; D051716:Replication Protein A; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D011494:Protein Kinases; C576324:ATM protein, human; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; D017346:Protein Serine-Threonine Kinases