RAD50 phosphorylation promotes ATR downstream signaling and DNA restart following replication stress.
The MRE11/RAD50/NBN (MRN) complex plays a key role in detecting DNA double-strand breaks, recruiting and activating ataxia-telangiectasia mutated and in processing the breaks. Members of this complex also act as adaptor molecules for downstream signaling to the cell cycle and other cellular processes. Somewhat more controversial are the results to support a role for MRN in the ataxia-telangiectasia and Rad3-related (ATR) activation and signaling. We provide evidence that RAD50 is required for ATR activation in mammalian cells in response to DNA replication stress. It is in turn phosphorylated at a specific site (S635) by ATR, which is required for ATR signaling through Chk1 and other downstream substrates. We find that RAD50 phosphorylation is essential for DNA replication restart by promoting loading of cohesin at these sites. We also demonstrate that replication stress-induced RAD50 phosphorylation is functionally significant for cell survival and cell cycle checkpoint activation. These results highlight the importance of the adaptor role for a member of the MRN complex in all aspects of the response to DNA replication stress.
Radiation Biology and Oncology, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia.
Magtouf
M
Gatei
Radiation Biology and Oncology, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia.
Amanda W
AW
Kijas
CEA, DSV/iMETI/SEPIA; BP6, 92265 Fontenay-aux-Roses Cedex, France.
Denis
D
Biard
Clinics of Obstetrics and Gynaecology, Hannover Medical School, Gynaecology Research Unit, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany and.
Thilo
T
Dörk
Radiation Biology and Oncology, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia Centre for Clinical Research, University of Queensland, Building 71/918, Royal Brisbane & Women's Hospital Campus, Herston, QLD 4029, Australia martin.lavin@qimrberghofer.edu.au m.lavin@uq.edu.au.
Martin F
MF
Lavin
D017766:Acid Anhydride Hydrolases; D001260:Ataxia Telangiectasia / Q000473:pathology*; D002460:Cell Line; D000071877:Checkpoint Kinase 1; D053903:DNA Breaks, Double-Stranded; D045643:DNA Repair Enzymes / Q000378:metabolism*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005347:Fibroblasts; D006801:Humans; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological
D004268:DNA-Binding Proteins; D012694:Serine; D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; D017766:Acid Anhydride Hydrolases; C112158:RAD50 protein, human; D045643:DNA Repair Enzymes