The deubiquitinating enzyme USP37 enhances CHK1 activity to promote the cellular response to replication stress |
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Authors: | Benjamin R. Stromberg Mayank Singh Adrian E. Torres Amy C. Burrows Debjani Pal Christine Insinna Yosup Rhee Andrew S. Dickson Christopher J. Westlake Matthew K. Summers |
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Affiliation: | 1.Department of Radiation Oncology, Arthur G James Comprehensive Cancer Center and Richard L. Solove Research Institute, The Ohio State University, Columbus, Ohio, USA;2.Biomedical Sciences Graduate Program, The Ohio State University, Columbus, Ohio, USA;3.Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;4.NCI-Frederick National Laboratory, Laboratory of Cellular and Developmental Signaling, Frederick, Maryland, USA |
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Abstract: | The deubiquitinating enzyme USP37 is known to contribute to timely onset of S phase and progression of mitosis. However, it is not clear if USP37 is required beyond S-phase entry despite expression and activity of USP37 peaking within S phase. We have utilized flow cytometry and microscopy to analyze populations of replicating cells labeled with thymidine analogs and monitored mitotic entry in synchronized cells to determine that USP37-depleted cells exhibited altered S-phase kinetics. Further analysis revealed that cells depleted of USP37 harbored increased levels of the replication stress and DNA damage markers γH2AX and 53BP1 in response to perturbed replication. Depletion of USP37 also reduced cellular proliferation and led to increased sensitivity to agents that induce replication stress. Underlying the increased sensitivity, we found that the checkpoint kinase 1 is destabilized in the absence of USP37, attenuating its function. We further demonstrated that USP37 deubiquitinates checkpoint kinase 1, promoting its stability. Together, our results establish that USP37 is required beyond S-phase entry to promote the efficiency and fidelity of replication. These data further define the role of USP37 in the regulation of cell proliferation and contribute to an evolving understanding of USP37 as a multifaceted regulator of genome stability. |
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Keywords: | cell cycle checkpoint control DNA replication DNA damage response deubiquitination ubiquitination CHK1 USP37 |
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