1
|
Yam CQX, Lim HH, Surana U. DNA damage checkpoint execution and the rules of its disengagement. Front Cell Dev Biol 2022; 10:1020643. [PMID: 36274841 PMCID: PMC9582513 DOI: 10.3389/fcell.2022.1020643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/21/2022] [Indexed: 11/13/2022] Open
Abstract
Chromosomes are susceptible to damage during their duplication and segregation or when exposed to genotoxic stresses. Left uncorrected, these lesions can result in genomic instability, leading to cells’ diminished fitness, unbridled proliferation or death. To prevent such fates, checkpoint controls transiently halt cell cycle progression to allow time for the implementation of corrective measures. Prominent among these is the DNA damage checkpoint which operates at G2/M transition to ensure that cells with damaged chromosomes do not enter the mitotic phase. The execution and maintenance of cell cycle arrest are essential aspects of G2/M checkpoint and have been studied in detail. Equally critical is cells’ ability to switch-off the checkpoint controls after a successful completion of corrective actions and to recommence cell cycle progression. Interestingly, when corrective measures fail, cells can mount an unusual cellular response, termed adaptation, where they escape checkpoint arrest and resume cell cycle progression with damaged chromosomes at the cost of genome instability or even death. Here, we discuss the DNA damage checkpoint, the mitotic networks it inhibits to prevent segregation of damaged chromosomes and the strategies cells employ to quench the checkpoint controls to override the G2/M arrest.
Collapse
Affiliation(s)
| | - Hong Hwa Lim
- A*STAR Singapore Immunology Network, Singapore, Singapore
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Uttam Surana
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Department of Pharmacology, National University of Singapore, Singapore, Singapore
- *Correspondence: Uttam Surana,
| |
Collapse
|
2
|
Yam CQX, Chia DB, Shi I, Lim HH, Surana U. Dun1, a Chk2-related kinase, is the central regulator of securin-separase dynamics during DNA damage signaling. Nucleic Acids Res 2020; 48:6092-6107. [PMID: 32402080 PMCID: PMC7293041 DOI: 10.1093/nar/gkaa355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 04/23/2020] [Accepted: 04/29/2020] [Indexed: 01/26/2023] Open
Abstract
The DNA damage checkpoint halts cell cycle progression in G2 in response to genotoxic insults. Central to the execution of cell cycle arrest is the checkpoint-induced stabilization of securin-separase complex (yeast Pds1-Esp1). The checkpoint kinases Chk1 and Chk2 (yeast Chk1 and Rad53) are thought to critically contribute to the stability of securin-separase complex by phosphorylation of securin, rendering it resistant to proteolytic destruction by the anaphase promoting complex (APC). Dun1, a Rad53 paralog related to Chk2, is also essential for checkpoint-imposed arrest. Dun1 is required for the DNA damage-induced transcription of DNA repair genes; however, its role in the execution of cell cycle arrest remains unknown. Here, we show that Dun1′s role in checkpoint arrest is independent of its involvement in the transcription of repair genes. Instead, Dun1 is necessary to prevent Pds1 destruction during DNA damage in that the Dun1-deficient cells degrade Pds1, escape G2 arrest and undergo mitosis despite the presence of checkpoint-active Chk1 and Rad53. Interestingly, proteolytic degradation of Pds1 in the absence of Dun1 is mediated not by APC but by the HECT domain-containing E3 ligase Rsp5. Our results suggest a regulatory scheme in which Dun1 prevents chromosome segregation during DNA damage by inhibiting Rsp5-mediated proteolytic degradation of securin Pds1.
Collapse
Affiliation(s)
- Candice Qiu Xia Yam
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Proteos, 61 Biopolis Drive, Singapore.,Bioprocessing Technology Institute, A*STAR, Singapore
| | - David Boy Chia
- Biotransformation Innovation Platform, A*STAR, Singapore
| | - Idina Shi
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Proteos, 61 Biopolis Drive, Singapore
| | - Hong Hwa Lim
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Proteos, 61 Biopolis Drive, Singapore.,Bioprocessing Technology Institute, A*STAR, Singapore
| | - Uttam Surana
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Proteos, 61 Biopolis Drive, Singapore.,Bioprocessing Technology Institute, A*STAR, Singapore.,Biotransformation Innovation Platform, A*STAR, Singapore.,Department of Pharmacology, National University of Singapore, Singapore
| |
Collapse
|