P21 Promotes Error-free Replication-coupled DNA Double-strand Break Repair
Overview
Authors
Affiliations
p21 is a well-established regulator of cell cycle progression. The role of p21 in DNA repair, however, remains poorly characterized. Here, we describe a critical role of p21 in a replication-coupled DNA double-strand break (DSB) repair that is mechanistically distinct from its cell cycle checkpoint function. We demonstrate that p21-deficient cells exhibit elevated chromatid-type aberrations, including gaps and breaks, dicentrics and radial formations, following exposure to several DSB-inducing agents. p21-/- cells also exhibit an increased DNA damage-inducible DNA-PKCS S2056 phosphorylation, indicative of elevated non-homologous DNA end joining. Concomitantly, p21-/- cells are defective in replication-coupled homologous recombination (HR), exhibiting decreased sister chromatid exchanges and HR-dependent repair as determined using a crosslinked GFP reporter assay. Importantly, we establish that the DSB hypersensitivity of p21-/- cells is associated with increased cyclin-dependent kinase (CDK)-dependent BRCA2 S3291 phosphorylation and MRE11 nuclear foci formation and can be rescued by inhibition of CDK or MRE11 nuclease activity. Collectively, our results uncover a novel mechanism by which p21 regulates the fidelity of replication-coupled DSB repair and the maintenance of chromosome stability distinct from its role in the G1-S phase checkpoint.
Du Y, Hu P, Ding X, Wang D, Luo J, Le S Clin Transl Med. 2024; 15(1):e70147.
PMID: 39731276 PMC: 11680558. DOI: 10.1002/ctm2.70147.
Olaparib combined with CDK12-IN-3 to promote genomic instability and cell death in ovarian cancer.
Liang J, Zhou X, Yuan L, Chen T, Wan Y, Jiang Y Int J Biol Sci. 2024; 20(11):4513-4531.
PMID: 39247812 PMC: 11380446. DOI: 10.7150/ijbs.94568.
Li L, Wu Y, Huang H, Yong J, Lv Z, Zhou Y J Cancer Res Clin Oncol. 2024; 150(8):377.
PMID: 39085725 PMC: 11291533. DOI: 10.1007/s00432-024-05858-4.
CIP/KIP and INK4 families as hostages of oncogenic signaling.
Csergeova L, Krbusek D, Janostiak R Cell Div. 2024; 19(1):11.
PMID: 38561743 PMC: 10985988. DOI: 10.1186/s13008-024-00115-z.
The Role of Genetic Polymorphisms in Differentiated Thyroid Cancer: A 2023 Update.
Tiuca R, Tiuca O, Pascanu I Biomedicines. 2023; 11(4).
PMID: 37189693 PMC: 10135953. DOI: 10.3390/biomedicines11041075.