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53BP1 is a DNA damage protein that forms phosphorylated H2AX (γ-H2AX) dependent foci in a 1 Mb region surrounding DNA double-strand breaks (DSBs). In addition, 53BP1 promotes genomic stability by regulating the metabolism of DNA ends. We have compared the joining rates of paired DSBs separated by 1.2 kb to 27 Mb on chromosome 12 in the presence or absence of 53BP1. 53BP1 facilitates joining of intrachromosomal DSBs but only at distances corresponding to γ-H2AX spreading. In contrast, DNA end protection by 53BP1 is distance independent. Furthermore, analysis of 53BP1 mutants shows that chromatin association, oligomerization, and N-terminal ATM phosphorylation are all required for DNA end protection and joining as measured by immunoglobulin class switch recombination. These data elucidate the molecular events that are required for 53BP1 to maintain genomic stability and point to a model wherein 53BP1 and H2AX cooperate to repress resection of DSBs.
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http://dx.doi.org/10.1016/j.molcel.2011.03.019 | DOI Listing |
Sci Bull (Beijing)
August 2025
MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China; Key Laboratory of Reproductive Medicine of Guangdong Province, School of Life Sciences and the First Affiliated Hospital, Sun Yat-sen Univ
Increased chromosomal instability impairs oocyte quality, contributing to female reproductive aging. The telomeric DNA damage response (DDR) is essential for genomic stability; however, how oocytes respond to telomeric damage remains elusive. Here, we observed that aged human germinal vesicle (GV) oocytes accumulated telomeric DNA damage.
View Article and Find Full Text PDFExp Gerontol
September 2025
Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA; Salk Institute for Biological Studies, La Jolla, CA, 92037, USA; Department of Molecular Biology, University of Utah, Salt Lake City, UT, USA; Department of Biochemistry, University of Utah, Salt Lake Ci
Aging is the greatest risk factor for cardiovascular diseases (CVD) and is characterized by inflammation, oxidative stress, and cellular senescence. Cellular senescence is a state of persistent cell cycle arrest triggered by stressors such as DNA damage and telomere attrition. Senescent endothelial cells (ECs) can impair vascular function and promote inflammation, thereby contributing to CVD progression.
View Article and Find Full Text PDFCell Chem Biol
September 2025
Department of Cancer Biology and the Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA. Electronic address:
Deubiquitinating enzymes (DUBs) are crucial regulators of ubiquitin signaling and protein degradation that remain incompletely understood in part due to the lack of high-quality chemical probes. To address this challenge, we developed CAS-010, a low nanomolar, ubiquitin-competitive inhibitor of USP28 that demonstrates preferential activity against USP28 over other DUBs, while also exhibiting some activity against the closely related USP25. We rationalized our SAR trends and observed selectivity using a crystal structure of USP28 in complex with an inhibitor.
View Article and Find Full Text PDFGaucher disease type 1 is a lysosomal storage disorder caused by mutations that reduce glucocerebrosidase activity, leading to glycolipid buildup, particularly in macrophages. To develop a curative approach, we established a high-efficiency genome editing platform for human and murine hematopoietic stem-progenitor cells using CRISPR/Cas9, recombinant adeno-associated virus serotype 6. To enhance homology-directed DNA repair while minimizing genotoxicity, we incorporated a new 53BP1 inhibitor, a ubiquitin variant that promotes DNA end resection and significantly increases editing efficiency.
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