Protecting stalled DNA replication forks from degradation by promiscuous nucleases is essential to prevent genomic instability, a major driving force of tumorigenesis. Several proteins commonly associated with the repair of DNA double-strand breaks (DSBs) by homologous recombination (HR) have been implicated in the stabilization of stalled forks. Human CtIP, in conjunction with the MRE11 nuclease complex, plays an important role in HR by promoting DSB resection. Here, we report an unanticipated function for CtIP in protecting reversed forks from degradation. Unlike BRCA proteins, which defend nascent DNA strands from nucleolytic attack by MRE11, we find that CtIP protects perturbed forks from erroneous over-resection by DNA2. Finally, we uncover functionally synergistic effects between CtIP and BRCA1 in mitigating replication-stress-induced genomic instability. Collectively, our findings reveal a DSB-resection- and MRE11-independent role for CtIP in preserving fork integrity that contributes to the survival of BRCA1-deficient cells.
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http://dx.doi.org/10.1016/j.molcel.2018.09.014 | DOI Listing |
J Biol Chem
January 2025
Department of Chemistry and Biochemistry, Baylor University, Waco, Texas, 76798-7348, USA. Electronic address:
Coupling interactions between the alpha (α) subunit of the polymerase III core (α-Pol III core) and the tau (τ) subunit of the clamp loader complex (τ-CLC) are vital for efficient and rapid DNA replication in Escherichia coli (E. coli). Specific and targeted mutations in the C-terminal τ-interaction region of the Pol III α-subunit disrupted efficient coupled rolling circle DNA synthesis in vitro and caused significant genomic defects in CRISPR-Cas9 dnaE edited cell strains.
View Article and Find Full Text PDFMol Diagn Ther
January 2025
Istituto Europeo di Oncologia, IRCCS, Via Adamello 16, 20139, Milan, Italy.
Background: Predicting response to targeted cancer therapies increasingly relies on both simple and complex genetic biomarkers. Comprehensive genomic profiling using high-throughput assays must be evaluated for reproducibility and accuracy compared with existing methods.
Methods: This study is a multicenter evaluation of the Oncomine™ Comprehensive Assay Plus (OCA Plus) Pan-Cancer Research Panel for comprehensive genomic profiling of solid tumors.
Nucleic Acids Res
January 2025
MOE Key Laboratory of Biosystems Homeostasis and Protection, College of Life Sciences, Zhejiang University, No.866 Yuhangtang Road, 310058, Hangzhou, China.
Meiosis in mammalian oocytes is interrupted by a prolonged arrest at the germinal vesicle stage, during which oocytes have to repair DNA lesions to ensure genome integrity or otherwise undergo apoptosis. The FIRRM/FLIP-FIGNL1 complex dissociates RAD51 from the joint DNA molecules in both homologous recombination (HR) and DNA replication. However, as a type of non-meiotic, non-replicative cells, whether this RAD51-dismantling mechanism regulates genome integrity in oocytes remains elusive.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Centro de Investigación Biomédica en Red de Cáncer, CIBERONC CB16/12/00284, Instituto de Salud Carlos III, 28029 Madrid, Spain.
Recent studies have demonstrated the association between constitutional ring chromosome 21 (r(21)c) and the development of B-cell acute lymphoblastic leukemia (B-ALL) with intrachromosomal amplification of chromosome 21 (iAMP21). iAMP21 acts as a driver which is often accompanied by secondary alterations that influence disease progression. Here, we report an atypical case of iAMP21 B-ALL with a unique molecular profile in the context of r(21)c.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
Classical radiation biology as we understand it clearly identifies genomic DNA as the primary target of ionizing radiation. The evidence appears rock-solid: ionizing radiation typically induces DSBs with a yield of ~30 per cell per Gy, and unrepaired DSBs are a very cytotoxic lesion. We know very well the kinetics of induction and repair of different types of DNA damage in different organisms and cell lines.
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