The accurate repair of DNA double-strand breaks (DSBs), highly toxic DNA lesions, is crucial for genome integrity and is tightly regulated during the cell cycle. In mitosis, cells inactivate DSB repair in favor of a tethering mechanism that stabilizes broken chromosomes until they are repaired in the subsequent cell cycle phases. How this is achieved mechanistically is not yet understood, but the adaptor protein TOPBP1 is critically implicated in this process. Here, we identify CIP2A as a TOPBP1-interacting protein that regulates TOPBP1 localization specifically in mitosis. Cells lacking CIP2A display increased radio-sensitivity, micronuclei formation and chromosomal instability. CIP2A is actively exported from the cell nucleus in interphase but, upon nuclear envelope breakdown at the onset of mitosis, gains access to chromatin where it forms a complex with MDC1 and TOPBP1 to promote TOPBP1 recruitment to sites of mitotic DSBs. Collectively, our data uncover CIP2A-TOPBP1 as a mitosis-specific genome maintenance complex.
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http://dx.doi.org/10.1038/s41467-022-31865-5 | DOI Listing |
Cell Rep
January 2025
School of Infection, Inflammation and Immunology, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK. Electronic address:
Interleukin (IL)-7 promotes T cell expansion during lymphopenia. We studied the metabolic basis in CD4 T cells, observing increased glucose usage for nucleotide synthesis and oxidation in the tricarboxylic acid (TCA) cycle. Unlike other TCA metabolites, glucose-derived citrate does not accumulate upon IL-7 exposure, indicating diversion into other processes.
View Article and Find Full Text PDFCell Rep
January 2025
Translational Cardiomyology Laboratory, Stem Cell and Developmental Biology, Department of Development and Regeneration, KU Leuven, Herestraat 49, 3000 Leuven, Belgium; Histology and Medical Embryology Unit, Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University of Rome, Rome, Italy. Electronic address:
Rhabdomyosarcoma (RMS), the most common pediatric soft tissue sarcoma, arises in skeletal muscle and remains in an undifferentiated state due to transcriptional and post-transcriptional regulators. Among its subtypes, fusion-negative RMS (FN-RMS) accounts for the majority of diagnoses in the pediatric population. MicroRNAs (miRNAs) are non-coding RNAs that modulate cell identity via post-transcriptional regulation of messenger RNAs (mRNAs).
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January 2025
Instituto de Investigación de La Viña y El Vino, Escuela de Ingeniería Agraria, Universidad de León, Avenida de Portugal, 41, León, 24009, Spain.
NPJ Regen Med
January 2025
Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA.
Cardiomyocytes (CMs) lost during ischemic cardiac injury cannot be replaced due to their limited proliferative capacity. Calcium is an important signal transducer that regulates key cellular processes, but its role in regulating CM proliferation is incompletely understood. Here we show a robust pathway for new calcium signaling-based cardiac regenerative strategies.
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