Telomeres are essential chromosomal regions that prevent critical shortening of linear chromosomes and genomic instability in eukaryotic cells. The bulk of telomeric DNA is replicated by semi-conservative DNA replication in the same way as the rest of the genome. However, recent findings revealed that replication of telomeric repeats is a potential cause of chromosomal instability, because DNA replication through telomeres is challenged by the repetitive telomeric sequences and specific structures that hamper the replication fork. In this review, we summarize current understanding of the mechanisms by which telomeres are faithfully and safely replicated in mammalian cells. Various telomere-associated proteins ensure efficient telomere replication at different steps, such as licensing of replication origins, passage of replication forks, proper fork restart after replication stress, and dissolution of post-replicative structures. In particular, shelterin proteins have central roles in the control of telomere replication. Through physical interactions, accessory proteins are recruited to maintain telomere integrity during DNA replication. Dormant replication origins and/or homology-directed repair may rescue inappropriate fork stalling or collapse that can cause defects in telomere structure and functions.
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http://dx.doi.org/10.3390/genes8040112 | DOI Listing |
Breast Cancer (Dove Med Press)
January 2025
The Second Surgical Department of Breast Cancer, Tianjin Medical University Cancer Institute & Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, People's Republic of China.
Purpose: Cell division cycle protein 45 (CDC45) plays a crucial role in DNA replication. This study investigates its role in breast cancer (BC) and its impact on tumor progression.
Methods: We utilized the GEO database to screen differentially expressed genes (DEGs) and conducted enrichment analysis on these genes.
Chem Res Toxicol
January 2025
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Cobalt is a crucial trace element that widely exists in natural environments and is necessary for normal physiological function. However, excessive cobalt exposure leads to various adverse health effects, especially hematological and endocrine dysfunctions. Here, we investigated the toxicity of cobalt on early erythropoiesis by using ex vivo cultured erythroid progenitor cells (EPCs).
View Article and Find Full Text PDFNat Chem Biol
January 2025
Department of Gynecology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
The regressed arms of reversed replication forks exhibit structural similarities to one-ended double-stranded breaks and need to be protected against uncontrolled nucleolytic degradation. Here, we identify MSANTD4 (Myb/SANT-like DNA-binding domain-containing protein 4), a functionally uncharacterized protein that uniquely counters the replication protein A (RPA)-Bloom (BLM)/Werner syndrome helicase (WRN)-DNA replication helicase/nuclease 2 (DNA2) complex to safeguard reversed replication forks from detrimental degradation, independently of the breast cancer susceptibility proteins (BRCA1/2)-DNA repair protein RAD51 pathway. MSANTD4 specifically interacts with the junctions between single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) in DNA substrates harboring a 3' overhang, which resemble the structural features of regressed arms processed by WRN-DNA2.
View Article and Find Full Text PDFCell Death Dis
January 2025
Tianjian Laboratory of Advanced Biomedical Sciences, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China.
Mitochondrial oxidative phosphorylation (OXPHOS) is a therapeutic vulnerability in glycolysis-deficient cancers. Here we show that inhibiting OXPHOS similarly suppresses the proliferation and tumorigenicity of glycolytically competent colorectal cancer (CRC) cells in vitro and in patient-derived CRC xenografts. While the increased glycolytic activity rapidly replenished the ATP pool, it did not restore the reduced production of aspartate upon OXPHOS inhibition.
View Article and Find Full Text PDFJ Psychiatr Res
January 2025
Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA, 52246, USA; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, 52246, USA; Yale Child Study Center, Yale School of Medicine, New Haven, CT, 06510, USA. Electronic address:
Prenatal stress is a risk factor for neurodevelopmental disorders (NDDs), including autism spectrum disorder (ASD). However, how early stress modification of brain development contributes to this pathophysiology is poorly understood. Ventral forebrain regions such as dorsal striatum are of particular interest: dorsal striatum modulates movement and cognition, is altered in NDDs, and has a primarily GABAergic population.
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