N(6)-(2-Deoxy-D-erythro-pentofuranosyl)-2,6-diamino-3,4-dihydro-4-oxo-5-N-methylformamidopyrimidine (MeFapy-dG) arises from N7-methylation of deoxyguanosine followed by imidazole ring opening. The lesion has been reported to persist in animal tissues. Previous in vitro replication bypass investigations of the MeFapy-dG adduct revealed predominant insertion of C opposite the lesion, dependent on the identity of the DNA polymerase (Pol) and the local sequence context. Here we report crystal structures of ternary Pol·DNA·dNTP complexes between MeFapy-dG-adducted DNA template:primer duplexes and the Y-family polymerases human Pol η and P2 Pol IV (Dpo4) from Sulfolobus solfataricus. The structures of the hPol η and Dpo4 complexes at the insertion and extension stages, respectively, are representative of error-free replication, with MeFapy-dG in the anti conformation and forming Watson-Crick pairs with dCTP or dC.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4545269 | PMC |
http://dx.doi.org/10.1021/jacs.5b02701 | DOI Listing |
Cell Commun Signal
January 2025
Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China.
Background: Ovarian cancer (OC), particularly high-grade serous ovarian carcinoma (HGSOC), is the leading cause of mortality from gynecological malignancies worldwide. Despite the initial effectiveness of treatment, acquired resistance to poly(ADP-ribose) polymerase inhibitors (PARPis) represents a major challenge for the clinical management of HGSOC, highlighting the necessity for the development of novel therapeutic strategies. This study investigated the role of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), a pivotal regulator of glycolysis, in PARPi resistance and explored its potential as a therapeutic target to overcome PARPi resistance.
View Article and Find Full Text PDFNat Commun
January 2025
Sorbonne Université, CNRS, Laboratory of Computational and Quantitative Biology, LCQB, Paris, France.
Telomere shortening ultimately causes replicative senescence. However, identifying the mechanisms driving replicative senescence in cell populations is challenging due to the heterogeneity of telomere lengths and the asynchrony of senescence onset. Here, we present a mathematical model of telomere shortening and replicative senescence in Saccharomyces cerevisiae which is quantitatively calibrated and validated using data of telomerase-deficient single cells.
View Article and Find Full Text PDFTransl Psychiatry
January 2025
Department of Genetic Psychology, Faculty of Psychology, Ruhr-University Bochum, Universitätsstraße 150, Bochum, Germany.
Cell-free DNA (cfDNA) is continuously shed by all cells in the body, but the regulation of this process and its physiological functions are still largely unknown. Previous research has demonstrated that both nuclear (cf-nDNA) and mitochondrial (cf-mtDNA) cfDNA levels increase in plasma in response to acute psychosocial and physical stress in males. This study further investigated these findings by testing 31 female participants (16 using oral hormonal contraception and 15 not using oral hormonal contraception), and the results were subsequently compared with those of 16 male participants.
View Article and Find Full Text PDFNat Commun
January 2025
Robson DNA Science Centre, Charbonneau Cancer Institute, Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
To tolerate oxidative stress, cells enable DNA repair responses often sensitive to poly(ADP-ribose) (PAR) polymerase 1 and 2 (PARP1/2) inhibition-an intervention effective against cancers lacking BRCA1/2. Here, we demonstrate that mutating the CHD6 chromatin remodeler sensitizes cells to PARP1/2 inhibitors in a manner distinct from BRCA1, and that CHD6 recruitment to DNA damage requires cooperation between PAR- and DNA-binding domains essential for nucleosome sliding activity. CHD6 displays direct PAR-binding, interacts with PARP-1 and other PAR-associated proteins, and combined DNA- and PAR-binding loss eliminates CHD6 relocalization to DNA damage.
View Article and Find Full Text PDFLung Cancer
January 2025
Department of Radiation Oncology, Instituto de Biomedicina de Sevilla-University Hospital Virgen del Rocio (IBIS/HUVR/CSIC/Universidad de Sevilla), Seville, Spain.
Purpose: Hematological toxicities (HTs) in lung cancer (LCa) may compromise the delivery of Radio-Chemotherapy (RTCT), and consequently affect the control of the disease. The aim of this study is to evaluate the association of Single nucleotide polymorphisms (SNPs) with HT.
Material/methods: In this prospective multicentre study, 264 patients with primary LCa treated with RTCT between 2012 and 2018 were included.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!