To monitor gradual changes in the replication foci distribution during early S phase, different segments of newly synthesized DNA were visualized by immunocytochemical mapping of two consecutively incorporated deoxythymidine analogs in pulse-chase-pulse experiments in HeLa cells. The resulting dual-labeled fluorescence images were evaluated using cross-correlation function (CCF) analysis. General changes of CCF shape due to image deterioration caused by blur, noise, and lateral sampling (pixel size) were also discussed. Using CCF analysis of model images simulating either random initiation of new replication foci, or the firing of new foci in close proximity to completed ones, we were able to ascribe the changes in the early S replication foci distribution to the latter mechanism. In contrast to the data published previously, we monitored the dynamics of all replication foci for up to 3 h. In addition, we showed that the replication foci dynamics is well described by random walk model, so that the average de-localization of individual foci is proportional to square root of the applied chase.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.jsb.2005.03.011 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Replication-Poison Treatment in BRCA1-Deficient Breast Cancer Causes MRE11 Over-Resection that Induces Single-Stranded DNA Accumulation and Mitotic Catastrophe.
Cancer Res
January 2025
INSERM U1194, Montpellier Cedex 05, Occitanie, France.
BRCA1 deficiency is observed in approximately 25% of triple-negative breast cancer (TNBC). BRCA1, a key player of homologous recombination (HR) repair, is also involved in stalled DNA replication fork protection and repair. Here, we investigated the sensitivity of BRCA1-deficient TNBC models to the frequently used replication chain terminator gemcitabine, which does not directly induce DNA breaks.
View Article and Find Full Text PDFA novel mouse model of pulmonary fibrosis: twice-repeated oropharyngeal bleomycin administration mimicking human pathology.
Biochem Cell Biol
January 2025
Department of Histology and Embryology, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, Sun Yat-Sen University, Shenzhen, China.
Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible lung disease with high mortality and limited treatment options. While single-dose bleomycin-induced models are commonly used to investigate the pathogenesis of IPF, they fail to adequately replicate the complex pathological features in human patients, thereby hindering comprehensive investigations. Previous studies utilizing repetitive bleomycin injections have demonstrated a closer resemblance to human IPF pathology; however, the time- and resource-intensive nature of this approach presents significant drawbacks.
View Article and Find Full Text PDFCHD6 has poly(ADP-ribose)- and DNA-binding domains and regulates PARP1/2-trapping inhibitor sensitivity via abasic site repair.
Nat 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 PDFThe kinetics of uracil-N-glycosylase distribution inside replication foci.
Sci Rep
January 2025
Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Olomouc, Czech Republic.
Mismatched nucleobase uracil is commonly repaired through the base excision repair initiated by DNA uracil glycosylases. The data presented in this study strongly indicate that the nuclear uracil-N-glycosylase activity and nuclear protein content in human cell lines is highest in the S phase of the cell cycle and that its distribution kinetics partially reflect the DNA replication activity in replication foci. In this respect, the data demonstrate structural changes of the replication focus related to the uracil-N-glycosylase distribution several dozens of minutes before end of its replication.
View Article and Find Full Text PDFDynamic interactions of retroviral Gag condensates with nascent viral RNA at transcriptional burst sites: implications for genomic RNA packaging.
bioRxiv
January 2025
Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033.
Retroviruses are responsible for significant pathology in humans and animals, including the acquired immunodeficiency syndrome and a wide range of malignancies. A crucial yet poorly understood step in the replication cycle is the recognition and selection of unspliced viral RNA (USvRNA) by the retroviral Gag protein, which binds to the psi (Ψ) packaging sequence in the 5' leader, to package it as genomic RNA (gRNA) into nascent virions. It was previously thought that Gag initially bound gRNA in the cytoplasm.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!