We report that POL5 encodes the fifth essential DNA polymerase in Saccharomyces cerevisiae. Pol5p was identified and purified from yeast cell extracts and is an aphidicolin-sensitive DNA polymerase that is stimulated by yeast proliferating cell nuclear antigen (PCNA). Thus, we named Pol5p DNA polymerase phi. Temperature-sensitive pol5-1-- -3 mutants did not arrest at G(2)/M at the restrictive temperature. Furthermore, the polymerase active-site mutant POL5dn gene complements the lethality of Delta pol5. These results suggest that the polymerase activity of Pol5p is not required for the in vivo function of Pol5p. rRNA synthesis was severely inhibited at the restrictive temperature in the temperature-sensitive pol5-3 mutant cells, suggesting that an essential function of Pol5p is rRNA synthesis. Pol5p is localized exclusively to the nucleolus and binds near or at the enhancer region of rRNA-encoding DNA repeating units.
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http://dx.doi.org/10.1073/pnas.142277999 | DOI Listing |
BMC Infect Dis
December 2024
Department of Medical Laboratory Science, Faculty of Applied Health Sciences, Edo State University, Uzairue, Edo State, Nigeria.
Background: Hepatitis B virus (HBV) infection remains a major health challenge in Nigeria, with high prevalence rates among pregnant women. The prevalence of overt and occult hepatitis B infection (HBI and HBI) among pregnant women was investigated to understand the burden and associated risk factors in this population.
Methods: A cross-sectional study was conducted among 200 pregnant women.
Parasitol Res
December 2024
Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
Coccidiosis is caused by apicomplexan parasites of the genus Eimeria, which infect epithelial cells of the intestinal tract causing diarrhea and negatively impacting production in the poultry industry. The self-limiting and highly immunogenic nature of infection by Eimeria spp. make live vaccination an effective means of coccidiosis control.
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December 2024
Division of Radiation Oncology, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Aggressive breast cancers often fail or acquire resistance to radiotherapy. To develop new strategies to improve the outcome of aggressive breast cancer patients, we studied how PARP inhibition radiosensitizes breast cancer models to proton therapy, which is a radiotherapy modality that generates more DNA damage in the tumor than standard radiotherapy using photons. Two human BRCA1-mutated breast cancer cell lines and their isogenic BRCA1-recovered pairs were treated with a PARP inhibitor and irradiated with photons or protons.
View Article and Find Full Text PDFIn Saccharomyces cerevisiae cells, the bulk of mitochondrial DNA (mtDNA) replication is mediated by the replicative high-fidelity DNA polymerase γ. However, upon UV irradiation low-fidelity translesion polymerases: Polη, Polζ and Rev1, participate in an error-free replicative bypass of UV-induced lesions in mtDNA. We analysed how translesion polymerases could function in mitochondria.
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December 2024
Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, NHO Kyoto Medical Center, 1-1 Mukaihata-cho, Fukakusa, Fushimi-ku, Kyoto, 612-8555, Japan.
In order to elucidate novel actions of degalactosylated whey protein (D-WP) in comparison with intact whey protein (WP), the effects of oral intake of D-WP on peripheral blood telomere length and telomerase were examined in young and aged mice. In young mice, peripheral blood telomere length was significantly elongated following oral intake of D-WP for 4 weeks. mRNA expression of both telomerase reverse transcriptase (TERT) and telomerase RNA component (TERC) was significantly increased in the peripheral blood following oral intake of D-WP for 4 weeks.
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