We investigated the numbers of DNA-synthesizing cells in mouse submandibular glands (SMGs) during chronic isoproterenol (IPR) administration, using an immunohistochemical method with anti-bromodeoxyuridine (BrdU) antibodies. Adult and immature female mice were injected with IPR daily or every other day up to a total of seven injections. Whereas hypertrophic enlargement of acinar cells continued with repeated IPR injections, induction of DNA synthesis was transient. With one IPR injection, more than 50% of the acinar cells were induced to synthesize DNA, but after five daily injections the numbers of cells in the DNA synthetic phase decreased and returned to control values. This pattern was basically the same for immature mice and for adult mice stimulated by IPR every other day. The responsiveness of the SMGs of immature mice to IPR was somewhat lower than that of adults. Prolongation of the interval between injections of IPR, compared to daily injections, did not cause sustained induction of DNA synthesis. These data suggest that the hypertrophic enlargement and the induction of DNA synthesis by IPR are mediated through different intracellular pathways after the stimulation of beta-adrenergic receptors, and that the regulatory mechanism for the induction of DNA synthesis is complex.
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http://dx.doi.org/10.1177/002215549704500811 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.
Ribonucleotide reductase (RNR) is essential for DNA synthesis and repair in all living organisms. The mechanism of RNR requires long-range radical transport through a proton-coupled electron transfer (PCET) pathway spanning two different protein subunits. Herein, the direct PCET reaction between the interfacial tyrosine residues, Y356 and Y731, is investigated with a vibronically nonadiabatic theory that treats the transferring proton and all electrons quantum mechanically.
View Article and Find Full Text PDFCancer Chemother Pharmacol
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Cancer Therapeutics Program, UPMC Hillman Cancer Center, Pittsburgh, PA, USA.
Background: ATR is an apical DDR kinase activated at damaged replication forks. Elimusertib is an oral ATR inhibitor and potentiates irinotecan in human colorectal cancer models.
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J Virol
January 2025
College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China.
Unlabelled: Avian leukosis virus subgroup J (ALV-J) poses a significant threat to the poultry industry; yet, our understanding of its replication and pathogenic mechanisms is limited. The Ten-Eleven Translocation 2 (TET2) is an indispensable regulatory factor in active DNA demethylation and immune response regulation. This study reports a significant and time-dependent decrease in TET2 levels following ALV-J infection and shows that the reduction of TET2 protein is mediated by the autophagy pathway.
View Article and Find Full Text PDFBiochem J
January 2025
School of Science, University of Waikato, Hamilton, Waikato, 3216, New Zealand.
DNA-joining by ligase and polymerase enzymes has provided the foundational tools for generating recombinant DNA and enabled the assembly of gene and genome-sized synthetic products. Xenobiotic nucleic acid (XNA) analogues of DNA and RNA with alternatives to the canonical bases, so-called 'unnatural' nucleobase pairs (UBP-XNAs), represent the next frontier of nucleic acid technologies, with applications as novel therapeutics and in engineering semi-synthetic biological organisms. To realise the full potential of UBP-XNAs, researchers require a suite of compatible enzymes for processing nucleic acids on a par with those already available for manipulating canonical DNA.
View Article and Find Full Text PDFFront Oncol
January 2025
Department of Biology, Tufts University, Medford, MA, United States.
REV7, also known as MAD2B, MAD2L2, and FANCV, is a HORMA-domain family protein crucial to multiple genome stability pathways. REV7's canonical role is as a member of polymerase ζ, a specialized translesion synthesis polymerase essential for DNA damage tolerance. REV7 also ensures accurate cell cycle progression and prevents premature mitotic progression by sequestering an anaphase-promoting complex/cyclosome activator.
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