Thymine glycols (Tg) are major pyrimidine oxidation products produced by chemical agents and ionizing radiation. Recent improvements in purification procedures gave us the opportunity to examine the incision of DNA duplexes containing a single (5S,6R)- or (5R,6S)-Tg lesion by mouse NTH1 DNA glycosylase and mammalian cell nuclear extracts. Time course experiments and steady state enzyme kinetics indicated that mNTH1 discriminates between the cis-Tg isomers. In addition, a variety of mammalian cell nuclear extracts showed a similar discrimination between the cis-Tg isomers. Trapping of Schiff base intermediates with sodium borohydride demonstrated that a single protein-DNA complex was formed in the presence of the nuclear extracts. The electrophoretic mobility of trapped complexes formed with both Tg isomers was identical to one another and similar to that of the complex formed with recombinant mNTH1. These results suggest that among all Tg-active DNA glycosylases, NTH1 is the major enzyme in mammalian cell nuclear extracts responsible for incision of duplexes containing cis-Tg isomers.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.dnarep.2003.11.009 | DOI Listing |
Sci Prog
January 2025
Department of Obstetrics and Gynecology, Hebei Medical University Third Hospital, Shijiazhuang, China.
Objective: Endometrial cancer (EC) is a malignant tumor with various histological subtypes and molecular phenotypes. The evaluation of drug resistance is important for cancer treatment. Progesterone resistance is the major challenge in EC.
View Article and Find Full Text PDFHypertension
January 2025
Cardiology Division, Department of Medicine, Emory University School of Medicine, Atlanta, GA. (X.Z., Q.X., A.V., Z.L.).
Background: Recent studies show that hyperactivation of mTOR (mammalian target of rapamycin) signaling plays a causal role in the development of thoracic aortic aneurysm and dissection. Modulation of PP2A (protein phosphatase 2A) activity has been shown to be of significant therapeutic value. In light of the effects that PP2A can exert on the mTOR pathway, we hypothesized that PP2A activation by small-molecule activators of PP2A could mitigate AA progression in Marfan syndrome (MFS).
View Article and Find Full Text PDFAlzheimers Dement
January 2025
Department of Neuroscience, City University of Hong Kong, Hong Kong, Hong Kong.
Introduction: Antisense oligonucleotides (ASOs) have shown promise in reducing amyloid precursor protein (APP) levels in neurons, but their effects in astrocytes, key contributors to neurodegenerative diseases, remain unclear. This study evaluates the efficacy of APP ASOs in astrocytes derived from an individual with Down syndrome (DS), a population at high risk for Alzheimer's disease (AD).
Methods: Human induced pluripotent stem cells (hiPSCs) from a healthy individual and an individual with DS were differentiated into astrocytes.
Biol Cell
January 2025
CNRS, Univ Rennes, IGDR [(Institut de Génétique et Développement de Rennes)]-UMR 6290, Rennes, France.
Understanding the spatiotemporal organization of components within living systems requires the highest resolution possible. Microscopy approaches that allow for a resolution below 250 nm include electron and super-resolution microscopy (SRM). The latter combines advanced imaging techniques and the optimization of image processing methods.
View Article and Find Full Text PDFPhysiol Rep
February 2025
Berlin Institute of Health at Charité, Universitätsmedizin Berlin, Center of Functional Genomics, Berlin, Germany.
The zona glomerulosa (ZG) synthesizes the mineralocorticoid aldosterone. The primary role of aldosterone is the maintenance of volume and electrolyte homeostasis. Aldosterone synthesis is primarily regulated via tightly controlled oscillations in intracellular calcium levels in response to stimulation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!