The first or/and the second guanines of the human Ha-ras codon 12 (normally GGC) were substituted by O6 meG residues and the modified sequence was subsequently introduced into an SV40-based shuttle vector able to replicate in both simian cells and bacteria. After replication in simian COS7 cells (proficient in O6-alkyl-guanine transferase), plasmid DNA was extracted and mutations were screened in E. coli DH5 alpha cells. The vast majority of the mutations induced by O6 meG were G----A transitions. The mutation frequency observed at the second guanine of codon 12 (12G2 position: 3.75% +/- 0.4) was higher than the one observed at the first guanine (12G1 position: 1.09% +/- 0.6). This difference was confirmed by the results obtained when two adjacent O6 meG residues were positioned within codon 12. The higher mutation frequency observed for the 12G2 position could be attributed to differential repair or/and variation in polymerase fidelity. These results are in agreement with animal experiments where alkylating agents gave rise to mutation on G2 position of codon 12.
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http://dx.doi.org/10.1093/nar/20.18.4897 | DOI Listing |
Circ Res
October 2024
Cardiovascular Medicine and the Robert M. Berne Cardiovascular Research Center (A.H.P., L.M., K.-D.M., Y.Y., J.D.C., M.A.E., E.P., H.D., E.M.-Y., B.E.I., K.W.), University of Virginia School of Medicine, Charlottesville.
Background: Hypertension incidence increases with age and represents one of the most prevalent risk factors for cardiovascular disease. Clonal events in the hematopoietic system resulting from somatic mutations in driver genes are prevalent in elderly individuals who lack overt hematologic disorders. This condition is referred to as age-related clonal hematopoiesis (CH), and it is a newly recognized risk factor for cardiovascular disease.
View Article and Find Full Text PDFInt J Biol Macromol
February 2024
College of Food Science and Technology, Henan University of Technology, Zhengzhou, China.
Comp Biochem Physiol C Toxicol Pharmacol
November 2023
Department of Biochemistry, North-Eastern Hill University, Shillong 793022, Meghalaya, India. Electronic address:
Excessive use of herbicides in agricultural fields has become a major environmental concern due to the negative effects on the ecosystem. Microbial degradation has been well-known as an effective approach for combating such non-natural substances in soil. In the present study, the degradation of 2,4-Dichlorophenoxyacetic acid (2,4-D) as a result of metabolic activities of a cyanobacterium Nostoc muscorum Meg 1 was investigated using GC-MS analysis.
View Article and Find Full Text PDFACS Omega
June 2023
Institute of Advanced Machines and Design, Seoul National University, Seoul 08826, Korea.
The manufacturing process can modify the micromechanical structure, usefulness, and functionality of foams. Although one-step foaming is a simple process, controlling the morphology of the foams is difficult compared to the two-step processing method. In this study, we investigated the experimental differences in thermal and mechanical properties, particularly combustion behavior, between PET-PEN copolymers prepared by the two methods.
View Article and Find Full Text PDFEnviron Sci Technol
February 2023
Department of Psychology, College of Sciences, San Diego State University, 9245 Sky Park Court, Suite 225, San Diego, California 92123, United States.
While the thirdhand smoke (THS) residue from tobacco smoke has been recognized as a distinct public health hazard, there are currently no gold standard biomarkers to differentiate THS from secondhand smoke (SHS) exposure. This study used machine learning algorithms to assess which combinations of biomarkers and reported tobacco smoke exposure measures best differentiate children into three groups: no/minimal tobacco smoke exposure (NEG); predominant THS exposure (TEG); and mixed SHS and THS exposure (MEG). Participants were 4485 nonsmoking 3-17-year-olds from the National Health and Nutrition Examination Survey 2013-2016.
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