Although the genetic information of DNA is embodied in its primary structure, the topological state of the nucleic acid molecule has a profound influence on its physiological function. In vivo, the topological structure of DNA is modulated by a ubiquitous class of enzymes known as DNA topoisomerases. In prokaryotes, these enzymes affect such fundamental processes as DNA replication, recombination, repair, and transcription. Unfortunately, the cellular functions of eukaryotic topoisomerases are not yet clear. Therefore, the ultimate goal of this project is to define the role of DNA topoisomerases in eukaryotic organisms. To this end, the function and biology of the type II topoisomerase from the fly, Drosophila melanogaster, will be determined. More specifically, the aims of this proposal are 1) to describe in detail the interactions between Drosophila topoisomerase II and its substrates, DNA and ATP; 2) to isolate and characterize the gene which codes for the enzyme; 3) to determine how the activity of topoisomerase II is regulated in D. melanogaster; and 4) to define the in vivo function of the enzyme. This research is designed to take advantage of the known physicochemical properties of the enzyme and the biological attributes of Drosophila. The enzymology of topoisomerase II will be characterized by a variety of biochemical and physical techniques, such as kinetic studies, binding assays, chemical modification, electron microscopy, and fluorescence spectroscopy. The regulation and cellular function of the enzyme will be elucidated by classical genetic and biological techniques coupled with recombination DNA methodologies. Procedures to be employed include genetic crosses, isolation of mutant flies, in situ hybridization, molecular cloning, DNA sequencing, and transformation on Drosophila with mobile genetic elements. Since topoisomerases affect several aspects of DNA metabolism, this study may illuminate the events which underlie those congenetal birth defects resulting from gross chromosomal abnormalities. Moreover, the topological structure of DNA is altered in cancerous cells and DNA topology and/or topoisomerase activity is important for the transformation of host genomes by viruses and mobile genetic elements. Therefore, this work may provide insight into some of the mechanisms of cancer.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM033944-03
Application #
3284166
Study Section
Genetics Study Section (GEN)
Project Start
1984-07-01
Project End
1987-06-30
Budget Start
1986-07-01
Budget End
1987-06-30
Support Year
3
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37203
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Dahlman, Kimberly Brown; Weinger, Matthew B; Lomis, Kimberly D et al. (2018) Integrating Foundational Sciences in a Clinical Context in the Post-Clerkship Curriculum. Med Sci Educ 28:145-154
Niederhoffer, Eric C; Cline, Susan D; Osheroff, Neil et al. (2017) Teaching Biochemistry and Genetics to Students of Dentistry, Medicine, and Pharmacy 6th International Conference of the Association of Biochemistry Educators (ABE) Clearwater Beach, FL, USA, May 7-11, 2017. Med Sci Educ 27:855-859
Ashley, Rachel E; Dittmore, Andrew; McPherson, Sylvia A et al. (2017) Activities of gyrase and topoisomerase IV on positively supercoiled DNA. Nucleic Acids Res 45:9611-9624
Ashley, Rachel E; Lindsey Jr, R Hunter; McPherson, Sylvia A et al. (2017) Interactions between Quinolones and Bacillus anthracis Gyrase and the Basis of Drug Resistance. Biochemistry 56:4191-4200
Minniti, Elirosa; Byl, Jo Ann W; Riccardi, Laura et al. (2017) Novel xanthone-polyamine conjugates as catalytic inhibitors of human topoisomerase II?. Bioorg Med Chem Lett 27:4687-4693
Infante Lara, Lorena; Sledge, Alexis; Laradji, Amine et al. (2017) Novel trifluoromethylated 9-amino-3,4-dihydroacridin-1(2H)-ones act as covalent poisons of human topoisomerase II?. Bioorg Med Chem Lett 27:586-589
Kristoffersen, Emil L; Givskov, Asger; Jørgensen, Line A et al. (2017) Interlinked DNA nano-circles for measuring topoisomerase II activity at the level of single decatenation events. Nucleic Acids Res 45:7855-7869
Yu, Xiang; Davenport, James W; Urtishak, Karen A et al. (2017) Genome-wide TOP2A DNA cleavage is biased toward translocated and highly transcribed loci. Genome Res 27:1238-1249
Ashley, Rachel E; Blower, Tim R; Berger, James M et al. (2017) Recognition of DNA Supercoil Geometry by Mycobacterium tuberculosis Gyrase. Biochemistry 56:5440-5448

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