Biopolym. Cell. 1985; 1(1):32-40.
Cell Biology
DNA-topoisomerases of proliferating animal cells
1Terskikh V. V., 1Bronstein I. B., 1Gromova I. I., 1Timofeev A. V., 1Kafiani K. A.
  1. Institute of Molecular Biology, Academy of Sciences of the USSR
    Moscow, USSR


Chinese hamster fibroblasts were stimulated to proliferate by adding 10 % embryonic serum to the culture. Specific activity of type 1 topoisomerase in partially purified nuclear extracts, prepared at various times after serum addition, markedly increased, peaking at the 10th hour, 10 hour before a mass entry of the cells into the S-phase. This indicates a role of topoisomerase I in the control of cell proliferation. With the aim of developing an approach to isolation and analysis DNA sequences that are the targets for topoisomerases in the cell, complex formation between the highly purified topoisomerase I and circular supertwisted DNA (of the plasmid pBR322) or nuclear DNA of Chinese hamster fibroblasts was studied. Isolation and characterization of the complexes by sedimentation and equilibrium density centrifugation are described, which allows characterizing the protein as well as the DNA moieties of the complexes.


[1] Gellert M. DNA topoisomerases. Annu Rev Biochem. 1981;50:879-910.
[2] Bronshteyn IB, Kafiani KA. Proteins that alter the conformation of DNA and their alleged role in genetic recombination. Usp Sovrem Biol. 1983; 96(1):13-27.
[3] Tereshchenko OD, Khaydarova NV. Eukaryotic DNA topoisomerase: properties and possible functions. Usp Sovrem Biol. 1983; 96(1):28-45.
[4] Klevati L, Tse Y-C. Chemical modification of essential tyrosine residues in DNA topoisomerases. Biochim biophys acta. 1983; 745(2):175—180.
[5] Duguet M, Lavenot C, Harper F, Mirambeau G, De Recondo AM. DNA topoisomerases from rat liver: physiological variations. Nucleic Acids Res. 1983;11(4):1059-75.
[6] Rosenberg BH, Ungers G, Deutsch JF. Variation in DNA swivel enzyme activity during the mammalian cell cycle. Nucleic Acids Res. 1976;3(12):3305-11.
[7] Miskimins R, Miskimins WK, Bernstein H, Shimizu N. Epidermal growth factor-induced topoisomerase(s). Intracellular translocation and relation to DNA synthesis. Exp Cell Res. 1983;146(1):53-62.
[8] Poccia DL, LeVine D, Wang JC. Activity of a DNA topoisomerase (nicking-closing enzyme) during sea urchin development and the cell cycle. Dev Biol. 1978;64(2):273-83.
[9] Champoux JJ. Proteins that affect DNA conformation. Annu Rev Biochem. 1978;47:449-79.
[10] Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976;72:248-54.
[11] Bronshtein IB, Shakhbazian GK, Kafiani KA. Isolation and properties of endodeoxyribonuclease from the ovicells of the loach. Biokhimiia. 1983;48(1):92-103.
[12] Shakhbazian GK, Bronshtein IB, Kafiani KA. Isolation and characterization of DNA topoisomerase from the oocytes of loach. Biokhimiia. 1984; 49(8):1211—1220.
[13] Mattern MR, Painter RB. Dependence of mammalian DNA replication on DNA supercoiling. I. Effects of ethidium bromide on DNA synthesis in permeable Chinese hamster ovary cells. Biochim Biophys Acta. 1979;563(2):293-305.
[14] Mattern MR, Painter RB. Dependence of mammalian DNA replication on DNA supercoiling. II. Effects of novobiocin on DNA synthesis in Chinese hamster ovary cells. Biochim Biophys Acta. 1979;563(2):306-12.
[15] Yoshida S, Ungers G, Rosenberg BH. DNA swivel enzyme activity in a nuclear membrane fraction. Nucleic Acids Res. 1977;4(1):223-8.