Biopolym. Cell. 1985; 1(4):203-207.
Cell Biology
Topoisomerase II. Its role in conformation changes in superhelical nuclear DNA of lymphocytes after γ-irradiation
1Vashchenko V. I., 1Shchedrina L. V., 1Komar V. E.
  1. Central Research Institute for Roentgenology and Radiology, Ministry of Public Health
    Leningrad, USSR

Abstract

Inhibitors of DNA topoisomerase system (novobiocin, nalidixic acid) are studied for their effect on the repair of superhelical DNA structure damaged by ionizing radiation (8 Gy) in rat lymphocytes. The data obtained show that the topoisomerase II participates in the appearance of the second relaxation of superhelical domains in nuclear DNA after irradiation. The scheme is suggested concerning the participation of this enzyme in the structure of nucleoids in their interaction with chemical and physical agents. BND-cellulose chromatography reveals the presence of repair synthesis in human lymphocytes after their γ-irradiation (20 Gy) in vitro.

References

[1] Klimov NA, Vashchenko VI, Kolyubaeva SN, Komar VE. Changes in the supercoiled structure of nuclear DNA in rat and human peripheral blood lymphocytes after gamma-irradiation.
[2] Vashchenko VI, Koliubaeva SN, Klimov NA, Komar VE. Changes in the supercoiled structure of the nuclear DNA of rat peripheral blood lymphocytes under gamma irradiation. Radiobiologiia. 1980;20(4):483-8.
[3] Filippovich IV, Sorokina NI, Soldatenkov VA, Romantzev EF. Supercoiled DNA repair in thymocyte fractions differing in radiosensitivity. Int J Radiat Biol Relat Stud Phys Chem Med. 1982;42(1):31-44.
[4] Gellert M. DNA topoisomerases. Annu Rev Biochem. 1981;50:879-910.
[5] Lavin MF. Effect of novobiocin on DNA synthesis and structure in human lymphoblastoid cells. Biochem Biophys Res Commun. 1981;100(1):328-35.
[6] Mattern MR, Zwelling LA, Kerrigan D, Kohn KW. The reconstitution of higher-order DNA structure after X-irradiation of mammalian cells. Biochem Biophys Res Commun. 1983;112(3):1077-84.
[7] Nakayama K, Sugino A. Novobiocin and nalidixic acid target proteins in yeast. Biochem Biophys Res Commun. 1980;96(1):306-12.
[8] Vashchenko VI, Reshchikov AM, Komar VE, Khanson KP. Effect of novobiocin on degradation and repair of the superhelical structure of nuclear DNA from rat thymocyte fractions. Radiobiologiia. 1983;23(6):786-9.
[9] Javaherian K, Liu LF. Association of eukaryotic DNA topoisomerase I with nucleosomes and chromosomal proteins. Nucleic Acids Res. 1983;11(2):461-72.
[10] Glikin GC, Ruberti I, Worcel A. Chromatin assembly in Xenopus oocytes: in vitro studies. Cell. 1984;37(1):33-41.
[11] Hollatz R, Tempel K. Unscheduled DNA-synthesis in UV-irradiated spleen lymphocytes of the rat after whole-body X-irradiation. Radiat Environ Biophys. 1978;15(1):77-83.
[12] Lavin MF, Kidson C. Repair of ionizing radiation induced DNA damage in human lymphocytes. Nucleic Acids Res. 1977;4(11):4015-22.