TY - JOUR
T1 - The DNA of UV-irradiated normal and excision-deficient mammalian cells undergoes relaxation in an initial stage of DNA repair
AU - Mitchell, David L.
AU - Clarkson, Judith M.
AU - Adair, Gerald M.
N1 - Funding Information:
We wish to thank Dr. J. Ross for helpful suggestions throughout the course of this work and Carrie Haipek for excellent technical assistance. This work was supported by NIH grant CA 19281.
PY - 1986/3
Y1 - 1986/3
N2 - Using a radioimmunoassay specific for Pyr(6-4)Pyo photoproducts, we have demonstrated the removal of these lesions from denaturated DNA isolated from UV-irradiated Chinese hamster ovary cells at various times post irradiation. When assayed undenatured, these same DNA samples, which are initially 10-20 times less capable of binding antibody, show a substantial increase in binding capacity during the first few hours of repair. At 3 h post irradiation the difference between native and heat-denatured DNA samples is negligle, indicating that all of the residual lesions are contained in a single-stranded (relaxed) configuration. This relaxation also occurs in UV-hypersensitive cell lines, that are deficient in the ability to remove Pyr(6-4)Pyo photoproducts. Novobiocin, an inhibitor of topoisomerase II, prevents both the initial increase in binding and the subsequent excision of the antibody-binding sites.
AB - Using a radioimmunoassay specific for Pyr(6-4)Pyo photoproducts, we have demonstrated the removal of these lesions from denaturated DNA isolated from UV-irradiated Chinese hamster ovary cells at various times post irradiation. When assayed undenatured, these same DNA samples, which are initially 10-20 times less capable of binding antibody, show a substantial increase in binding capacity during the first few hours of repair. At 3 h post irradiation the difference between native and heat-denatured DNA samples is negligle, indicating that all of the residual lesions are contained in a single-stranded (relaxed) configuration. This relaxation also occurs in UV-hypersensitive cell lines, that are deficient in the ability to remove Pyr(6-4)Pyo photoproducts. Novobiocin, an inhibitor of topoisomerase II, prevents both the initial increase in binding and the subsequent excision of the antibody-binding sites.
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U2 - 10.1016/0167-8817(86)90068-4
DO - 10.1016/0167-8817(86)90068-4
M3 - Article
C2 - 3951464
AN - SCOPUS:0022580361
SN - 0167-8817
VL - 165
SP - 123
EP - 128
JO - Mutation Research DNA Repair Reports
JF - Mutation Research DNA Repair Reports
IS - 2
ER -