Microinjected photoreactivating enzymes from Anacystis and Saccharomyces monomerize dimers in chromatin of human cells
Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis , Volume 146 p. 71- 77
Photoreactivating enzymes (PRE) from the yeast Saccharomyces cerevisiae and the cyanobacterium Anacystis nidulans have been injected into the cytoplasm of repair-proficient human fibroblasts in culture. After administration of photoreactivation light, PRE-injected cells displayed a significantly lower level of UV-induced unscheduled DNA synthesis (UDS) than non-injected cells. This indicates that monomerization of the UV-induced pyrimidine dimers in the mammalian chromatin had occurred as a result of photoreactivation by the injected PRE at the expense of repair by the endogenous excision pathway. Purified PRE from yeast is able to reduce UDS to 20-25% of the UDS found in non-injected cells, whereas the in vitro more active PRE from A. nidulans gives a reduction to only 70%. This suggests that the eukaryotic enzyme is more efficient in the removal of pyrimidine dimers from mammalian chromatin than its equivalent purified from the prokaryote A. nidulans.
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|Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis|
|Organisation||Erasmus MC: University Medical Center Rotterdam|
Zwetsloot, J.C.M, Vermeulen, W, Hoeijmakers, J.H.J, Yasui, A, Eker, A.P.M, & Bootsma, D. (1985). Microinjected photoreactivating enzymes from Anacystis and Saccharomyces monomerize dimers in chromatin of human cells. Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, 146, 71–77. Retrieved from http://hdl.handle.net/1765/2985