INDUCTION OF CYCLOBUTANE PYRIMIDINE DIMER PHOTOLYASE IN CULTURED FISHCELLS BY UVA AND BLUE-LIGHT

The cyclobutane pyrimidine dimer (CPD) photolyase in fish cells is kno wn to be regulated by environmental factors, such as light, hydrogen p eroxide and growth inhibition, The induction of CPD photolyase by ligh t in cultured goldfish cells was dependent on the wavelength of the li ght, and UVA and blue light had high inductive activity, The spectrum for CPD photolyase activity was different from that for the induction. Treatment with blue or yellow light for a short time, which did not i nduce any CPD photolyase, induced high CPD photolyase activity in the presence of the photosensitizers, TPPS (monosulfonated meso-tetrapheny l porphine) and ALPS (aluminum phthalocyanine tetrasulfonate), respect ively, These results suggest that the induction of CPD photolyase migh t be triggered by active oxygen produced by light and cellular photose nsitizers. We also found that immediately after treatment with UVA, bl ue light or a photosensitizer in combination with light, cellular atta chment to the substratum was enhanced, as was the CPD photolyase activ ity, Pretreatment with a flavonoid, quercetin, inhibited both photoind uction of CPD photolyase and enhancement of cellular attachment, Vitam in E inhibited only photoinduction of CPD photolyase activity, Treatme nt with H7, a strong inhibitor for protein kinase C, after light treat ment inhibited photoinduction of CPD photolyase activity, but an analo gue of H7, Ha1004, which is a weak inhibitor of protein kinase C, did not have such an effect.