title: The effects of gamma radiation, UV and visible light on ATP levels in yeast cells depend on cellular melanization.
abstract: Previously we have shown that growth of melanized fungi is stimulated by low levels of gamma radiation. The goal of this study was to examine the effects of visible light, UV light, and gamma radiation on the energy level (ATP concentration) in melanized Cryptococcus neoformans cells. Melanized C. neoformans cells as well as non-melanized controls were subjected to visible, UV or gamma radiation, and ATP was quantified by measuring the amount of light emitted by the ATP-dependent reaction of luciferase with luciferin. We found that all three forms of radiation led to a reduction in the ATP levels in melanized C. neoformans cells. This points to a universal melanin-related mechanism underlying observation of ATP decrease in irradiated melanized cells. In contrast, in non-melanized cells visible light led to increase in ATP levels; gamma radiation did not cause any changes while UV exposure resulted in some ATP decrease, however, much less pronounced than in melanized cells.
authors.affiliation: Department of Nuclear Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
authors.forename: Ruth
authors.initials: R
authors.lastname: Bryan
authors.forename: Zewei
authors.initials: Z
authors.lastname: Jiang
authors.forename: Matthew
authors.initials: M
authors.lastname: Friedman
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Dadachova
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D003455:Cryptococcus neoformans / Q000378:metabolism* / Q000528:radiation effects*; D005720:Gamma Rays; D008027:Light; D008543:Melanins / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D008543:Melanins; D000255:Adenosine Triphosphate