Optical manipulation of Saccharomyces cerevisiae cells reveals that green light protection against UV irradiation is favored by low Ca2+ and requires intact UPR pathway

Abstract

Optical manipulation of Saccharomyces cerevisiae cells with high density green photons conferred protection against the deleterious effects of UV radiation. Combining chemical screening with UV irradiation of yeast cells, it was noted that the high density green photons relied on the presence of intact unfolded protein response (UPR) pathway to exert their protective effect and that the low Ca(2+) conditions boosted the effect. UPR chemical inducers tunicamycin, dithiotreitol and calcium chelators augmented the green light effect in a synergic action against UV-induced damage. Photo-manipulation of cells was a critical factor since the maximum protection was achieved only when cells were pre-exposed to green light.

Keywords: 1,2-bis(o-aminophenoxy)-ethane-N,N,N′,N′-tetraacetic acid; BAPTA; BL; Calcium; DTT; EGTA; ER; GL; High density green photon; MU; Miller units; ONPG; Optical manipulation; RT-PCR; SD; SD-Ura; Saccharomyces cerevisiae; TM; UPR; Unfolded protein response; YPD; blue light; dithiothreitol; endoplasmic reticulum; ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid; green light; o-nitrophenyl-β-d-galactopyranoside; reverse transcriptase-PCR; synthetic dextrose medium (complete); synthetic dextrose medium lacking uracil; tunicamycin; unfolded protein response; yeast extract–peptone–dextrose medium.