Abstract

This work aims to elucidate the relationship between nitrogen depletion and Glutathione (GSH) level in Schizosaccharomyces pombe. The total GSH level was much higher in the Pap1-positive KP1 cells than in the Pap1-negative TP108-3C cells, suggesting that synthesis of GSH is dependent on Pap1. When the Pap1-positive KP1 cells were transferred to the nitrogen-depleted medium, total GSH level significantly increased up to 6 h and then slightly declined after 9 h. Elevation of the total GSH level was observed to be much less with the Pap1-negative cells. However, glucose deprivation was not able to enhance the GSH level in the KP1 cells. Activity of γ-glutamyltranspeptidase (γ-GT), an enzyme in the first step of GSH catabolism, also increased during nitrogen depletion. The total GSH level was more significantly enhanced in the KP1 cells overexpressing γ-GT2 than γ-GT1 during nitrogen starvation. Reactive oxygen species (ROS) levels were not changed during nitrogen starvation in both Pap1-positive and Pap1-negative cells. Collectively, nitrogen depletion causes up-regulation of GSH synthesis and γ-GT in a Pap1-dependent manner.

• Keywords: fission yeast; glutathione; γ-glutamyltranspeptidase; Pap1; Schizosaccharomyces pombe