Fig. 1

Biosynthetic pathways of GSH. G pathway, Gsh1 catalyzes the reaction between glutamic acid and cysteine to form γ-GC, which is subsequently conjugated to glycine by Gsh2 to synthesize GSH. F pathway, GshF accounts for Gsh1 and Gsh2 activities and carries out complete synthesis of GSH. P pathway, Pro1 converts glutamate to γ-glutamyl phosphate, which reacts with cysteine to generate γ-GC, and then Gsh2 adds glycine to γ-GC to form GSH