Glutathione precursor amino acids, permeases and enzymes, involved in the hypothesized mechanism for high GSH production.

Methionine (Met) and cysteine (Cys) are transported by the permeases Mup3p, Gnp1p, Yct1p, and Agp1p. Glutamate (Glu) and glycine (Gly) are transported by Dip5p and Agp1p. The same amino acids are also transported by the common Gap1p permease. Sul1p: sulfate transporter; Met5p: sulfite reductase; Glt1p: glutamate synthetase; Ser3p: phosphoglycerate dehydrogenase; Gsh1p: γ-glutamylcysteine synthetase; Gsh2p: glutathione synthetase.