Figure 7. A mechanism by which mTORC1-Sch9 regulates H2S production via transsulfuration pathway. mTORC1-Sch9 controls the intracellular level of cysteine which is one of substrates for endogenous H2S production. On the other hand, cysteine regulates the expression of key transsulfuration pathway enzymes CBS and CGL which catalyze H2S production from homocysteine or cysteine. CBS is encoded by CBS in human and CYS4 in Saccharomyces cerevisiae while CGL is encoded by CTH in human and CYS3 in Saccharomyces cerevisiae. Dash lines indicate indirect regulations.