Steps in the glutathiolation cycle include: 1) Thiol activation: nitric oxide synthases (NOS), cellular oxidases, or the electron transport chain (ETC) generate reactive nitrogen or oxygen species that promote the formation of nitrosated or sulfenylated proteins; 2) Glutathiolation: GSH can react non-enzymatically with the activated thiols, or the glutathiolation reaction can be accelerated in the presence of GSH-loaded GSTP; 3) Thiol recovery: GSH can reduce glutathiolated proteins non-enzymatically, or the reaction can be catalyzed via glutaredoxin (GRX), sulfiredoxin (SRX), protein disulfide isomerase (PDI), or other proteins with reactive cysteines such as FXYD protein.