The ChaC family of proteins function as gamma-glutamyl cyclotransferases acting specifically to degrade glutathione but not other gamma-glutamyl peptides [1, 2]. It is is conversed across all phyla and represents a new pathway for glutathione degradation in living cells.

1: Mammalian proapoptotic factor ChaC1 and its homologues function as gamma-glutamyl cyclotransferases acting specifically on glutathione. Kumar A, Tikoo S, Maity S, Sengupta S, Sengupta S, Kaur A, Bachhawat AK; EMBO Rep. 2012;13:1095-1101. PMID:23070364

2: Defining the cytosolic pathway of glutathione degradation in Arabidopsis thaliana: role of the ChaC/GCG family of gamma-glutamyl cyclotransferases as glutathione-degrading enzymes and AtLAP1 as the Cys-Gly peptidase. Kumar S, Kaur A, Chattopadhyay B, Bachhawat AK; Biochem J. 2015;468:73-85. PMID:25716890