S-glutathiolation of c-Abl in vitro and in vivo

CHED 218

Yuh-Cherng Chai, ychai@jcu.edu, Amanda Leonberg, and John Sullivan. Department of Chemistry, John Carroll University, 20700 North Park Boulevard, University Heights, OH 44118
S-glutathiolation, the formation of mixed disulfides of glutathione with cysteine residues of proteins, is a broadly physiological modification that occurs in response to oxidative stress. S-glutathiolation can protect proteins from irreversible oxidation. In this study, we show that the kinase activity of the non-receptor tyrosine kinase c-Abl is inhibited by in vitro thiol modification: S-glutathiolation and thiol alkylating agents. Modification of c-Abl tyrosine kinase corresponds to a concomitant loss of kinase activity. We also demonstrate that S-glutathiolation of c-Abl can be reversed using a physiological system involving glutaredoxin and this reversal restores c-Abl kinase activity. c-Abl transfected HEK 293 cells were used to study S-glutathiolation in vivo. S-glutathiolated c-Abl was detected from oxidant treated cells. To our knowledge, these are the first data to show S-glutathiolation of c-Abl, and this modification may represent a mechanism of regulation of c-Abl kinase activity in cells under oxidative stress.