title: The functional role of cysteine residues for c-Abl kinase activity.
abstract: S-glutathionylation, the formation of mixed disulfides of glutathione with cysteine residues of proteins, is a broadly observed physiological modification that occurs in response to oxidative stress. Since cysteine residues are particularly susceptible to oxidative modification by reactive oxygen species, S-glutathionylation 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; specifically, the cysteine residues of c-Abl are modified by S-glutathionylation and by thiol alkylating agents such as 4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid and N-ethylmaleimide. Modification of cysteine residues of c-Abl tyrosine kinase using glutathione disulfide and thiol alkylating agents corresponds to a concomitant loss of kinase activity. We also demonstrate that S-glutathionylation of c-Abl can be reversed using a physiological system involving glutaredoxin and this reversal restores c-Abl kinase activity. To our knowledge, these are the first data to show S-glutathionylation of c-Abl, and this modification may represent a mechanism of regulation of c-Abl kinase activity in cells under oxidative stress.
authors.affiliation: Department of Chemistry, John Carroll University, 20700 North Park Boulevard, University Heights, OH 44118, USA.
authors.forename: Amanda Kae
authors.initials: AK
authors.lastname: Leonberg
authors.forename: Yuh-Cherng
authors.initials: YC
authors.lastname: Chai
mesh_terms: D000477:Alkylating Agents / Q000494:pharmacology; D000818:Animals; D003545:Cysteine / Q000378:metabolism / Q000502:physiology*; D004789:Enzyme Activation / Q000187:drug effects; D054477:Glutaredoxins / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D007313:Insecta; D016315:Proto-Oncogene Proteins c-abl / Q000737:chemistry* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D000477:Alkylating Agents; D054477:Glutaredoxins; D011994:Recombinant Proteins; D016315:Proto-Oncogene Proteins c-abl; D005978:Glutathione; D003545:Cysteine