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.

Biological chemistry and functionality of protein sulfenic acids and related thiol modifications

“…Both ionizing radiation and addition of extracellular H 2 O 2 increase c-Abl activity which is critical to the initiation of pathways involved in the DNA damage response [112,113]. However, glutathionylation of recombinant c-Abl was shown to inhibit the kinase activity, a process which was reversed by addition of glutaredoxin [114]. Clearly, both Src and c-Abl are subject to diverse layers of redox regulation which would need to be clarified in future studies.…”

Redox regulation of protein kinases

“…For instance, S -glutathionylation of c-Abl, a non-receptor Tyr kinase, serves to regulate kinase activity under conditions of oxidation stress (Leonberg and Chai, 2007). Specific cysteine residues in two other kinases, ataxia-telangiectasia mutated (ATM) kinase and pyruvate kinase M2 (PKM2), have recently been identified and exhibit distinct functional responses to oxidation.…”

Discovering mechanisms of signaling-mediated cysteine oxidation

“…cGMP-dependent protein kinase (PKGIα) was shown to form an interpro tein disulfide bond between Cys46 on two subunits after treatment of isolated perfused rat hearts with hydrogen peroxide that correlated with an increase in kinase activity and cellular relocalization of PKGIα; neither response was observed in the C46S mutant. On the other hand, the nonreceptor tyrosine kinase c-Abl was shown to be inactivated by modification of cysteine residues by thiol alkylating agents and S-glutathionylation [51]. Other kinases that have been shown to be regulated by cysteine modification include IKKβ and MEKK1 (reviewed in [49,52]).…”