How widespread is stable protein S-nitrosylation as an end-effector of protein regulation?

Abstract

Over the last 25 years protein S-nitrosylation, also known more correctly as S-nitrosation, has been progressively implicated in virtually every nitric oxide-regulated process within the cardiovascular system. The current, widely-held paradigm is that S-nitrosylation plays an equivalent role as phosphorylation, providing a stable and controllable post-translational modification that directly regulates end-effector target proteins to elicit biological responses. However, this concept largely ignores the intrinsic instability of the nitrosothiol bond, which rapidly reacts with typically abundant thiol-containing molecules to generate more stable disulfide bonds. These protein disulfides, formed via a nitrosothiol intermediate redox state, are rationally anticipated to be the predominant endeffector modification that mediates functional alterations when cells encounter nitrosative stimuli. In this review we present evidence and explain our reasoning for arriving at this conclusion that may be controversial to some researchers in the field.

Regulation of protein function by S-nitrosation and S-glutathionylation: processes and targets in cardiovascular pathophysiology

“…A number of studies have focused on the mechanistic aspects of protein nitrosation (see e.g. Wolhuter and Eaton, 2017), however it has been shown that de-nitrosation reactions also play critical roles in the control of nitrosated proteins levels as well as of NO release. In the specific case of S-nitrosation, the formed S-nitrosothiols (RSNOs) can undergo spontaneous or assisted trans-nitrosations, resulting in the transfer of the NO moiety from high molecular weight (protein) thiols to low molecular ones, and inversely.…”

“…Conversely, as the intrinsic instability of the nitrosothiol bond facilitates its rapid reaction with other species to generate more stable disulfide bonds, it has been suggested that protein (mixed) disulfides formed in this way, via a nitrosothiol intermediate redox state, likely represent the end modifications actually mediating functional alterations in target proteins (Wolhuter and Eaton, 2017). There are emerging data suggesting that both PTMs play an important role in cardioprotection, for they not only lead to changes in protein structure and function but also protect these thiol(s) from further irreversible oxidative/nitrosative modification.…”

“…Finally, an emerging concept suggests that S-nitrosation could be considered as an intermediate step to S-glutathionylation (Wolhuter and Eaton, 2017). Indeed, the S-nitrosothiol itself represents another activated form of the protein cysteine thiol, and can react with GSH leading to S-glutathionylation (i):…”

Detection of ROS Induced Proteomic Signatures by Mass Spectrometry

“…The formation of S-nitrosylation on thiol groups can occur directly through interaction with NO, indirectly through ONOO − and there are also reports of transfer of nitrosyl or transnitrosylation by the actions of proteins, such as thioredoxins (Benhar, 2015). S-nitrosylation on target proteins is considered an important mechanism for NO signaling transduction and there are a large number of articles identifying specific Cysteine residues as S-nitrosylation targets in a variety of cellular systems from plants to cardiovascular systems (Hess et al, 2005), however as this PTM is reversible and highly labile PTM it has been suggested as an intermediate in the formation of disulphide bonds (Wolhuter and Eaton, 2017). Identification of S-nitrosylation is generally performed using a combination of selective reduction of S-nitrosylation proteins and labeling with a more stable reagent (Jaffrey and Snyder, 2001).…”

Stimulation of brain nicotinic acetylcholine receptors activates adrenomedullary outflow via brain inducible NO synthase‐mediated S‐nitrosylation

“…One is the NO‐induced activation of soluble guanylate cyclase (sGC), thereby producing cGMP and activating (Kots et al, ). Another mechanism is mediated through S ‐nitrosylation, which is a posttranslational modification of protein cysteine residues that alters the functions of many target proteins (Jaffrey et al, ; Hess et al, ; Wolhuter and Eaton, ; Koriyama and Furukawa, ).…”