Protein CoAlation: a redox-regulated protein modification by coenzyme A in mammalian cells

Abstract

Coenzyme A (CoA) is an obligatory cofactor in all branches of life. CoA and its derivatives are involved in major metabolic pathways, allosteric interactions and the regulation of gene expression. Abnormal biosynthesis and homeostasis of CoA and its derivatives have been associated with various human pathologies, including cancer, diabetes and neurodegeneration. Using an anti-CoA monoclonal antibody and mass spectrometry, we identified a wide range of cellular proteins which are modified by covalent attachment of CoA to cysteine thiols (CoAlation). We show that protein CoAlation is a reversible post-translational modification that is induced in mammalian cells and tissues by oxidising agents and metabolic stress. Many key cellular enzymes were found to be CoAlated in vitro and in vivo in ways that modified their activities. Our study reveals that protein CoAlation is a widespread post-translational modification which may play an important role in redox regulation under physiological and pathophysiological conditions.

Glyceraldehyde‐3‐phosphate dehydrogenase from Citrobacter sp. S‐77 is post‐translationally modified by CoA (protein CoAlation) under oxidative stress

“…D clearly showed the characteristic peaks of CoA fragments from the precursor ion as indicated by the loss of 410, 428 and 508 Da (Fig. C,D), as has been observed in the recently reported publication . The peptide peaks of corresponding precursor ions minus CoA fragments (−409, −427 and −507 Da) were also abundant in the MS/MS spectrum.…”

“…In our case, the treatment with CoASSCoA even at micromolar concentrations led to inactivation of CbGAPDH, whereas 10 mM GSSG, which is much higher than the physiological concentration, was required for complete inactivation of the enzyme. Consistently, it has been shown that the physiological concentration of GSSG is unlikely to lead to S-glutathionylation of GAPDH [6,33,34]. Although the significance of a CoASSCoAmediated mechanism in vivo remains unclear, accumulation of an intercellular concentration of CoASSCoA under oxidative stress would be a cause of CoAlation of CbGAPDH.…”

“…The target cysteine residues of CoAlation in mammalian GAPDH were identified as Cys23 and Cys245, both of which are not conserved but are cysteine residues specific to mammalian GAPDH (Fig. S1) . It was demonstrated that Sa GAPDH is CoAlated at active‐site Cys151 and GapA2 isoform is CoAlated at noncatalytic Cys202 .…”

“…For instance, 3-hydroxymethylglutaryl coenzyme A reductase was rapidly (t 1/2 < 2 min) and completely inactivated reversibly with 1.5 lM CoASSCoA [48], and the activity of phosphofructokinase was reduced to 15% with > 2 h incubation of 46 lM CoASSCoA [49]. Mammalian creatine kinase, GAPDH, isocitrate dehydrogenase and pyruvate dehydrogenase kinase were also reversibly inactivated by CoASSCoA, with varying extents of inactivation [6]. In our case, the treatment with CoASSCoA even at micromolar concentrations led to inactivation of CbGAPDH, whereas 10 mM GSSG, which is much higher than the physiological concentration, was required for complete inactivation of the enzyme.…”

“…Protein S‐thiolation is an important redox post‐translational modification that involves formation of mixed disulphides between the redox‐sensitive cysteines of proteins and cellular low‐molecular‐weight thiols, such as glutathione (GSH), cysteine (Cys), bacillithiol, mycothiol and coenzyme A (CoA) . This modification can protect protein thiols against irreversible oxidation and functions via a redox‐controlled mechanism to regulate the activity and functions of thiol proteins in response to oxidative and nitrosative stresses .…”