Molecular recognition of S-nitrosothiol substrate by its cognate protein denitrosylase.
Protein S-nitrosylation mediates a large part of nitric oxide's influence on cellular function by providing a fundamental mechanism to control protein function across different species and cell types. At steady state, cellular S-nitrosylation reflects dynamic equilibria between S-nitrosothiols (SNOs) in proteins and small molecules (low-molecular-weight SNOs) whose levels are regulated by dedicated S-nitrosylases and denitrosylases. S-Nitroso-CoA (SNO-CoA) and its cognate denitrosylases, SNO-CoA reductases (SCoRs), are newly identified determinants of protein S-nitrosylation in both yeast and mammals. Because SNO-CoA is a minority species among potentially thousands of cellular SNOs, SCoRs must preferentially recognize this SNO substrate. However, little is known about the molecular mechanism by which cellular SNOs are recognized by their cognate enzymes. Using mammalian cells, molecular modeling, substrate-capture assays, and mutagenic analyses, we identified a single conserved surface Lys (Lys-127) residue as well as active-site interactions of the SNO group that mediate recognition of SNO-CoA by SCoR. Comparing SCoRK127A versus SCoRWT HEK293 cells, we identified a SNO-CoA-dependent nitrosoproteome, including numerous metabolic protein substrates. Finally, we discovered that the SNO-CoA/SCoR system has a role in mitochondrial metabolism. Collectively, our findings provide molecular insights into the basis of specificity in SNO-CoA-mediated metabolic signaling and suggest a role for SCoR-regulated S-nitrosylation in multiple metabolic processes.
['Stomberski|Colin T|CT|', 'Zhou|Hua-Lin|HL|', 'Wang|Liwen|L|', 'van den Akker|Focco|F|', 'Stamler|Jonathan S|JS|']
D000818:Animals D057809:HEK293 Cells D006801:Humans D051379:Mice D018345:Mice, Knockout D008958:Models, Molecular D009569:Nitric Oxide D010088:Oxidoreductases D011499:Protein Processing, Post-Translational D059748:Proteolysis D040901:Proteomics D026403:S-Nitrosothiols D013379:Substrate Specificity
denitrosylase S-nitrosylation nitric oxide SNO-CoA SCoR AKR1A1 coenzyme A (CoA) denitrosylation enzyme kinetics mutagenesis