iProXProteomicsBaolin SunStaphylococcus Aureushttp://www.iprox.org/page/project.html?id=IPX0006165000sunb@ustc.edu.cnUniversity of Science and Technology of ChinaiProXTreatment of Staphylococcus aureus infections is a constant challenge due to emerging resistance to vancomycin, a last-resort drug. S-nitrosylation, the covalent attachment of a nitric oxide (NO) group to a cysteine thiol, mediates redox-based signaling for eukaryotic cellular functions. However, its role in bacteria is largely unknown. Here, proteomic analysis revealed that S-nitrosylation is a prominent growth feature of vancomycin-intermediate S. aureus. Deletion of NO synthase (NOS) or removal of S-nitrosylation from the redox-sensitive regulator MgrA or WalR resulted in thinner cell walls and increased vancomycin susceptibility, which was due to attenuated promoter binding and released repression of genes involved in cell wall metabolism. These genes failed to respond to H₂O₂-induced oxidation, suggesting distinct transcriptional responses to alternative modifications of the cysteine residue. Furthermore, treatment with a NOS inhibitor significantly decreased vancomycin resistance in S. aureus. This study reveals that transcriptional regulation via S-nitrosylation underlies a mechanism for NO-mediated bacterial antibiotic resistance.Transcription tuned by S-nitrosylation underlies a mechanism for Staphylococcus aureus to circumvent vancomycin killing.Shu Xueqin X, Shi Yingying Y, Huang Yi Y, Yu Dan D, Sun Baolin BfalseS-nitrosylated cysteine residues identification in Staphylococcus aureus XN108Staphylococcus aureus is a major human pathogen that causes diverse severe infections. The emergence of multi-drug resistance has caused S. aureus infection a global concern, especially resistance to vancomycin, a drug of last resort. A growing body of research focuses on the resistance mechanisms and antibiotic discovery. S-nitrosylation, a posttranslational modification on cysteine thiol mediated by Nitric oxide (NO) has been found to drive a large part of the ubiquitous influence of NO on mediating cellular functions. Several gram-positive microorganisms, including S. aureus, possess a bacterial NO synthase (bNOS) to generate NO endogenously. bNOS was reported to play an important role in protecting bacteria against a wide spectrum of antibiotics, but the precise underlying mechanism remains elusive. Here, S-nitrosylation patterns were analyzed in a clinically isolated vancomycin-intermediate staphylococcus aureus strain XN108 by liquid chromatography-mass spectrometry (LC-MS)/MS. The MS data of samples XN_1 and XN_2 were integrated and analyzed.Mon Mar 27 00:00:00 GMT+01:00 2023PXD041143128037085493