Monitoring global protein thiol-oxidation and protein S- mycothiolation in Mycobacterium smegmatis under hypochlorite stress

• Verfasst von: Hillion, Melanie [VerfasserIn]
• Verfasst von: Wirtz, Markus [VerfasserIn]
• Verfasst von: Hell, Rüdiger [VerfasserIn]
• Titel: Monitoring global protein thiol-oxidation and protein S- mycothiolation in Mycobacterium smegmatis under hypochlorite stress
• Verf.angabe: Melanie Hillion, Jörg Bernhardt, Tobias Busche, Martina Rossius, Sandra Maaß, Dörte Becher, Mamta Rawat, Markus Wirtz, Rüdiger Hell, Christian Rückert, Jörn Kalinowski & Haike Antelmann
• Jahr: 2017
• Umfang: 20 S.
• Fussnoten: Published online: 26 April 2017 ; Gesehen am 22.06.2018
• Titel Quelle: Enthalten in: Scientific reports
• Ort Quelle: [London] : Macmillan Publishers Limited, part of Springer Nature, 2011
• Jahr Quelle: 2017
• Band/Heft Quelle: 7(2017) article number 1195, 20 Seiten
• ISSN Quelle: 2045-2322
• DOI: doi:10.1038/s41598-017-01179-4
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1576759776

Abstract

Mycothiol (MSH) is the major low molecular weight (LMW) thiol in Actinomycetes. Here, we used shotgun proteomics, OxICAT and RNA-seq transcriptomics to analyse protein S-mycothiolation, reversible thiol-oxidations and their impact on gene expression in Mycobacterium smegmatis under hypochlorite stress. In total, 58 S-mycothiolated proteins were identified under NaOCl stress that are involved in energy metabolism, fatty acid and mycolic acid biosynthesis, protein translation, redox regulation and detoxification. Protein S-mycothiolation was accompanied by MSH depletion in the thiol-metabolome. Quantification of the redox state of 1098 Cys residues using OxICAT revealed that 381 Cys residues (33.6%) showed >10% increased oxidations under NaOCl stress, which overlapped with 40 S-mycothiolated Cys-peptides. The absence of MSH resulted in a higher basal oxidation level of 338 Cys residues (41.1%). The RseA and RshA anti-sigma factors and the Zur and NrdR repressors were identified as NaOCl-sensitive proteins and their oxidation resulted in an up-regulation of the SigH, SigE, Zur and NrdR regulons in the RNA-seq transcriptome. In conclusion, we show here that NaOCl stress causes widespread thiol-oxidation including protein S-mycothiolation resulting in induction of antioxidant defense mechanisms in M. smegmatis. Our results further reveal that MSH is important to maintain the reduced state of protein thiols.