Monitoring global protein thiol-oxidation and protein S- mycothiolation in Mycobacterium smegmatis under hypochlorite stress
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 stre...
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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
2017
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| In: |
Scientific reports
Year: 2017, Volume: 7, Pages: 1195 |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-017-01179-4 |
| Online Access: | Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1038/s41598-017-01179-4 Verlag, kostenfrei, Volltext: https://www.nature.com/articles/s41598-017-01179-4 
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| Author Notes: | Melanie Hillion, Jörg Bernhardt, Tobias Busche, Martina Rossius, Sandra Maaß, Dörte Becher, Mamta Rawat, Markus Wirtz, Rüdiger Hell, Christian Rückert, Jörn Kalinowski & Haike Antelmann |
| Summary: | 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. |
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| Item Description: | Published online: 26 April 2017 Gesehen am 22.06.2018 |
| Physical Description: | Online Resource |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-017-01179-4 |