S-cysteinylation is a general mechanism for thiol protection of Bacillus subtilis proteins after oxidative stress.
S-Thiolation is crucial for protection and regulation of thiol-containing proteins during oxidative stress and is frequently achieved by the formation of mixed disulfides with glutathione. However, many Gram-positive bacteria including Bacillus subtilis lack the low molecular weight (LMW) thiol glutathione. Here we provide evidence that S-thiolation by the LMW thiol cysteine represents a general mechanism in B. subtilis. In vivo labeling of proteins with [(35)S]cysteine and nonreducing two-dimensional PAGE analyses revealed that a large subset of proteins previously identified as having redox-sensitive thiols are modified by cysteine in response to treatment with the thiol-specific oxidant diamide. By means of multidimensional shotgun proteomics, the sites of S-cysteinylation for six proteins could be identified, three of which are known to be S-glutathionylated in other organisms.
Hochgräfe
Falko
F
Institute for Microbiology, Ernst-Moritz-Arndt-University Greifswald, D-17487 Greifswald, Germany.
Mostertz
Jörg
J
Pöther
Dierk-Christoph
DC
Becher
Dörte
D
Helmann
John D
JD
Hecker
Michael
M
D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000032:analysis / Q000378:metabolism*; D003545:Cysteine / Q000032:analysis / Q000378:metabolism*; D003958:Diamide / Q000032:analysis / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D005978:Glutathione / Q000172:deficiency / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D011499:Protein Processing, Post-Translational / Q000502:physiology*
D001426:Bacterial Proteins; D003958:Diamide; D005978:Glutathione; D003545:Cysteine