AUTHOR=Madeira Jean-Paul , Alpha-Bazin Béatrice , Armengaud Jean , Duport Catherine 

TITLE=Time dynamics of the Bacillus cereus exoproteome are shaped by cellular oxidation

JOURNAL=Frontiers in Microbiology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.00342

DOI=10.3389/fmicb.2015.00342

ISSN=1664-302X

ABSTRACT=<p>At low density, <italic>Bacillus cereus</italic> cells release a large variety of proteins into the extracellular medium when cultivated in pH-regulated, glucose-containing minimal medium, either in the presence or absence of oxygen. The majority of these exoproteins are putative virulence factors, including toxin-related proteins. Here, <italic>B. cereus</italic> exoproteome time courses were monitored by nanoLC-MS/MS under low-oxidoreduction potential (ORP) anaerobiosis, high-ORP anaerobiosis, and aerobiosis, with a specific focus on oxidative-induced post-translational modifications of methionine residues. Principal component analysis (PCA) of the exoproteome dynamics indicated that toxin-related proteins were the most representative of the exoproteome changes, both in terms of protein abundance and their methionine sulfoxide (Met(O)) content. PCA also revealed an interesting interconnection between toxin-, metabolism-, and oxidative stress–related proteins, suggesting that the abundance level of toxin-related proteins, and their Met(O) content in the <italic>B. cereus</italic> exoproteome, reflected the cellular oxidation under both aerobiosis and anaerobiosis.</p>