The extracellular proteome of Bacillus subtilis under secretion stress conditions.
The accumulation of malfolded proteins in the cell envelope of the Gram-positive eubacterium Bacillus subtilis was previously shown to provoke a so-called secretion stress response. In the present studies, proteomic approaches were employed to identify changes in the extracellular proteome of B. subtilis in response to secretion stress. The data shows that, irrespective of the way in which secretion stress is imposed on the cells, the levels of only two extracellular proteins, HtrA and YqxI, display major variations in a parallel manner. Whereas the extracellular level of the HtrA protease is determined through transcriptional regulation, the level of YqxI in the growth medium is determined post-transcriptionally in an HtrA-dependent manner. In the absence of secretion stress, the extracellular levels of HtrA and YqxI are low because of extracytoplasmic proteolysis. Finally, the protease active site of HtrA is dispensable for post-transcriptional YqxI regulation. It is known that Escherichia coli HtrA has combined protease and chaperone-like activities. As this protein shares a high degree of similarity with B. subtilis HtrA, it can be hypothesized that both activities are conserved in B. subtilis HtrA. Thus, a chaperone-like activity of B. subtilis HtrA could be involved in the appearance of YqxI on the extracellular proteome.
Antelmann
Haike
H
Institut für Mikrobiologie und Molekularbiologie, Ernst-Moritz-Arndt-Universität Greifswald, F. -L. -Jahn-Str. 15, D-17487 Greifswald, Germany.
Darmon
Elise
E
Noone
David
D
Veening
Jan-Willem
JW
Westers
Helga
H
Bron
Sierd
S
Kuipers
Oscar P
OP
Devine
Kevin M
KM
Hecker
Michael
M
van Dijl
Jan Maarten
JM
D000217:Acyltransferases; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D033903:Periplasmic Proteins / Q000235:genetics / Q000378:metabolism*; D017510:Protein Folding; D020543:Proteome / Q000032:analysis*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D003470:Culture Media; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D033903:Periplasmic Proteins; D020543:Proteome; D011993:Recombinant Fusion Proteins; D000217:Acyltransferases; C492237:LpxL protein, E coli; C118473:LpxL protein, bacteria; C061682:DegP protease; D012697:Serine Endopeptidases