Stabilization of cell wall proteins in Bacillus subtilis: A proteomic approach

Abstract

Even though cell wall proteins of Bacillus subtilis are characterized by specific cell wall retention signals, some of these are also components of the extracellular proteome. In contrast to the majority of extracellular proteins, wall binding proteins disappeared from the extracellular proteome during the stationary phase and are subjected to proteolysis. Thus, the extracellular proteome of the multiple protease-deficient strain WB700 was analyzed which showed an increased stability of secreted WapA processing products during the stationary phase. In addition, stabilization of the WapA processing products was observed also in a sigD mutant strain which is impaired in motility and cell wall turnover. Next, we analyzed if proteins that can be extracted from B. subtilis cell walls are stabilized in the WB700 strain as well as in the sigD mutant. Thus, the cell wall proteome of B. subtilis wild type was defined showing most abundantly cell wall binding proteins (CWBPs) resulting from the WapA and WprA precursor processing. The inactivation of extracellular proteases as well as SigmaD caused an increase of CWBP105 and a decrease of CWBP62 in the cell wall proteome. We conclude that WapA processing products are substrates for the extracellular proteases which are stabilized in the absence of sigD due to an impaired cell wall turnover.

Selective Contribution of the Twin-Arginine Translocation Pathway to Protein Secretion in Bacillus subtilis

“…On the other hand, pre-PhoD is processed at a very low rate and substantial amounts of this protein can be detected at the membrane-cell wall interface (43). As no Tat-dependently exported proteins are detectable on the cell wall proteome of B. subtilis (44), it is the aim of our ongoing research to determine to what extent the Tat pathway of B. subtilis is involved in the biogenesis of membrane proteins. assistance, and H. Tjalsma, G. Venema, and members of the ExporteRRs consortium for stimulating discussions.…”

Characterization of new l,d-endopeptidase gene product CwlK (previous YcdD) that hydrolyzes peptidoglycan in Bacillus subtilis

“…3), and some cell wall hydrolases are degraded by several proteases (Antelmann et al 2002;Yamamoto et al 2003), it is better to use Western blotting for the detection of CwlK. A protease-deficient mutant, cdD3FL (cwlK::cwlK-3xFLAG wprA epr), which has the cwlK-3xFLAG translational gene instead of original cwlK, was constructed for Western blotting.…”

Alkaline Serine Protease AprE Plays an Essential Role in Poly-γ-glutamate Production during Natto Fermentation

“…12) Although the levels of most extracellular proteins were not affected in the WB700 strain, the levels of some proteins, the WapA-and YvcE-processing form, increased. 13) This result suggests that released forms of the cell wall-associated WapA and YvcE were degraded by extracellular proteases.…”