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Anatomy of the bacillus subtilis cell envelope stress response
| Content Provider | Semantic Scholar |
|---|---|
| Author | Radeck, Jara |
| Copyright Year | 2017 |
| Abstract | The bacterial cell wall withstands the turgor pressure and is an essential structure for most bacteria. The lipid II cycle is responsible for transporting cell wall building blocks across the cytoplasmic membrane by means of the carrier molecule undecaprenyl phosphate (UP). One essential step is the recycling of undecaprenyl pyrophosphate (UPP) to UP by UPP phosphatases. This step is targeted by bacitracin, an UPP-binding anti-microbial peptide (AMP). In the course of this thesis, the effect of deletion and depletion of bacitracin resistance modules and UPP phosphatase genes on the cell envelope stress response in Bacillus subtilis was evaluated. The main resistance determinant against bacitracin, the ABC-transporter BceAB was found to be homeostatically regulated “to need” by flux-sensing of its own activity. The full effect of the secondary layer of resistance determinants, consisting of the UPP phosphatase BcrC and the phage shock protein-like response of the Lia-system, is only revealed in the absence of BceAB. For the first time, a resistance phenotype for LiaIH toward bacitracin was reported. The genes uppP and bcrC encode UPP phosphatases and were found to be synthetic lethal. Depletion of either UPP phosphatase in a double mutant background lead to bulging cells in exponential growth phase. BcrC is the main UPP phosphatase during growth. In contrast, UppP is primarily responsible for normal sporulation. The generation of UP in the lipid II cycle is essential and can be impaired by (i) addition of the UPP-binding AMP bacitracin, (ii) deletion and depletion of UPP phosphatases (BcrC and UppP), or, to a limited degree, (iii) deletion of the undecaprenol kinase (UDPK) DgkA. There is a marked difference in the CESR toward these challenges: while the addition of bacitracin activates two damage driven promoters, PliaI and PbcrC, a lack of UPP phosphatases or DgkA is only detected by the latter. This indicates that the blocking of UPP with bacitracin has a different effect on the cell envelope than the shortage of UPP phosphatases. Our analysis of the dephosphorylation of UPP in B. subtilis lays another cornerstone for the holistic understanding of the lipid II cycle. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://edoc.ub.uni-muenchen.de/21630/1/Radeck_Jara.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
