Journal article
The WalRK Two-Component System Is Essential for Proper Cell Envelope Biogenesis in Clostridioides difficile
Journal of bacteriology, Vol.204(6), pp.e0012122-e0012122
05/16/2022
DOI: 10.1128/jb.00121-22
PMCID: PMC9210968
PMID: 35575581
Abstract
The WalR-WalK two-component regulatory system (TCS) is found in all
, in which it regulates the expression of multiple genes required for remodeling the cell envelope during growth and division. Unlike most TCSs, WalRK is essential for viability, so it has attracted interest as a potential antibiotic target. In this study, we used overexpression of WalR and CRISPR interference to investigate the Wal system of Clostridioides difficile, a major cause of hospital-associated diarrhea in high-income countries. We confirmed that the
operon is essential and identified morphological defects and cell lysis as the major terminal phenotypes of altered
expression. We also used transcriptome sequencing (RNA-seq) to identify over 150 genes whose expression changes in response to WalR levels. This gene set is enriched in cell envelope genes and includes genes encoding several predicted PG hydrolases and proteins that could regulate PG hydrolase activity. A distinct feature of the C. difficile cell envelope is the presence of an S-layer, and we found that WalR affects expression of several genes which encode S-layer proteins. An unexpected finding was that some Wal-associated phenotypic defects were inverted in comparison to what has been reported for other
. For example, downregulation of Wal signaling caused C. difficile cells to become longer rather than shorter, as in Bacillus subtilis. Likewise, downregulation of Wal rendered C. difficile more sensitive to vancomycin, whereas reduced Wal activity is linked to increased vancomycin resistance in Staphylococcus aureus.
The WalRK two-component system (TCS) is essential for coordinating synthesis and turnover of peptidoglycan in
. We investigated the WalRK TCS in Clostridioides difficile, an important bacterial pathogen with an atypical cell envelope. We confirmed that WalRK is essential and regulates cell envelope biogenesis, although several of the phenotypic changes we observed were opposite to what has been reported for other
. We also identified over 150 genes whose expression is controlled either directly or indirectly by WalR. Overall, our findings provide a foundation for future investigations of an important regulatory system and potential antibiotic target in C. difficile.
Details
- Title: Subtitle
- The WalRK Two-Component System Is Essential for Proper Cell Envelope Biogenesis in Clostridioides difficile
- Creators
- Ute Müh - University of IowaCraig D Ellermeier - University of IowaDavid S Weiss - Department of Microbiology and Immunology, University of Iowagrid.214572.7, Iowa City, Iowa, USA
- Resource Type
- Journal article
- Publication Details
- Journal of bacteriology, Vol.204(6), pp.e0012122-e0012122
- DOI
- 10.1128/jb.00121-22
- PMID
- 35575581
- PMCID
- PMC9210968
- NLM abbreviation
- J Bacteriol
- ISSN
- 0021-9193
- eISSN
- 1098-5530
- Grant note
- R01 AI087834 / NIAID NIH HHS R01 AI155492 / NIAID NIH HHS
- Language
- English
- Date published
- 05/16/2022
- Academic Unit
- Microbiology and Immunology
- Record Identifier
- 9984297327402771
Metrics
22 Record Views