Accessibility navigation


The CtsR regulator of Listeria monocytogenes contains a variant glycine repeat region that affects piezotolerance, stress resistance, motility and virulence

Karatzas, K.-A., Wouters, J. A., Gahan, C. G. M. , Hill, C. , Tjakko, A. and Bennik, M. H. J. (2003) The CtsR regulator of Listeria monocytogenes contains a variant glycine repeat region that affects piezotolerance, stress resistance, motility and virulence. Molecular Microbiology, 49 (5). pp. 1227-1238. ISSN 0950-382X

Full text not archived in this repository.

To link to this item DOI: 10.1046/j.1365-2958.2003.03636.x

Abstract/Summary

A spontaneous high hydrostatic pressure (HHP)-tolerant mutant of Listeria monocytogenes ScottA, named AK01, was isolated previously. This mutant was immotile and showed increased resistance to heat, acid and H2O2 compared with the wild type (wt) (Karatzas, K.A.G. and Bennik, M.H.J. 2002 Appl Environ Microbiol 68: 3183–3189). In this study, we conclusively linked the increased HHP and stress tolerance of strain AK01 to a single codon deletion in ctsR (class three stress gene repressor) in a region encoding a highly conserved glycine repeat. CtsR negatively regulates the expression of the clp genes, including clpP, clpE and the clpC operon (encompassing ctsR itself), which belong to the class III heat shock genes. Allelic replacement of the ctsR gene in the wt background with the mutant ctsR gene, designated ctsRΔGly, rendered mutants with phenotypes and protein expression profiles identical to those of strain AK01. The expression levels of CtsR, ClpC and ClpP proteins were significantly higher in ctsRΔGly mutants than in the wt strain, indicative of the CtsRΔGly protein being inactive. Further evidence that the CtsRΔGly protein lacks its repressor function came from the finding that the Clp proteins in the mutant were not further induced upon heat shock, and that HHP tolerance of a ctsR deletion strain was as high as that of a ctsRΔGly mutant. The high HHP tolerance possibly results from the increased expression of the clp genes in the absence of (active) CtsR repressor. Importantly, the strains expressing CtsRΔGly show significantly attenuated virulence compared with the wt strain; however, no indication of disregulation of PrfA in the mutant strains was found. Our data highlight an important regulatory role of the glycine-rich region of CtsR in stress resistance and virulence.

Item Type:Article
Refereed:Yes
Divisions:Faculty of Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences > Food Microbial Sciences Research Group
ID Code:29202
Publisher:Wiley-Blackwell

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation