Header

UZH-Logo

Maintenance Infos

The Streptococcus mutans serine/threonine kinase, PknB, regulates competence development, bacteriocin production, and cell wall metabolism


Banu, L D; Conrads, G; Rehrauer, H; Hussain, H; Allan, E; van der Ploeg, J R (2010). The Streptococcus mutans serine/threonine kinase, PknB, regulates competence development, bacteriocin production, and cell wall metabolism. Infection and Immunity, 78(5):2209-2220.

Abstract

Bacteria can detect, transmit, and react to signals from the outside world by using two-component systems (TCS) and serine-threonine kinases and phosphatases. Streptococcus mutans contains one serine-threonine kinase, encoded by pknB. A gene encoding a serine-threonine phosphatase, pppL, is located upstream of pknB. In this study, the phenotypes of pknB and pppL single mutants and a pknB pppL double mutant were characterized. All mutants exhibited a reduction in genetic transformability and biofilm formation, showed abnormal cell shapes, grew slower than the wild-type strain in several complex media, and exhibited reduced acid tolerance. The mutants had reduced cariogenic capacity but no significant defects in colonization in a rat caries model. Whole-genome transcriptome analysis revealed that a pknB mutant showed reduced expression of genes involved in bacteriocin production and genetic competence. Among the genes that were differentially regulated in the pknB mutant, several were likely to be involved in cell wall metabolism. One such gene, SMU.2146c, and two genes encoding bacteriocins were shown to also be downregulated in a vicK mutant, which encodes a sensor kinase involved in the response to oxidative stress. Collectively, the results lead us to speculate that PknB may modulate the activity of the two-component signal transduction systems VicKR and ComDE. Real-time reverse transcriptase PCR (RT-PCR) showed that genes downregulated in the pknB mutant were upregulated in the pppL mutant, indicating that PppL serves to counteract PknB.

Abstract

Bacteria can detect, transmit, and react to signals from the outside world by using two-component systems (TCS) and serine-threonine kinases and phosphatases. Streptococcus mutans contains one serine-threonine kinase, encoded by pknB. A gene encoding a serine-threonine phosphatase, pppL, is located upstream of pknB. In this study, the phenotypes of pknB and pppL single mutants and a pknB pppL double mutant were characterized. All mutants exhibited a reduction in genetic transformability and biofilm formation, showed abnormal cell shapes, grew slower than the wild-type strain in several complex media, and exhibited reduced acid tolerance. The mutants had reduced cariogenic capacity but no significant defects in colonization in a rat caries model. Whole-genome transcriptome analysis revealed that a pknB mutant showed reduced expression of genes involved in bacteriocin production and genetic competence. Among the genes that were differentially regulated in the pknB mutant, several were likely to be involved in cell wall metabolism. One such gene, SMU.2146c, and two genes encoding bacteriocins were shown to also be downregulated in a vicK mutant, which encodes a sensor kinase involved in the response to oxidative stress. Collectively, the results lead us to speculate that PknB may modulate the activity of the two-component signal transduction systems VicKR and ComDE. Real-time reverse transcriptase PCR (RT-PCR) showed that genes downregulated in the pknB mutant were upregulated in the pppL mutant, indicating that PppL serves to counteract PknB.

Statistics

Citations

37 citations in Web of Science®
33 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

195 downloads since deposited on 16 Jul 2010
23 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Functional Genomics Center Zurich
04 Faculty of Medicine > Center for Dental Medicine > Institute of Oral Biology
08 University Research Priority Programs > Systems Biology / Functional Genomics
Dewey Decimal Classification:570 Life sciences; biology
610 Medicine & health
Language:English
Date:May 2010
Deposited On:16 Jul 2010 15:57
Last Modified:07 Dec 2017 02:58
Publisher:American Society for Microbiology
ISSN:0019-9567
Free access at:PubMed ID. An embargo period may apply.
Publisher DOI:https://doi.org/10.1128/IAI.01167-09
Official URL:http://iai.asm.org/cgi/content/full/78/5/2209?view=long&pmid=20231406
PubMed ID:20231406

Download