HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Nair, S. Articles by Trieu-Cuot, P. Search for Related Content PubMed PubMed Citation Articles by Nair, S. Articles by Trieu-Cuot, P. Agricola Articles by Nair, S. Articles by Trieu-Cuot, P.

Role of the Streptococcus agalactiae ClpP serine protease in heat-induced stress defence and growth arrest

¹ INSERM U411, Faculté de Médecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France
² Laboratoire Mixte Pasteur–Necker de Recherche sur les Streptocoques et Streptococcies, Faculté de Médecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France
³ INSERM U345, Faculté de Médecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France

Correspondence
Shamila Nair
nair{at}necker.fr

The main causes of microbial death after heat exposure are not well understood. Here, it is shown that the heat-shock protein ClpP plays a major role in heat-induced growth arrest in Streptococcus agalactiae. A mutant lacking the ClpP protease was more sensitive to the inhibitory effects of heat, salt and oxidative stress than the isogenic wild-type strain. During growth arrest, this mutant displayed important modifications of its total protein content, including a decreased level of essential metabolic enzymes such as the alcohol dehydrogenase. Analysis of protein carbonylation demonstrated that the ClpP protease plays a role in preventing accelerated protein oxidation. Higher levels of oxidized DnaK, a key modulator of the heat-shock regulon, were observed in the ClpP mutant and these were increased following heat shock. Accumulation of oxidized/inactivated DnaK might explain why the ClpP mutant was unable to properly synthesize DNA and proteins, and why it exhibited an aberrant cell morphology. Even though ClpP plays a minor role in the virulence of S. agalactiae in a murine infection model, the data presented here point to the importance of ClpP in oxidative stress defence in preventing heat-induced cell alterations.

The GenBank accession number for the Streptococcus agalactiae clpP gene sequence reported in this paper is AJ413168.

This article has been cited by other articles:

				A. Fredriksson, M. Ballesteros, C. N. Peterson, O. Persson, T. J. Silhavy, and T. Nystrom Decline in ribosomal fidelity contributes to the accumulation and stabilization of the master stress response regulator {sigma}S upon carbon starvation Genes & Dev., April 1, 2007; 21(7): 862 - 874. [Abstract] [Full Text] [PDF]