This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Susin, M. F.
Right arrow Articles by Gomes, S. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Susin, M. F.
Right arrow Articles by Gomes, S. L.

 Previous Article  |  Next Article 

Journal of Bacteriology, December 2006, p. 8044-8053, Vol. 188, No. 23
0021-9193/06/$08.00+0     doi:10.1128/JB.00824-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

GroES/GroEL and DnaK/DnaJ Have Distinct Roles in Stress Responses and during Cell Cycle Progression in Caulobacter crescentus{triangledown}

Michelle F. Susin, Regina L. Baldini, Frederico Gueiros-Filho, and Suely L. Gomes*

Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil

Received 9 June 2006/ Accepted 6 September 2006

Misfolding and aggregation of protein molecules are major threats to all living organisms. Therefore, cells have evolved quality control systems for proteins consisting of molecular chaperones and proteases, which prevent protein aggregation by either refolding or degrading misfolded proteins. DnaK/DnaJ and GroES/GroEL are the best-characterized molecular chaperone systems in bacteria. In Caulobacter crescentus these chaperone machines are the products of essential genes, which are both induced by heat shock and cell cycle regulated. In this work, we characterized the viabilities of conditional dnaKJ and groESL mutants under different types of environmental stress, as well as under normal physiological conditions. We observed that C. crescentus cells with GroES/EL depleted are quite resistant to heat shock, ethanol, and freezing but are sensitive to oxidative, saline, and osmotic stresses. In contrast, cells with DnaK/J depleted are not affected by the presence of high concentrations of hydrogen peroxide, NaCl, and sucrose but have a lower survival rate after heat shock, exposure to ethanol, and freezing and are unable to acquire thermotolerance. Cells lacking these chaperones also have morphological defects under normal growth conditions. The absence of GroE proteins results in long, pinched filamentous cells with several Z-rings, whereas cells lacking DnaK/J are only somewhat more elongated than normal predivisional cells, and most of them do not have Z-rings. These findings indicate that there is cell division arrest, which occurs at different stages depending on the chaperone machine affected. Thus, the two chaperone systems have distinct roles in stress responses and during cell cycle progression in C. crescentus.

* Corresponding author. Mailing address: Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brasil. Phone: 55-11-3091-3826. Fax: 55-11-3091-2186. E-mail: sulgomes{at}iq.usp.br.

{triangledown} Published ahead of print on 15 September 2006.

Journal of Bacteriology, December 2006, p. 8044-8053, Vol. 188, No. 23
0021-9193/06/$08.00+0     doi:10.1128/JB.00824-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Dori-Bachash, M., Dassa, B., Pietrokovski, S., Jurkevitch, E. (2008). Proteome-Based Comparative Analyses of Growth Stages Reveal New Cell Cycle-Dependent Functions in the Predatory Bacterium Bdellovibrio bacteriovorus. Appl. Environ. Microbiol. 74: 7152-7162 [Abstract] [Full Text]  
  • Fujiwara, K., Taguchi, H. (2007). Filamentous Morphology in GroE-Depleted Escherichia coli Induced by Impaired Folding of FtsE. J. Bacteriol. 189: 5860-5866 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»