JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
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 Langen, G. R.
Right arrow Articles by Howard, S. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Langen, G. R.
Right arrow Articles by Howard, S. P.

 Previous Article  |  Next Article 

Journal of Bacteriology, September 2001, p. 5230-5238, Vol. 183, No. 18
0021-9193/01/$04.00+0   DOI: 10.1128/JB.183.18.5230-5238.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.

Absence of the Outer Membrane Phospholipase A Suppresses the Temperature-Sensitive Phenotype of Escherichia coli degP Mutants and Induces the Cpx and sigma E Extracytoplasmic Stress Responses

Geoffrey R. Langen,1 Jill R. Harper,2 Thomas J. Silhavy,2 and S. Peter Howard1,*

Department of Biology, University of Regina, Regina, Saskatchewan, Canada S4S 0A2,1 and Department of Molecular Biology, Princeton University, Princeton, New Jersey 085442

Received 17 April 2001/Accepted 26 June 2001

DegP is a periplasmic protease that is a member of both the sigma E and Cpx extracytoplasmic stress regulons of Escherichia coli and is essential for viability at temperatures above 42°C. [U-14C]acetate labeling experiments demonstrated that phospholipids were degraded in degP mutants at elevated temperatures. In addition, chloramphenicol acetyltransferase, beta -lactamase, and beta -galactosidase assays as well as sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated that large amounts of cellular proteins are released from degP cells at the nonpermissive temperature. A mutation in pldA, which encodes outer membrane phospholipase A (OMPLA), was found to rescue degP cells from the temperature-sensitive phenotype. pldA degP mutants had a normal plating efficiency at 42°C, displayed increased viability at 44°C, showed no degradation of phospholipids, and released far lower amounts of cellular protein to culture supernatants. degP and pldA degP mutants containing chromosomal lacZ fusions to Cpx and sigma E regulon promoters indicated that both regulons were activated in the pldA mutants. The overexpression of the envelope lipoprotein, NlpE, which induces the Cpx regulon, was also found to suppress the temperature-sensitive phenotype of degP mutants but did not prevent the degradation of phospholipids. These results suggest that the absence of OMPLA corrects the degP temperature-sensitive phenotype by inducing the Cpx and sigma E regulons rather than by inactivating the phospholipase per se.

* Corresponding author. Mailing address: Department of Biology, University of Regina, 3737 Wascana Pkwy., Regina, Saskatchewan S4S 0A2, Canada. Phone: (306) 585-5223. Fax: (306) 585-4894. E-mail: peter.howard{at}uregina.ca.

Journal of Bacteriology, September 2001, p. 5230-5238, Vol. 183, No. 18
0021-9193/01/$04.00+0   DOI: 10.1128/JB.183.18.5230-5238.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2001 by the American Society for Microbiology. All rights reserved.