This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gentz, R Articles by Ibrahimi, I Search for Related Content PubMed PubMed Citation Articles by Gentz, R Articles by Ibrahimi, I

 Previous Article  |  Next Article 

J Bacteriol. 1988 May; 170(5): 2212-2220

research-article

Association of degradation and secretion of three chimeric polypeptides in Escherichia coli.

F. Hoffmann La Roche & Co. A.G., Basel, Switzerland.

ABSTRACT

We investigated the stability of fusion proteins composed of the signal peptide of the heat-labile enterotoxin of Escherichia coli and three polypeptides: the bacterial cytoplasmic chloramphenicol acetyltransferase, the mouse dihydrofolate reductase, and human immune interferon. We demonstrate that these proteins are rapidly degraded as a result of being targeted to the secretion apparatus of E. coli, with the extent of degradation varying among the three fusion proteins. Four lines of experimental evidence are presented in support of this suggestion. First, the chimeric polypeptides containing a functional signal peptide were detected in low amounts in vivo. When a mutation was introduced in the signal peptide, resulting in lack of recognition by the secretion apparatus, the chimeric proteins accumulated at high levels in the cytoplasm of the cell. Second, both the wild-type and mutant polypeptides accumulated in a purified and reconstituted in vitro translation system from E. coli and were equally susceptible to digestion by an exogenous protease. Third, the chimeric polypeptides lacking the signal peptide accumulated in a stable form in vivo. Fourth, the precursors of the proteins containing a functional signal peptide accumulated in a secA ts mutant at the restrictive temperature when secretion was blocked, suggesting that degradation is tightly linked to the secretion apparatus.

This article has been cited by other articles:

• Lee, V. T., Schneewind, O. (2002). Yop Fusions to Tightly Folded Protein Domains and Their Effects on Yersinia enterocolitica Type III Secretion. J. Bacteriol. 184: 3740-3745 [Abstract] [Full Text]  
• Bui, D. M., Gregan, J., Jarosch, E., Ragnini, A., Schweyen, R. J. (1999). The Bacterial Magnesium Transporter CorA Can Functionally Substitute for Its Putative Homologue Mrs2p in the Yeast Inner Mitochondrial Membrane. J. Biol. Chem. 274: 20438-20443 [Abstract] [Full Text]  
• Stephenson, K., Harwood, C. R. (1998). Influence of a Cell-Wall-Associated Protease on Production of alpha -Amylase by Bacillus subtilis. Appl. Environ. Microbiol. 64: 2875-2881 [Abstract] [Full Text]