This Article Full Text 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 Warren, S. M. Articles by Young, G. M. Search for Related Content PubMed PubMed Citation Articles by Warren, S. M. Articles by Young, G. M.

An Amino-Terminal Secretion Signal Is Required for YplA Export by the Ysa, Ysc, and Flagellar Type III Secretion Systems of Yersinia enterocolitica Biovar 1B

Microbiology Graduate Group,¹ Department of Food Science and Technology, University of California, Davis, California 95616²

Received 1 April 2005/ Accepted 2 June 2005

Yersinia enterocolitica biovar 1B maintains three distinct type III secretion (TTS) systems, which independently operate to target proteins to extracellular sites. The Ysa and Ysc systems are prototypical contact-dependent TTS systems that translocate toxic effectors to the cytosols of targeted eukaryotic host cells during infection. The flagellar TTS system is utilized during the assembly of the flagellum and is required for secretion of the virulence-associated phospholipase YplA to the bacterial milieu. When ectopically produced, YplA is also a secretion substrate for the Ysa and Ysc TTS systems. In this study, we define elements that allow YplA recognition and export by the Ysa, Ysc, and flagellar TTS systems. Fusion of various amino-terminal regions of YplA to Escherichia coli alkaline phosphatase (PhoA) lacking its native secretion signal demonstrated that the first 20 amino acids or corresponding mRNA codons of YplA were sufficient for export of YplA-PhoA chimeras by each TTS system. Export of native YplA by each of the three TTS systems was also found to depend on the integrity of its amino terminus. Introduction of a frameshift mutation or deletion of yplA sequences encoding the amino-terminal 20 residues negatively impacted YplA secretion. Deletion of other yplA regions was tolerated, including that resulting in the removal of amino acid residues 30 through 40 of the polypeptide and removal of the 5' untranslated region of the mRNA. This work supports a model in which independent and distantly related TTS systems of Y. enterocolitica recognize protein substrates by a similar mechanism.

This article has been cited by other articles:

• Broms, J. E., Francis, M. S., Forsberg, A. (2007). Diminished LcrV Secretion Attenuates Yersinia pseudotuberculosis Virulence. J. Bacteriol. 189: 8417-8429 [Abstract] [Full Text]