Formation of a novel surface structure encoded by Salmonella Pathogenicity Island 2.

Chakravortty, D and Rohde, M and Jäger, L and Deiwick, J and Hensel, M (2005) Formation of a novel surface structure encoded by Salmonella Pathogenicity Island 2. In: EMBO Journal, 24 (11). 2043 -2052.

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Abstract

The type III secretion system (T3SS) encoded by Salmonella Pathogenicity Island 2 (SPI2) is essential for virulence and intracellular proliferation of Salmonella enterica. We have previously identified SPI2-encoded proteins that are secreted and function as a translocon for the injection of effector proteins. Here, we describe the formation of a novel SPI2-dependent appendage structure in vitro as well as on the surface of bacteria that reside inside a vacuole of infected host cells. In contrast to the T3SS of other pathogens, the translocon encoded by SPI2 is only present singly or in few copies at one pole of the bacterial cell. Under in vitro conditions, appendages are composed of a filamentous needle-like structure with a diameter of 10 nm that was sheathed with secreted protein. The formation of the appendage in vitro is dependent on acidic media conditions. We analyzed SPI2-encoded appendages in infected cells and observed that acidic vacuolar pH was not required for induction of SPI2 gene expression, but was essential for the assembly of these structures and their function as translocon for delivery of effector proteins.

Item Type:	Journal Article
Publication:	EMBO Journal
Publisher:	Nature Publishing Group
Additional Information:	Copyright of this article belongs to Nature Publishing Group.
Keywords:	intracellular pathogen,protein translocation,Salmonella-containing vacuole,surface appendage,type III secretion
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	24 Feb 2010 06:26
Last Modified:	19 Sep 2010 05:55
URI:	http://eprints.iisc.ac.in/id/eprint/25629

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