Host cell-dependent secretion and translocation of the LepA and LepB effectors of Legionella pneumophila.

Host cell-dependent secretion and translocation of the LepA and LepB effectors of Legionella pneumophila. Research Abstract Details 

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Host cell-dependent secretion and translocation of the LepA and LepB effectors of Legionella pneumophila. Abstract Text:

John Chen,Moraima Reyes,Margaret Clarke,Howard A Shuman,

Legionella pneumophila is the Gram-negative bacterial agent of Legionnaires' disease, an acute, often fatal pneumonia. L. pneumophila infects alveolar macrophages, evading the antimicrobial defences of the phagocyte by preventing fusion of the phagosome with lysosomes and avoiding phagosome acidification. The bacteria then modulate the composition of the vacuole so that it takes on the characteristics of the endoplasmic reticulum. Similar events occur when the bacteria infect unicellular protozoa. It is thought that replication in fresh water protozoa provides an environmental reservoir for the organism. Several effector proteins are delivered to the host by the Icm/Dot type IV secretion system (TFSS). Some of these have been shown to participate in the trafficking of the Legionella phagosome. Here we describe the ability of the Icm/Dot TFSS to translocate two effectors, LepA and LepB, that play a role in the non-lytic release of Legionella from protozoa. We report that translocation of the Lep proteins is inhibited by agents that depolymerize actin filaments and that effectors may be secreted into the extracellular medium upon cell contact. Depletion of the Lep proteins by deletion of their genes results in increased ability to lyse red blood cells. In contrast, overexpression of Lep-containing hybrid proteins appears to specifically inhibit the activity of the Icm/Dot TFSS and may prevent the delivery of other effectors that are critical for intracellular multiplication.

Host cell-dependent secretion and translocation of the LepA and LepB effectors of Legionella pneumophila. Publishing Authors By Initials

J Chen,M Reyes,M Clarke,HA Shuman,

For similar cells: cells, cultured: cell line: cell line, tumor: u937 cells research abstracts see: cells: cells, cultured: cell line: cell line, tumor: u937 cells research

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Host cell-dependent secretion and translocation of the LepA and LepB effectors of Legionella pneumophila. Journal Published:

PUBLICATION TYPE: Research Support, U.S. Gov't,

Journal: Cellular microbiology

VOLUME: 9

Page Numbers: 1660-71

Journal Abbreviation: Cell. Microbiol.

ISSN: 1462-5814

DAY: 16

MONTH: 02

YEAR: 2007

Host cell-dependent secretion and translocation of the LepA and LepB effectors of Legionella pneumophila. Information

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LANGUAGE: eng

NlmUniqueID: 100883691

Host cell-dependent secretion and translocation of the LepA and LepB effectors of Legionella pneumophila. Keywords Mesh Terms:

KEYWORDS: U937 Cells

MESH TERMS: metabolism

Chemical & Substance for Abstract: Host cell-dependent secretion and translocation of the LepA and LepB effectors of Legionella pneumophila. Information

Substance Name: Adenylate Cyclase

Registry Number: EC 4.6.1.1

Grant and Affiliation Information for Host cell-dependent secretion and translocation of the LepA and LepB effectors of Legionella pneumophila.

AFFILIATION: Department of Microbiology, Columbia University Medical Center, New York, NY 10032, USA.

Country: England

AGENCY: United States NIAID

GRANT: AI23549

ACRONYM: AI

MEDLINETA: Cell Microbiol

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