You can manage bookmarks using lists, please log in to your user account for this.
Media type:
E-Article
Title:
The Legionella pneumophila IcmS–LvgA protein complex is important for Dot/Icm‐dependent intracellular growth
Contributor:
Vincent, Carr D.;
Vogel, Joseph P.
imprint:
Wiley, 2006
Published in:Molecular Microbiology
Language:
English
DOI:
10.1111/j.1365-2958.2006.05243.x
ISSN:
0950-382X;
1365-2958
Origination:
Footnote:
Description:
<jats:title>Summary</jats:title><jats:p>Many bacterial pathogens require a functional type IV secretion system (T4SS) for virulence. <jats:italic>Legionella pneumophila</jats:italic>, the causative agent of Legionnaires' disease, employs the Dot/Icm T4SS to inject a large number of protein substrates into its host, thereby altering phagosome trafficking. The <jats:italic>L. pneumophila</jats:italic> T4SS substrate SdeA has been shown to require the accessory factor IcmS for its export. IcmS, defined as a type IV adaptor, exists as a heterodimer with IcmW and this complex functions in a manner similar to a type III secretion chaperone. Here we report an interaction between IcmS and the previously identified virulence factor LvgA. Similar to the <jats:italic>icmS</jats:italic> mutant, the <jats:italic>lvgA</jats:italic> mutant appears to assemble a fully functional Dot/Icm complex. Both LvgA and IcmS are small, acidic proteins localized to the cytoplasm and are not exported by the Dot/Icm system, suggesting they form a novel type IV adaptor complex. Inactivation of <jats:italic>lvgA</jats:italic> causes a minimal defect in growth in the human monocytic cell line U937 and the environmental host <jats:italic>Acanthamoeba castellanii</jats:italic>. However, the <jats:italic>lvgA</jats:italic> mutant was severely attenuated for intracellular growth of <jats:italic>L. pneumophila</jats:italic> in mouse macrophages, suggesting LvgA may be a critical factor that confers host specificity.</jats:p>