Role of the Type II Protein Secretion Pathway in Pathogenesis of Legionella pneumophila

Legionella ◽  
2014 ◽  
pp. 13-17
Author(s):  
Ombeline Rossier ◽  
Paul H. Edelstein ◽  
Nicholas P. Cianciotto
Keyword(s):  
Protein Secretion ◽  
Legionella Pneumophila ◽  
Type Ii ◽  
Secretion Pathway ◽  
Protein Secretion Pathway

A signal peptide-independent protein secretion pathway

1992 ◽  
Vol 61 (2) ◽  
pp. 111-113 ◽  
Author(s):  
C�cile Wandersman ◽  
Philippe Delepelaire ◽  
Sylvie Letoffe ◽  
Jean-Marc Ghigo
Keyword(s):  
Protein Secretion ◽  
Signal Peptide ◽  
Secretion Pathway ◽  
Protein Secretion Pathway ◽  
Independent Protein

scholarly journals Legionella pneumophila Contains a Type II General Secretion Pathway Required for Growth in Amoebae as Well as for Secretion of the Msp Protease

1999 ◽  
Vol 67 (7) ◽  
pp. 3662-3666 ◽  
Author(s):  
Laura M. Hales ◽  
Howard A. Shuman
Keyword(s):  
Legionella Pneumophila ◽  
Acanthamoeba Castellanii ◽  
Gram Negative Bacteria ◽  
Type Ii ◽  
Free Living ◽  
Gram Negative ◽  
Secretion Pathway ◽  
Free Living Amoeba ◽  
Substitution Mutation

ABSTRACT We report the identification of a set of Legionella pneumophila genes that encode products with homology to proteins of the type II general secretion pathway of gram-negative bacteria. A strain containing a deletion-substitution mutation of two of these genes was unable to secrete the Msp protease. This strain was unable to multiply within the free-living amoeba Acanthamoeba castellanii yet was able to kill HL-60-derived macrophages. Because Msp is not required for growth in amoebae, other proteins which are important for growth in amoebae are likely secreted by this pathway.

scholarly journals Mutations in the Extracellular Protein Secretion Pathway Genes (eps) Interfere with Rugose Polysaccharide Production in and Motility of Vibrio cholerae

2000 ◽  
Vol 68 (4) ◽  
pp. 1967-1974 ◽  
Author(s):  
Afsar Ali ◽  
Judith A. Johnson ◽  
Augusto A. Franco ◽  
Daniel J. Metzger ◽  
Terry D. Connell ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Protein Secretion ◽  
Diarrheal Disease ◽  
Extracellular Protein ◽  
Aquatic Environments ◽  
Wild Type ◽  
Causal Organism ◽  
Secretion Pathway ◽  
Protein Secretion System ◽  
Protein Secretion Pathway

ABSTRACT Vibrio cholerae is the causal organism of the diarrheal disease cholera. The rugose variant of V. cholerae is associated with the secretion of an exopolysaccharide. The rugose polysaccharide has been shown to confer increased resistance to a variety of agents, such as chlorine, bioacids, and oxidative and osmotic stresses. It also promotes biofilm formation, thereby increasing the survival of the bacteria in the aquatic environments. Here we show that the extracellular protein secretion system (gene designated eps) is involved directly or indirectly in the production of rugose polysaccharide. A TnphoA insertion inepsD gene of the eps operon abolished the production of rugose polysaccharide, reduced the secretion of cholera toxin and hemolysin, and resulted in a nonmotile phenotype. We have constructed defined mutations of the epsD andepsE genes that affected these phenotypes and complemented these defects by plasmid clones of the respective wild-type genes. These results suggest a major role for the eps system in pathogenesis and environmental survival of V. cholerae.

scholarly journals Type IV pili and type II secretion play a limited role in Legionella pneumophila biofilm colonization and retention

Microbiology ◽  
2006 ◽  
Vol 152 (12) ◽  
pp. 3569-3573 ◽  
Author(s):  
Claressa E. Lucas ◽  
Ellen Brown ◽  
Barry S. Fields
Keyword(s):  
Legionella Pneumophila ◽  
Wild Type Strain ◽  
Water Systems ◽  
Type Iv Pili ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Wild Type ◽  
Intracellular Replication ◽  
Type Iv

Legionellae colonize biofilms in building water systems, yet little is known about their interaction with the organisms in these microbial communities. The role of Legionella pneumophila type IV pili and the type II secretion pre-pilin peptidase was evaluated in a model biofilm system. L. pneumophila strains 130b (wild-type), BS100 (a type IV pili mutant) and NU243 (a pre-pilin peptidase mutant) were assessed for attachment and retention in an established biofilm. Strains 130b and NU243 colonized the biofilm at a similar level while BS100 attached at a tenfold lower level. Over time, NU243 dropped below the level of detection while BS100 remained in the biofilm throughout the course of the experiment. The wild-type strain decreased but remained at a considerably higher level than either of the mutants. Inclusion of amoebae with BS100 allowed for attachment and retention at a level similar to 130b. NU243, which displays reduced intracellular replication, was able to establish itself and persist in the presence of amoebae. Thus, type IV pili and the pre-pilin peptidase facilitate L. pneumophila colonization of biofilms but are not required in the presence of a host for intracellular replication.

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