Probing the cellular effects of bacterial effector proteins with the Yersinia toolbox

2012 ◽  
Vol 7 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Stefan Wölke ◽  
Jürgen Heesemann
Keyword(s):  
Effector Proteins ◽  
Cellular Effects ◽  
Bacterial Effector Proteins

scholarly journals Host Pathways Important for Coxiella burnetii Infection Revealed by Genome-Wide RNA Interference Screening

mBio ◽  
2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Justin A. McDonough ◽  
Hayley J. Newton ◽  
Scott Klum ◽  
Rachel Swiss ◽  
Hervé Agaisse ◽  
...  
Keyword(s):  
Coxiella Burnetii ◽  
Secretion System ◽  
Effector Proteins ◽  
Host Factors ◽  
Content Type ◽  
Host Determinants ◽  
Genome Wide ◽  
Type Ivb Secretion ◽  
Type Ivb Secretion System ◽  
Bacterial Effector Proteins

ABSTRACTCoxiella burnetiiis an intracellular pathogen that replicates within a lysosome-like vacuole. A Dot/Icm type IVB secretion system is used byC. burnetiito translocate effector proteins into the host cytosol that likely modulate host factor function. To identify host determinants required forC. burnetiiintracellular growth, a genome-wide screen was performed using gene silencing by small interfering RNA (siRNA). Replication ofC. burnetiiwas measured by immunofluorescence microscopy in siRNA-transfected HeLa cells. Newly identified host factors included components of the retromer complex, which mediates cargo cycling between the endocytic pathway and the Golgi apparatus. Reducing the levels of the retromer cargo-adapter VPS26-VPS29-VPS35 complex or retromer-associated sorting nexins abrogatedC. burnetiireplication. Several genes, when silenced, resulted in enlarged vacuoles or an increased number of vacuoles withinC. burnetii-infected cells. Silencing of theSTX17gene encoding syntaxin-17 resulted in a striking defect in homotypic fusion of vacuoles containingC. burnetii, suggesting a role for syntaxin-17 in regulating this process. Lastly, silencing host genes needed forC. burnetiireplication correlated with defects in the translocation of Dot/Icm effectors, whereas, silencing of genes that affected vacuole morphology, but did not impact replication, did not affect Dot/Icm translocation. These data demonstrate thatC. burnetiivacuole maturation is important for creating a niche that permits Dot/Icm function. Thus, genome-wide screening has revealed host determinants involved in sequential events that occur duringC. burnetiiinfection as defined by bacterial uptake, vacuole transport and acidification, activation of the Dot/Icm system, homotypic fusion of vacuoles, and intracellular replication.IMPORTANCEQ fever in humans is caused by the bacteriumCoxiella burnetii. Infection withC. burnetiiis marked by its unique ability to replicate within a large vacuolar compartment inside cells that resembles the harsh, acidic environment of a lysosome. Central to its pathogenesis is the delivery of bacterial effector proteins into the host cell cytosol by a Dot/Icm type IVB secretion system. These proteins can interact with and manipulate host factors, thereby leading to creation and maintenance of the vacuole that the bacteria grow within. Using high-throughput genome-wide screening in human cells, we identified host factors important for several facets ofC. burnetiiinfection, including vacuole transport and membrane fusion events that promote vacuole expansion. In addition, we show that maturation of theC. burnetiivacuole is necessary for creating an environment permissive for the Dot/Icm delivery of bacterial effector proteins into the host cytosol.

scholarly journals Effector Protein Cig2 Decreases Host Tolerance of Infection by Directing Constitutive Fusion of Autophagosomes with the Coxiella -Containing Vacuole

mBio ◽  
2016 ◽  
Vol 7 (4) ◽  
Author(s):  
Lara J. Kohler ◽  
Shawna R. Reed ◽  
Shireen A. Sarraf ◽  
David D. Arteaga ◽  
Hayley J. Newton ◽  
...  
Keyword(s):  
Coxiella Burnetii ◽  
Host Response ◽  
Galleria Mellonella ◽  
Secretion System ◽  
Effector Proteins ◽  
Host Cells ◽  
Effector Protein ◽  
Autophagy Pathway ◽  
Host Tolerance ◽  
Bacterial Effector Proteins

ABSTRACT Coxiella burnetii replicates in an acidified lysosome-derived vacuole. Biogenesis of the Coxiella -containing vacuole (CCV) requires bacterial effector proteins delivered into host cells by the Dot/Icm secretion system. Genetic and cell biological analysis revealed that an effector protein called Cig2 promotes constitutive fusion of autophagosomes with the CCV to maintain this compartment in an autolysosomal stage of maturation. This distinguishes the CCV from other pathogen-containing vacuoles that are targeted by the host autophagy pathway, which typically confers host resistance to infection by delivering the pathogen to a toxic lysosomal environment. By maintaining the CCV in an autolysosomal stage of maturation, Cig2 enabled CCV homotypic fusion and enhanced bacterial virulence in the Galleria mellonella (wax moth) model of infection by a mechanism that decreases host tolerance. Thus, C. burnetii residence in an autolysosomal organelle alters host tolerance of infection, which indicates that Cig2-dependent manipulation of a lysosome-derived vacuole influences the host response to infection. IMPORTANCE Coxiella burnetii is an obligate, intracellular bacterial pathogen that replicates inside a unique, lysosome-like compartment called the Coxiella -containing vacuole (CCV). Over 130 bacterial effector proteins are delivered into the host cell cytosol by the C. burnetii Dot/Icm type IV secretion system. Although the Dot/Icm system is essential for pathogenesis, the functions of most effectors remain unknown. Here we show that the effector protein Cig2 is essential for converting the CCV to an organelle that is similar to the autolysosome. Cig2 function promotes constitutive fusion between the CCV and autophagosomes generated by selective autophagy. Cig2-directed biogenesis of an autolysosomal vacuole is essential for the unique fusogenic properties of the CCV and for virulence in an animal model of disease. This work highlights how bacterial subversion of the host autophagy pathway can influence the cell biological properties of the CCV and influence the host response to infection.

scholarly journals ‘Drugs from Bugs’: bacterial effector proteins as promising biological (immune-) therapeutics

2013 ◽  
Vol 351 (2) ◽  
pp. 126-132 ◽  
Author(s):  
Christian Rüter ◽  
Philip R. Hardwidge
Keyword(s):  
Effector Proteins ◽  
Bacterial Effector Proteins

Cell-Penetrating Bacterial Effector Proteins: Better Tools than Targets

2017 ◽  
Vol 35 (2) ◽  
pp. 109-120 ◽  
Author(s):  
Christian Rüter ◽  
M. Alexander Schmidt
Keyword(s):  
Effector Proteins ◽  
Cell Penetrating ◽  
Bacterial Effector Proteins

scholarly journals Quantitative Yeast Genetic Interaction Profiling of Bacterial Effector Proteins Uncovers a Role for the Human Retromer in Salmonella Infection

Cell Systems ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 323-338.e6 ◽  
Author(s):  
Kristin L. Patrick ◽  
Jason A. Wojcechowskyj ◽  
Samantha L. Bell ◽  
Morgan N. Riba ◽  
Tao Jing ◽  
...  
Keyword(s):  
Genetic Interaction ◽  
Effector Proteins ◽  
Salmonella Infection ◽  
Yeast Genetic ◽  
Bacterial Effector Proteins

scholarly journals Structural basis for arginine glycosylation of host substrates by bacterial effector proteins

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Jun Bae Park ◽  
Young Hun Kim ◽  
Youngki Yoo ◽  
Juyeon Kim ◽  
Sung-Hoon Jun ◽  
...  
Keyword(s):  
Effector Proteins ◽  
Structural Basis ◽  
Bacterial Effector Proteins
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