The ultimate goal of this application is to identify the host signaling pathways targeted by the type III secretion system 1 (T3SS1) of the gram-negative bacterium Vibrio parahaemolyticus;a major agent responsible for gastroenteritis outbreaks associated with the consumption of contaminated seafood. The prevalence of V. parahaemolyticus in the environment and incidence of infection have been linked to rising water temperatures caused by global warming. A T3SS is a needle-like structure that efficiently translocates virulence factors from bacteria into the cytosol of a host cell. The virulence factors (also called bacterial effectors) have evolved in a manner similar to many of the viral oncogenes;a eukaryotic activity is usurped and modified by the pathogen for its own advantage. Genomic sequencing of V. parahaemolyticus revealed the existence of two pathogenicity islands that encode both a T3SS and putative effectors. The first pathogenicity island contains T3SS1 and is associated with a cytotoxicity, while the second pathogenicity island contains T3SS2 and is associated with an enterotoxicity. The effectors on the first pathogenicity island have been identified as open reading frames with no obvious homology to any known protein. Recently, we have demonstrated that the V. parahaemolyticus uses T3SS1 to orchestrate a multifaceted host cell infection by induction of autophagy, cell rounding and then cell lysis. We have shown one of the T3SS1 effectors, VopS, utilizes a novel posttranslational modification called AMPylation to disrupt host signaling. Herein, we propose Specific Aims to study the multifaceted death induced by T3SS1 by identifying the activity and host targets of three known effectors, identify other effectors secreted by T3SS1 and characterize the host signaling pathways that are disrupted by V. parahaemolyticus during infection. These studies provide molecular insight into the molecular mechanisms used by this harmful gastrointestinal bacterial pathogen V. parahaemolyticus.

Public Health Relevance

The gram-negative bacterium Vibrio parahaemolyticus is a major agent responsible for gastroenteritis outbreaks associated with the consumption of contaminated seafood. The prevalence of V. parahaemolyticus in the environment and incidence of infection have been linked to rising water temperatures caused by global warming. Genomic sequencing of the marine bacterium V. parahaemolyticus revealed the existence of two pathogenicity islands that encode both a type III secretion system (T3SS) and putative effectors. Herein, we propose Specific Aims to study the multifaceted death induced by T3SS1 by identifying the activity and host targets of three known effectors, identify other effectors secreted by T3SS1 and characterize the host signaling pathways that are disrupted by V. parahaemolyticus during infection.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI087808-05
Application #
8624653
Study Section
Host Interactions with Bacterial Pathogens Study Section (HIBP)
Program Officer
Hall, Robert H
Project Start
2010-03-05
Project End
2015-02-28
Budget Start
2014-03-01
Budget End
2015-02-28
Support Year
5
Fiscal Year
2014
Total Cost
$393,525
Indirect Cost
$146,025
Name
University of Texas Sw Medical Center Dallas
Department
Biochemistry
Type
Schools of Medicine
DUNS #
800771545
City
Dallas
State
TX
Country
United States
Zip Code
75390
Lewallen, Daniel M; Sreelatha, Anju; Dharmarajan, Venkatasubramanian et al. (2014) Inhibiting AMPylation: a novel screen to identify the first small molecule inhibitors of protein AMPylation. ACS Chem Biol 9:433-42
Yu, Xiaobo; Woolery, Andrew R; Luong, Phi et al. (2014) Copper-catalyzed azide-alkyne cycloaddition (click chemistry)-based detection of global pathogen-host AMPylation on self-assembled human protein microarrays. Mol Cell Proteomics 13:3164-76
Salomon, Dor; Orth, Kim (2013) What pathogens have taught us about posttranslational modifications. Cell Host Microbe 14:269-79
Salomon, Dor; Orth, Kim (2013) Lost after translation: post-translational modifications by bacterial type III effectors. Curr Opin Microbiol 16:213-20
Sreelatha, Anju; Bennett, Terry L; Zheng, Hui et al. (2013) Vibrio effector protein, VopQ, forms a lysosomal gated channel that disrupts host ion homeostasis and autophagic flux. Proc Natl Acad Sci U S A 110:11559-64
Krachler, Anne Marie; Orth, Kim (2013) Targeting the bacteria-host interface: strategies in anti-adhesion therapy. Virulence 4:284-94
Rahman, Mokhlasur; Ham, Hyeilin; Liu, Xinran et al. (2012) Visual neurotransmission in Drosophila requires expression of Fic in glial capitate projections. Nat Neurosci 15:871-5
Krachler, Anne Marie; Ham, Hyeilin; Orth, Kim (2012) Turnabout is fair play: use of the bacterial Multivalent Adhesion Molecule 7 as an antimicrobial agent. Virulence 3:68-71
Li, Yan; Al-Eryani, Rowaida; Yarbrough, Melanie L et al. (2011) Characterization of AMPylation on threonine, serine, and tyrosine using mass spectrometry. J Am Soc Mass Spectrom 22:752-61
Krachler, Anne Marie; Woolery, Andrew R; Orth, Kim (2011) Manipulation of kinase signaling by bacterial pathogens. J Cell Biol 195:1083-92

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