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Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
Published on: December 17, 2013
The enteropathogenic Escherichia coli type III secretion system effector Map binds EBP50/NHERF1: implication for cell
Nandi Simpson1, Rob Shaw, Valerie F Crepin
1Division of Cell and Molecular Biology, Flowers Building, Imperial College London, London SW7 2AZ, UK.
Molecular Microbiology
|April 1, 2006
Summary
Enteropathogenic Escherichia coli (EPEC) causes child diarrhea. Researchers identified EBP50/NHERF1 as a host protein interacting with the EPEC effector Map, revealing new insights into EPEC pathogenesis and diarrhea mechanisms.
Area of Science:
- Microbiology
- Cell Biology
- Pathogenesis
Background:
- Enteropathogenic Escherichia coli (EPEC) is a leading cause of diarrhea in children, particularly in developing nations.
- The precise mechanisms driving EPEC-induced diarrhea remain incompletely understood.
- Understanding host-pathogen interactions is crucial for developing effective treatments.
Purpose of the Study:
- To identify the host cell protein targeted by the EPEC type III secretion system effector Map.
- To elucidate the molecular interactions between Map and its host target.
- To investigate the role of Map in EPEC pathogenesis and diarrhea.
Main Methods:
- Yeast two-hybrid system for protein interaction screening.
- Co-immunoprecipitation and immunostaining for protein localization and interaction validation.
- In vitro cell culture models (HeLa, Caco-2) for studying cellular effects.
- Citrobacter rodentium mouse model to assess diarrhea in vivo.
Main Results:
- The EPEC effector Map interacts with ezrin/radixin/moesin (ERM)-binding phosphoprotein 50 (EBP50), also known as Na+/H+ exchanger regulatory factor 1 (NHERF1).
- Map binding to EBP50/NHERF1 involves Map's TRL motif and EBP50/NHERF1's PDZ1 domain.
- Map induces EBP50/NHERF1 proteolysis and promotes filopodia formation and brush border elongation.
- Infection with wild-type C. rodentium caused significantly more diarrhea than C. rodentium lacking Map.
Conclusions:
- EBP50/NHERF1 is a novel host target of the EPEC effector Map.
- Map-EBP50/NHERF1 interaction plays a role in EPEC-induced cellular changes and contributes to diarrhea.
- These findings provide critical insights into the molecular mechanisms underlying EPEC pathogenesis.
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