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Quantifying Yersinia pseudotuberculosis Type III Secretion System Activity Following Iron Starvation and Anaerobic Growth
Published on: May 31, 2024
The RACK1 signaling scaffold protein selectively interacts with Yersinia pseudotuberculosis virulence function
Sara E Thorslund1, Tomas Edgren, Jonas Pettersson
1Department of Molecular Biology, Umeå University, Umeå, Sweden.
Plos One
|February 25, 2011
Summary
Yersinia bacteria use YopK to block phagocytosis by binding RACK1, a host protein. This interaction ensures targeted delivery of antiphagocytic effectors, crucial for Yersinia virulence and survival.
Area of Science:
- Microbiology
- Cell Biology
- Immunology
Background:
- Gram-negative bacteria employ type III secretion systems (T3SS) to inject effector proteins into host cells.
- Yersinia species utilize Yop effectors for antiphagocytosis, a key virulence mechanism enabling survival in immune-rich environments.
Purpose of the Study:
- To elucidate the role of the virulence protein YopK in orchestrating effector translocation for antiphagocytosis.
- To investigate the interaction of YopK with host factors and its impact on Yersinia virulence.
Main Methods:
- Analysis of Yop effector translocation modulation by YopK.
- Investigating YopK interaction with translocators and RACK1 within host cells.
- Assessing the effect of RACK1 downregulation on antiphagocytosis and Yersinia virulence in vivo.
Main Results:
- YopK modulates Yop effector translocation by influencing the YopB/YopD ratio in the target cell membrane.
- YopK interacts with host RACK1, which is recruited to phagocytic cups upon Yersinia infection.
- Downregulation of RACK1 confers resistance to antiphagocytosis without affecting effector translocation or cytotoxicity.
- A YopK mutant deficient in RACK1 binding exhibits an avirulent phenotype in a mouse infection model.
Conclusions:
- YopK binding to RACK1 is essential for Yersinia virulence.
- YopK-RACK1 interaction facilitates spatially targeted delivery of antiphagocytic effectors, ensuring effective inhibition of phagocytosis.
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