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Analysis of Yersinia enterocolitica Effector Translocation into Host Cells Using Beta-lactamase Effector Fusions
Published on: October 13, 2015
A solvent-exposed patch in chaperone-bound YopE is required for translocation by the type III secretion system
Loren Rodgers1, Romila Mukerjea, Sara Birtalan
1Section of Molecular Biology, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA.
Journal of Bacteriology
|April 13, 2010
Summary
Bacterial type III secretion (T3S) effectors use chaperone proteins for host cell entry. A specific region on the effector protein acts as a translocation signal, facilitating entry into host cells.
Area of Science:
- Microbiology
- Molecular Biology
- Bacterial Pathogenesis
Background:
- Bacterial type III secretion (T3S) systems translocate effector proteins into host cells.
- Effector translocation requires chaperone proteins that bind effectors in an extended conformation.
- This chaperone-bound conformation is hypothesized to act as a translocation signal.
Purpose of the Study:
- To identify the translocation signal site within the chaperone-binding (Cb) region of the Yersinia pseudotuberculosis effector YopE.
- To test the model that the chaperone-bound effector conformation serves as a translocation signal.
Main Methods:
- Site-directed mutagenesis of the YopE Cb region.
- Assessing YopE expression, SycE binding, secretion, stability, and translocation.
- Analyzing the structural and functional roles of specific YopE residues.
Main Results:
- A set of YopE residues essential for translocation was identified.
- These residues are not required for SycE binding, secretion, or stability.
- The identified residues form a solvent-exposed patch on the chaperone-bound effector.
Conclusions:
- The chaperone-bound Cb region of YopE contains a translocation signal.
- This signal is composed of specific solvent-exposed residues.
- The findings support the model that the effector's conformation bound to its chaperone mediates translocation.
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