Mapping C. difficile TcdB interactions with host cell-surface and intracellular factors using proximity-dependent
Jennifer S Ward1,2, Karl J Schreiber2, John Tam2
1Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
Mbio
|January 17, 2025
Summary
Researchers used proximity-dependent biotinylation to identify host factors exploited by Clostridioides difficile toxin B (TcdB). This method revealed both cell-surface receptors and intracellular targets, offering new insights into bacterial toxin mechanisms.
Area of Science:
- Microbiology
- Cell Biology
- Biochemistry
Background:
- Bacterial toxins cause disease by targeting host cells.
- Understanding toxin mechanisms requires identifying host factors involved in cellular intoxication.
- Proximity-dependent biotinylation offers a method to map host-toxin interactions.
Purpose of the Study:
- To identify host factors proximal to Clostridioides difficile toxin B (TcdB) using proximity-dependent biotinylation.
- To explore both cell-surface and intracellular targets of TcdB.
- To evaluate the utility of proximity labeling for studying bacterial toxins.
Main Methods:
- Utilized TurboID, a proximity-dependent biotinylation enzyme, fused to fragments of TcdB.
- Applied both intracellular and extracellular proximity labeling strategies.
- Analyzed biotinylated proteins to identify TcdB interactors.
Main Results:
- Identified cytosolic interactors, including Rho GTPase and actin cytoskeleton network proteins.
- Discovered cell-surface targets, confirming LRP1 as a TcdB receptor.
- Highlighted the potential and limitations of proximity labeling for toxin research.
Conclusions:
- Proximity labeling effectively identifies host factors exploited by bacterial toxins.
- TcdB interacts with key cellular networks for intoxication.
- This approach reveals host vulnerabilities and aids in developing countermeasures.
