Cholera toxin (CT) and heat-labile enterotoxin (LT) are two similar AB5 toxins that are responsible for the diarrhea caused by Vibrio cholerae and enterotoxigenic Escherichia coli (ETEC) infections, respectively. These toxins are secreted into the lumen of the small intestine, but attack targets within the host cytosol. Upon endocytosis, CT and LT travel to the endoplasmic reticulum (ER), where their catalytic component – the A1 subunit – dissociates from the rest of the toxin. Once free, the A1 subunit naturally unfolds and is retrotranslocated to the cytosol by hijacking components of the ER associated degradation pathway (ERAD). Both steps, toxin disassembly and transport to the cytosol, involve interactions with host chaperones and are crucial for intoxication.

This HALRIC project aims to investigate how these human chaperones bind to foreign substrates such as cholera toxin by using cross-linking mass spectrometry (XL-MS). The target proteins will be produced at the University of Oslo (UiO), and the protein-protein complexes will be cross-linked and analysed by mass-spectrometry at the Swedish National Infrastructure for Biological Mass Spectrometry (BioMS) and the Science for Life Laboratory (SciLifeLab) Structural Proteomics unit at Lund University (LU).

This work will provide valuable insights into toxin-chaperone interactions and could lead to the development of new drugs that prevent cholera toxin activation inside the host.

For further information about this HALRIC pilot project, please contact:

 

Ute Krengel
University of Oslo
ute.krengel@kjemi.uio.no