Identification of Cellular Components Interacting with the Shiga-like Toxin 1 A1 Chain (SLT-1 A1)

Shiga-like toxin 1 (SLT-1) is produced by Escherichia coli strains like the pathogenic strain O157:H7. These bacterial strains are responsible for worldwide cases of food poisoning and water contamination, and the toxin is a major cause of hemorrhagic colitis and the hemolytic uremia syndrome. SLT-1 is defined as a type II ribosome-inactivating protein (RIP) and belongs to a family of plant and bacterial AB toxins. The A1 chain blocks protein synthesis in eukaryotic cells by depurinating a single adenine base in 28S rRNA. The mechanisms by which the A chain of SLT-1 interacts with the host components to route itself to the cytosol remains largely unknown. This thesis project identified a list of putative cellular proteins that interact with the SLT-1 A1 chain by the use of yeast-2-hybrid (Y2H) screens and HeLa lysate pull down/mass spectrometry analyses. Further assessment of the top 8 host interactors did not yield true interactions.MAS