Insecticidal toxins of Yersinia enterocolitica

• Applicant: Professor Dr. Thilo Martin Fuchs
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens ; African, American and Oceania Studies
• Term: from 2008 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 58161030

Recently, the insecticidal toxin complexes Tca and Tcc were identified in Yersinia enterocolitica by the applicant’s group. The tc genes are localized on the pathogenicity island tc-PAIYe and are also present in Y. pestis, the plague agent. It was shown that the tc genes of Y. enterocolitica are repressed at 37°C and strongly expressed at 10°C, indicating a toxin activity not in mammals but in the environment. In biological tests, Y. enterocolitica strain W22703 cultivated at low temperature was toxic against larvae of the butterfly Manduca sexta that feeds on tobacco plants. In the working program proposed, three main questions will be addressed: (A) How are the genes of the insecticidal pathogenicity island regulated in vitro and in vivo? Using the luciferase reporter technology, the impact of two putative regulators, the quorum sensing and external factors including the insect hemolymph on the insecticidal toxin expression shall be investigated. (B) By which molecular mechanism are the high molecular weight Tc toxins released? The function of phage-derived lysis genes that are highly conserved and located on the pathogenicity island shall be investigated, and the putative extracellular Tc enrichment shall be demonstrated in vitro and in vivo. (C) What is the biological relevance of the sequence variability that has been found in several Yersinia species and in biovars of Y. enterocolitica? The insecticidal activity of recombinant Yersinia strains shall be quantified in the established model systems.

• DFG Programme: Research Grants