Congratulations to the Best Poster Award Winner at the 4th German Pharm-Tox Summit, Stuttgart, Germany, 2019 (Sponsored by Toxins)

The editorial team of Toxins would like to congratulate the winner of the Best Poster Award at the 4th German Pharm-Tox Summit—Stefanie Kowarschik.

The title and abstract of her work are presented below:

Title: Binding of the Yersinia pseudotuberculosis Cytotoxic Necrotizing Factor (CNFY) to its Cellular Receptor

Authors: Stefanie Kowarschik and Gudula Schmidt

Affiliation: Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Albertstr. 25, 79104 Freiburg, Germany

Abstract: CNFY is one of the major virulence factors of Yersinia pseudotuberculosis. The exotoxin belongs to the AB-like toxin family and shows a high similarity (~ 68%) to the other known CNFs. Their cellular targets are RhoGTPases, which are deamidated at a single glutamine, Gln 63 in RhoA. This glutamine is crucial for GTP hydrolysis. The toxin consists of three domains, an N-terminal, translocation and C-terminal catalytic domain. CNF1 and CNFY are homologous; however, we show that they bind to different cellular receptors. CNF1 is known to bind to Lu/BCAM, but the cellular receptor for CNFY remains unknown. Additionally, CNFY shows a different binding behaviour in cell intoxication studies compared with CNF1. Our data indicate that CNFY binds to HSPGs (heparansulfate proteoglycan), which are highly abundant structures on the cell surface, and it may also bind to a yet unidentified surface protein. Furthermore, differential intoxication of human and murine cell lines correlates with the relative abundance of HSPGs in these cells.