Tyrosine-modifying glycosylation by Yersinia effectors.

Mono-O-glycosylation of target proteins by bacterial toxins or effector proteins is a well-known mechanism by which bacteria interfere with essential functions of host cells. The respective glycosyltransferases are important virulence factors such as the Clostridioides difficile toxins A and B. Here, we describe two glycosyltransferases of Yersinia species that have a high sequence identity: YeGT from the zoonotic pathogen Yersinia enterocolitica and YkGT from the murine pathogen Yersinia kristensenii.

Antibodies Directed Against GalNAc- and GlcNAc-O-Tyrosine Posttranslational Modifications - a New Tool for Glycoproteomic Detection.

In the last decade, it was discovered that protein mucin-type O-glycosylation and O-GlcNAcylation modify Tyr residues besides the well explored Thr and Ser amino acids. Several glycoproteomic studies have identified α-GalNAc-O-Tyr modifications, and studies propose that β-GlcNAc-O-Tyr also exists as a new group of posttranslational modifications (PTMs). Specific bacterial toxins have further been identified to modify host GTPases with α-GlcNAc-O-Tyr to promote bacterial virulence.

Inhibition of Arp2/3 Complex after ADP-Ribosylation of Arp2 by Binary Toxins.

Clostridioides bacteria are responsible for life threatening infections. Here, we show that in addition to actin, the binary toxins CDT, C2I, and Iota from , , and , respectively, ADP-ribosylate the actin-related protein Arp2 of Arp2/3 complex and its additional components ArpC1, ArpC2, and ArpC4/5. The Arp2/3 complex is composed of seven subunits and stimulates the formation of branched actin filament networks.