Disruption of signaling by Yersinia effector YopJ, a ubiquitin-like protein protease

Homologs of the Yersinia virulence effector YopJ are found in both plant an d animal bacterial pathogens, as well as plant symbionts. These YopJ family members were shown to act as cysteine proteases. The catalytic triad of th e protease was required for inhibition of the mitogen-activated protein kin ase (MAPK) and nuclear factor kappaB (NF-kappaB) signaling in animal cells and for induction of Localized cell death in plants. The substrates for Yop J were shown to be highly conserved ubiquitin-like molecules, which are cov alently added to numerous regulatory proteins. YopJ family members exert th eir pathogenic effect on cells by disrupting this posttranslational modific ation.