Cysteine protease avirulence protein AvrRpt2
Pseudomonas syringae pv. tomato
Effector protein involved in gene-for-gene resistance in plants expressing RPS2. Its thiol protease activity is required for the degradation of plant cell RIN4 and consequent activation of RPS2 during bacterial infection. The activation of RPS2 is sufficient for the induction of hypersensitive response (HR) and plant resistance. Cleavage of RIN4 by AvrRpt2 also interferes with RPM1-mediated resistance activated by either AvrRpm1 or AvrB. Contributes to virulence in plants lacking the resistance protein RPS2 promoting pathogen growth and disease symptoms. Inhibits PAMP (pathogen-associated molecular patterns)-induced signaling compromising the host's basal defense system. Blocks plant callose deposition, flg22 (a peptide corresponding to the most conserved domain of flagellin) induced accumulation of PR-1, PR-2 and PR-5 and activation of GST6 transcription. The mechanism of virulence is unknown, but this activity is independent of ethylene and salicylic acid response pathways and independent of RIN4 disappearance.
Belongs to the peptidase C70 family.