Acetylation of ARID proteins by Ralstonia solanacearum effector PopP2 in plants

Like many gram-negative phytopathogenic bacteria, Ralstonia solanacearum uses a type III secretion system to deliver into host cells a cocktail of effector proteins that can interfere with plant defences and promote infection. One of these effectors, the nuclear-targeted PopP2 acetyltransferase, was reported to inhibit many defensive WRKY transcription factors through acetylation. To gain a better understanding of the mechanisms by which PopP2 might exert its virulence functions, we searched for other PopP2-interacting partners. Here we report the identification of the Arabidopsis thaliana AT-Rich Interaction Domain protein 3 (ARID3) and its close homologs, ARID2 and ARID4 as additional targets of PopP2.