Molecular Determinants of Resistance Activation and Suppression by Phytophthora infestans Effector IPI-O
The top panel represents a resistance response. In the absence of IPI-O1, RB remains in a resting state. The presence of IPI-O1 elicits a conformational change that enables RB oligomerization through the CC domain and leads to an activated protein state. As shown in the bottom panel, when IPI-O4 is present, this effector interacts with the CC domain and prevents CC oligomerization, thus suppressing RB activation.