Figure 4.

A Generalized Scheme Illustrating the Functional Diversity of Rop GTPases.

Rop signaling controls many processes and involves many Rop-interacting proteins. Different Rops may interact differentially with different Rop regulators and target proteins to produce functionally distinct Rop signaling pathways. Rop regulation involves not only activation by an unknown mechanism and deactivation by RopGAPs and Rop GDIs, but also compartmentation in specific membranes or membrane domains. In addition to the PM as shown in this figure, Rop is also found in specific PM domains and other compartments such as vacuoles. Targeting to specific compartments could require specific unknown recruiting or docking proteins. Functionally distinct Rop targets including various RICs and possibly other unknown proteins are proposed to control specific downstream effects to achieve functional specificity of each Rop-dependent pathway.