Identification and Classification of Rho GTPases in Plants

Abstract

Small GTPases have emerged as a key molecular switch for the fine modulation of many plant-specific signaling pathways and their related functions. Some novel plant-specific GTPases have evolved with the functional innovation of already conserved GTPase together with the birth of new members that has equipped plant kingdom with unique functional capability. Plant small GTPase superfamily is divided into four families: Rho, Rab, Arf, and Ran. Plant Rhos are referred to as ROP (for Rho of plants), RAC (for the sequence similarity they share with animal Racs, a Rho subfamily). The Rab, Arf, and Ran families are widely conserved across eukaryotes and they participate in characteristic eukaryotic cellular processes. Moreover, Arf, Rab, and Ran appear to play a role in fundamental cellular responses; they are not usually considered as signaling proteins that transmit extracellular signals.