Comparative proteomic identification of Rab GTPase interactors in Arabidopsis

Rab GTPases are key spatio-temporal regulators of endomembrane trafficking and endomembrane compartment identity across eukaryotes. This therefore makes them ideal targets for study of endomembrane compartment and trafficking pathway composition. In plants, few definitive interactors of Rab GTPases and cargoes of their associated trafficking pathways are known, hindering our understanding of how plants may accomplish and support some unique aspects and requirements of their post-Golgi trafficking systems. The purpose of this work was to identify candidate interactors of different post-Golgi Rab GTPases in Arabidopsis. Co-IPs were performed against tagged-versions of three different post-Golgi Rab GTPases: RAB-A5c, RAB-A2a and RAB-G3f, as well as against control wild-type (Col-0) plants. Comparative ranking of the different proteomes produced candidate interactor lists enriched in possible specific interactors of each Rab GTPase, as well as generic shared interactors. This dataset forms the basis of the characterisation work of several upcoming publications.