ROPGEF1 and ROPGEF4 are functional regulators of ROP11 GTPase in ABA-mediated stomatal closure in Arabidopsis

ROPs constitute a family of plant-specific, RHO-like small GTPases that serve as molecular switches in a wide range of signaling pathways. The activities of ROPs are regulated by guanine nucleotide exchange factors (GEFs). ROP11, a member of the ROP GTPase family in Arabidopsis, is a negative regulator of multiple ABA responses. In this study, we show that ROPGEF1 and ROPGEF4 interact with ROP11 on plasma membranes in guard cells. Furthermore, our analyses of ROPGEF1/4 knockout mutants and overexpressing lines suggested that ROPGEF1 and ROPGEF4 are specific regulators of ROP11 function in ABA-mediated stomatal closure. Structured summary of protein interactions: ROPGEF9 and Rop11 physically interact by protein complementation assay (View interaction) ROPGEF9 physically interacts with Rop11 by two hybrid (View interaction) ROPGEF1 and Rop11 physically interact by bimolecular fluorescence complementation (View interaction) ROPGEF4 physically interacts with Rop11 by two hybrid (View interaction) ROPGEF2 and Rop11 physically interact by protein complementation assay (View interaction) Rop11 physically interacts with ROPGEF1 by anti tag coimmunoprecipitation (View interaction) ROPGEF1 and Rop11 physically interact by protein complementation assay (View interaction) ROPGEF4 and Rop11 physically interact by protein complementation assay (View interaction) ROPGEF8 physically interacts with Rop11 by two hybrid (View interaction) ROPGEF8 and Rop11 physically interact by protein complementation assay (View interaction) ROPGEF2 physically interacts with Rop11 by two hybrid (View interaction) Rop11 physically interacts with ROPGEF4 by anti tag coimmunoprecipitation (View interaction) ROPGEF4 and Rop11 physically interact by bimolecular fluorescence complementation (View interaction) ROPGEF1 physically interacts with Rop11 by two hybrid (View interaction) (C) 2012 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.