Main content area

Heterotrimeric G proteins interact with defense-related receptor-like kinases in Arabidopsis

Aranda-Sicilia, María Nieves, Trusov, Yuri, Maruta, Natsumi, Chakravorty, David, Zhang, Yuelin, Botella, José Ramón
Journal of plant physiology 2015 v.188 pp. 44-48
Arabidopsis, G-protein coupled receptors, G-proteins, animals, eukaryotic cells, fluorescence, phosphotransferases (kinases), signal transduction, yeasts
Heterotrimeric G proteins (G-proteins) are versatile signaling elements conserved in Eukaryotes. In animals G-proteins relay signals from 7-transmembrane spanning G protein-coupled receptors (GPCRs) to intracellular downstream effectors; however, the existence of GPCRs in plants is controversial. Contrastingly, a surplus of receptor-like kinases (RLKs) provides signal recognition at the plant cell surface. It is established that G proteins are involved in plant defense and suggested that they relay signals from defense-related RLKs. However, it is unclear how the signaling is conducted, as physical interaction between the RLKs and G proteins has not been demonstrated. Using yeast split-ubiquitin system and Bimolecular Fluorescence Complementation assays, we demonstrate physical interaction between the Gα, Gγ1 and Gγ2 subunits, and the defense-related RD-type receptor like kinases CERK1, BAK1 and BIR1. At the same time, no interaction was detected with the non-RD RLK FLS2. We hypothesize that G-proteins mediate signal transduction immediately downstream of the pathogenesis-related RLKs.