Heterotrimeric G proteins control stem cell proliferation through CLAVATA signaling in Arabidopsis

Abstract

Cell-to-cell communication is a fundamental mechanism for coordinating developmental and physiological events in multicellular organisms. Heterotrimeric G proteins are key molecules that transmit extracellular signals; similarly, CLAVATA signaling is a crucial regulator in plant development. Here, we show that Arabidopsis thaliana Gb mutants exhibit an enlarged stem cell region, which is similar to that of clavata mutants. Our genetic and cell biological analyses suggest that the G protein beta-subunit1 AGB1 and RPK2, one of the major CLV3 peptide hormone receptors, work synergistically in stem cell homeostasis through their physical interactions. We propose that AGB1 and RPK2 compose a signaling module to facilitate meristem development.

Phosphorylation-Dependent Regulation of G-Protein Cycle during Nodule Formation in Soybean

“…In metazoan systems, Ga proteins are known to interact with GPCRs, whereas data from various plant species suggest that the plant Ga proteins may couple with additional cell surfacelocalized receptors such as LRR family receptor kinases (Bommert et al, 2013;Liu et al, 2013;Ishida et al, 2014). Toward this, we have previously shown that the soybean Ga proteins interact with the NFR1 receptors .…”

“…These include several receptor-like kinases (RLKs) that have been shown to directly interact with Ga proteins (Bommert et al, 2013;. Similarly, many established pathways that are controlled by well-defined RLKs have been shown to involve members of G-protein complex (Llorente et al, 2005;Bommert et al, 2013;Liu et al, 2013;Ishida et al, 2014). However, in most cases, the mechanism by which the receptors regulate the G-protein cycle remains unknown.…”

Membrane-Localized Extra-Large G Proteins and Gβγ of the Heterotrimeric G Proteins Form Functional Complexes Engaged in Plant Immunity in Arabidopsis

“…Recently, a direct interaction between Gb subunit and Receptor-like Protein Kinase2, a receptor for the CLAVATA3 (CLV3) peptide, has been reported (Ishida et al, 2014). Intriguingly, this study showed that Gb and Gg subunits, but not Ga, are involved in CLV3 signaling (Ishida et al, 2014). Further research is needed to understand a mechanism of action involving RLKs, Gbg, and XLGs.…”

Direct Modulation of Heterotrimeric G Protein-coupled Signaling by a Receptor Kinase Complex

“…Arabidopsis has more than 400 receptor-like kinases (RLKs) consisting of an extracellular domain, each potentially recognizing one among a wide range of ligands, a single-pass transmembrane domain, and a cytoplasmic kinase domain having homology to the Drosophila Pelle family of kinases (10 -12). Accumulating genetic evidence suggests that some of these RLKs serve as receptors or co-receptors in G protein-coupled signaling in plants to mediate proper development, pathogen defense, and cell death (13)(14)(15)(16)(17)(18); however, there is no direct biochemical evidence to support this idea.…”