title: The role of PLDα1 in providing specificity to signal-response coupling by heterotrimeric G-protein components in Arabidopsis.
abstract: Heterotrimeric G-proteins comprised of Gα, Gβ and Gγ subunits are important signal transducers in all eukaryotes. In plants, G-proteins affect multiple biotic and abiotic stress responses, as well as many developmental processes, even though their repertoire is significantly limited compared with that in metazoan systems. One canonical and three extra-large Gα, 1 Gβ and 3 Gγ proteins represent the heterotrimeric G-protein complex in Arabidopsis, and a single regulatory protein, RGS1, is one of the few known biochemical regulators of this signaling complex. This quantitative disparity between the number of signaling components and the range of processes they influence is rather intriguing. We now present evidence that the phospholipase Dα1 protein is a key component and modulator of the G-protein complex in affecting a subset of signaling pathways. We also show that the same G-protein subunits and their modulators exhibit distinct physiological and genetic interactions depending on specific signaling and developmental pathways. Such developmental plasticity and interaction specificity likely compensates for the lack of multiplicity of individual subunits, and helps to fine tune the plants' responses to constantly changing environments.
authors.affiliation: Donald Danforth Plant Science Center, 975 N. Warson Road, St. Louis, MO, 63132, USA.
authors.forename: Swarup
authors.initials: S
authors.lastname: Roy Choudhury
authors.affiliation: Donald Danforth Plant Science Center, 975 N. Warson Road, St. Louis, MO, 63132, USA.
authors.forename: Sona
authors.initials: S
authors.lastname: Pandey
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018525:Germination; D020962:Heterotrimeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D025941:Protein Interaction Mapping; D021122:Protein Subunits; D020710:RGS Proteins / Q000235:genetics / Q000378:metabolism; D012313:RNA; D036226:Seedlings / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D021122:Protein Subunits; D020710:RGS Proteins; C477755:RGS1 protein, Arabidopsis; C039919:RNA, recombinant; D012313:RNA; D000040:Abscisic Acid; C582894:PLDA1 protein, Arabidopsis; D010739:Phospholipase D; D020962:Heterotrimeric GTP-Binding Proteins
keywords: Arabidopsis thaliana; G-protein cycle regulation; GAP activity; RGS1; abscisic acid; heterotrimeric G-proteins; phospholipase Dα1; protein-protein interaction; regulator of G-protein signaling