title: Aequorin luminescence-based functional calcium assay for heterotrimeric G-proteins in Arabidopsis.
abstract: Heterotrimeric GTP-binding proteins (G-proteins) and G-protein-coupled receptors are important signaling components in eukaryotes. In plants, the G-proteins are involved in diverse physiological processes, some of which are exerted via changes in the level of cytosolic free calcium concentration ([Ca(2+)]cyt). Various techniques have been developed to measure the change of [Ca(2+)]cyt, e.g., calcium-sensitive microelectrodes, chemical fluorescent dyes, and biosensors based on luminescent or fluorescent indicators. In this chapter, we describe a protocol for in vivo [Ca(2+)]cyt measurement in G-protein mutants expressing aequorin, a luminescent-based calcium biosensor, to extend our knowledge about G-protein mediated Ca(2+) signaling. This method is also applicable to other early signaling events that are mediated by changes in [Ca(2+)]cyt levels.
authors.affiliation: Divisions of Plant Science and Biochemistry, University of Missouri, Columbia, MO, USA.
authors.forename: Kiwamu
authors.initials: K
authors.lastname: Tanaka
authors.forename: Jeongmin
authors.initials: J
authors.lastname: Choi
authors.forename: Gary
authors.initials: G
authors.lastname: Stacey
mesh_terms: D000331:Aequorin / Q000737:chemistry; D017360:Arabidopsis / Q000378:metabolism; D015374:Biosensing Techniques / Q000379:methods*; D002118:Calcium / Q000302:isolation & purification* / Q000378:metabolism; D020013:Calcium Signaling / Q000235:genetics; D003600:Cytosol / Q000378:metabolism; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism*; D049449:Luminescence; D008163:Luminescent Measurements / Q000379:methods
chemical_list: D000331:Aequorin; D020962:Heterotrimeric GTP-Binding Proteins; D002118:Calcium