title: N-terminal EF-hand-like domain is required for phosphoinositide-specific phospholipase C activity in Arabidopsis thaliana.
abstract: Phosphoinositide-specific phospholipase C's (PI-PLCs) are ubiquitous in eukaryotes, from plants to animals, and catalyze the hydrolysis of phosphatidylinositol 4,5-bisphosphate into the two second messengers inositol 1,4,5-trisphosphate and diacylglycerol. In animals, four distinct subfamilies of PI-PLCs have been identified, and the three-dimensional structure of one rat isozyme, PLC-delta1, determined. Plants appear to contain only one gene family encoding PI-PLCs. The catalytic properties of plant PI-PLCs are very similar to those of animal enzymes. However, very little is known about the regulation of plant PI-PLCs. All plant PI-PLCs comprise three domains, X, Y and C2, which are also conserved in isoforms from animals and yeast. We here show that one PI-PLC isozyme from Arabidopsis thaliana, AtPLC2, is predominantly localized in the plasma membrane, and that the conserved N-terminal domain may represent an EF-hand domain that is required for catalytic activity but not for lipid binding.
authors.affiliation: Department of Plant Biochemistry, Lund University, P.O. Box 117, SE-221 00, Lund, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Otterhag
authors.forename: M
authors.initials: M
authors.lastname: Sommarin
authors.forename: C
authors.initials: C
authors.lastname: Pical
mesh_terms: D017360:Arabidopsis / Q000201:enzymology*; D002384:Catalysis; D002462:Cell Membrane / Q000201:enzymology; D017124:Conserved Sequence; D004075:Diglycerides / Q000096:biosynthesis; D020832:EF Hand Motifs / Q000502:physiology*; D015544:Inositol 1,4,5-Trisphosphate / Q000096:biosynthesis; D007527:Isoenzymes / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D017434:Protein Structure, Tertiary / Q000502:physiology; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D010738:Type C Phospholipases / Q000378:metabolism*
chemical_list: D004075:Diglycerides; D007527:Isoenzymes; D019269:Phosphatidylinositol 4,5-Diphosphate; D015544:Inositol 1,4,5-Trisphosphate; D010738:Type C Phospholipases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase