title: Subcortical Ca2+ waves sneaking under the plasma membrane in endothelial cells.
abstract: Subplasmalemmal Ca2+, dynamically equilibrated with extracellular Ca2+, affects numerous signaling molecules, effectors, and events within this restricted space. We demonstrated the presence of a novel Ca2+ wave propagating beneath the plasma membrane in response to acute elevation of extracellular [Ca2+], by targeting a Ca2+ sensor, cameleon, to the endothelial plasmalemma. These subcortical waves, spatially distinct from classical cytosolic Ca2+ waves, originated in localized regions and propagated throughout the subplasmalemma. Translocation of an expressed GFP fused with a PH domain of PLC from the plasma membrane to the cytosol accompanied these subcortical waves, and U73122 attenuated not only the GFP-PH translocation, but also the peak amplitude of the subcortical Ca2+ waves; this finding suggests the involvement of local IP3 production through PLC-mediated PIP2 hydrolysis in the initiation of these waves. Changes in NO production as well as PKCbeta-GFP translocation from the cytosol to the plasma membrane, but not of GFP-PLA2 to perinuclear endomembranes, were associated with the subplasmalemmal Ca2+ changes. Thus, extracellular Ca2+ maintains the basal PLC activity of the plasma membrane, is involved in the initiation of compartmentalized subcortical Ca2+ waves, and regulates Ca2+-dependent signaling molecules residing in or translocated to the plasma membrane. The full text of this article is available online at http://circres.ahajournals.org.
authors.affiliation: Department of Nephrology and Endocrinology, Faculty of Medicine, Tokyo University, Tokyo 113-8655, Japan. isshiki-tky@umin.ac.jp
authors.forename: Masashi
authors.initials: M
authors.lastname: Isshiki
authors.forename: Akiko
authors.initials: A
authors.lastname: Mutoh
authors.forename: Toshiro
authors.initials: T
authors.lastname: Fujita
mesh_terms: D020816:Amino Acid Motifs; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000378:metabolism; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000502:physiology*; D003600:Cytosol / Q000378:metabolism; D042783:Endothelial Cells / Q000502:physiology* / Q000648:ultrastructure; D004730:Endothelium, Vascular / Q000166:cytology* / Q000502:physiology; D004963:Estrenes / Q000494:pharmacology; D045604:Extracellular Fluid / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000032:analysis; D019922:GAP-43 Protein / Q000235:genetics; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics; D017136:Ion Transport / Q000502:physiology; D007527:Isoenzymes / Q000235:genetics; D008565:Membrane Proteins / Q000502:physiology*; D018613:Microscopy, Confocal; D009569:Nitric Oxide / Q000378:metabolism; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D054803:Phospholipase C delta; D010741:Phospholipases A / Q000235:genetics; D054467:Phospholipases A2; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D064546:Protein Kinase C beta; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011760:Pyrrolidinones / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D010738:Type C Phospholipases / Q000235:genetics
chemical_list: D002135:Calcium-Binding Proteins; D004963:Estrenes; D005456:Fluorescent Dyes; D019922:GAP-43 Protein; D007527:Isoenzymes; D008565:Membrane Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; D011760:Pyrrolidinones; D011993:Recombinant Fusion Proteins; C485192:green fluorescent protein, Aequorea victoria; C495639:yellow cameleon; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D049452:Green Fluorescent Proteins; D009569:Nitric Oxide; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D010741:Phospholipases A; D054467:Phospholipases A2; D010738:Type C Phospholipases; D054803:Phospholipase C delta; D002118:Calcium