title: Regulation of presynaptic phosphatidylinositol 4,5-biphosphate by neuronal activity.
abstract: Phosphatidylinositol 4,5-biphosphate (PIP2) has been implicated in a variety of cellular processes, including synaptic vesicle recycling. However, little is known about the spatial distribution of this phospholipid in neurons and its dynamics. In this study, we have focused on these questions by transiently expressing the phospholipase C (PLC)-delta1 pleckstrin homology (PH) domain fused to green fluorescent protein (GFP) in cultured hippocampal neurons. This PH domain binds specifically and with high affinity to PIP2. Live confocal imaging revealed that in resting cells, PH-GFP is localized predominantly on the plasma membrane. Interestingly, no association of PH-GFP with synaptic vesicles in quiescent neurons was observed, indicating the absence of detectable PIP2 on mature synaptic vesicles. Electrical stimulation of hippocampal neurons resulted in a decrease of the PH-GFP signal at the plasma membrane, most probably due to a PLC-mediated hydrolysis of PIP2. This was accompanied in the majority of presynaptic terminals by a marked increase in the cytoplasmic PH-GFP signal, localized most probably on freshly endocytosed membranes. Further investigation revealed that the increase in PH-GFP signal was dependent on the activation of N-methyl-D-aspartate receptors and the consequent production of nitric oxide (NO). Thus, PIP2 in the presynaptic terminal appears to be regulated by postsynaptic activity via a retrograde action of NO.
authors.affiliation: Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA. kmicheva@stanford.edu
authors.forename: K D
authors.initials: KD
authors.lastname: Micheva
authors.forename: R W
authors.initials: RW
authors.lastname: Holz
authors.forename: S J
authors.initials: SJ
authors.lastname: Smith
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004558:Electric Stimulation; D004705:Endocytosis / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005089:Exocytosis / Q000187:drug effects; D049452:Green Fluorescent Proteins; D006624:Hippocampus; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics; D008856:Microscopy, Fluorescence; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D009569:Nitric Oxide / Q000096:biosynthesis; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D054803:Phospholipase C delta; D010750:Phosphoproteins / Q000235:genetics; D017729:Presynaptic Terminals / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000502:physiology; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D013572:Synaptic Vesicles / Q000378:metabolism; D014162:Transfection; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D001798:Blood Proteins; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D008164:Luminescent Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; D010750:Phosphoproteins; D016194:Receptors, N-Methyl-D-Aspartate; D011993:Recombinant Fusion Proteins; C039077:platelet protein P47; D049452:Green Fluorescent Proteins; D009569:Nitric Oxide; D010738:Type C Phospholipases; D054803:Phospholipase C delta; C518026:Plcd1 protein, rat