title: Inhibition of protein kinase C affects on mode of synaptic vesicle exocytosis due to cholesterol depletion.
abstract: Previous studies demonstrated that depletion of membrane cholesterol by 10mM methyl-beta-cyclodextrin (MCD) results in increased spontaneous exocytosis at both peripheral and central synapses. Here, we investigated the role of protein kinase C in the enhancement of spontaneous exocytosis at frog motor nerve terminals after cholesterol depletion using electrophysiological and optical methods. Inhibition of the protein kinase C by myristoylated peptide and chelerythrine chloride prevented MCD-induced increases in FM1-43 unloading, whereas the frequency of spontaneous postsynaptic events remained enhanced. The increase in FM1-43 unloading still could be observed if sulforhodamine 101 (the water soluble FM1-43 quencher that can pass through the fusion pore) was added to the extracellular solution. This suggests a possibility that exocytosis of synaptic vesicles under these conditions could occur through the kiss-and-run mechanism with the formation of a transient fusion pore. Inhibition of phospholipase C did not lead to similar change in MCD-induced exocytosis.
authors.affiliation: Department of Normal Physiology, Kazan State Medical University, Kazan 420012, Russia. Electronic address: fysio@rambler.ru.
authors.forename: Alexey M
authors.initials: AM
authors.lastname: Petrov
authors.affiliation: Department of Normal Physiology, Kazan State Medical University, Kazan 420012, Russia. Electronic address: guzik121192@mail.ru.
authors.forename: Guzalija F
authors.initials: GF
authors.lastname: Zakyrjanova
authors.affiliation: Department of Normal Physiology, Kazan State Medical University, Kazan 420012, Russia. Electronic address: nastya1234qwer@mail.ru.
authors.forename: Anastasia A
authors.initials: AA
authors.lastname: Yakovleva
authors.affiliation: Department of Normal Physiology, Kazan State Medical University, Kazan 420012, Russia. Electronic address: zefiroval@rambler.ru.
authors.forename: Andrei L
authors.initials: AL
authors.lastname: Zefirov
mesh_terms: D000818:Animals; D053119:Benzophenanthridines / Q000737:chemistry; D002784:Cholesterol / Q000378:metabolism*; D004594:Electrophysiology; D004791:Enzyme Inhibitors / Q000737:chemistry*; D005089:Exocytosis / Q000187:drug effects*; D008856:Microscopy, Fluorescence; D019814:Myristic Acid / Q000737:chemistry; D009469:Neuromuscular Junction / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011898:Ranidae; D012235:Rhodamines / Q000737:chemistry; D009435:Synaptic Transmission / Q000187:drug effects; D013572:Synaptic Vesicles / Q000187:drug effects / Q000201:enzymology*; D010738:Type C Phospholipases / Q000378:metabolism; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D053119:Benzophenanthridines; D004791:Enzyme Inhibitors; D012235:Rhodamines; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D019814:Myristic Acid; D002784:Cholesterol; C016299:chelerythrine; D011493:Protein Kinase C; D010738:Type C Phospholipases; C050829:sulforhodamine 101
keywords: Cholesterol; Kiss-and-run; Neuromuscular junction; Protein kinase C; Synaptic vesicle exocytosis