論文 - 詳細
| RRC ID | 42727 |
|---|---|
| 著者 | Sakai H, Kawawaki J, Moriura Y, Mori H, Morihata H, Kuno M. |
| タイトル | pH dependence and inhibition by extracellular calcium of proton currents via plasmalemmal vacuolar-type H+-ATPase in murine osteoclasts. |
| ジャーナル | J Physiol |
| Abstract |
The vacuolar-type H(+)-ATPase (V-ATPase) in the plasma membrane of a variety of cells serves as an acid-secreting pathway, and its activity is closely related to cellular functions. Massive proton secretion often leads to electrolyte disturbances in the vicinity of the cell and may in turn affect the activity of the V-ATPase. We characterized, for the first time, the proton currents mediated by plasmalemmal V-ATPase in murine osteoclast-like cells and investigated its activity over a wide range of pH gradients across the membrane (DeltapH = extracellular pH - intracellular pH). The V-ATPase currents were identified as outward H(+) currents and were dependent on ATP and sensitive to the inhibitors bafilomycin A(1) and N,N'-dicyclohexylcarbodiimide. Although H(+) was transported uphill, the electrochemical gradient for H(+) affected the current. The currents were increased by elevating DeltapH and depolarization, and were reduced by lowering DeltapH and hyperpolarization. Elevation of extracellular Ca(2+) (5-40 mm) diminished the currents in a dose-dependent manner and made the voltage dependence more marked. Extracellular Mg(2+) mimicked the inhibition. With 40 mm Ca(2+), the currents decreased to < 40% at 0 mV and to < 10% at about -80 mV. Increases in the intracellular Ca(2+) (0.5-5 microm) did not affect the current. The data suggest that acid secretion through the plasmalemmal V-ATPase is regulated by a combination of the pH gradient, the membrane potential and the extracellular divalent cations. In osteoclasts, the activity-dependent accumulation of acids and Ca(2+) in the closed extracellular compartment might serve as negative feedback signals for regulating the V-ATPase. |
| 巻・号 | 576(Pt 2) |
| ページ | 417-25 |
| 公開日 | 2006-10-15 |
| DOI | 10.1113/jphysiol.2006.117176 |
| PII | jphysiol.2006.117176 |
| PMID | 16901940 |
| PMC | PMC1890368 |
| MeSH | Animals Calcium / pharmacology* Cell Line Cell Membrane / enzymology* Dicyclohexylcarbodiimide / pharmacology Dose-Response Relationship, Drug Electrophysiology Enzyme Inhibitors / pharmacology Hydrogen-Ion Concentration Intracellular Membranes / enzymology Macrolides / pharmacology Membrane Potentials / drug effects Membrane Potentials / physiology Mice Osteoclasts / drug effects Osteoclasts / enzymology Osteoclasts / physiology Patch-Clamp Techniques Proton-Translocating ATPases / physiology* Protons* |
| IF | 4.547 |
| 引用数 | 13 |
| WOS 分野 | PHYSIOLOGY NEUROSCIENCES |
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オルトメトリクス指標項目
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| 最多言及媒体 | Blogs |
| 各媒体での言及数の合計 | 1 |
| 過去6か月間でのオルトメトリクス指標の変動値 | 0.0 |
| リソース情報 | |
| ヒト・動物細胞 | RAW 264(RCB0535) |