| RRC ID |
18749
|
| 著者 |
Sakai H, Moriura Y, Notomi T, Kawawaki J, Ohnishi K, Kuno M.
|
| タイトル |
Phospholipase C-dependent Ca2+-sensing pathways leading to endocytosis and inhibition of the plasma membrane vacuolar H+-ATPase in osteoclasts.
|
| ジャーナル |
Am J Physiol Cell Physiol
|
| Abstract |
In osteoclasts, elevation of extracellular Ca2+ is an endogenous signal that inhibits bone resorption. We recently found that an elevation of extracellular Ca2+ decreased proton extrusion through the plasma membrane vacuolar H+-ATPase (V-ATPase) rapidly. In this study we investigated mechanisms underlying this early Ca2+-sensing response, particularly in reference to the activity of the plasma membrane V-ATPase and to membrane retrieval. Whole cell clamp recordings allowed us to measure the V-ATPase currents and the cell capacitance (C(m)) simultaneously. C(m) is a measure of cell surface. Extracellular Ca2+ (2.5-40 mM) decreased C(m) and the V-ATPase current simultaneously. The decreased C(m), together with the enhanced uptake of a lipophilic dye (FM1-43), indicated that Ca2+ facilitated endocytosis. The endocytosis was blocked by dynamin inhibitors (dynasore and dynamin-inhibitory peptide), by small interfering RNA (siRNA) targeting for dynanmin-2 and also by bafilomycin A(1), a blocker of V-ATPases. The extracellular Ca2+-induced endocytosis and inhibition of the V-ATPase current were diminished by a phospholipase C inhibitor (U73122) and siRNA targeting for phospholipase C gamma2 subunit. Holding the cytosolic Ca2+ at either high (0.5-5 microM) or low levels or inhibiting calmodulin by an inhibitor (W7) or an antibody (anti-CaM) decreased the stimulated endocytosis and the inhibition of the V-ATPase current. These data suggest that extracellular Ca2+ facilitated dynamin- and V-ATPase-dependent endocytosis in association with an inhibition of the plasma membrane V-ATPase. Phospholipase C, cytosolic Ca2+, and calmodulin were involved in the signaling pathways. Membrane retrieval and the plasma membrane V-ATPase activity may cooperate during the early phase of Ca2+-sensing response in osteoclasts.
|
| 巻・号 |
299(3)
|
| ページ |
C570-8
|
| 公開日 |
2010-9-1
|
| DOI |
10.1152/ajpcell.00486.2009
|
| PII |
ajpcell.00486.2009
|
| PMID |
20592242
|
| MeSH |
Animals
Calcium / metabolism*
Calmodulin / metabolism
Cell Line
Cell Membrane / metabolism*
Cytosol / metabolism
Dynamins / metabolism
Electric Capacitance
Endocytosis*
Extracellular Space / metabolism
Mice
Osteoclasts / metabolism*
Patch-Clamp Techniques
Signal Transduction
Type C Phospholipases / physiology*
Vacuolar Proton-Translocating ATPases / antagonists & inhibitors*
Vacuolar Proton-Translocating ATPases / physiology
|
| IF |
3.485
|
| 引用数 |
21
|
|
WOS 分野
|
PHYSIOLOGY
CELL BIOLOGY
|
| リソース情報 |
| ヒト・動物細胞 |
RAW 264(RCB0535) |
