The Store-operated Calcium Entry Pathways in Human Carcinoma A431 Cells
| Autor: | Elena Kaznacheyeva, Zhengnan Wang, Alexander Zubov, Konstantin Gusev, Lyuba Glouchankova, Ilya Bezprozvanny, Galina N. Mozhayeva |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
chemistry.chemical_classification
Membrane potential 0303 health sciences Phospholipase C Voltage-dependent calcium channel Physiology Store-operated calcium entry 3. Good health Divalent Cell biology 03 medical and health sciences 0302 clinical medicine chemistry Patch clamp 030217 neurology & neurosurgery Intracellular 030304 developmental biology Calcium signaling |
| Zdroj: | Journal of General Physiology. 122:81-94 |
| ISSN: | 1540-7748 0022-1295 |
| DOI: | 10.1085/jgp.200308815 |
| Popis: | Activation of phospholipase C (PLC)-mediated signaling pathways in nonexcitable cells causes the release of Ca2+ from intracellular Ca2+ stores and activation of Ca2+ influx across the plasma membrane. Two types of Ca2+ channels, highly Ca2+–selective ICRAC and moderately Ca2+–selective ISOC, support store-operated Ca2+ entry process. In previous patch-clamp experiments with a human carcinoma A431 cell line we described store-operated Imin/ICRACL plasma membrane Ca2+ influx channels. In the present paper we use whole-cell and single-channel recordings to further characterize store-operated Ca2+ influx pathways in A431 cells. We discovered that (a) ICRAC and ISOC are present in A431 cells; (b) ICRAC currents are highly selective for divalent cations and fully activate within 150 s after initiation of Ca2+ store depletion; (c) ISOC currents are moderately selective for divalent cations (PBa/PCs = 14.5) and require at least 300 s for full activation; (d) ICRAC and ISOC currents are activated by PLC-coupled receptor agonists; (e) ISOC currents are supported by Imin/ICRACL channels that display 8.5–10 pS conductance for sodium; (f) ICRAC single channel conductance for sodium is estimated at 0.9 pS by the noise analysis; (g) Imin/ICRACL channels are activated in excised patches by an amino-terminal fragment of InsP3R1 (InsP3R1N); and (h) InsP3 binding to InsP3R1N is necessary for activation of Imin/ICRACL channels. Our findings provide novel information about store-operated Ca2+ influx pathways in A431 cells. |
| Databáze: | OpenAIRE |
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