Abstract
We have examined the electrophysiological responses induced by aluminium fluoride (AlF4-) and carbachol in Xenopus oocytes. Application of AlF4- induced Ca2+-dependent oscillatory and smooth C1- currents. Pre-treatment of oocytes with microinjected guanosine 5'-0 (2-thiodiphosphate) diminished the currents, indicating that the effect of AlF4- occurred through G-protein activation. Confocal imaging of intracellular Ca2+ clearly demonstrated that AlF4- could increase the internal Ca2+ concentration in oocytes in the absence of external Ca2+. A protein kinase (PK) activator (4-β-phorbol 12,13-dibutyrate) decreased the AlF4- induced membrane currents, whereas a PK inhibitor (staurosporine) caused an increase. On the other hand, the protein phosphatase inhibitor (okadaic acid) showed little effect. Although the effects of the phosphorylating/dephosphorylating agents on the carbachol-induced currents were qualitatively similar to the case of AlF4-, some quantitative difference was noted. The results are discussed in terms of the signaling pathways involving muscarinic receptors and G-protein(s) in Xenopus oocytes.
Original language | English (US) |
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Pages (from-to) | 497-504 |
Number of pages | 8 |
Journal | Cellular Signalling |
Volume | 9 |
Issue number | 7 |
DOIs | |
State | Published - Nov 1997 |
Externally published | Yes |
Keywords
- Acetylcholine
- Aluminium fluoride
- Calcium
- G-protein
- Phosphatidyl inositol
- Phosphorylation
- Xenopus oocyte
ASJC Scopus subject areas
- Cell Biology