| 7566122 |
Jouaville LS, Ichas F, Holmuhamedov EL, Camacho P, Lechleiter JD: Synchronization of calcium waves by mitochondrial substrates in Xenopus laevis oocytes. J Neurosci. 2005 Oct 26;25(43):10029-40.
In Xenopus oocytes, as well as other cells, inositol-1,4,5-trisphosphate (Ins (1,4,5) P3)-induced Ca2+ release is an excitable process that generates propagating Ca2+ waves that annihilate upon collision. The fundamental property responsible for excitability appears to be the Ca2+ dependency of the Ins (1,4,5) P3 receptor. Here we report that Ins (1,4,5) P3-induced Ca2+ wave activity is strengthened by oxidizable substrates that energize mitochondria, increasing Ca2+ wave amplitude, velocity and interwave period. The effects of pyruvate/malate are blocked by ruthenium red at the Ca2+ uniporter, by rotenone at complex I, and by antimycin A at complex III, and are subsequently rescued at complex IV by ascorbate tetramethylphenylenediamine (TMPD). Our data reveal that potential-driven mitochondrial Ca2+ uptake is a major factor in the regulation of Ins (1,4,5) P3-induced Ca2+ release and clearly demonstrate a physiological role of mitochondria in intracellular Ca2+ signalling. |
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