a-Latrotoxin Triggers an Increase of Ionized Calcium in Xenopus Oocytes Injectedwith Rat Brain mRNA

摘要

When Xenopus oocytes are injected with rat brain mRNA, they acquire the abilityto respond to bath applied a-latrotoxin. This spider venom toxin is normally highly selective for nerve endings, where its binding is associated with a high-frequency, quantal discharge of neurotransmitter. By transplanting toxin acceptor sites to Xenopus oocytes, we have observed both a toxin-mediated rise in cellular ionized Ca along with the triggering of a calcium-dependent chloride channel in these cells. This approach may contribute both to a better understanding of the mechanism of action of this toxin and to efforts to clone the cDNA for this binding site. Keywords: Xenopus oocyte; Alpha Latrotoxin; mRNA; Cytoplasmic calcium. (js)