Expression of receptor for α-latrotoxin in Xenopus oocytes after injection of mRNA from rat brain
| Autor: | G.P. Tsurupa, E.M. Kobrinsky, Eugene V. Grishin, A.K. Filippov, V.N. Pashkov |
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| Rok vydání: | 1990 |
| Předmět: |
Microinjections
Receptors Peptide Latrotoxin Xenopus Spider Venoms Biology complex mixtures Membrane Potentials Xenopus laevis chemistry.chemical_compound Concanavalin A Animals Receptors Cholinergic RNA Messenger Receptor Reversal potential Egtazic Acid Membrane potential HEPES General Neuroscience Brain Cobalt biology.organism_classification Molecular biology Rats EGTA chemistry Oocytes Biophysics biology.protein Calcium Female |
| Zdroj: | Neuroscience. 39:809-814 |
| ISSN: | 0306-4522 |
| DOI: | 10.1016/0306-4522(90)90263-4 |
| Popis: | alpha-Latrotoxin, the major toxin of black widow spider venom, was suggested to bind to the specific receptor on the membrane of presynaptic cells and to activate a nonselective cation channel. The aim of this investigation was to express the receptor to alpha-latrotoxin in the membrane of Xenopus laevis oocytes. Responses to alpha-latrotoxin were studied using a double microelectrode voltage-clamp technique on X. laevis oocytes previously injected with poly(A+)-RNA from rat brain. alpha-Latrotoxin (10 nM) was shown to induce a slow activating reversible inward membrane current at a clamp potential of -60 mV. A second application of alpha-latrotoxin immediately after washing out induced a smaller response. Reversal potential of this current was near to 0 mV; it hardly changed in low Cl- external solution. Response to alpha-latrotoxin did not depend significantly on the variation of Ca2+ concentration in external solution. Ethyleneglycolbis(aminoethylether)tetra-acetate (EGTA) injection into oocytes did not decrease alpha-latrotoxin-induced current, but seemed to slow the kinetics of the response. Inorganic Ca-channel blocker Co2+ had no effect on alpha-latrotoxin response. These results indicate that alpha-latrotoxin-induced inward current flows mainly through cation nonspecific channel. A lectin concanavalin A irreversibly inhibited alpha-latrotoxin-evoked inward current. Many of these observations are similar to those reported for nerve cells after alpha-latrotoxin application. The data obtained suggest that functional receptor to alpha-latrotoxin can be successively expressed in the membrane of Xenopus oocytes providing future search of DNA encoding receptor subunits and study of receptor structure-function relationship. |
| Databáze: | OpenAIRE |
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