Expression and functional characterization of a melatonin‐sensitive receptor in Xenopus oocytes

[摘要]

Melatonin (MEL) plays a central role in the regulation of seasonal cycles and in the control of circadian rhythms in mammals. Functional MEL-sensitive receptors were expressed in Xenopus laevis oocytes following injection of poly (A)⁺ RNA from rat brain. Administration of 0.1–100 μmol/l MEL to voltage-clamped oocytes (holding potential: −70 mV) elicited oscillatory inward currents (reversal potential: −24 mV) which could be blocked by 9-anthracenecarboxylic acid and caffeine. After preincubation with pertussis toxin (PTX) the MEL response disappeared. The expressed MEL-sensitive receptor probably activates Ca²⁺-dependent chloride currents via a PTX-sensitive G protein and the phosphoinositol pathway.

[学科分类] 生物化学/生物物理

[关键词] Melatonin;Xenopus oocyte;Ca2+-activated chloride current;G protein;IP3;Xenopus laevis;MEL;melatonin;G protein;guanyl nucleotide binding protein;cAMP;cyclic adenosine 5′-monophosphate;PTX;pertussis toxin;IP3;inositol 1;4;5-triphosphate;DMSO;dimethyl sulfoxide;9-AC;9-anthracenecarboxylic acid;Tris;Tris(hydroxymethyl)aminomethane;BSA;bovine serum albumine;HEPES;N-(2-hydroxyethyl)-piperazine-N′-2-ethane sulfonic acid