Jockers R, Petit L, Brydon L, de Coppet P, Strosberg A D
Institut Cochin de Génétique Moléculaire, Laboratoire d'Immuno-Pharmacologie Moléculaire, CNRS UPR, Paris, France.
C R Seances Soc Biol Fil. 1998;192(4):659-67.
Melatonin receptors belong to the super-family of G protein-coupled receptors. They modulate a large spectrum of physiological functions including regulation of circadian rhythms and seasonal reproduction. Pharmacological evidence suggests the expression of two types of receptors, called Mel1 and Mel2. So far, only Mel1 receptors have been cloned and classified into three subtypes (Mel1A, Mel1B, Mel1C). Mel1 receptors are expressed in the brain, the retina and several other peripheral tissues. All Mel1 subtypes show comparable pharmacological profiles including inhibition of adenylyl cyclase. Cloning and expression of two allelic isoforms of the Mel1 receptor from Xenopus laevis has revealed another signalling pathway, inhibition of cGMP levels via the soluble guanylyl cyclase pathway. The two isoforms are differentially coupled to the cAMP and cGMP pathways indicating the existence of functional differences between melatonin receptors. Future research topics will include cloning of the Mel2 receptor, receptor regulation and the elucidation of melatonin receptor's function in peripheral tissues.
褪黑素受体属于G蛋白偶联受体超家族。它们调节多种生理功能，包括昼夜节律的调节和季节性繁殖。药理学证据表明存在两种类型的受体，称为Mel1和Mel2。到目前为止，仅Mel1受体已被克隆并分为三个亚型（Mel1A、Mel1B、Mel1C）。Mel1受体在脑、视网膜和其他几种外周组织中表达。所有Mel1亚型均表现出相似的药理学特征，包括对腺苷酸环化酶的抑制作用。从非洲爪蟾克隆和表达Mel1受体的两种等位基因亚型揭示了另一种信号通路，即通过可溶性鸟苷酸环化酶途径抑制cGMP水平。这两种亚型与cAMP和cGMP途径的偶联方式不同，表明褪黑素受体之间存在功能差异。未来的研究课题将包括Mel2受体的克隆、受体调节以及褪黑素受体在外周组织中的功能阐明。
