Use of G-protein-coupled receptor subtype genes for novel drug discovery

本文从分子生物学的最新进展出发，探讨了一种新的药物发现策略。近年来，许多g蛋白偶联受体（GPCR）被克隆出来，并被发现具有一个大的基因家族。每个GPCR都有几个亚型，GPCR的生理功能是由这些亚型介导的。我们计划用PCR同源克隆的方法克隆人类某一GPCR的所有成员，然后构建稳定表达克隆受体的细胞系，分析其信号转导，最终利用该细胞发现一种新型亚型受体特异性药物。以alpha1-肾上腺素受体（alpha1-AR）为模型，我们研究了这种药物发现的新策略。我们克隆了三种不同的人类α 1- ar亚型（a、b和d型），并获得了稳定表达这三种亚型的细胞。所有的alpha1-AR都被发现与Gq/ 11蛋白和Ca2+信号通路偶联。利用这些细胞系，我们发现一种新的α -AR拮抗剂KMD-3213对α 1 a亚型具有很强的选择性，可以非常有效地治疗良性前列腺肥大，而不会对血压产生不良影响。此外，我们开发了针对alpha1 b-AR的抗体，首次成功地检测了alpha1 b-AR蛋白的组织定位。综上所述，目前的研究清楚地表明，分子生物学方法可以潜在地用于药物发现，特别是靶向GPCR。

In the present study, we examined a new strategy for drug discovery based on the recent development in molecular biology. Recently, a number of G-protein coupled receptors (GPCR) have been cloned and are found to have a large gene family. Each GPCR has several subtypes and physiological function of the GPCR is mediated by these subtypes. We planed to clone all members of a certain GPCR in human by homology cloning method with PCR, and then construct cell lines stably expressing the cloned receptor, analyze the signal transduction, and as a final goal to discover a novel subtype receptor-specific drug by using the cells. Using alpha1-adrenoceptor (alpha1-AR) as a model, we examined this new strategy for drug discovery. We cloned three different human alpha1-AR subtypes (a, b and d-type), and obtained the cells stably expressing these three subtypes. All alpha1-AR s are found to be coupled to Gq/1 1 proteins and Ca2+ signaling. Utilizing these cell lines, we found that a novel alphal -AR antagonist KMD-3213 is very selective for alpha1 a-subtype, and can be very useful for the treatment of benign prostate hypertrophy without no untoward effect on the blood pressure. Furthermore, developing antibodies against alpha1 b-AR, we first succeeded in detecting the tissue localization of the alpha1 b-AR protein. Taken together, the present study clearly showed that molecular biological methodology can be potentially of use for drug discovery, targeted GPCR in particular.