Discrepancy between molecular structure and ligand selectivity of a testicular follicle-stimulating hormone receptor of the African catfish (Clarias gariepinus)
Discrepancy between molecular structure and ligand selectivity of a testicular follicle-stimulating hormone receptor of the African catfish (Clarias gariepinus)
复制标题
DOI：
10.1095/biolreprod64.6.1633
复制
发表时间：
2001-06-01
影响因子：
3.6
通讯作者：
Schulz, RW
中科院分区：
文献类型：
--
作者：
Bogerd, J;Blomenröhr, M;Schulz, RW
从非洲鲶鱼睾丸中克隆了一个推测的FSH受体（FSH- r） cDNA，与其他推测的糖蛋白激素受体的氨基酸序列比对和非洲鲶鱼基因分析表明，克隆的FSH受体属于FSH受体亚家族。观察鲶鱼睾丸和卵巢中FSH-R (cfFSH-R) mRNA的表达；精囊中也检测到丰富的mRNA表达。分离的cDNA编码了一个功能性受体，因为它在人胚胎肾（HEK-T） 293细胞中的短暂表达导致了配体依赖性cAMP的产生。值得注意的是，非洲鲶鱼LH （cfLH；鲶鱼fsh样促性腺激素尚未纯化）在该系统中具有最高的效力。从其他测试的配体来看，只有人重组FSH （hrFSH）有活性，其效力比cfLH低4倍，而hCG和人TSH （hTSH）无活性。人CG以及cfLH、hrFSH、eCG（但不包括hTSH）在体外刺激睾丸雄激素分泌，但似乎不能与cfFSH-R结合。然而，已知hCG在非洲鲶鱼中具有生物活性（例如，诱导排卵）。这表明在非洲鲶鱼睾丸中也有LH受体的表达。我们从非洲鲶鱼的睾丸中克隆了一个编码功能性FSH-R的cDNA。与鸟类和哺乳动物相比，cfFSH-R对其物种特异性LH的歧视似乎更小。
A putative FSH receptor (FSH-R) cDNA was cloned from African catfish testis, Alignment of the deduced amino acid sequence with other (putative) glycoprotein hormone receptors and analysis of the African catfish gene indicated that the cloned receptor belonged to the FSH receptor subfamily. Catfish FSH-R (cfFSH-R) mRNA expression was observed in testis and ovary; abundant mRNA expression was also detected in seminal vesicles. The isolated cDNA encoded a functional receptor since its transient expression in human embryonic kidney (HEK-T) 293 cells resulted in ligand-dependent cAMP production. Remarkably, African catfish LH (cfLH; the catfish FSH-like gonadotropin has not been purified yet) had the highest potency in this system. From the other ligands tested, only human recombinant FSH (hrFSH) was active, showing a fourfold lower potency than cfLH, while hCG and human TSH (hTSH) were inactive. Human CG las well as cfLH, hrFSH, eCG, but not hTSH) stimulated testicular androgen secretion in vitro but seemed to be unable to bind to the cfFSH-R. However, it was known that hCG is biologically active in African catfish (e.g., induction of ovulation). This indicated that an LH receptor is also expressed in African catfish testis. We conclude that we have cloned a cDNA encoding a functional FSH-R from African catfish testis. The cfFSH-R appears to be less discriminatory for its species-specific LH than its avian and mammalian counterparts.