Structure and regulation of expression for LH/hCG receptor

促性腺激素对睾丸和卵巢功能的调节是由特异性的、高亲和力的受体介导的，这些受体位于各自靶细胞的质膜上。靶细胞对这些激素结合的直接反应是由G蛋白介导的腺苷酸环化酶的增加。卵巢卵泡的成熟和向黄体的转化是由一组特定的激素调控的，这是本项目的主要研究方向。卵泡成熟后，给予hCG诱导其黄体生成。黄体的出现伴随着hCG结合的增加。我们的研究表明，PMSG和hCG对卵巢促性腺激素受体的影响与其对促性腺激素受体mRNA水平的影响密切相关。这些研究再次证明了HCG诱导的LH/HCG受体结合下降与HCG诱导的信息水平下调有关。另一方面，我们分离并测序了编码人促性腺激素受体的cDNA。从人卵巢聚腺苷化rna中制备了寡引cDNA。从大鼠LH/hCG和FSH受体cDEIA克隆中筛选^<32> p标记的2.5Kb和2.0Kb片段。人类LH/hCG受体和FSH受体的推测外域分别位于335和359个氨基酸的7个跨膜片段区域之前。成熟蛋白应该由674和695个氨基酸（75632和76464道尔顿）组成，并且在LH/hCG和FSH受体的假定细胞外区域发现了6个和4个潜在的n -链糖基化位点。在此基础上，我们将进一步研究促性腺激素受体的结构与功能之间的关系。

The regulation of testicular and ovarian function by gonadotopic hormone is is mediated by specific, high-affinity receptors that are located in the plasma membrane of the respective target cells. The immediate response of target cells to the binding of these hormones are an increase in adenyl cyclase mediated by G protein. The maturation of ovarian follicles and their transformation to corpus luteum is regulated by a specific set of hormones and has been a major research area for this project.After follicle maturation, administration of hCG induce its luteinization. The appearance of corpus lutea was accompanied by increase of hCG binding. Our studies demonstrate that the effect of PMSG and hCG on ovarian gonadotropin receptors are closely related to the action of these hormones on gonadotropin receptor mRNA levels. These studies again demonstrated hCG-induced decline in LH/HCG receptor binding was associated with hCG induced down regulation of message levels.On the other hand, We have isolated and sequenced cDNA encoding the human gonadotropin receptors. Oligo-primed cDNA were prepared from human ovary polyadenylated RNAs. The library was screened with ^<32>P-labeled 2.5Kb and 2.0Kb fragment from rat LH/hCG and FSH receptor cDEIA clones. A putative extradomain of 335 and 359 amino acid precedes a region of seven transmembrane segments for the human LH/hCG receptor and FSH receptor, respectively. Mature protein should consist of 674 and 695 amino acids(75632 and 76464 daltons), and six and four potential N-linked glycosylation sites were found in the putative extracellular domain for the LH/hCG and FSH receptor.Based upon these finding, we are going to study more detail relationship between structure and function of gonadotropin receptors.