GONADOTROPIN ACTIONS IN LEYDIG TUMOR CELLS

促性腺激素在间质瘤细胞中的作用

• 批准号: 2090293
• 负责人: Mario Ascoli
• 金额: $ 25.8万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-02-22 至 1998-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2090293
• 关键词: DNA footprinting; G protein; Leydig cells; acylation; adenylate cyclase; chorionic gonadotropin; endocytosis; gel mobility shift assay; genetic promoter element; genetic regulatory element; genetic transcription; hormone metabolism; hormone receptor; hormone regulation /control mechanism; immunoprecipitation; mutant; neoplastic cell culture for noncancer research; nuclear runoff assay; phosphorylation; posttranslational modifications; proteolysis; receptor binding; receptor coupling; receptor expression; site directed mutagenesis; transcription factor; transfection

One of the principal loci involved in the regulation of the actions of lutropin/choriogonadotropin (LH/CG) is the LH/CG receptor (LH/CG-R). The regulation that occurs at this level can be due to an attenuation of the ability of a constant number of receptors to activate the effector system (uncoupling) or to a decrease in the actual number of receptors (down-regulation). Uncoupling and/or down-regulation of the LH/CG-R can be elicited not only by LH/CG, but also by other hormones that do not bind to the LH/CG-R (such as epidermal growth factor) and by some second messengers such as phorbol esters and cAMP analogues. Although it may appear as if down-regulation and uncoupling are redundant (given that they are elicited by the same stimuli), their different time courses suggest that their relative importance in the overall refractoriness of the cell may vary in a temporal fashion. The studies proposed herein seek to understand the molecular basis of the regulation of the actions of LH/CG that occur at the level of the LH/CG-R. Using clonal strains of cultured Leydig tumor cells that express functional LH/CG-Rs, and novel clonal cell lines obtained by permanent transfection with the wild type or mutated forms of the LH/CG-R cDNA we propose to (1) identify post-translational modifications of the LH/CG-R that are responsible for uncoupling the receptor from Gs; (2) determine if the rapid rate of endocytosis of LH/CG requires the interaction of the LH/CG-R with Gs; and (3) characterize the transcriptional regulation of the LH/CG-R gene in MA- 10 Leydig tumor cells. A complete understanding of the regulation of hormone action is a major aspect of the field of endocrinology. Since the LH/CG-R is a member of the growing family of G-protein coupled receptors, our data will provide important information not only about the regulation of the actions of LH/CG, but also about the mechanisms involved in the regulation of the numbers and functional activity of this important family of receptors.

参与调节行为的主要基因座之一 促黄体激素/绒毛膜促性腺激素 (LH/CG) 是 LH/CG 受体 (LH/CG-R)。 这 在这个水平上发生的调节可能是由于衰减 恒定数量的受体激活效应系统的能力 （解偶联）或受体实际数量减少 （下调）。 LH/CG-R 的解偶联和/或下调可以 不仅由 LH/CG 引起，还由其他不影响的激素引起。 与 LH/CG-R（例如表皮生长因子）结合，并通过一些第二 信使，如佛波酯和 cAMP 类似物。 虽然可能会 似乎下调和解偶联是多余的（鉴于 他们是由相同的刺激引起的），他们不同的时间进程 表明它们在整体耐火度中的相对重要性 细胞可能会随时间变化。 本文提出的研究旨在了解该现象的分子基础 LH/CG 作用的调节发生在 LH/CG-R。 使用培养的 Leydig 肿瘤细胞的克隆株 表达功能性 LH/CG-R，以及通过以下方法获得的新型克隆细胞系 用野生型或突变型 LH/CG-R 进行永久转染 我们建议 (1) 鉴定 cDNA 的翻译后修饰 LH/CG-R 负责将受体与 Gs 解偶联； (2) 确定 LH/CG 的快速内吞作用是否需要 LH/CG-R 与 Gs 的相互作用； (3) 表征 MA-10 Leydig 肿瘤中 LH/CG-R 基因的转录调控 细胞。 全面了解激素作用的调节是一个重要的 属于内分泌学领域。 由于 LH/CG-R 是 不断增长的 G 蛋白偶联受体家族，我们的数据将提供 重要信息不仅涉及行为规范 LH/CG，还涉及调节 LH/CG 的机制 这个重要受体家族的数量和功能活性。