HCG STRUCTURE-FUNCTION RELATIONSHIPS

HCG 结构与功能的关系

• 批准号: 3232393
• 负责人: J DAVID PUETT
• 金额: $ 16.85万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-09-01 至 1993-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3232393
• 关键词: Leydig cells; RNA binding protein; biological signal transduction; cell growth regulation; chorionic gonadotropin; conformation; cyclic AMP; cytoskeletal proteins; extracellular matrix proteins; genetic mapping; genetic transcription; glycoproteins; gonadotropins; growth factor; hormone binding protein; hormone receptor; hormone regulation /control mechanism; intracellular transport; laboratory rat; luteinizing hormone; mutant; nucleic acid sequence; oncogenes; pituitary hormones; protein structure function; radioimmunoassay; receptor binding; second messengers; site directed mutagenesis; somatotropin; tissue /cell culture

The long-range goals of this project include elucidation of the conformational and structure-function relationships of the placental-derived glycoprotein hormone, human chorionic gonadotropin (hCG), delineation of the various intracellular signaling pathways, and characterization of relatively unexplored cellular responses to hCG. A working model has been developed for CG and its pituitary-derived counterpart, luteinizing hormone (LH), that combines the results of chemical and enzymatic modifications, immunological mapping, and physicochemical studies. In order to experimentally test this model, site-directed mutagenesis and trace labeling studies have been designed to elucidate the subunit contact sites for heterodimer formation and the amino acid sequence determinants for receptor binding and activation. Numerous studies have emphasized the role of cAMP in gonadotropin-mediated intracellular signaling, and we also have tentative evidence for the involvement of inositol-1,4,5 trisphosphate and possibly other inositol-- containing phospholipids; this hypothesis of alternate signaling will be experimentally tested in transformed Leydig cells. This project will also delineate some of the cellular responses to gonadotropin and mutant proteins. These include a dramatic CG/LH-mediated morphological change in transformed Leydig cells (MA-10), which we propose is due to cytoskeletal reorganization; a proposed CG/LH-regulated interaction of cells with the extracellular matrix, involving such modulators as SPARC (Secreted Protein that is Acidic and Rich in Cysteine); and CG/LH regulation of the oncogenes c-fos, c-jun, and c-myc. This. comprehensive project is designed to elucidate amino acid sequence determinants regulating heterodimer formation and receptor recognition/activation, intracellular signaling pathways possibly distinct from cAMP, and relatively unexplored aspects of hCG function.

该项目的长期目标包括阐明 的构象和结构-功能关系 胎盘源性糖蛋白激素、人绒毛膜促性腺激素 (hCG)、 描述各种细胞内信号传导途径，以及 相对未探索的 hCG 细胞反应特征。 一个 CG及其垂体衍生的工作模型已经开发出来 对应物，黄体生成素（LH），结合了以下结果 化学和酶促修饰、免疫图谱和 物理化学研究。 为了通过实验测试这个模型， 定点诱变和痕量标记研究旨在 阐明异二聚体形成的亚基接触位点和氨基 受体结合和激活的酸序列决定因素。 很多的 研究强调了 cAMP 在促性腺激素介导中的作用 细胞内信号转导，我们也有初步证据 肌醇-1,4,5三磷酸盐和可能的其他肌醇的参与-- 含有磷脂；这种替代信号的假设将是 在转化的 Leydig 细胞中进行了实验测试。 该项目还将 描绘了一些细胞对促性腺激素和突变体的反应 蛋白质。 其中包括 CG/LH 介导的形态学变化 转化的 Leydig 细胞 (MA-10)，我们认为这是由于细胞骨架 重组；拟议的 CG/LH 调节的细胞与 细胞外基质，涉及 SPARC（分泌蛋白）等调节剂 这是酸性且富含半胱氨酸）；和 CG/LH 对癌基因的调节 c-fos、c-jun 和 c-myc。 这。综合项目旨在 阐明调节异二聚体形成的氨基酸序列决定因素 和受体识别/激活、细胞内信号传导途径 可能与 cAMP 不同，以及 hCG 相对未探索的方面 功能。