STEROID ACTION AT THE OOCYTE PLASMA MEMBRANE

类固醇对卵母细胞质膜的作用

• 批准号: 3311305
• 负责人: GENE A MORRILL
• 金额: $ 14.07万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-02-01 至 1992-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3311305
• 关键词: Anura; biological signal transduction; calcium flux; cell membrane; egg /ovum; electron spin resonance spectroscopy; fluid; hormone regulation /control mechanism; insulin; iontophoresis therapy; meiosis; methylation; methyltransferase; peptidases; phosphatidylethanolamines; phosphatidylinositols; phospholipids; phosphorylation; progesterone; propranolol; protein kinase C

Hormone action at the oocyte plasma membrane induces meiotic division and enables the oocyte to be fertilized, to expand the sperm nucleus, and to synthesize DNA. The maturation promoting factor which is synthesized in response to the meiotic stimulus may be a universal mitogen. Our recent work demonstrates that the earliest responses to progesterone induction (0-5 min) occur within the oocyte plasma membrane in Rana, and include a transient increase in phospholipid N-methylation, protease activation, Ca2+ release, protein kinase C activation, membrane phosphorylation, and, within 10 min, increased polyphosphoinositol turnover and increased membrane fluidity. We propose that the earliest response to progesterone may be the activation of methyltransferase I to produce phosphatidylmonomethylethanolamine (PME). PME in turn activates membrane protease(s) and limited proteolysis initiates the cascade of phospholipid changes associated with release of the prophase block. Our general aims include: 1) analysis of the composition and purity of the plasma membrane preparations used in the study, 2) determine whether PME synthesis in response to progesterone is the requisite step for activation of membrane protease and/or change the physical characteristics of the plasma membrane following progesterone treatment. 3) a more complete analysis of the protease activity changes following progesterone and/or PME treatment followed by a more specific plan to isolate and characterize the protease(s), and 4) to clearly establish the cause and effect relationships between protease activation, Ca2+ release, protein kinase activation, and oocyte activation. We will use biochemical methods involving protein and phospholipid isolation and purification and biophysical methods that include electrophysiological, nuclear magnetic resonance, and electron spin resonance techniques. This information will help explain the mechanism by which a membrane signal (progesterone) is transduced into metabolic changes that commit previously quiescent cells to undergo cell division and become responsive to a second mitogen (sperm). Knowledge in this area is essential to the understanding of problems related to fertility and to the control of cell growth, for example, the facilitation of tissue regeneration or the repression of cancer cells.

卵母细胞质膜的激素作用诱导减数分裂 分裂并使卵母细胞受精，扩大 精子核并合成DNA。 成熟促进 根据减数分裂刺激而合成的因素可能 成为普遍有丝分裂原。 我们最近的工作表明 最早对孕酮诱导的反应（0-5分钟）发生 RANA中的卵母细胞质膜，包括瞬态 磷脂N-甲基化，蛋白酶激活，Ca2+的增加 释放，蛋白激酶C活化，膜磷酸化， 并且，在10分钟内，多磷酸肌醇的周转率增加了 膜流动性增加。 我们建议最早的回应 孕酮可能是甲基转移酶I的激活 产生磷脂酰甲基乙醇胺（PME）。 PME依次 激活膜蛋白酶（S）和有限的蛋白水解启动 与释放有关的磷脂变化的级联变化 预言块。 我们的一般目标包括：1）分析 质膜制剂的组成和纯度 研究，2）确定PME合成是否响应 孕酮是激活膜的必要步骤 蛋白酶和/或更改等离子体的物理特征 孕酮治疗后的膜。 3）更完整 孕酮后蛋白酶活性变化的分析 和/或PME处理，然后是更具体的计划来分离 并描述蛋白酶（s），4）清楚地建立 蛋白酶激活之间的因果关系和作用关系 释放，蛋白激酶激活和卵母细胞活化。 我们将 使用涉及蛋白质和磷脂的生化方法 隔离，纯化以及包括 电生理，核磁共振和电子自旋 共振技术。 这些信息将有助于解释 膜信号（孕酮）转导的机制 变成代谢变化，使以前静止的细胞提交 进行细胞分裂并对第二个有丝分裂原反应 （精子）。 该领域的知识对于理解至关重要 与生育和控制细胞生长有关的问题， 例如，组织再生或 抑制癌细胞。