Multiple Pathways Regulate Na+-H+ Antiporter in the Sea Urchin Egg and Early Embryo

多途径调控海胆卵和早期胚胎中的 Na -H 逆向转运蛋白

• 批准号: 8903837
• 负责人: Sheldon Shen
• 金额: $ 27.13万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-15 至 1993-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8903837&HistoricalAwards=false
• 关键词: Multiple; Pathways; Regulate; Na+; H+

The changes of two ions, calcium and proton, are of importance in fertilization . Increasing calcium activity and decreasing proton activity are parthenogenetic, while suppression of the normal changes during fertilization blocks development. Past research has demonstrated a second messenger pathway initiated with hydrolysis of phosphatidylinositol 4,5-bisphosphate in the egg membrane, similar to that suggested during mammalian cell proliferation. Further analysis of the control of ion fluxes during fertilization suggests another regulatory pathway, which is independent of inositol lipid hydrolysis. The proposed research is directed towards the identification of this alternative regulatory pathway. Attention is focused towards possible calcium-calmodulin dependent protein kinase regulation. Multiple regulatory pathways on ionic fluxes during mitogen stimulated mammalian cell proliferation have also been reported. An important group of mitogen that do not require inositol lipid hydrolysis have receptors with tyrosine kinase activity. Phosphorylation-dephosphorylation has been recognized as an important cellular regulatory mechanism. The steady state of phosphorylation of a protein depends upon the kinase and phosphatase activities specific for the protein. Tyrosine phosphatase and phosphatase inhibitor activities have been measured in the sea urchin egg. Their possible regulatory actions during fertilization will be investigated. Finally, a novel feature of fertilization is the formation of acid compartments. A procedure to isolate these organelles is described and is utilized for characterizing the formation of the acid compartment. %%% Fertilization of the egg initiates a dramatic series of that lead to the quiescent egg becoming metabolically very active and its beginning to divide. Among the earliest changes are changes in the intracellular activities of calcium and hydrogen ions. This study is to investigate these changes and to relate similar changes known to be involved in regulating cell division in mammalian cells.

钙离子和质子离子在施肥过程中的变化具有重要意义。钙活性的增加和质子活性的降低是孤雌生殖，而受精过程中正常变化的抑制会阻碍发育。过去的研究表明，卵膜中磷脂酰肌醇4,5-二磷酸水解启动了第二信使途径，类似于哺乳动物细胞增殖过程。对受精过程中离子通量控制的进一步分析表明另一种独立于肌醇脂质水解的调控途径。拟议的研究旨在确定这种替代的调节途径。关注的焦点是可能的钙钙调蛋白依赖性蛋白激酶调控。在有丝分裂原刺激的哺乳动物细胞增殖过程中，离子通量的多种调控途径也有报道。一组不需要肌醇脂质水解的有丝分裂原具有酪氨酸激酶活性的受体。磷酸化-去磷酸化是一种重要的细胞调控机制。蛋白质磷酸化的稳定状态取决于该蛋白质特有的激酶和磷酸酶的活性。测定了海胆卵中酪氨酸磷酸酶和磷酸酶抑制剂的活性。将研究它们在受精过程中可能的调节作用。最后，施肥的一个新特征是酸室的形成。描述了一种分离这些细胞器的方法，并将其用于表征酸室的形成。卵子受精开始了一系列戏剧性的变化，使静止的卵子新陈代谢变得非常活跃，并开始分裂。其中最早的变化是细胞内钙离子和氢离子活动的变化。这项研究是为了调查这些变化，并将类似的变化与哺乳动物细胞的细胞分裂调节联系起来。