REGULATION OF PHOSPHATIDYLINOSITOL METABOLISM

磷脂酰肌醇代谢对真核生物的生长具有重要意义 有机体 激动剂刺激的膜水解 动物体内的多聚磷酸肌醇导致刺激各种 细胞反应。 这种酶能催化 合成聚磷酸肌醇的是磷脂酰肌醇激酶。 本申请将集中在磷脂酰肌醇的调节 在简单的真核生物，酿酒酵母中的激酶。 磷脂酰肌醇激酶将被纯化至同质，并将被纯化。 具有酶学、化学和物理特性 特性. 纯化的酶将被重构成良好定义的酶。 单层磷脂囊泡，以研究活性的调节。 调节将通过改变的组成和环境进行研究， 囊泡和可能的磷酸化和去磷酸化的 酵素 磷脂酰肌醇激酶的特异性抗体将被 制备并用作探针来研究 磷脂酰肌醇激酶形成的细胞生长在各种 条件 拟议的研究应提供深入了解 多磷酸肌醇合成的调节。 结果表明，S. 酿酒酵母应该与高等真核生物有关。

Phosphatidylinositol metabolism is important to the growth of eukaryotic organisms. The agonist-stimulated hydrolysis of membrane polyphosphoinositides in animals result in the stimulation of various cellular responses. The enzyme that catalyzes the initial step in the synthesis of the polyphosphoinositides is phosphatidylinositol kinase. This application will focus on the regulation of phosphatidylinositol kinase in the simple eukaryote, Saccharomyces cerevisiae. Phosphatidylinositol kinase will be purified to homogeneity and will be characterized with respect to enzymological, chemical, and physical properties. The purified enzyme will be reconstituted into well defined unilamellar phospholipid vesicles to study the regulation of activity. Regulation will be studied by altering the composition and environment of the vesicles and by possible phosphorylation and dephosphorylation of the enzyme. Antibodies specific for phosphatidylinositol kinase will be prepared and used as a probe to study the regulation of phosphatidylinositol kinase formation in cells grown under various conditions. The proposed studies should provide insight into the regulation of polyphosphoinositide synthesis. The results found with S. cerevisiae should be relevant to higher eukaryotic organisms.