PHOSPHOFRUCTOKINASE IN MYOGENIC CELLS & HORMONE ACTION

成肌细胞中的磷酸果糖激酶

• 批准号: 3354082
• 负责人: TAG E. MANSOUR
• 金额: $ 14.01万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-04-01 至 1991-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3354082
• 关键词: 6 phosphofructokinase; autoradiography; carbohydrate metabolism; cyclic AMP; cycloheximide; enzyme biosynthesis; enzyme induction /repression; enzyme mechanism; epinephrine; gel electrophoresis; glycolysis; hormone regulation /control mechanism; immunoprecipitation; insulin; myoblasts; myocardium; myogenesis; phorbols; phosphoproteins; phosphorylation; protein kinase; protein kinase C; radiotracer; striated muscles; tissue /cell culture

Phosphofructokinase (PFK) is a rate-limiting enzyme that regulates carbohydrate metabolism in the heart and skeletal muscle. It is also involved in the effect of epinephrine and of insulin on cellular metabolism. The enzyme appears to be regulated during development to meet cellular needs for energy. In spite of the vast knowledge obtained in many laboratories including our own on the kinetic and biophysical properties of PFK, details of its in vivo regulation in intact animals and tissues remain elusive. We plan to use a muscle cell line that is more amenable to experimental manipulation than intact animals or isolated tissues to study cellular regulation of PFK and how it is influenced by insulin and epinephrine. We will consider the regulatory role of subcellular distribution of PFK, its property to undergo association-dissociation conversion, and the effect of macromolecular crowding on its activity. PFK will be studied in two stages of muscle cell development, the mononucleated proliferating myoblasts and the differentiated multinucleated myotubes. We plan (1) to investigate the nature of isozymes of PFK in the two muscle cell types and the mechanism of the marked increase of PFK in the myotubes compared to the myoblasts; (2) to investigate the effect of phosphorylation of pure muscle and liver PFK isozymes by different protein kinases and by a combination of these enzymes on PFK activity, and to identify the phosphorylated peptides in each isozyme as a result of phosphorylation; (3) to characterize the phosphopeptides of PFK from myoblasts and myotubes and compare their phosphopeptide patterns with those of pure liver and muscle isozymes, with the ultimate goal of identifying the protein kinase(s) involved in phosphorylation of PFK in these cells; (4) to investigate the effect of epinephrine and of insulin on glycolysis on PFK activity and on phosphopeptide patterns of PFK in myoblasts and myotubes; and (5) to determine the role of fructose-2,6-P2 in the regulation of PFK during development from myoblasts to myotubes and to assess changes in the activity of 6-phosphofructo-2-kinase and fructose-2,6-biphosphatase during development; and (6) to study the effect of epinephrine and of insulin on fructose-26-P2 levels in both muscle cell types, and the possible effects of both hormones on 6-phosphofructo-2-kinase and fructose-2,6- biphosphatase. Because of the critical role that PFK plays in regulation of metabolism in heart and skeletal muscle, information on PFK modulation during development and by hormones should contribute to a better understanding of heart and muscle diseases.

磷酸果糖激酶（PFK）是一种限制酶， 调节心脏和骨骼中的碳水化合物代谢 肌肉。 它也参与肾上腺素和 细胞代谢上的胰岛素。 酶似乎是 在开发过程中受到调节，以满足能量的细胞需求。 尽管在许多实验室中获得了广泛的知识 包括我们自己的动力学和生物物理特性 PFK，其在完整动物和组织中体内调节的细节 保持难以捉摸。 我们计划使用更多的肌肉细胞系 比完整动物或 孤立的组织研究PFK的细胞调节及其如何 受胰岛素和肾上腺素的影响。 我们将考虑 PFK亚细胞分布的调节作用，其特性 进行关联分解转换，以及 大分子的活动。 PFK将在 肌肉细胞发育的两个阶段，单核细胞 增生的肌细胞和分化的多核 肌管。 我们计划（1）研究的同工酶的性质 两种肌肉细胞类型的PFK和 与 成肌细胞； （2）研究纯磷酸化的作用 不同蛋白激酶的肌肉和肝PFK同工酶以及 这些酶在PFK活性上的组合，并确定 由于 磷酸化； （3）表征PFK的磷酸肽 从肌细胞和肌管中，比较其磷酸肽 具有纯肝和肌肉同工酶的模式， 确定涉及的蛋白激酶的最终目标 这些细胞中PFK的磷酸化； （4）调查效果 肾上腺素和胰岛素在PFK活性上的糖酵解和胰岛素 肌细胞和肌管中PFK的磷酸肽模式；和 （5）确定果糖-2,6-P2在调节中的作用 PFK在从肌细胞到肌管的发育过程中 评估6-磷酸2-激酶和 发育过程中果糖2,6-磷酸酶； （6）学习 肾上腺素和胰岛素对果糖-26-P2水平的影响 在两种肌肉细胞类型中，都可能影响 6-磷酸2-激酶和果糖-2,6-的激素 双磷酸酶。 因为PFK在 调节心脏和骨骼肌的代谢， 有关开发过程中PFK调制的信息 激素应该有助于更好地理解心脏和 肌肉疾病。