PROTEIN PHOSPHORYLATION AND SECRETION AND ETHANOL ACTIONS

蛋白质磷酸化、分泌和乙醇作用

• 批准号: 3821269
• 负责人: H C PANT
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3821269
• 关键词: axon; brain metabolism; caudate nucleus; cell membrane; central nervous system; cyclic AMP; cyclic nucleoside monophosphate; drug metabolism; ethanol; neural transmission; neurochemistry; neuropharmacology; neurotoxins; phosphorylation; protein kinase; radiotracer; saltwater environment

The phosphorylation of protein has been proposed to be one of the molecular mechanisms involved in cellular regulation. The protein kinases catalyze these phosphorylation reactions. In this investigation, properties of protein kinase activity associated with cell cytoskeletal proteins have been studied in both neuronal and non-neuronal tissues. Extensive studies were carried out to characterize the squid axon neurofilament kinase. These investigations led to conclude that this kinase is a cyclic nucleotide- and calcium-independent protein kinase which is different from casein type I and type II kinases. The axoplasm and neurofilament preparation had no detectable protein kinase inhibitor activity, but strong inhibitor activity, which was not dialyzable but was heat inactivitable, was found in ganglion cells. This inhibitor activity may account for the low phosphorylation activity found in the stellite ganglion cells and may indicate inhibitory regulation of squid axon neurofilament kinase activity in the ganglion cell bodies. In rat brain, the kinase activity is associated with microtubule-associated proteins and phosphorylates them. Effects of ethanol on phosphorylation of microtubule associated protein (MAP 2) were investigated. Ethanol (4-24 mM) increased phosphorylation of MAP 2. In the presence of cAMP or mM ethanol, increased phosphorylation of MAP 2 was observed over control. Much higher phosphorylation of MAP 2 was observed in the presence of cAMP and ethanol than the sum of phosphorylation of MAP 2 by cAMP and ethanol separately. Kinetic studies of the influence of ethanol on MAP 2 phosphorylation reveal an increased rate of phosphorylation of MAP 2 and a decreased Km in the presence of ethanol. These studies suggest that protein kinase(s) other than cAMP dependent protein kinase are influenced by ethanol and the enzyme(s) phosphorylate at distinct sites on MAP 2. The observation that ethanol affects MAP 2 provides an experimental basis for investigating the effects of ethanol on the structure and function of these cytoskeletal proteins and enzymes.

蛋白质的磷酸化被认为是 参与细胞调控的分子机制。这个 蛋白激酶催化这些磷酸化反应。在这 与蛋白激酶活性相关的研究、特性 细胞细胞骨架蛋白在神经元和 非神经性组织。进行了广泛的研究，以 描述了鱿鱼轴突神经丝蛋白激酶的特征。这些 研究得出结论，这种激酶是一种环状的 核苷酸和钙非依赖性蛋白激酶，它是 不同于酪蛋白I型和II型激酶。轴浆 神经丝制剂中没有可检测到的蛋白激酶 抑制剂活性，但很强的抑制剂活性，这不是 神经节细胞内可透析，但热失活。 这种抑制活性可能是低磷酸化的原因。 在卫星神经节细胞中发现的活性，可能表明 鱿鱼轴突神经丝蛋白激酶活性的抑制调节 在神经节细胞体中。在大鼠的大脑中，激酶的活性是 与微管相关蛋白和 使它们磷酸化。乙醇对肌动蛋白磷酸化的影响 检测微管相关蛋白(MAP-2)的表达。 乙醇(4-24 mM)可增加MAP-2的磷酸化。 CAMP或mM乙醇的存在，增加磷酸化 观察到MAP 2高于对照组。更高的磷酸化程度 在cAMP和乙醇存在下，MAP 2的活性高于 CAMP和乙醇对MAP-2的磷酸化总和 分开的。乙醇对MAP_2影响的动力学研究 磷酸化显示磷酸化的速度增加 在乙醇存在的情况下，MAP 2和a Km减小。这些 研究表明，蛋白激酶(S)不依赖cAMP 蛋白激酶受酒精和酶的影响(S) 在地图2上的不同位置进行磷酸化。观察到 乙醇对MAP 2的影响为 乙醇对细胞结构和功能影响的研究 这些细胞骨架蛋白和酶。