GTP-BINDING PROTEINS AND SIGNAL TRANSDUCTION--STRUCTURE AND FUNCTION

GTP 结合蛋白和信号转导——结构和功能

• 批准号: 3876996
• 负责人: M RODBELL
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 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/3876996
• 关键词: ADP ribosylation; G protein; actins; adipocytes; ankyrins; biological signal transduction; brain cell; crosslink; environmental stressor; enzyme substrate; guanine nucleotide binding protein; hamsters; hormone regulation /control mechanism; immunologic techniques; laboratory rat; liver cells; membrane proteins; muscarinic receptor; neurotransmitters; pertussis toxin; phagocytosis; protein structure function; receptor binding; receptor coupling; site directed mutagenesis; solubility; synaptosomes; transfection; tubulin; vesicle /vacuole

G-proteins (GTP binding regulatory proteins) are the transducing elements that transmit the actions of hormones, neurotransmitters, odorants, light, antigens, and a variety of chemical signals that interact with receptors on the external surfaces of all eukaryotic cells, from yeast to man. Based on actions of cross-linking agents and hydrodynamic properties, these proteins isolated from rat brain synaptoneurosomes behave as multimeric, polydisperse structures. They resemble in their temperature sensitivities and disaggregating effects of guanine nucleotides cytoskeletal proteins such as actin and tubulin. Four of the prominent G-proteins found in brain display similar but varying properties depending on the species. Assuming these findings with extracted materials apply to intact cells, a new con- cept of signal transduction has been developed. In a related study, 100 kDa GTPbinding proteins containing epitopes reactive with antibodies against classical transduction proteins have been discovered in the liver and characterized. Finally hormones acting through G proteins have been shown to regulate fluid phase endocytosis in rat adipocytes and in Chinese Hamster Cells transfected with genes for muscarinic receptors I and III. These studies reveal a new function of G-proteins and suggest that the processing of pinosomes may be an important route for the dissemination of environmental signals and adaptation to the constantly changing levels of these signals in the environment.

G蛋白（GTP结合调节蛋白）是转导元件 传递激素、神经递质、气味、光 抗原，以及各种与受体相互作用的化学信号， 所有真核细胞的外表面，从酵母到人类。 交联剂的作用和流体力学性质，这些蛋白质 从大鼠脑突触神经体分离的神经体表现为多聚体， 多分散结构它们对温度的敏感性相似 鸟嘌呤核苷酸和细胞骨架蛋白的解聚作用 如肌动蛋白和微管蛋白。在大脑中发现的四种主要G蛋白 显示相似但不同的属性取决于物种。假设 这些发现与提取的材料适用于完整的细胞，一个新的概念， 发展了信号转导的概念。在一项相关研究中，100 kDa 含有可与抗人IgG抗体反应的表位的GTP结合蛋白 已经在肝脏中发现了经典的转导蛋白， 表征了最后，通过G蛋白发挥作用的激素已被证明 调节大鼠脂肪细胞和中国人的液相内吞作用 转染毒蕈碱受体I和III基因的细胞。 这些研究揭示了G蛋白的一种新功能， 对胞饮体的加工可能是一种重要的传播途径， 环境信号和适应不断变化的 环境中的这些信号。