Negative and positive feedback in cell signaling

细胞信号传导的负反馈和正反馈

• 批准号: 10388378
• 负责人: Henrik G. Dohlman
• 金额: $ 65.91万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10388378
• 关键词: Affect; Autophagocytosis; Biochemical; Branched-Chain Amino Acids; Calcium; Cells; Chemicals; Cues; Cyclic AMP; Feedback; G-Protein-Coupled Receptors; GTP-Binding Protein alpha Subunits, Gs; GTP-Binding Proteins; Glucose; Guanosine Triphosphate; Hormones; Hydrolysis; Investigation; Mass Spectrum Analysis; Measures; Molecular; Neurotransmitters; Nutrient; Pharmacologic Substance; Pharmacology; Pheromone; Phosphorylation; Phosphotransferases; Physiological; RGS Proteins; Recycling; Regulation; Research; Roentgen Rays; Role; Scientist; Second Messenger Systems; Signal Pathway; Signal Transduction; Stress; Structure; detection of nutrient; flexibility; novel; programs; protein metabolite; receptor; reconstitution; response

PROJECT SUMMARY Over the past half century scientists have learned much about how cells detect hormones, nutrients and other chemical cues. Typically, these signals are detected by a G protein-coupled receptor and are transduced by a chemical second messenger, such as cAMP or calcium. Our lab has long focused on the identification and characterization of feedback regulators, most notably RGS proteins. Whereas receptors activate G proteins, RGS proteins inactivate G proteins through accelerated GTP hydrolysis. In the next five years our lab will focus on the identification and characterization of novel second messengers and their roles in two aspects of signal coordination. The first is focused on signal coordination by a pheromone GPCR and by another GPCR that detects nutrients. The second is how the pheromone GPCR regulates nutrient availability, through autophagy and the recycling of molecular building blocks. This new initiative builds on our discovery that G proteins regulate, and are regulated by, physiological changes in intracellular pH and of 2-hydroxy branched chain amino acids. These metabolites are second messengers of glucose limitation and osmotic stress, respectively, and share the ability to trigger G protein phosphorylation and inactivation. Our overall approach is to systematically determine the effects of stimulating (pharmacologically) the cell, deleting (genetically) signaling pathway components, measuring (NMR and mass spectrometry) changes in cellular proteins and metabolites, reconstituting (biochemically) the activity of G proteins and effector kinases, and solving (x-ray and NMR) the structures of second messengers bound to their physiological targets. If successful, our research program will lead to the identification of novel second messengers, their mechanism of action, and their functional consequences in the cell. Our investigations will require the implementation of multiple research platforms and strategies, and thus benefit greatly from the flexibility and stability provided by the MIRA program.

项目摘要 在过去的半个世纪中，科学家对细胞如何检测激素，营养素有了很多了解 和其他化学提示。通常，这些信号由G蛋白偶联受体检测到，并且是 由化学第二使者（例如cAMP或钙）传递。我们的实验室长期以来关注 反馈调节剂的识别和表征，最著名的是RGS蛋白。而受体 激活G蛋白，RGS蛋白通过加速的GTP水解使G蛋白灭活。 在接下来的五年中，我们的实验室将重点关注新颖的第二 信使及其在信号协调两个方面的角色。第一个专注于信号协调 信息素GPCR和另一个检测营养素的GPCR。第二个是信息素GPCR 通过自噬和分子构建块的回收来调节营养的可用性。 这项新倡议是基于我们发现蛋白质调节的发现，并受生理调节的调节 细胞内pH和2-羟基分支链氨基酸的变化。这些代谢物是第二 葡萄糖限制和渗透压的使者分别具有触发G蛋白的能力 磷酸化和失活。 我们的整体方法是系统地确定刺激（药理）细胞的影响， 删除（遗传）信号通路组件，测量（NMR和质谱法）变化 细胞蛋白和代谢物，在生化上重建G蛋白和效应激酶的活性， 并解决（X射线和NMR）第二使者与其生理目标结合的结构。 如果成功，我们的研究计划将导致识别新型第二使者，他们 作用机理及其在细胞中的功能后果。我们的调查将需要 实施多个研究平台和策略，因此从灵活性和 MIRA计划提供的稳定性。