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.

项目概要 在过去的半个世纪里，科学家们对细胞如何检测激素、营养物质有了很多了解 和其他化学线索。通常，这些信号由 G 蛋白偶联受体检测，并被 由化学第二信使（例如 cAMP 或钙）转导。我们实验室长期致力于 反馈调节因子（尤其是 RGS 蛋白）的识别和表征。而受体 激活 G 蛋白，RGS 蛋白通过加速 GTP 水解使 G 蛋白失活。 未来五年我们实验室将重点研究新型第二类化合物的鉴定和表征 信使及其在信号协调两个方面的作用。第一个重点是信号协调 信息素 GPCR 和另一个检测营养物质的 GPCR。第二个是信息素GPCR如何 通过自噬和分子构建块的回收来调节营养的可用性。 这项新举措建立在我们发现 G 蛋白调节生理学并受生理学调节的基础上。 细胞内pH值和2-羟基支链氨基酸的变化。这些代谢物排在第二位 分别是葡萄糖限制和渗透应激的信使，并具有触发 G 蛋白的能力 磷酸化和失活。 我们的总体方法是系统地确定刺激（药理学）细胞的效果， 删除（基因）信号通路成分，测量（核磁共振和质谱）变化 细胞蛋白质和代谢物，重建（生化）G 蛋白和效应激酶的活性， 并解决（X 射线和核磁共振）与其生理目标结合的第二信使的结构。 如果成功，我们的研究计划将导致识别新的第二信使，它们的 作用机制及其在细胞中的功能后果。我们的调查需要 实施多个研究平台和策略，从而大大受益于灵活性和 MIRA 程序提供的稳定性。