Molecular mechanisms of proton-sensing in CO2-dependent breathing

CO2 依赖性呼吸中质子传感的分子机制

• 批准号: 10740838
• 负责人: Nick Hoppe
• 金额: $ 0.73万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2023-09-06
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10740838
• 关键词: Agonist; Allosteric Site; Apnea; Attenuated; Binding; Biochemistry; Biological Assay; Biological Process; Biology; Brain Stem; Breathing; Carbon Dioxide; Cell Nucleus; Central Sleep Apnea; Cryoelectron Microscopy; Cues; Development; Disease; FFAR3 gene; Frequencies; Functional disorder; Future; G-Protein-Coupled Receptors; GPR4 gene; Genetic; Goals; Ion Channel; Knock-out; Knowledge; Ligands; Link; Mediating; Mentorship; Methods; Modeling; Molecular; Mutagenesis; Neurons; Pathologic; Pathology; Pharmacology; Phenotype; Process; Protons; Receptor Activation; Regulation; Research; Respiration; Respiration Disorders; Respiratory Disease; Signal Transduction; Site; Structure; Sudden infant death syndrome; Symptoms; Techniques; Therapeutic; antagonist; carbon dioxide receptor; congenital central hypoventilation syndrome; drug development; insight; intermolecular interaction; novel; novel therapeutics; particle; premature; receptor; respiratory; small molecule; structural biology

Abstract GPR4 is a G-protein coupled receptor required for CO2-dependent breathing. In the brainstem, rising CO2 levels cause a decrease in pH that activates GPR4. Genetic knockout of GPR4 results in two pathological phenotypes - reduced CO2-dependent breathing and frequent apneas, which are both rescued by specific re-expression of GPR4 in the brainstem. This establishes a link between inactivation of GPR4 and symptoms for severe breathing disorders including congenital central hypoventilation syndrome (CCHS) and central sleep apnea (CSA). However we do not know how GPR4 senses pH, and we do not know how existing small molecules modulate GPR4. Through this proposal, I will determine the molecular mechanism of GPR4 activation to provide insights into the regulation of CO2-dependent breathing and to enable the development of small molecules that activate GPR4. In Aim 1, I will determine the molecular details of how protons activate GPR4. In Aim 2, I will decipher how current antagonists bind and inactive GPR4. To accomplish these aims, I will combine the techniques of biochemistry, structural biology (cryogenic electron microscopy), and pharmacology (mutagenesis and signaling assays). These studies will provide mechanistic insight into the regulation of GPR4 activity through protons and small molecules. This will expand our fundamental understanding of how protons drive CO2-dependent breathing, and this will enable the future development of small molecules that activate GPR4, which could be novel therapeutics for CCHS and CSA.

摘要 GPR4是一种G蛋白偶联受体，是依赖CO2呼吸所必需的。在脑干中，不断上升的二氧化碳 水平导致pH值降低，从而激活GPR4。GPR4基因敲除导致两种病理性 表型-减少CO2依赖性呼吸和频繁的呼吸暂停，这两者都是由特定的 脑干中GPR4的再表达。这建立了GPR4失活和症状之间的联系 用于严重呼吸障碍，包括先天性中枢性通气不足综合征（CCHS）和中枢性睡眠 呼吸暂停（CSA）。然而，我们不知道GPR4是如何感知pH值的，我们也不知道存在的小 分子调节GPR4。通过这一方案，我将确定GPR4的分子机制 激活，以提供对CO2依赖性呼吸调节的见解，并使 激活GPR4的小分子。在目标1中，我将确定质子如何激活的分子细节 GPR4。在目标2中，我将破译当前拮抗剂如何结合和失活GPR4。为了实现这些目标，我 将联合收割机结合生物化学，结构生物学（低温电子显微镜）， 药理学（诱变和信号传导试验）。这些研究将提供机械的洞察力， 通过质子和小分子调节GPR4活性。这将扩大我们的基础 了解质子如何驱动依赖二氧化碳的呼吸，这将使未来的发展， 激活GPR4的小分子，这可能是CCHS和CSA的新型治疗方法。