Novel interactions of Slo1 channel and Thromboxane A2 receptor in blood vessels

血管中 Slo1 通道和血栓素 A2 受体的新相互作用

• 批准号: 7851419
• 负责人: ENRICO STEFANI
• 金额: $ 66.55万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7851419
• 关键词: Address; Agonist; Aorta; Arteries; Binding; Biochemistry; Blood Vessels; Calcium-Activated Potassium Channel; Cardiovascular Diseases; Cardiovascular Physiology; Cardiovascular system; Cells; Characteristics; Complex; Coronary; Coronary artery; Coupled; Coupling; Data; Development; Ectopic Expression; Equilibrium; Event; Family; Figs - dietary; Fluorescence Microscopy; G-Protein-Coupled Receptors; GTP-Binding Proteins; Goals; Health; Human; Hypertension; Kinetics; Knowledge; Laboratories; Lead; Left; Link; Lipid Bilayers; Macromolecular Complexes; Mediating; Membrane; Membrane Proteins; Methods; Modeling; Molecular; Molecular Biology; Muscle Cells; Myocardial Infarction; Nature; Physiological; Physiology; Play; Probability; Procedures; Prostaglandins; Proteins; Rattus; Receptor Activation; Recombinants; Regulation; Rhodopsin; Role; Signal Transduction; Smooth Muscle; Stroke; System; Testing; Thromboxane A2; Thromboxane A2 Receptor; Transmembrane Domain; Vasoconstrictor Agents; Vasodilation; Vasodilator Agents; Work; analog; base; design; dimer; disorder prevention; extracellular; large-conductance calcium-activated potassium channels; member; mimetics; new therapeutic target; novel; protein activation; public health relevance; receptor; reconstitution; research study; tumorigenesis; vasoconstriction; voltage

Our long term goal is to obtain an integral view of the mechanisms by which Thromboxane A2- prostanoid receptor (TPR) and the large conductance Ca2+-activated K+ channel (MaxiK, BK) interact with each other to regulate vascular function. TPR and MaxiK play significant roles in determining vascular health. In addition, both proteins are known to be involved in the modulation of tumorigenesis and myocardial infarction. In coronary arteries, TPR are activated by the prostanoid thromboxane A2 (TXA2) leading to powerful vasoconstrictions; while MaxiK channel aided by its β1 subunit can fine tune arterial tone determined by the degree of channel activity. Our early work showed that TXA2 mimetic U46119 inhibits MaxiK channel activity in membranes from coronary smooth muscle reconstituted in lipid bilayers, which suggested a strong functional association between both TPR and MaxiK that endured dissociative reconstitution procedures. Recent preliminary experiments also show that: 1) TPR modulates MaxiK pore-forming α subunit (Slo1) via a novel mechanism that is G-protein independent, where MaxiK channel activity can be reduced by the specific TPR agonist U46619, 2) TPR and MaxiK channel subunits form heteromultimeric complexes in native arteries and in expression systems, 3) TPR and MaxiK channel functional coupling occurs in native human coronary arterial myocytes and can be reproduced after ectopic expression of TPR and Slo1, and 4) agonist-stimulation enhances TPR and Slo1 association. Here, we will test the hypothesis that agonist stimulation changes TPR-Slo1-β1 associations resulting in Slo1 channel inhibition. The specific aims are to: 1. Unravel the molecular mechanism(s) of Slo1 channel inhibition by agonist (U46619)- activated TPR, and 2. Define the role of β1 subunit in agonist-TPR-Slo1 channel inhibition. Experiments will be performed using modern approaches such as biochemistry, molecular biology, and opto-biophysical methods including fluorescence microscopy at the diffraction limit. Because of the broad impact of MaxiK and TPR in mammalian physiology, the knowledge derived from these studies may provide new opportunities for the prevention of disease not only in the cardiovascular system but in other systems as well.

我们的长期目标是获得对血栓烷A2-的机制的整体视图 前列腺素受体（TPR）和大电导Ca2+激活的K+ 频道（Maxik，BK）互动 彼此调节血管功能。 TPR和Maxik在确定血管中起着重要作用 健康。另外，已知两种蛋白质都参与肿瘤发生和心肌的调节 梗塞。在冠状动脉中，TPR被前列腺类动脉蛋白A2（TXA2）激活 强大的血管收缩；虽然Maxik通道由其β1亚基提供了帮助，可以微调伪像的音调 根据通道活动的程度。我们的早期工作表明TXA2模拟U46119抑制Maxik通道 在脂质双层中重构的冠状动脉平滑肌机制活性，这表明很强 TPR和Maxik之间的功能关联，均忍受了解离性重构程序。 最近的初步实验还表明：1）TPR通过 G蛋白独立的一种新型机制，其中Maxik通道活性可以通过 特定的TPR激动剂U46619，2）TPR和Maxik通道亚基形成异种复合物 天然动脉和表达系统中，3）TPR和MAXIK通道功能耦合发生在天然 人类冠状动脉肌细胞，可以在TPR和SLO1的生态表达后再现 4）激动剂刺激增强了TPR和SLO1关联。在这里，我们将检验以下假设 激动剂刺激会改变TPR-SLO1-β1的关联，导致SLO1通道抑制。具体目标 为：1。揭开激动剂（U46619）SLO1通道抑制的分子机制 - 激活 TPR和2。定义β1亚基在激动剂-TPR-SLO1通道抑制中的作用。实验将是 使用现代方法（例如生物化学，分子生物学和OPT-Biophysical方法）进行 包括在衍射极限处的荧光显微镜。由于Maxik和TPR在 哺乳动物的生理学，这些研究得出的知识可能为 不仅在心血管系统中，而且在其他系统中也预防疾病。