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

基本信息

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
项目类别：
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

项目摘要

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.

我们的长期目标是全面了解血栓素 A2- 前列腺素受体 (TPR) 和大电导 Ca2+ 激活的 K+ 通道（MaxiK、BK）交互 TPR 和 MaxiK 相互调节血管功能，在决定血管功能方面发挥着重要作用。此外，已知这两种蛋白质都参与肿瘤发生和心肌的调节。在冠状动脉中，TPR 被前列腺素血栓素 A2 (TXA2) 激活，从而导致梗死。强大的血管收缩作用；而 MaxiK 通道在其 β1 亚基的帮助下可以微调所确定的动脉张力我们的早期工作表明 TXA2 模拟物 U46119 抑制 MaxiK 通道。在脂质双层中重建的冠状平滑肌膜的活性，这表明强 TPR 和 MaxiK 之间的功能关联经受了分离重建程序。最近的初步实验还表明：1）TPR 通过调节 MaxiK 成孔 α 亚基（Slo1）一种独立于 G 蛋白的新机制，其中 MaxiK 通道活性可以通过特异性 TPR 激动剂 U46619，2) TPR 和 MaxiK 通道亚基形成异源多聚体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冠状动脉肌细胞，异位表达TPR和Slo1后可复制， 4) 激动剂刺激增强 TPR 和 Slo1 关联在这里，我们将检验以下假设。激动剂刺激改变 TPR-Slo1-β1 关联，导致 Slo1 通道抑制。目的是： 1. 揭示激动剂 (U46619) 激活抑制 Slo1 通道的分子机制 TPR 和 2. 定义 β1 亚基在激动剂-TPR-Slo1 通道抑制中的作用。使用生物化学、分子生物学和光生物物理方法等现代方法进行由于 MaxiK 和 TPR 的广泛影响，包括衍射极限的荧光显微镜。哺乳动物生理学，从这些研究中获得的知识可能为研究提供新的机会不仅预防心血管系统疾病，还预防其他系统疾病。