Functional interaction between cardiac Na channels and KATP channels

心脏 Na 通道和 KATP 通道之间的功能相互作用

• 批准号: 10160950
• 负责人: William A Coetzee
• 金额: $ 68.26万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-07 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10160950
• 关键词: ANK3 gene; Action Potentials; Adherens Junction; Animal Model; Ankyrins; Area; Binding; Binding Sites; Biochemistry; Cardiac; Cardiac Electrophysiologic Techniques; Cardiac Myocytes; Cardiovascular system; Caveolae; Cell Adhesion; Cell Communication; Cells; Characteristics; Code; Complex; Couples; Coupling; Data; Disease; Event; Fluorescence Microscopy; Genes; Heart; Heart Rate; Hybrids; Inherited; Intercalated disc; Investigation; Ion Channel; Knowledge; Lateral; Mediating; Membrane; Microscopy; Modeling; Molecular; Molecular Biology; Muscle Cells; Na(+)-K(+)-Exchanging ATPase; Peptides; Physiological; Proteins; Research Personnel; Resolution; Role; Ryanodine Receptors; Shapes; Site; Small Interfering RNA; Stress; Surface; System; Techniques; Testing; Time; Ventricular; density; design; genetic variant; imaging modality; innovation; insight; ischemic injury; medical schools; nanometer; patch clamp; response; scanning ion conductance microscopy; syntrophin; voltage

SUMMARY Cardiac Na+ channels and KATP channels are generally thought to have very different roles in cardiac electrophysiology. They do, however, share certain characteristics such as being expressed at higher levels at the intercalated disk compared to the lateral membranes and they coexist with desmosomal proteins. Our new data demonstrate that cardiac KATP channels interact with Na+ channels (and with the Na+/K+ ATPase). This proposal will utilize innovate super-resolution microscopy techniques and patch clamping to examine the interaction between Na+ channels and KATP channels. We will identify the membrane subdomains where interaction occurs, the molecular mechanisms responsible for interaction and the functional consequences of interactions. The overall hypotheses is that interaction is particularly prominent at membrane domains at the ICD, that interaction is mediated by specific binding sites in ankyrin-G, and that interaction leads to functional coupling between Na+ channels and KATP channels (via the Na+/K+ ATPase). In a first Aim, we will localize Na+ channels and KATP channels with nanometer precision to membrane subdomains in the lateral membrane (e.g. t-tubules, caveolae, etc.) as well as membrane subdomains at the intercalated disk (e.g. hybrid adhering junctions). A role for ankyrins in targeting channels to these domains will be investigated with siRNA approaches. In a second Aim, we will investigate the molecular mechanisms involved in interaction, testing the hypothesis that Na+ channels and KATP channels bind to similar sites on ankyrins. We will also test the functional consequences of interaction of Na+ channels and KATP channels. These studies will significantly move forward our understanding of Na+ channel and KATP channel and function in the cardiovascular system, and more generally, advance our knowledge on how channel systems in ventricular myocytes physically and functionally interact.

概括 心脏 Na+ 通道和 KATP 通道通常被认为在心脏中具有非常不同的作用。 电生理学。然而，它们确实具有某些共同特征，例如在更高水平上表达 闰盘与侧膜相比，它们与桥粒蛋白共存。我们的新 数据表明心脏 KATP 通道与 Na+ 通道（以及 Na+/K+ ATP 酶）相互作用。这 该提案将利用创新的超分辨率显微镜技术和膜片钳来检查 Na+通道和KATP通道之间的相互作用。我们将确定膜子域 相互作用发生、负责相互作用的分子机制以及相互作用的功能后果 互动。总体假设是，相互作用在膜域中尤其突出 ICD，该相互作用是由锚蛋白-G 中的特定结合位点介导的，并且该相互作用导致功能性 Na+ 通道和 KATP 通道之间的耦合（通过 Na+/K+ ATP 酶）。第一个目标是，我们将本地化 Na+ 通道和 KATP 通道以纳米精度连接到侧膜中的膜子域（例如 t 型小管、小窝等）以及闰盘处的膜子域（例如混合粘附 路口）。将使用 siRNA 研究锚蛋白在靶向这些结构域的通道中的作用 接近。在第二个目标中，我们将研究相互作用所涉及的分子机制，测试 假设 Na+ 通道和 KATP 通道与锚蛋白上的相似位点结合。我们还将测试 Na+ 通道和 KATP 通道相互作用的功能后果。这些研究将显着 推进我们对 Na+ 通道和 KATP 通道及其在心血管系统中的功能的理解， 更一般地说，增进我们对心室肌细胞通道系统如何物理和 功能上相互作用。