Role of Desmosomes in Cardiac Electrical Function

细胞间通讯对心脏正常功能至关重要。机械和 电活动需要同步， 转化为器官的泵功能。连接复合物优先 存在于肌细胞之间的端-端接触部位，在闰盘内。也 存在于闰盘中的是传统上不被认为是“连接”的分子， 即不涉及在相邻小区之间提供物理连续性。在这里， 我们寻求更好地理解机械连接、间隙 连接和电压门控钠通道（VGSC）复合物。实验茎 根据我们的观察，桥粒蛋白质斑嗜蛋白-2的表达缺失 （PKP 2）导致钠电流的振幅降低和动力学偏移。 我们的初步数据进一步表明，细胞骨架衔接蛋白anks-G （ankG），已知其与心脏钠通道蛋白相关， 在功能上与PKP 2和与差距连接蛋白连接蛋白43（Cx43）相互作用。 因此，我们测试的整体假设，有一个功能的相互依赖性， 与电压门控钠通道复合物的机械连接， 两种成分中的分子都可以影响间隙连接介导的细胞间 沟通在心中。具体目标是：1：表征 与差距连接蛋白connexin 43的结合蛋白-G。2：研究互惠 在细胞间机械偶联中涉及的蛋白质与anklycer-G的相互作用。第三章： 评估钠电流对桥粒表达的依赖性， proteins.我们推测，这种“其他”机电耦合，发生在 闰盘，可能不仅与理解 罕见的遗传性疾病，但也在后天条件（心肌病）影响 椎间盘的完整性。

Intercellular communication is essential for proper cardiac function. Mechanical and electrical activity need to be synchronized so that the work of individual myocytes transforms into the pumping function of the organ. Junctional complexes preferentially reside at the site of end-end contact between myocytes, within the intercalated disc. Also resident to the intercalated disc are molecules not traditionally considered "junctional," that is, not involved in providing a physical continuum between neighboring cells. Here, we seek a better understanding of the association between mechanical junctions, gap junctions and the voltage-gated sodium channel (VGSC) complex. Experiments stem from our observations that loss of expression of the desmosomal protein plakophilin-2 (PKP2) leads to a decrease in amplitude and a shift in kinetics of the sodium current. Our preliminary data further indicate that the cytoskeletal adaptor protein ankyrin-G (ankG), which is known to associate with the cardiac sodium channel protein, functionally interacts with PKP2 and with the gap junction protein connexin43 (Cx43). Thus, we test the overall hypothesis that there is a functional interdependence of the mechanical junctions with the voltage-gated sodium channel complex, and that molecules within both components can influence gap junction mediated intercellular communication in the heart. Specifics Aims are: 1: To characterize the interaction of ankyrin-G with the gap junction protein connexin43. 2: To study the reciprocal interaction of ankyrin-G with proteins involved in mechanical coupling between cells. 3: To assess the dependence of the sodium current on the expression of desmosomal proteins. We speculate that this "other" electromechanical coupling, occurring at the intercalated disc, may be relevant not only in the understanding of arrhythmogenesis in rare inherited diseases, but also in acquired conditions (cardiomyopathies) affecting the integrity of the intercalated disc.