Functional Studies of Erythrocyte Dematin

在此输入文本，它是应用程序的新摘要信息。此部分不得超过30行文本。 血影蛋白-肌动蛋白连接对于维持红细胞膜的稳定性和机械性能是非常重要的。流行的范例是这些连接通过蛋白4.1和血型糖蛋白C之间的相互作用连接到质膜。我们目前的模型预测，dematin，与内收蛋白，组装一个新的细胞骨架复合物的血影蛋白多肽，连接这些路口的质膜的尾端。在这个竞争性更新应用中，我们将使用以下实验方法来验证我们的假设：小鼠去角质蛋白和内收蛋白的联合缺失会导致严重贫血和红细胞高度脆弱。为了阐明削弱血影蛋白肌动蛋白连接到质膜的机制，我们将研究肌动蛋白原丝的状态，拯救膜不稳定性缺陷，研究已知的垂直相互作用的双重突变的影响，并测试直接结合的dematin与内收蛋白及其调节磷酸化和寡聚化。重要的是，我们将使用完全缺乏dematin和β内收蛋白的双敲除小鼠来研究dematin的残余核心结构域是否对红细胞膜的稳定性产生显性负性。由于dematin和adducin广泛表达，包括血小板和心肌，因此拟议的研究对于理解心血管疾病如溶血性贫血和相关出血性疾病的分子基础具有潜在意义。

Enter the text here that is the new abstract information for your application. This section must be no longer than 30 lines of text. It is well recognized that the "spectrin-actin junctions" are functionally essential for the maintenance of erythrocyte membrane stability and mechanical properties. The prevailing paradigm is that these junctions are linked to the plasma membrane via an interaction between protein 4.1 and glycophorin C. Our current model predicts that dematin, in conjunction with adducin, assembles a novel cytoskeletal complex at the tail ends of spectrin polypeptides that link these junctions to the plasma membrane. In this competitive renewal application, we will use the following experimental approaches to validate our hypothesis: Combined deletion of mouse dematin and adducin results in severe anemia with highly fragile erythrocytes. To elucidate the mechanism of weakened spectrin-actin linkage to the plasma membrane, we will investigate the status of actin protofilaments, rescue membrane instability defect, examine the effect of double mutation on known vertical interactions, and test direct binding of dematin with adducin and its regulation by phosphorylation and oligomerization. Importantly, we will use the double knockout mice that completely lack dematin and beta adducin to investigate whether the residual core domain of dematin exerts a dominant negative on the stability of the erythrocyte membrane. Since dematin and adducin are widely expressed, including the platelets and heart muscle, the proposed studies are potentially significant for understanding the molecular basis of cardiovascular diseases such as hemolytic anemia and related bleeding disorders.