Abstract:
Functional membrane proteins in the plasma membrane are suggested to have specific membrane environments that play important roles to maintain and regulate their function. However, the local membrane environments of membrane proteins remain largely unexplored due to the lack of available techniques. We have developed a method to probe the local membrane environment surrounding membrane proteins in the plasma membrane by covalently tethering a solvatochromic, environment-sensitive dye, Nile Red, to a GPI-anchored protein and the insulin receptor through a flexible linker. The fluidity of the membrane environment of the GPI-anchored protein depended upon the saturation of the acyl chains of the lipid anchor. The local environment of the insulin receptor was distinct from the average plasma membrane fluidity and was quite dynamic and heterogeneous. Upon addition of insulin, the local membrane environment surrounding the receptor specifically increased in fluidity in an insulin receptor-kinase dependent manner and on the distance between the dye and the receptor.
摘要:
提示质膜中的功能性膜蛋白具有特定的膜环境,在维持和调节其功能方面起着重要作用。然而,由于缺乏可用的技术,膜蛋白的局部膜环境仍未被开发。我们开发了一种通过共价连接溶剂化色素来探测质膜中膜蛋白周围的局部膜环境的方法,环境敏感染料,尼罗河红,GPI锚定蛋白和胰岛素受体通过柔性接头。GPI锚定蛋白的膜环境的流动性取决于脂质锚的酰基链的饱和度。胰岛素受体的局部环境与平均质膜流动性不同,并且非常动态和异质。添加胰岛素后,受体周围的局部膜环境以胰岛素受体-激酶依赖性方式和染料与受体之间的距离特异性地增加了流动性。