Morphofunctional analysis of the membrane skeletal protein 4.1B

红细胞动态地改变其膜下的膜骨架，以抵抗血管内流动时的剪切力，从而在整个身体内运输氧气。其中一个膜骨架蛋白，4.1个家族成员，与血影蛋白肌动蛋白网络相互作用，也与膜内蛋白相互作用。蛋白4.1B最初被发现定位于有髓神经纤维的副神经节和旁肝节。通过使用4.1B的特异性抗体，我们发现4.1B也定位在无髓神经纤维轴突的细胞膜上。除神经系统外，4.1B和另一个4.1家族成员4.1G广泛分布于肾、肠、胰腺、睾丸和胸腺。我们最近对蛋白4.1家族蛋白的免疫组织化学研究表明，它们在啮齿动物各种器官的细胞-细胞和/或细胞-基质黏附中具有重要意义。另一方面，利用活体冷冻技术对组织器官进行动态分析。因此，在本研究中，我们证明了4.1家族的膜骨架是细胞膜下的一个普遍结构，我们的研究可能为哪些组织和/或器官使用这个系统来分析分子复合体提供了线索。

Erythrocytes dynamically change their membrane skeletons under their membranes to resist shear stresses during flowing in vessels, to transport oxygen in whole body. One of the membrane skeletal proteins, 4.1 family members, interacts with spectrin-actin networks and also to the intramembranous proteins. The protein 4.1B was originally found to be localized in paranodes and juxtaparanodes of myelinated nerve fibers. By using specific antibody against 4.1B, we found that 4.1B localized also along cell membranes of unmyelinated nerve fiber axons. In addition to the nervous system, 4.1B and another 4.1 family member, 4.1G, are broadly immunolocalized in the kidney, intestine, pancreas, testis and the thymus. Our recent immunohistochemical studies on protein 4.1 family proteins have indicated their significance for the cell-cell and/or cell-matrix adhesion in various rodent organs. On the other hand, analyses for dynamic states of tissues and organs were performed with in vivo cryotechnique. Thus, in this study, we have proven that the 4.1 family-containing membrane skeletons are a general structure under the cell membranes, and our studies probably give clues what tissues and/or organs use this system for analyzing molecular complexes.