Three-dimensional, computer-tomographic analysis of membrane proteins (TrkA, caveolin, clathrin) in PC12 cells.
Three-dimensional, computer-tomographic analysis of membrane proteins (TrkA, caveolin, clathrin) in PC12 cells.
复制标题
DOI：
10.1267/ahc.07009
复制
发表时间：
2007-07-03
影响因子：
2.4
通讯作者：
Endo, Yasuhisa
中科院分区：
文献类型：
--
作者：
Nishida, Tomoki;Arii, Tatsuo;Takaoka, Akio;Yoshimura, Ryoichi;Endo, Yasuhisa
神经生长因子（NGF）及其受体（TrkA）的信号传导促进神经元分化、突触形成和存活。已知NGF和TrkA的复合物被内化到细胞质中并被转运以进行进一步的信号转导，但这一过程的超微结构信息几乎是未知的。为了阐明TrkA的内化与膜相关蛋白（caveolin和clatherin）之间的关系，利用高压电子显微镜的计算机断层扫描技术研究了这些蛋白在PC 12细胞中的定位和三维结构。TrkA免疫反应仅在质膜的特定区域发现，呈环状和簇状结构。它的三维图像显示，这些集群结构包含小坑，这些小坑在大小和形状上看起来不是典型的小窝。网格蛋白和小窝蛋白-1免疫反应性的3D图像表明，这些小坑的形成与网格蛋白有关，但与小窝蛋白-1无关。小窝蛋白-1免疫反应被发现为一个网状结构，就在质膜下。这些结果表明，网格蛋白，而不是小窝蛋白主要参与的过程中的TrkA内化，至少在分化的PC 12细胞。
Signaling of nerve growth factor (NGF) and its receptor (TrkA) promotes neuronal differentiation, synapse formation and survival. It has been known that the complex of NGF and TrkA is internalized into the cytoplasm and transported for further signal transduction, but the ultrastructural information of this process is virtually unknown. In order to clarify the relationship between the internalization of TrkA and the membrane-associated proteins (caveolin and clathrin), the localization and three-dimensional structures of those proteins were examined with computer tomography of high voltage electron microscopy in PC12 cells. TrkA immunoreactivity was found only at definite areas in the plasma membrane, as ring and cluster structures. Its 3D image indicated that those cluster structures contained small pits, which did not appear to be typical caveolae in size and shape. 3D images of clathrin and caveolin-1 immunoreactivities indicated that the formation of those small pits was associated with clathrin, but not with caveolin-1. Caveolin-1 immunoreactivity was found as a mesh-like structure just beneath the plasma membrane. These results suggest that clathrin rather than caveolin is mainly involved in the process of TrkA internalization, at least in differentiated PC12 cells.