Takemura R, Okabe S, Kobayashi N, Hirokawa N
Department of Anatomy and Cell Biology, School of Medicine, University of Tokyo, Japan.
Neuroscience. 1993 Jan;52(2):381-91. doi: 10.1016/0306-4522(93)90165-c.
Fodrin has been shown to redistribute dynamically between cytoplasmic and plasma membrane-associated compartments upon the differentiation of T lymphocytes. We studied the changes of distribution of fodrin in PC12 cells upon neuronal differentiation induced by nerve growth factor. To visualize preferentially the elements that were tightly associated with cytoskeletal structures, we performed immunofluorescence and immunoelectron microscopy on saponin-extracted cells. In undifferentiated PC12 cells, fodrin was distributed mostly underneath the plasma membrane. However, after the administration of nerve growth factor, perinuclear spot-like aggregates of fodrin appeared. Double-labeling immunofluorescence revealed that the cytoplasmic fodrin spot was co-localized with the intermediate filament proteins, peripherin and neurofilament. Immunogold electron microscopy showed that fodrin and neurofilament were localized in close association in the perinuclear regions enriched with intermediate filaments. With prolonged exposure to nerve growth factor, fodrin and intermediate filaments spread to the cytoplasm and neurites. These results suggest that there is a dynamic reorganization of fodrin during differentiation of PC12 cells, and that fodrin is first recruited in the perinuclear region closely associated with intermediate filaments. This dynamic reorganization of fodrin may represent important, previously unrecognized aspects of the morphological differentiation of neurons.
已证明，在T淋巴细胞分化时，血影蛋白会在细胞质和质膜相关区室之间动态重新分布。我们研究了神经生长因子诱导PC12细胞神经元分化时血影蛋白分布的变化。为了优先观察与细胞骨架结构紧密相关的成分，我们对皂素提取的细胞进行了免疫荧光和免疫电子显微镜检查。在未分化的PC12细胞中，血影蛋白大多分布在质膜下方。然而，给予神经生长因子后，出现了血影蛋白的核周点状聚集物。双重标记免疫荧光显示，细胞质血影蛋白斑点与中间丝蛋白外周蛋白和神经丝共定位。免疫金电子显微镜显示，血影蛋白和神经丝在富含中间丝的核周区域紧密定位。随着长时间暴露于神经生长因子，血影蛋白和中间丝扩散到细胞质和神经突。这些结果表明，在PC12细胞分化过程中存在血影蛋白的动态重组，并且血影蛋白首先在与中间丝紧密相关的核周区域被募集。血影蛋白的这种动态重组可能代表了神经元形态分化中重要的、以前未被认识的方面。
