Yorifuji H, Kanda K, Sobue K, Hirokawa N
Department of Anatomy, Faculty of Medicine, University of Tokyo/Japan.
Eur J Cell Biol. 1989 Feb;48(1):104-15.
Localization of 4.1 related proteins in neurons was studied with immunofluorescence microscopy and with immunoelectron microscopy on ultrathin cryosections. In rat cerebellum, 4.1 immunoreactive proteins were demonstrated in Purkinje cell bodies, dendrites and other neurons in the cerebellar cortex. Some glial cells showed staining, but no labeling was found in myelinated axons of the white matter and of the glomeruli in the granule cell layer. At the ultrastructural level, the 4.1 related proteins were localized mainly in the cytoplasmic matrix, while some labeling was found underneath the plasma membrane. To determine whether 4.1 related proteins in neuronal cytoplasm exist as part of the cytoskeleton or not, PC12 cells cultured in the presence of nerve growth factor were stained with the anti-4.1 antibody. Since cytoplasmic staining was retained after detergent treatment, the 4.1 related proteins seem to exist as a component of the neural cell cytoskeleton. Localization of 4.1 related proteins during the postnatal development of the cerebellum was also studied. In Purkinje cells, localization of 4.1 related proteins changed according to the stages of the postnatal development. The present data suggest that 4.1 related proteins in neurons localized mainly in the cytoplasm and may play some role in organizing cytoskeletal networks in the cytomatrix. Their distribution is developmentally regulated in some neurons, possibly in relationship to their maturation in the cytoskeleton.
利用免疫荧光显微镜以及超薄冰冻切片免疫电子显微镜技术研究了4.1相关蛋白在神经元中的定位。在大鼠小脑中，浦肯野细胞体、树突以及小脑皮质中的其他神经元均显示出4.1免疫反应性蛋白。一些神经胶质细胞也有染色，但在白质的有髓轴突以及颗粒细胞层的小球中未发现标记。在超微结构水平上，4.1相关蛋白主要定位于细胞质基质中，同时在质膜下方也发现了一些标记。为了确定神经元细胞质中的4.1相关蛋白是否作为细胞骨架的一部分存在，用抗4.1抗体对在神经生长因子存在下培养的PC12细胞进行染色。由于在去污剂处理后细胞质染色仍保留，4.1相关蛋白似乎作为神经细胞骨架的一个组成部分存在。还研究了小脑出生后发育过程中4.1相关蛋白的定位。在浦肯野细胞中，4.1相关蛋白的定位根据出生后发育阶段而变化。目前的数据表明，神经元中的4.1相关蛋白主要定位于细胞质中，可能在细胞质基质中组织细胞骨架网络中发挥一些作用。它们的分布在一些神经元中受到发育调控，可能与其在细胞骨架中的成熟有关。
