Shimizu T
Department of Dermatology, Hokkaido University School of Medicine, Sapporo, Japan.
Hokkaido Igaku Zasshi. 1993 Jan;68(1):42-53.
Recent biochemical studies have shown that spectrin, protein 4.1, and actin form a skeletal protein network that underlines the inner surface of the erythrocyte membrane. The skeleton is a flexible structure that appears to be important in maintaining the shape and mechanical properties of the erythrocyte. Recent studies indicate that immunoanalogues of erythrocyte membrane skeletal proteins and ankyrin (protein 2.1) have been found in a wide variety of non-erythroid tissues. In the present study, in order to examine if human skin contains membrane skeletal proteins, immunochemical analysis was utilized using antibodies against anti-spectrin, anti-beta-fodrin (non-erythroid spectrin), anti-protein 4.1 and anti-ankyrin antibodies. Immunoblot analysis of human epidermis with anti-spectrin and anti-beta-fodrin antibodies revealed that human epidermis contains 240 kDa and 235 kDa spectrin-like proteins, which might be identical to brain fodrin. Human epidermis also contains 4.1-like proteins of 80 kDa and 78 kDa that cross react with anti-protein 4.1 antibodies, and contains ankyrin-like proteins of 210 kDa that cross react with anti-ankyrin antibodies. Analysis with immunofluorescence microscopy revealed that these antibodies reacted along the plasma membranes of human epidermal keratinocytes, eccrine sweat gland cells and sweat ductal cells. These results suggest that a membrane skeletal protein lattice might exist in these cells. Cultured human epidermal keratinocyte in the low Ca2+ medium (0.15 mM) showed that immunoreactive form of protein 4.1 and actin were present diffusely in the cytoplasm. When the cells were cultured with standardized Ca2+ medium (1.85 mM), protein 4.1 and actin were observed linearly along the cell margin and in the cytoplasm. Similar patterns of distribution were observed when anti-beta-fodrin antibody was used. Movement of membrane skeletal proteins from cytosol to the membrane suggest that these proteins or membrane skeletal lattice might play an important role in the formation of intercellular junctions.
近期的生化研究表明，血影蛋白、蛋白4.1和肌动蛋白形成了一个骨骼蛋白网络，该网络位于红细胞膜的内表面之下。这个骨架是一个灵活的结构，似乎对维持红细胞的形状和机械性能很重要。近期研究表明，在多种非红细胞组织中发现了红细胞膜骨骼蛋白和锚蛋白（蛋白2.1）的免疫类似物。在本研究中，为了检测人类皮肤是否含有膜骨骼蛋白，使用了抗血影蛋白、抗β- fodrin（非红细胞血影蛋白）、抗蛋白4.1和抗锚蛋白抗体进行免疫化学分析。用抗血影蛋白和抗β- fodrin抗体对人表皮进行免疫印迹分析显示，人表皮含有240 kDa和235 kDa的血影蛋白样蛋白，它们可能与脑fodrin相同。人表皮还含有与抗蛋白4.1抗体发生交叉反应的80 kDa和78 kDa的4.1样蛋白，以及与抗锚蛋白抗体发生交叉反应的210 kDa的锚蛋白样蛋白。免疫荧光显微镜分析显示，这些抗体沿着人表皮角质形成细胞、外分泌汗腺细胞和汗腺导管细胞的质膜发生反应。这些结果表明，这些细胞中可能存在膜骨骼蛋白晶格。在低钙培养基（0.15 mM）中培养的人表皮角质形成细胞显示，蛋白4.1和肌动蛋白的免疫反应形式弥漫性地存在于细胞质中。当细胞在标准化钙培养基（1.85 mM）中培养时，蛋白4.1和肌动蛋白沿细胞边缘和细胞质呈线性分布。使用抗β- fodrin抗体时观察到类似的分布模式。膜骨骼蛋白从胞质溶胶向膜的移动表明，这些蛋白或膜骨骼晶格可能在细胞间连接的形成中起重要作用。
