Nelson W J, Hammerton R W, Wang A Z, Shore E M
Institute for Cancer Research, Philadelphia, PA 19111.
Semin Cell Biol. 1990 Oct;1(5):359-71.
The generation of cell surface polarity in transporting epithelial cells occurs in three distinct stages that involve cell-cell recognition and adhesion, cell surface remodelling to form biochemically and functionally distinct cell surface domains, and development of vectorial function. A widely used model system to study mechanisms involved in these stages is the Madin-Darby canine kidney (MDCK) cell line. Under appropriate growth conditions, MDCK cells develop in similar stages into polarized, multicellular epithelial structures. Analysis of membrane-cytoskeletal proteins ankyrin and fodrin during development of MDCK cell surface polarity shows that they gradually assemble into an insoluble protein complex on the basal-lateral membrane domain upon cell-cell adhesion, concomitantly with the redistribution of Na+,K(+)-ATPase, a marker protein of the basal-lateral membrane. Biochemical analysis shows that ankyrin, fodrin occur in a complex with Na+,K(+)-ATPase and the cell adhesion molecule uvomorulin in MDCK cells. A model is presented in which assembly of membrane-cytoskeletal complexes at sites of uvomorulin-induced cell-cell contact causes a remodelling of the cell surface distribution of specific membrane proteins which, in turn, contributes to the generation of epithelial cell surface polarity.
在转运上皮细胞中，细胞表面极性的产生经历三个不同阶段，包括细胞间识别与黏附、细胞表面重塑以形成生化和功能上不同的细胞表面结构域，以及向量功能的发展。研究这些阶段所涉及机制的一个广泛使用的模型系统是麦氏犬肾（MDCK）细胞系。在适当的生长条件下，MDCK细胞以相似的阶段发育成极化的多细胞上皮结构。对MDCK细胞表面极性发育过程中膜细胞骨架蛋白锚蛋白和血影蛋白的分析表明，在细胞间黏附时，它们逐渐在基底外侧膜结构域组装成不溶性蛋白复合物，同时伴随着基底外侧膜标记蛋白钠钾ATP酶的重新分布。生化分析表明，在MDCK细胞中，锚蛋白、血影蛋白与钠钾ATP酶和细胞黏附分子埃-钙黏蛋白形成复合物。本文提出了一个模型，即在埃-钙黏蛋白诱导的细胞间接触位点处膜细胞骨架复合物的组装导致特定膜蛋白细胞表面分布的重塑，进而有助于上皮细胞表面极性的产生。
