DISTRIBUTION OF FERRITIN RECEPTORS AND COATED PITS ON GIANT HELA-CELLS
DISTRIBUTION OF FERRITIN RECEPTORS AND COATED PITS ON GIANT HELA-CELLS
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DOI：
10.1002/j.1460-2075.1983.tb01469.x
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发表时间：
1983-01-01
期刊：
影响因子：
11.4
通讯作者：
THOMSON, JN
中科院分区：
文献类型：
--
作者：
BRETSCHER, MS;THOMSON, JN
当 HeLa 细胞在 0°C 下孵育时，两者会结合马脾铁蛋白。 C.由于大部分结合的铁蛋白位于包被的凹坑中，因此铁蛋白必须与参与内吞循环的特定受体结合。当底物附着且充分铺展的巨型 HeLa 细胞在 0°C 下被短暂标记时。 C 与铁蛋白相比，发现铁蛋白颗粒集中在细胞外围，在那里它们主要存在于包被的凹坑之外。该外周浓度是循环（而不仅仅是新合成的）受体的特性，因为它不受先前在放线菌酮中孵育的巨细胞的影响。包被的凹坑本身大致均匀地分布在这些细胞的表面上。被这些细胞上的涂层凹坑内化的膜返回到细胞前缘的细胞表面。由于胞吞作用和胞吐作用位点的这种分离，必须在细胞表面上发生膜流动。该流由脂质加受体组成。讨论了这对于封盖和细胞扩散的影响。
HeLa cells bind horse spleen ferritin when the 2 are incubated at 0.degree. C. Since the majority of this bound ferritin is located in coated pits, the ferritin must bind to a specific receptor which takes part in an endocytic cycle. When substrate-attached and well-spread giant HeLa cells are briefly labeled at 0.degree. C with ferritin, ferritin particles are found to be concentrated towards the cell periphery, where they exist largely outside coated pits. This peripheral concentration is a property of circulating (and not just newly synthesized) receptors because it is not affected by prior incubation of giant cells in cycloheximide. Coated pits are themselves roughly uniformly distributed over the surface of these cells. The membrane internalized by coated pits on these cells is returned to the cell surface at the leading edge of the cell. Because of this separation of the sites of endocytosis and exocytosis, a flow of membrane must occur across the cell surface. This flow is composed of lipid plus receptors. The implications of this for capping and for cell spreading are discussed.