TRANSMEMBRANE INTERACTIONS AND MECHANISM OF CAPPING OF SURFACE RECEPTORS BY THEIR SPECIFIC LIGANDS
TRANSMEMBRANE INTERACTIONS AND MECHANISM OF CAPPING OF SURFACE RECEPTORS BY THEIR SPECIFIC LIGANDS
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DOI：
10.1073/pnas.74.11.5031
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发表时间：
1977-01-01
影响因子：
11.1
通讯作者：
SINGER, SJ
中科院分区：
文献类型：
--
作者：
BOURGUIGNON, LYW;SINGER, SJ
细胞表面受体的封端机制通过双荧光染色程序进行了研究，该程序允许同时观察表面结合的配体与细胞内肌动蛋白或肌球蛋白的分布。在T-25抗原或H2组织相容性抗原在小鼠脾T[胸腺来源]淋巴细胞或[人]HeLa细胞的刀豆蛋白A受体的封端的早期阶段，当所讨论的特定受体被收集成分布在整个细胞表面的贴片时，细胞内膜相关的肌动蛋白或肌球蛋白也积聚到位于受体贴片正下方的贴片中。提出了封端过程的一般分子机制，肌动蛋白和肌球蛋白直接参与其中。膜相关肌动蛋白显然直接或间接地与真核细胞质膜中的一个或一类完整的蛋白质X结合。当膜上的任何受体被外部多价配体聚集时，聚集的受体有效地与X结合，而未聚集的受体不与X结合。通过X连接到肌动蛋白(和肌球蛋白)的受体聚集体，然后通过类似肌动蛋白-肌球蛋白滑动细丝机制的肌肉收缩被主动收集到帽中。
The mechanism of capping of cell surface receptors was examined by a double fluorescence staining procedure that permitted simultaneous observations of the distribution of a surface-bound ligand together with intracellular actin or myosin. At an early stage in the capping of the T-25 antigen or the H2 histocompatibility antigens on mouse splenic T [thymus-derived] lymphocytes, or of concanavalin A receptors of [human] HeLa cells, when the specific receptors in question were collected into patches that were distributed over the entire cell surface, the intracellular membrane-associated actin or myosin was also accumulated into patches that were located directly under the receptor patches. A general molecular mechanism was proposed for the process of capping, in which actin and myosin are directly involved. Membrane-associated actin is apparently directly or indirectly bound to an integral protein or class of proteins, X, in the plasma membranes of eukaryotic cells. When any receptor in the membrane is aggregated by an external multivalent ligand, the aggregate binds effectively to X, whereas unaggregated receptors do not bind to X. The receptor aggregates, linked to actin (and myosin) through X, are then actively collected into a cap by an analogue of the actin-myosin sliding filament mechanism of muscle contraction.