Ligand-induced association of surface immunoglobulin with the detergent-insoluble cytoskeletal matrix of the B lymphocyte.
Ligand-induced association of surface immunoglobulin with the detergent-insoluble cytoskeletal matrix of the B lymphocyte.
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DOI：
10.4049/jimmunol.128.3.1198
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发表时间：
1982-03
影响因子：
4.4
通讯作者：
J. Braun;P. Hochman;E. Unanue
中科院分区：
文献类型：
--
作者：
J. Braun;P. Hochman;E. Unanue
配体结合被认为诱导表面免疫球蛋白（IG）与下面的细胞骨架形成物理缔合。我们研究了这种相互作用，通过使用非离子洗涤剂，这是已知的溶解膜蛋白，但保留洗涤剂不溶性的细胞骨架残留物。在配体处理的情况下，表面IG在B细胞质膜完全溶解的非离子去污剂，然而，与配体的相互作用转换成一种新的，去污剂不溶的状态的受体。表面IG转化为洗涤剂不溶性形式需要受体交联，但发生独立的封盖。几种类型的实验表明，这种形式的IG不是由于免疫复合物的大小不溶性，并涉及一个稳定的，非共价缔合的受体与洗涤剂不溶性，细胞骨架残基。在37 ℃下孵育配体结合的细胞促进了表面IG的降解和新的较低m.w.种，包括与表面IG抗原相关的主要可溶性蛋白（50，000道尔顿）。这些事件对应于受体内吞作用的几个标准（时间过程，温度敏感性和能量依赖性）。总之，这些结果与配体诱导的受体跨膜附着到下面的细胞骨架基质，然后受体内化和catalysts一致。
Ligand binding is believed to induce surface immunoglobulin (Ig) to form a physical association with the underlying cell cytoskeleton. We investigated this interaction by use of nonionic detergents, which are known to dissolve membrane proteins but preserve a detergent-insoluble cytoskeletal residue. In the absence of ligand treatment, surface Ig in the B cell plasma membrane was fully dissolved by nonionic detergent; however, interaction with a ligand converted the receptor to a novel, detergent-insoluble state. The conversion of surface Ig to a detergent-insoluble form required receptor cross-linking but occurred independently of capping. Several types of experiments demonstrated that this form of Ig was not due to the size insolubility of immune complexes and involved a stable, noncovalent association of the receptor with the detergent-insoluble, cytoskeletal residue. Incubation of ligand-bound cells at 37 degrees C promoted the degradation of surface Ig and the appearance of new, lower m.w. species, including a major soluble protein (50,000 daltons) that was antigenically related to surface Ig. These events corresponded to receptor endocytosis by several criteria (time course, temperature sensitivity, and energy dependence). Taken together, these results were consistent with the ligand-induced transmembrane attachment of receptors to the underlying cytoskeletal matrix followed by receptor internalization and catabolism.