Role of the secretion vesicle in the transport of receptors: modulation of somatostatin binding to pancreatic islets.
Role of the secretion vesicle in the transport of receptors: modulation of somatostatin binding to pancreatic islets.
复制标题
分泌囊泡在受体转运中的作用：调节生长抑素与胰岛的结合。
DOI：
10.1210/endo-111-1-316
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发表时间：
1982
期刊：
影响因子：
4.8
通讯作者：
B. Draznin
中科院分区：
文献类型：
--
作者：
K. Sussman;P. Mehler;J. Leitner;B. Draznin
葡萄糖通过增加受体浓度增强胰岛生长抑素结合，但受体亲和力不变。生长抑素结合的增加可能是由于1)重新合成受体，2)受体内化率的降低，或3)在细胞增多症期间受体从高尔基体转移到质膜。对这三种可能性进行了研究。足以使蛋白质合成减少81±2%的剂量环己亚胺（1mm）并不能抑制16.7 mM葡萄糖诱导的生长抑素结合增加。通过将胰岛与[125I]碘生长抑素（pH 7.4）孵育以测量总细胞结合，然后用0.2 N乙酸（pH 2.5）处理以去除细胞表面结合的生长抑素并测定细胞内残留的放射性，间接评估配体-受体复合物的内化。醋酸处理导致配体表面受体复合物的解离。残余放射性反射……
Glucose augments islet somatostatin binding by increasing receptor concentration with no change in receptor affinity. The increased binding of somatostatin could be due to 1) de novo receptor synthesis, 2) decrease in the rate of receptor internalization, or 3) translocation of receptors from the Golgi apparatus to the plasma membrane during emiocytosis. Studies were undertaken to test these three possibilities. A dose of cycloheximide (1 mM) sufficient to produce an 81 ± 2% decrease in protein synthesis did not inhibit the increased somatostatin binding induced by 16.7 mM glucose. Internalization of ligand-receptor complex was indirectly assessed by incubating islets with [125I]iodosomatostatin (pH 7.4) in order to measure total cell binding and then treating them with 0.2 N acetic acid (pH 2.5) to remove cell surface bound somatostatin and determine residual intracellular radioactivity. The acetic acid treatment results in dissociation of the ligandsurface receptor complex. Residual radioactivity reflec...