RAPID ENDOCYTOSIS COUPLED TO EXOCYTOSIS IN ADRENAL CHROMAFFIN CELLS INVOLVES CA2+, GTP, AND DYNAMIN BUT NOT CLATHRIN
RAPID ENDOCYTOSIS COUPLED TO EXOCYTOSIS IN ADRENAL CHROMAFFIN CELLS INVOLVES CA2+, GTP, AND DYNAMIN BUT NOT CLATHRIN
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DOI：
10.1073/pnas.92.18.8328
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发表时间：
1995-08-29
影响因子：
11.1
通讯作者：
PALFREY, CH
中科院分区：
文献类型：
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作者：
ARTALEJO, CR;HENLEY, JR;PALFREY, CH
肾上腺嗜铬细胞胞吐爆发后立即发生快速内吞作用（rapidendocytosis，RE）。内吞作用的电容测量表明，胞膜的恢复是一个双相过程，在20秒内完成。膜回收的最终程度被精确地控制，并且电容总是返回到其刺激前的值。RE的作用机制需要胞内Ca ~（2+）、Sr ~（2+）和Ba ~（2+）的参与，但这三种阳离子都支持分泌，因此RE和胞吐作用的二价阳离子受体必须是不同的分子，RE依赖于GTP的水解;它被GTP去除或用鸟苷5 ′-[γ-硫代]三磷酸替换而阻断。在GTP存在下，RE需要发动蛋白（一种鸟嘌呤核苷酸结合蛋白）的参与，如该蛋白的细胞内免疫拮抗作用所揭示的。完整的微管可能是必需的，因为诺考达唑也阻断RE，而抗发动蛋白抗体阻断RE，抗网格蛋白抗体则没有，这表明网格蛋白包被的囊泡是参与这种形式的内吞作用的NDT。RE可能代表了嗜铬细胞中分泌颗粒快速再循环的初始步骤。
Rapid endocytosis (RE) occurs immediately after an exocytotic burst in adrenal chromaffin cells, Capacitance measurements of endocytosis reveal that recovery of membrane is a biphasic process that is complete within 20 sec. The ultimate extent of membrane retrieval is precisely controlled and capacitance invariably returns to its prestimulation value. The mechanism of RE specifically requires intracellular Ca2+; Sr2+ and Ba2+ do not substitute, although all three cations support secretion, Thus the divalent cation receptors for RE and exocytosis must be distinct molecules, RE is dependent on GTP hydrolysis; it is blocked by GTP removal or replacement with guanosine 5'-[gamma-thio]triphosphate, In the presence of GTP, multiple rounds of secretion followed by RE could be elicited from the same cell, RE requires participation of dynamin, a guanine nucleotide binding protein, as revealed by intracellular immunological antagonism of this protein, Intact microtubules may be essential, as nocodazole also blocked RE, Whereas anti-dynamin antibodies blocked RE, anti-clathrin antibodies did not, suggesting that clathrin-coated vesicles are ndt involved in this form of endocytosis. RE may represent the initial step in the rapid recycling of secretory granules in the chromaffin cell.