Movement of endocytic shuttle vesicles from the sinusoidal to the bile canalicular face of hepatocytes does not depend on occupation of receptor sites
Movement of endocytic shuttle vesicles from the sinusoidal to the bile canalicular face of hepatocytes does not depend on occupation of receptor sites
复制标题
内吞穿梭囊泡从肝细胞的肝窦到胆小管面的运动不依赖于受体位点的占据
DOI：
10.1016/0014-5793(80)80591-6
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发表时间：
1980
期刊：
影响因子：
3.5
通讯作者：
R. Hinton
中科院分区：
文献类型：
--
作者：
B. Mullock;Robin S. Jones;R. Hinton
大鼠胆汁的三种主要蛋白质，即 IgA、分泌成分和触珠蛋白：血红蛋白复合物，通过专门的内吞囊泡到达胆汁 [1-4]。 IgA 和分泌成分的运输途径已被了解。分泌成分在肝细胞中产生 [3, 5] 并转运至细胞的肝窦表面。这里，分泌成分仍然牢固地结合在细胞表面，但能够结合聚合 IgA [3, 6]。然后，IgA 分泌成分复合物被吸收到囊泡中，并穿过肝细胞转运至细胞的胆管面 [1, 2]。触珠蛋白：血红蛋白复合物的转运本质上是相同的[4]，尽管在这种情况下，受体尚未被识别。尽管现在已经了解了这些蛋白质跨肝细胞的转运途径，但该过程的机制需要进一步研究。对内吞小泡形成起始的最简单解释是 IgA 与分泌成分的结合，或触珠蛋白：血红蛋白复合物与其受体的结合，触发了摄取。然而，胆汁含有大量的游离分泌成分[7]。虽然这可能是由于胆汁中分泌性 IgA 的解离或由于质膜中邻近的一些游离分泌成分分子与已结合 IgA 的分泌成分分子的携带而引起，但大量表明无论 IgA 是否结合，受体都可能转移到胆汁中。我们现在报道内吞“关闭”的形成
Three of the major proteins of rat bile, namely IgA, secretory component and the haptoglobin: haemoglobin complex, reach bile by means of specialised endocytic vesicles [l-4]. The route for IgA and secretory component transport is understood. Secretory component is made in hepatocytes [3, 5] and transported to the sinusoidal surface of the cells. Here the secretory component remains firmly bound to the surface of the cells but is capable of binding polymeric IgA [3, 6]. The IgA-secretory component complex is then taken up into vesicles and transported across hepatocytes to the bile canalicular face of the cell [1, 2]. The transport of haptoglobin: haemoglobin complexes is essentially the same [4], although, in this case, the receptor has not been identified.Although the route of transfer of these proteins across hepatocytes is now understood, the mechanics of the process require further investigation. The simplest explanation for the initiation of formation of the endocytic vesicles is that the binding of IgA to secretory component, or ofhaptoglobin: haemoglobin complexes to their receptor, triggers the uptake. However, bile contains large amounts of free secretory component [7]. Although this might perhaps arise from dissociation of secretory IgA in the bile or from carriage of some free secretory component molecules adjacent in the plasma membrane to a secretory component molecule which had bound IgA, the large amounts suggested that the receptor might be transferred to bile whether or not IgA was bound. We now report that formation of the endocytic ‘shut-