Sorting of an apical plasma membrane glycoprotein occurs before it reaches the cell surface in cultured epithelial cells.
Sorting of an apical plasma membrane glycoprotein occurs before it reaches the cell surface in cultured epithelial cells.
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顶端质膜糖蛋白的排序是在培养的上皮细胞中到达细胞表面之前发生的。
DOI：
10.1083/jcb.99.6.2131
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发表时间：
1984-12
期刊：
影响因子：
--
通讯作者：
Simons K
中科院分区：
文献类型：
--
作者：
Matlin KS;Simons K
在感染流感病毒的Madin-Darby犬肾(MDCK)细胞(极化上皮细胞系)中，血凝素表现为顶端质膜糖蛋白。为了在生物化学上确定新合成的血凝素首次出现在质膜上的结构域，顶端或基侧，细胞培养在微孔过滤器上，使两个细胞表面域独立可达。病毒感染细胞中的血凝素被脉冲标记、追逐，并在质膜上用灵敏的胰酶试验进行检测。在所有测试条件下，新合成的血凝素同时出现在两个结构域上，大部分出现在顶膜上。在追逐过程中，当胰酶持续存在于基底外侧表面时，相对于顶端转运的血凝素，几乎没有被切割的血凝素。此外，抗血凝素的特异性抗体放置在基底部，对运输到顶端区域没有影响。这些观察表明，大多数新合成的血凝素并不是短暂地出现在基底外侧表面，而是以解释其最终极化分布的数量直接输送到心尖表面。
In Madin-Darby canine kidney (MDCK) cells (a polarized epithelial cell line) infected with influenza virus, the hemagglutinin behaves as an apical plasma membrane glycoprotein. To determine biochemically the domain on the plasma membrane, apical or basolateral, where newly synthesized hemagglutinin first appears, cells were cultured on Millipore filters to make both cell surface domains independently accessible. Hemagglutinin in virus-infected cells was pulse-labeled, chased, and detected on the plasma membrane with a sensitive trypsin assay. Under all conditions tested, newly made hemagglutinin appeared simultaneously on both domains, with the bulk found in the apical membrane. When trypsin was continuously present on the basolateral surface during the chase, little hemagglutinin was cleaved relative to the amount transported apically. In addition, specific antibodies against the hemagglutinin placed basolaterally had no effect on transport to the apical domain. These observations suggested that most newly synthesized hemagglutinin does not transiently appear on the basolateral surface but rather is delivered directly to the apical surface in amounts that account for its final polarized distribution.