AN ENZYMATIC ASSAY REVEALS THAT PROTEINS DESTINED FOR THE APICAL OR BASOLATERAL DOMAINS OF AN EPITHELIAL-CELL LINE SHARE THE SAME LATE GOLGI COMPARTMENTS
AN ENZYMATIC ASSAY REVEALS THAT PROTEINS DESTINED FOR THE APICAL OR BASOLATERAL DOMAINS OF AN EPITHELIAL-CELL LINE SHARE THE SAME LATE GOLGI COMPARTMENTS
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DOI：
10.1002/j.1460-2075.1985.tb03629.x
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发表时间：
1985-01-01
期刊：
影响因子：
11.4
通讯作者：
SIMONS, K
中科院分区：
文献类型：
--
作者：
FULLER, SD;BRAVO, R;SIMONS, K
病毒包膜蛋白在上皮细胞系MDCK的质膜结构域上的表达是极性的。这些细胞的流感病毒感染导致病毒血凝素和神经氨酸酶糖蛋白在质膜的顶端域上表达，而水泡性口炎病毒（VSV）感染产生具有唾液酸的G蛋白的基底外侧表达。利用流感病毒神经氨酸酶使VSV的G蛋白去唾液酸化的能力来测试这些蛋白质在细胞内转运至分离质膜结构域期间之间的接触。选择在双重感染的细胞中表达VSV-G蛋白，因为在用流感病毒预感染的细胞中VSV蛋白的产生加速。在双重感染的包膜蛋白的两种病毒表现出相同的极性定位在单一感染，但VSG-G蛋白的唾液酸化不足，由于流感神经氨酸酶的作用。在20 ℃下孵育单一感染的细胞。C阻断了VSV-G蛋白向细胞表面的转运，并导致该蛋白的唾液酸化作用比在37 ℃时所见的增加。C.在此温度下，G蛋白显然与唾液酸转移酶保持接触。20.degree. C孵育的双重感染的细胞也产生了唾液酸化不足的G蛋白的相互作用与神经氨酸苷酶的特点。大多数新合成的基底外侧定向G蛋白通过高尔基体加工的末端步骤与大多数神经氨酸酶物理接触。
The expression of viral envelope proteins on the plasma membrane domains of the epithelial cell line, MDCK, is polar. Influenza virus infection of these cells leads to expression of the viral hemagglutinin and neuraminidase glycoproteins on the apical domain of the plasma membrane while vesicular stomatitis virus (VSV) infection yields basolateral expression of the sialic acid-bearing G protein. The ability of the influenza neuraminidase to desialate the G protein of VSV was exploited to test for contact between these proteins during their intracellular transport to separate plasma membrane domains. VSV-G protein expression was selected for in doubly-infected cells because VSV protein production was accelerated in cells pre-infected with influenza virus. During double infection of the envelope proteins of both viruses displayed the same polar localization as during single infection but the VSG-G protein was undersialated due to the action of the influenza neuraminidase. Incubation of singly-infected cells at 20.degree. C blocked the transport of VSV-G protein to the cell surface and resulted in increased sialation of the protein over that seen at 37.degree. C. G protein is evidently held in contact with the sialyl transferase at this temperature. 20.degree. C incubations of doubly-infected cells also produced the undersialated G protein characteristic of interaction with the neuraminidse. Most of the newly synthesized basolaterally-directed G protein is in physical contact with the majority of the neuraminidase through the terminal steps of Golgi processing.