THE INTERFERON-INDUCED MX-PROTEIN OF CHICKENS LACKS ANTIVIRAL ACTIVITY
THE INTERFERON-INDUCED MX-PROTEIN OF CHICKENS LACKS ANTIVIRAL ACTIVITY
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DOI：
10.1089/jir.1995.15.47
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发表时间：
1995-01-01
影响因子：
2.3
通讯作者：
STAEHELI, P
中科院分区：
文献类型：
--
作者：
BERNASCONI, D;SCHULTZ, U;STAEHELI, P
鸡Mr蛋白由705个氨基酸组成，N端84个氨基酸与其它Mr蛋白没有明显的同源性，其后514个氨基酸残基包括一个三重GTP结合区，与哺乳动物和鸭Mr蛋白的同源性为50-70%，靠近C端的序列包括一个亮氨酸拉链基序，也是保守的，而插入的19个氨基酸缺乏序列相似性。该独特序列对应于哺乳动物Mr蛋白中的高度可变区，表明其作为功能结构域之间的间隔区。用cDNA表达构建体瞬时转染的鸡和小鼠细胞以可以容易地用特异性抗体检测的水平合成鸡Mr蛋白，在这些细胞中，鸡Mr蛋白主要为胞质，呈颗粒状，不能建立高水平表达鸡Mr蛋白的永久转染细胞系，提示鸡Mr蛋白的代谢稳定性低或与细胞增殖不相容。表达鸡Mr蛋白的转染细胞对甲型流感病毒、水泡性口炎病毒、Thogoto病毒或仙台病毒的抗性没有增强。因此，鸡Mr加入了没有公认的抗病毒活性的Mr蛋白的列表，支持Mr蛋白具有无关功能的概念。
cDNA sequencing revealed that chick Mr protein consists of 705 amino acids, Its 84 N-terminal amino acids show no significant sequence homology to other Mr proteins, They are followed by 514 residues that include a tripartite GTP binding consensus moth, This region shows 50-70% sequence identity to mammalian and duck Mr proteins, Sequences near the C terminus, including a leucine zipper motif, are also conserved, whereas the intervening 19 amino acids lack sequence similarity, This unique sequence corresponds to a highly variable region in mammalian Mr proteins, suggesting that it serves as a spacer between functional domains, Chick and mouse cells transiently transfected with cDNA expression constructs synthesized chick Mr protein at a level that could easily be detected with specific antibodies, Chick Mr protein in such cells was mainly cytoplasmic and had a granular appearance, Permanently transfected cell lines expressing high levels of chick Mr protein could not be established, suggesting low metabolic stability of chick Mr protein or incompatibility with cell proliferation, The antiviral activity of chick Mr protein was tested at the single-cell level using immunofluorescence techniques, Transfected cells expressing chick Mr protein showed no enhanced resistance to influenza A virus, vesicular stomatitis virus, Thogoto virus, or Sendai virus, Thus, chick Mr joins the list of Mr proteins without recognized antiviral activity, supporting the concept that Mr proteins serve unrelated functions.