Kolb A F, Maile J, Heister A, Siddell S G
Institute of Virology and Immunology, University of Wurzburg, Germany.
J Gen Virol. 1996 Oct;77 ( Pt 10):2515-21. doi: 10.1099/0022-1317-77-10-2515.
Human aminopeptidase N (hAPN or CD13) and porcine aminopeptidase N (pAPN) are functional receptors for human coronavirus (HCV) 229E and porcine transmissible gastroenteritis virus (TGEV), respectively. However, hAPN cannot function as a receptor for TGEV and pAPN cannot function as a receptor for HCV 229E. In this study, we constructed a series of chimeric hAPN/pAPN genes and expressed the corresponding proteins in transfected cells. Subsequently, we identified the chimeric proteins that can function as a receptor for HCV 229E. The results show that replacement of a small region of pAPN sequence (pAPN amino acids 255-348) with the corresponding hAPN sequence (hAPN amino acids 260-353) converts pAPN into a functional receptor for HCV 229E. The region of hAPN that we have defined in this way does not correspond to the region of pAPN that has been identified as essential for the TGEV-receptor interaction. We conclude that although both viruses use a homologous receptor protein, different regions of the protein are required to mediate susceptibility to infection with HCV 229E and TGEV.
人氨肽酶N（hAPN或CD13）和猪氨肽酶N（pAPN）分别是人类冠状病毒（HCV）229E和猪传染性胃肠炎病毒（TGEV）的功能性受体。然而，hAPN不能作为TGEV的受体发挥作用，pAPN也不能作为HCV 229E的受体发挥作用。在本研究中，我们构建了一系列嵌合的hAPN/pAPN基因，并在转染细胞中表达了相应的蛋白质。随后，我们鉴定出了可作为HCV 229E受体发挥作用的嵌合蛋白。结果表明，用相应的hAPN序列（hAPN氨基酸260 - 353）替换pAPN序列的一个小区域（pAPN氨基酸255 - 348）可使pAPN转变为HCV 229E的功能性受体。我们以这种方式确定的hAPN区域与已被确定为对TGEV - 受体相互作用至关重要的pAPN区域并不对应。我们得出结论，尽管两种病毒都使用同源受体蛋白，但该蛋白的不同区域对于介导对HCV 229E和TGEV感染的易感性是必需的。
