Amino acid substitutions at position 481 differently affect the ability of the measles virus hemagglutinin to induce cell fusion in monkey and marmoset cells co-expressing the fusion protein

作     者：Xie, MF Tanaka, K Ono, N Minagawa, H Yanagi, Y 

作者机构：Kyushu Univ Fac Med Dept Virol Fukuoka 8128582 Japan 

出 版 物：《ARCHIVES OF VIROLOGY》 (病毒学文献)

年 卷 期：1999年第144卷第9期

页      面：1689-1699页

核心收录：

学科分类：0710[理学-生物学] 1007[医学-药学(可授医学、理学学位)] 100705[医学-微生物与生化药学] 07[理学] 071005[理学-微生物学] 10[医学] 

主　　题：氨基酸取代 抗原 CD/代谢 细胞融合 细胞系 克隆 分子 流式细胞术 基因 病毒 血凝素类 病毒/遗传学 血凝素类 病毒/代谢 麻疹病毒/遗传学 麻疹病毒/代谢 麻疹病毒/生理学 分子序列数据 诱变 定点 序列分析 DNA 转染 病毒融合蛋白质类/遗传学 病毒融合蛋白质类/代谢 动物 人类 

摘      要：The hemagglutinin (H) protein of the measles virus (MV) Edmonston strain induced cell fusion in Cos (monkey) and B95a (marmoset) cells, when co-expressed with the fusion (F) protein, whereas the H protein of the wild-type KA strain induced fusion in B95a cells, but not in Cos cells. Asparagine residue at position 481 of the KA H protein was replaced by various amino acids through site-directed mutagenesis. Substitution with tyrosine, which was found at position 481 of the Edmonston H protein, enabled the mutant KA H protein (N481Y) to induce cell fusion in Cos cells co-expressing the F protein, which could be completely blocked by anti-CD46 antibody. This mutant, however, did not cause CD46 downregulation, unlike the Edmonston H protein. The other H protein mutants (N481S, N481T, N481D, N481H, N481F) did not produce syncytia in Cos cells. On the other hand, all of the mutants retained the ability to induce cell fusion in B95a cells. Thus, while tyrosine at position 481 was indispensable for the MV H protein s interaction with CD46, the residue at this position does not appear to be critically involved in the interaction with the receptor for wild-type strains present on B95a cells.