Cathomen T, Naim H Y, Cattaneo R
Institut für Molekularbiologie, Universität Zürich, Hönggerberg, Switzerland.
J Virol. 1998 Feb;72(2):1224-34. doi: 10.1128/JVI.72.2.1224-1234.1998.
The cytoplasmic tail of the measles virus (MV) fusion (F) protein is often altered in viruses which spread through the brain of patients suffering from subacute sclerosing panencephalitis (SSPE). We transferred the coding regions of F tails from SSPE viruses in an MV genomic cDNA. Similarly, we constructed and transferred mutated tail-encoding regions of the other viral glycoprotein hemagglutinin (H) gene. From the mutated genomic cDNAs, we achieved rescue of viruses that harbor different alterations of the F tail, deletions in the membrane-distal half of the H tail, and combinations of these mutations. Viruses with alterations in any of the tails spread rapidly through the monolayer via enhanced cell-cell fusion. Double-tail mutants had even higher fusion competence but slightly decreased infectivity. Analysis of the protein composition of released mutant viral particles indicated that the tails are necessary for accurate virus envelope assembly and suggested a direct F tail-matrix (M) protein interaction. Since even tail-altered glycoproteins colocalized with M protein in intracellular patches, additional interactions may exist. We conclude that in MV infections, including SSPE, the glycoprotein tails are involved not only in virus envelope assembly but also in the control of virus-induced cell fusion.
麻疹病毒（MV）融合（F）蛋白的细胞质尾部在通过患有亚急性硬化性全脑炎（SSPE）患者大脑传播的病毒中常发生改变。我们将来自SSPE病毒的F尾部编码区转移至MV基因组cDNA中。同样，我们构建并转移了另一种病毒糖蛋白血凝素（H）基因的突变尾部编码区。从这些突变的基因组cDNA中，我们成功拯救出了携带不同F尾部改变、H尾部膜远端一半缺失以及这些突变组合的病毒。尾部发生任何改变的病毒通过增强细胞间融合在单层细胞中快速传播。双尾部突变体具有更高的融合能力，但感染力略有下降。对释放的突变病毒颗粒的蛋白质组成分析表明，尾部对于准确的病毒包膜组装是必需的，并提示F尾部与基质（M）蛋白存在直接相互作用。由于即使是尾部改变的糖蛋白也在细胞内斑块中与M蛋白共定位，可能还存在其他相互作用。我们得出结论，在包括SSPE在内的MV感染中，糖蛋白尾部不仅参与病毒包膜组装，还参与病毒诱导的细胞融合的控制。
