Lindemann D, Goepfert P A
Institut für Virologie, Medizinische Fakultät Carl-Gustav-Carus, Technische Universität Dresden, Fetscherstrasse 74, 01307 Dresden, Germany.
Curr Top Microbiol Immunol. 2003;277:111-29. doi: 10.1007/978-3-642-55701-9_5.
The main functions of retroviral glycoproteins are recognition and binding to the cellular virus receptor as well as fusion of viral and cellular lipid membranes to release the viral particle into the cytoplasm of the host cell. Foamy viruses (FVs) are a special group of retroviruses with a very broad host range that use a currently unknown cellular receptor for entry. Nevertheless, many functions of the FV envelope glycoproteins in the viral replication cycle have been characterized in detail over the last years. Several unique features not found for any other retrovirus were identified. These include the presence of two types of FV Env proteins, gp170(Env-Bet) and gp130Env, and the strict requirement of gp130Env coexpression for the FV budding and particle release process, a function that cannot be compensated for by any other viral glycoprotein tested so far. Furthermore, domains in gp130Env could be characterized that influence its intracellular distribution, cell surface transport, and its specific interaction with the viral capsid during particle egress. In addition, it has recently been shown that gp130Env expression alone induces release of subviral particles from cells. This review summarizes the current knowledge about the nature of the FV Env proteins and their function in the viral replication cycle.
逆转录病毒糖蛋白的主要功能是识别并结合细胞病毒受体，以及促使病毒和细胞脂质膜融合，从而将病毒颗粒释放到宿主细胞的细胞质中。泡沫病毒（FV）是一类特殊的逆转录病毒，宿主范围非常广泛，其进入宿主细胞时使用目前未知的细胞受体。然而，在过去几年中，FV包膜糖蛋白在病毒复制周期中的许多功能已得到详细表征。人们发现了一些其他逆转录病毒所没有的独特特征。这些特征包括存在两种类型的FV Env蛋白，即gp170（Env-Bet）和gp130Env，以及gp130Env的共表达对于FV出芽和颗粒释放过程的严格要求，这一功能迄今为止无法被任何其他测试过的病毒糖蛋白所替代。此外，gp130Env中的结构域已得到表征，这些结构域会影响其细胞内分布、细胞表面运输以及在颗粒释放过程中与病毒衣壳的特异性相互作用。此外，最近有研究表明，单独表达gp130Env会诱导亚病毒颗粒从细胞中释放。本综述总结了目前关于FV Env蛋白的性质及其在病毒复制周期中功能的知识。
