Grosenbach D W, Hruby D E
Center for Gene Research and Biotechnology, Department of Microbiology, Oregon State University, Corvallis, Oregon 97331-3804, USA.
J Virol. 1998 Jun;72(6):5108-20. doi: 10.1128/JVI.72.6.5108-5120.1998.
Vaccinia virus encodes a 37-kDa palmitylated protein (p37) that is required for envelopment, translocation, and cell-to-cell spread of virions. We have analyzed the biological significance of the palmitate modification by constructing a recombinant vaccinia virus that expresses a nonpalmitylated p37 and comparing its biological activity to that of the wild-type virus. The mutant virus is inefficient at cell-to-cell spread and does not produce or release enveloped virions, although it produces normal amounts of nonenveloped virions. Furthermore, the mutant virus is not able to nucleate actin to propel itself through and out of the cell, a function requiring the indirect participation of p37. The deficiency in protein function appears to result from a lack of appropriate targeting to the membranes of the trans-Golgi network (TGN) which leaves p37 soluble in the cytoplasm. We conclude that the palmitate moiety is necessary for targeting or anchoring p37 to the TGN membrane, where, along with other vaccinia virus-encoded proteins, p37 is involved in the complex process of virion envelopment and release.
痘苗病毒编码一种37千道尔顿的棕榈酰化蛋白（p37），该蛋白是病毒粒子包膜形成、转运及细胞间传播所必需的。我们通过构建表达非棕榈酰化p37的重组痘苗病毒，并将其生物学活性与野生型病毒进行比较，分析了棕榈酸修饰的生物学意义。突变病毒在细胞间传播效率低下，不产生或释放包膜病毒粒子，尽管它能产生正常数量的无包膜病毒粒子。此外，突变病毒无法促使肌动蛋白成核以推动自身穿过并离开细胞，而这一功能需要p37的间接参与。蛋白质功能的缺陷似乎是由于缺乏对反式高尔基体网络（TGN）膜的适当靶向作用，使得p37溶解于细胞质中。我们得出结论，棕榈酸部分对于将p37靶向或锚定到TGN膜是必需的，在TGN膜上，p37与其他痘苗病毒编码的蛋白一起参与病毒粒子包膜形成和释放的复杂过程。
