Interaction between the Human Cytomegalovirus Tegument Proteins UL94 and UL99 Is Essential for Virus Replication
Interaction between the Human Cytomegalovirus Tegument Proteins UL94 and UL99 Is Essential for Virus Replication
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DOI：
10.1128/jvi.01078-12
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发表时间：
2012-09-01
影响因子：
5.4
通讯作者：
Bresnahan, Wade A.
中科院分区：
文献类型：
--
作者：
Phillips, Stacia L.;Cygnar, Daniel;Bresnahan, Wade A.
人巨细胞病毒（HCMV）病毒粒子结构复杂，并且它们组装的机制知之甚少，特别是关于组装的细胞质阶段，在此期间获得大部分被膜并发生最终的破坏。这些过程发生在一个独特的细胞质结构，称为组装复合体，这是通过重组细胞分泌装置形成的。HCMV被膜蛋白UL99（pp28）是病毒在次级增殖阶段复制所必需的。我们以前证明，UL99与感染细胞中的必需被膜蛋白UL94相互作用，以及在没有其他病毒蛋白的情况下。在这里，我们表明，UL94和UL99改变对方的本地化和UL99稳定UL94在结合依赖的方式。我们绘制了UL94和UL99之间的相互作用，以确定它们相互作用所需的每种蛋白质的氨基酸。在病毒基因组的背景下这些氨基酸的突变表明，在UL94和UL99之间不存在相互作用的情况下，HCMV完全有复制缺陷。此外，我们证明，在没有它们的相互作用，UL94和UL99表现出异常的定位，并不积累在组装复合物感染期间。综上所述，我们的数据表明，UL94和UL99之间的相互作用是必不可少的每个蛋白质的正确定位的组装复合物，从而产生感染性病毒。
Human cytomegalovirus (HCMV) virions are structurally complex, and the mechanisms by which they are assembled are poorly understood, especially with respect to the cytoplasmic phase of assembly, during which the majority of the tegument is acquired and final envelopment occurs. These processes occur at a unique cytoplasmic structure called the assembly complex, which is formed through a reorganization of the cellular secretory apparatus. The HCMV tegument protein UL99 (pp28) is essential for viral replication at the stage of secondary envelopment. We previously demonstrated that UL99 interacts with the essential tegument protein UL94 in infected cells as well as in the absence of other viral proteins. Here we show that UL94 and UL99 alter each other's localization and that UL99 stabilizes UL94 in a binding-dependent manner. We have mapped the interaction between UL94 and UL99 to identify the amino acids of each protein that are required for their interaction. Mutation of these amino acids in the context of the viral genome demonstrates that HCMV is completely defective for replication in the absence of the interaction between UL94 and UL99. Further, we demonstrate that in the absence of their interaction, both UL94 and UL99 exhibit aberrant localization and do not accumulate at the assembly complex during infection. Taken together, our data suggest that the interaction between UL94 and UL99 is essential for the proper localization of each protein to the assembly complex and thus for the production of infectious virus.