UL34 and herpes simplex virus envelopment

描述(申请人提供)：疱疹病毒复制并将其基因组打包在细胞核中。为了开始逃离细胞的过程，病毒必须穿过核膜，首先在一个称为初级包膜的过程中发芽进入内核膜。疱疹病毒包膜机制从两个角度对人类健康具有重要意义。首先，这一过程是一个有吸引力的治疗靶点，因为它在许多方面不同于任何正常的细胞过程，对病毒至关重要，对所有疱疹病毒来说都是共同的。第二，包膜机制改变了核包膜的结构，并为研究该组织提供了一个有用的工具。 这里提出的研究建立在我们对单纯疱疹病毒UL34的研究基础上，单纯疱疹病毒UL34是包膜装置的重要组成部分。我们最初资助期间的结果表明，该蛋白至少在包膜的三个方面发挥关键作用，包括(I)将病毒蛋白招募到核膜上，(Ii)分散阻止衣壳进入核膜的核膜成分，以及(Iii)将核衣壳包裹在核膜中。 这项拟议研究的具体目标有三个 1.我们将通过鉴定已有的七种无功能突变的UL34蛋白和我们将通过突变保守残基产生的其他蛋白来定义UL34蛋白的基本功能，因为它们具有执行包膜所需的各种功能的能力。 2.我们将描述UL34蛋白与其他参与包膜的病毒蛋白之间的关键相互作用。这将包括验证UL34介导衣壳膜包裹的假设的实验，以及UL34与其他可能参与包膜的病毒蛋白相互作用的筛选。 3.我们将全面描述与感染相关的宿主细胞核层的变化，并确定UL34和其他病毒蛋白完成这些变化的机制。

DESCRIPTION (provided by applicant): Herpesviruses replicate and package their genomes in the cell nucleus. In order to begin its process of escape from the cell, the virus must pass through the nuclear membrane by first budding into the inner nuclear membrane in a process called primary envelopment. The mechanism of herpesvirus envelopment is significant to human health from two points of view. First, this process represents an attractive target for therapy in that it is dissimilar in many ways to any normal cellular process, essential to the virus, and common to all herpesviruses. Second, the envelopment machinery alters the organization of the nuclear envelope and provides a useful tool for studying that organization. The research proposed here builds on our studies of herpes simplex virus UL34, an essential component of the envelopment apparatus. Results from our initial period of funding suggest that this protein plays critical roles in at least three aspects of envelopment including (i) recruitment of viral proteins to the nuclear envelope, (ii) dispersal of nuclear envelope components that prevent access of the capsid to the nuclear membrane, and (iii) wrapping of the nucleocapsid in the nuclear membrane. The specific goals of the proposed research are threefold 1. We will define essential functions of the UL34 protein by characterizing a set of seven non-functional mutant UL34 proteins already in hand, and others that we will generate by mutagenesis of conserved residues, for their ability to perform various functions required for envelopment. 2. We will characterize critical interactions between the UL34 protein and other viral proteins involved in envelopment. This will include experiments to test the hypothesis that UL34 mediates membrane wrapping of the capsid, and a screen for interactions of UL34 with other viral proteins that may participate in envelopment. 3. We will fully characterize changes in the host cell nuclear lamina associated with infection and determine the mechanism by which UL34 and other viral proteins accomplish those changes.