Host proteins in Vaccinia viral membrane biogenesis

描述（由申请方提供）：人们对了解牛痘病毒的复制非常感兴趣，因为它代表了了解痘病毒（包括天花病毒，天花的病原体）的模型系统。 病毒复制的一个关键阶段涉及膜的获得，因为这一事件将非感染性的组装病毒核心转化为感染性的病毒体。 累积的证据表明，病毒获得两套膜从宿主的细胞器室。 内层膜来自内质网高尔基中间复合体（ERGIC）以形成细胞内成熟病毒（IMV），而外层膜随后从trans-Golgi网络获得以形成细胞内包膜病毒。 参与膜包裹的病毒蛋白开始被鉴定，但由于膜来自宿主细胞器，因此预计在此过程中也将发挥关键作用的宿主蛋白仍然未知。 在初步研究中，我们发现牛痘病毒特异性地将一种宿主蛋白质（COPI外壳复合物的一个亚基）集中在其内层膜上。 因此，我们建议阐明COPI外壳复合物可能在病毒生物发生中发挥作用。 首先，我们将确定当首次在病毒膜上检测到COPI时病毒生物发生的阶段。 第二，我们将确定当COPI功能被废除时，哪个病毒阶段可能被阻止。 第三，我们将确定病毒是否篡夺任何已知的宿主调节蛋白来招募COPI到病毒膜上。 第四，我们将测试目前已知的任何调节病毒形态发生的病毒蛋白质是否会影响COPI在病毒膜上的募集。 这些连续的方法也提出了一种系统的方法来鉴定可能影响IMV形成的潜在的其他宿主蛋白质，因为这是病毒变得具有感染性的第一阶段。 因此，我们将筛选目前已知的在ERGIC隔室发挥作用的转运调节剂，以测试是否有任何类似的富集在病毒膜上。 随后，将废除候选宿主蛋白的功能，以确定病毒生物发生是否受到影响。 这些努力不仅可能提供更好地了解病毒在复制过程中如何与其宿主相互作用，而且还可能在未来合理设计针对痘病毒的治疗干预中提出新的生化靶点。

DESCRIPTION (provided by applicant): Much interest exists in understanding the replication of vaccinia virus, as it represents the model system to understand poxviruses that include variola virus, the causative agent of smallpox. A key phase of viral replication involves the acquisition of membranes, as this event transforms non-infectious assembling viral cores into infectious virions. Accumulated evidence suggests that the virus acquires two set of membranes from organellar compartments of the host. The inner set of membranes is derived from the Endoplasmic Reticulum Golgi Intermediate Compartment (ERGIC) to form an intracellular mature virus (IMV), while the outer set of membranes is subsequently acquired from the trans-Golgi network to form an intracellular envelope virus. Viral proteins that participate in membrane wrapping are beginning to be identified, but host proteins that would also be predicted to play a key role during this process, as the membranes are derived from host organelles, have remained unknown. In preliminary studies, we have found that vaccinia virus specifically concentrates a host protein, a subunit of the COPI coat complex, on its inner set of membranes. Thus, we propose to elucidate how the COPI coat complex might play a role in viral biogenesis. First, we will determine the stage of viral biogenesis when COPI is first detected on viral membranes. Second, we will determine which viral stage might be arrested when COPI function is abrogated. Third, we will determine whether the virus usurps any of the known host regulatory proteins to recruit COPI onto viral membranes. Fourth, we will test whether any of the current known viral proteins that regulate viral morphogenesis affects COPI recruitment onto viral membranes. These sequential approaches also suggest a systematic way of identifying potential other host proteins that would be predicted to affect IMV formation, as it is the first stage that the virus becomes infectious. Thus, we will screen the currently known transport regulators that function at the ERGIC compartment to test whether any is similarly enriched on viral membranes. Subsequently, the function of candidate host proteins will be abrogated to determine whether viral biogenesis is affected. These efforts will likely not only provide a better understanding of how the virus interacts with its host during replication, but also suggest novel biochemical targets in the future rational design of therapeutic intervention against poxviruses.