Baculovirus envelope proteins and insect cells

描述（由申请人提供）：我们的研究将集中在杆状病毒包膜蛋白作为病毒包膜蛋白功能和与宿主细胞，特别是昆虫中肠极化上皮细胞相互作用的模型。我们的工作将集中在四个具体领域：1)病毒受体结合；2)昆虫极化中肠上皮细胞的包膜蛋白靶向研究；3)病毒粒子组装和出芽；4) GP64蛋白的物理结构。病毒受体结合的研究将集中在GP64蛋白上。我们将首先确定GP64蛋白的受体结合域，然后我们将确定宿主细胞受体。因为杆状病毒，像许多由昆虫传播的病毒一样，必须通过中肠屏障移动感染性病毒颗粒，我们将研究GP64作为研究病毒通过昆虫中肠上皮运动的模型。GP64靶向极化中肠上皮细胞的基膜，在那里病毒粒子芽入血腔。我们的研究将确定GP64的中肠靶向结构域，我们将询问GP64靶向是否指导病毒粒子从中肠上皮细胞的基底表面出芽。含有GP64蛋白修饰形式的重组病毒将用于绘制基础靶向结构域，我们将在此过程中检查GP64与其他病毒或细胞蛋白的相互作用。由于GP64对于有效的病毒粒子出芽至关重要，我们也将使用类似的技术来鉴定和表征GP64出芽结构域以及在组装和出芽过程中与GP64相互作用的病毒或细胞蛋白。GP64似乎代表了一种结构和功能独特的病毒包膜融合蛋白。为了加速我们对GP64结构-功能关系的理解，我们将投入大量的精力来生成适合GP64结构研究的晶体。对于这些研究，我们已经开发了一个强大的遗传系统和许多工具，使我们能够在出芽病毒粒子和病毒感染周期的背景下研究GP64。这些研究将促进我们对病毒包膜蛋白的理解，它们也将在生物学、医学和公共卫生的重要领域有更广泛的应用。

DESCRIPTION (provided by applicant): Our studies will focus on baculovirus envelope proteins as models for viral envelope protein function and interaction with host cells, especially the polarized epithelial cells of the insect midgut. Our efforts will focus on four specific areas: 1) Viral receptor binding; 2) Envelope protein targeting in insect polarized midgut epithelial cells; 3) Virion assembly and budding; and 4) Physical structure of the GP64 protein. Studies of viral receptor binding will focus on the GP64 protein. We will first identify the receptor-binding domain of the GP64 protein and we will then identify the host cell receptor. Because baculoviruses, like many viruses transmitted by insects, must move infectious virus particles through the midgut barrier, we will examine GP64 as a model for studies of viral movement through the insect midgut epithelium. GP64 is targeted to the basal membranes in polarized midgut epithelial cells, where virions bud into the hemocoel. Our studies will identify the midgut-targeting domain of GP64 and we will ask whether GP64 targeting directs virion budding from basal surfaces of the midgut epithelial cells. Recombinant viruses containing modified forms of the GP64 protein will be used to map the basal targeting domain and we will examine interactions of GP64 and other viral or cellular proteins in this process. Because GP64 is critical for efficient virion budding, we will also use similar techniques to identify and characterize the GP64 budding domain and viral or cellular proteins that interact with GP64 during assembly and budding. GP64 appears to represent a structurally and functionally unique class of viral envelope fusion protein. To accelerate our understanding of GP64 structure-function relationships, we will devote substantial efforts toward the generation of crystals suitable for structural studies of GP64. For these studies, we have developed a powerful genetic system and many tools that permit us to study GP64 in the context of budded virions and the viral infection cycle. These studies will advance our understanding of viral envelope proteins and they will also have broader applications to important areas of biology, medicine, and public health.