AVIAN RETROVIRUS STRUCTURE AND ASSEMBLY

这项研究的主要目的是进一步了解 逆转录病毒（RNA肿瘤病毒）是如何从血浆中组装和出芽的 感染细胞的膜。 大部分工作将基于鸟类 肉瘤和白血病病毒作为模型系统，但它的一部分也将 关注蛋白水解加工缺陷的鼠肉瘤病毒 内部结构蛋白。 使用交联剂的实验 将继续进行调查，如何插科打诨（内部 结构）蛋白与病毒膜相互作用， proteins. 我们最近发现的小细胞编码的多肽， 禽流感病毒的特点及其在病毒结构和 组装检查。 五种鸟类gag蛋白的前体将是 纯化的天然多肽来自鹌鹑细胞，也来自E.杆菌 携带经工程改造以表达gag基因的质粒。 的相互作用 将检查具有病毒RNA和脂质禽类前体， 测试可能的蛋白水解活性。 未成熟岩心的结构 小鼠肉瘤病毒将被研究，并进行实验， 来自gag前体多肽的核心，和来自 将尝试使用核和脂质。 另外， 纯化藤波肉瘤病毒的融合蛋白， 酶学性质研究。

The primary aim of the proposed research is to further the understanding of how retroviruses (RNA tumor viruses) are assembled and bud from the plasma membrane of the infected cell. Most of the work will be based on avian sarcoma and leukemia viruses as a model system, but part of it also will focus on a murine sarcoma virus that is defective in proteolytic processing of the internal structural protein. Experiments with cross-linking agents will be carried out to continue the investigation of how the gag (internal structural) proteins interact with the membrane of the virus and with other proteins. The small cell-encoded polypeptide we have found recently in avian viruses will be characterized and its role in viral structure and assembly examined. The precursor of the five avian gag proteins will be purified as a native polypeptide from quail cells, and also from E. coli carrying a plasmid engineered to express the gag gene. The interactions of the avian precursor with viral RNA and with lipid will be examined and its possible proteolytic activity tested. The structure of the immature cores of murine sarcoma virus will be studied, and experiments to reconstitute cores from the gag precursor polypeptide, and virus-like particles from cores and lipids will be attempted. In addition, the transforming gag fusion protein of Fujinami sarcoma virus will be purified and its enzymological properties studied.