PARVOVIRUS DNA REPLICATION--NS1 AND DNA POLYMERASE DELTA

自主复制的细小病毒含有线性单链 DNA基因组长约5千克碱基。它们分布广泛，具有感染力。 无脊椎动物、鸟类和哺乳动物，包括人。细小病毒 非结构蛋白NSI在调节细小病毒中起核心作用 复制。NS1有6种表型：1.正向调节 外壳蛋白启动子，2.自身基因的负调控和 异源基因表达，3.对细小病毒DNA的要求 复制，4.如果病毒末端从质粒上切除的要求， 5.抑制sv40 dna复制；6.抑制细胞dna。 复制。我们的证据表明所有或几乎所有的细小病毒DNA 复制需要DNA聚合酶增量。我们建议使用特定于站点的 突变研究NSI在病毒DNA复制中的作用及其意义 与POL三角洲的交互。细小病毒DNA复制受到限制 正常的人成纤维细胞，肿瘤解除了这种限制 转型。正常细胞的缺陷是病毒dna水平的缺陷。 复制，不能归因于病毒基因的缺陷] 更确切地说，它似乎是由于核缺乏所致 NSI易位。本项目将研究DNA的功能 聚合酶Delta和NSI在病毒和细胞DNA复制中的作用及探讨 正常组织和肿瘤组织中病毒DNA复制的缺陷 转化的细胞。

The autonomously replicating parvoviruses contain linear single-stranded DNA genomes of about 5 kilo bases. They are widespread and infect invertebrates, birds, and mammals including man. The parvovirus nonstructural protein NSI has a central role in regulating parvovirus replication. NS1 has been assigned 6 phenotypes: 1. positive regulation of the coat protein promoter, 2. negative regulation of its own gene and heterologous gene expression, 3. requirement for parvovirus DNA replication, 4. requirement for excision if viral termini from a plasmid, 5. inhibition of SV40 DNA replication, and 6. inhibition of cell DNA replication. Our evidence suggests that all or nearly all parvovirus DNA replication requires DNA polymerase delta. We propose to use site-specific mutagenesis to study the roles of NSI in viral DNA replication and its interaction with pol delta. Parvovirus DNA replication is restricted in normal human fibroblasts and this restriction is relieved by neoplastic transformation. The defect in normal cells is at the level of viral DNA replication and it cannot be ascribed to a deficiency in viral] gene expression, rather it appears to result from a deficiency in nuclear translocation of NSI. This project will study the functions of DNA polymerase delta and NSI in viral and cellular DNA replication and explore the defect in viral DNA replication between normal and neoplastically transformed cells.