Study on the DNA replication of herpes simplex virus

我们的实验结果总结如下。1)研究表明，表臼毒素VP-16-213和喜树碱分别干扰哺乳动物DNA拓扑异构酶II和I的功能。这两种抑制剂都能强烈抑制单纯疱疹病毒的生长。我们使用这两种抑制剂的实验表明，细胞DNA拓扑异构酶II和I参与了HSV的复制；前者主要在病毒DNA复制中起作用，而后者似乎主要在转录水平上起作用。2)已分离出抗阿菲霉素或抗膦乙酸的HSV突变体并进行了鉴定。Aph^r突变的物理图谱限制包含在HSV DNA聚合酶位点的1.1 Kbp区域。结果表明，Aph^r突变型聚合酶在dna聚合酶的保守区域有一个从甲状腺素到组氨酸的氨基酸取代，dna表明该区域可能形成一个结构域，包含底物、PPi和蚜虫蛋白的结合位点。3)我们发现从柑橘根皮中分离的一种新的吖啶酮生物碱citrus rusinine-i在不影响HSV诱导的早期蛋白合成的浓度下抑制HSV DNA的合成。需要进一步的研究来确定这种化合物的靶标。

The results of our experiments are summarized as follows.1) The epipodophyllotoxin VP-16-213 and camptothecin have been shown to interfer with the functions of mammalian DNA topoisomerase II and I, respectively. Both inhibitors strongly suppressed the growth of herpes simplex virus. From our experiments using the two inhibitors, if was suggested that celluler DNA topoisomerase II and I are involved in the HSV replication; The former enzyme mainly plays a role in the viral DNA replication but the latter seems to primarily act at the level of transcription.2) Aphidicolin-resistant or phosphonoacetic acid-resistant mutants of HSV have been isolated and characterized. The physical map limits for the Aph^r mutation were contained in a 1.1 Kbp region within the HSV DNA polymerase locus. It was shown that the Aph^r mutant polymerase had an amino acid substitution from a thyrosin to a histidine in the wellconserved region of the dna polymerase, DNA suggested that this region may form a domain that contains the binding-sites for substrates, PPi and aphidicolin.3) We found that citrusinine-i, a new acridone alkaloid isolated from the root bark of citrus plant, inhibited HSV DNA synthesis at the concertrations that did not affect the synthesis of HSV-induced early proteins. Further studies will be required to determine the target of this compound.