Biphasic DNA synthesis in spumaviruses
Biphasic DNA synthesis in spumaviruses
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DOI：
10.1128/jvi.77.14.8141-8146.2003
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发表时间：
2003-07-01
影响因子：
5.4
通讯作者：
Sonigo, P
中科院分区：
文献类型：
--
作者：
Delelis, O;Saïb, A;Sonigo, P
泡沫病毒是复杂的逆转录病毒，其复制周期与嗜肝DNA病毒相似，尤其是通过晚发生的逆转录步骤。没有记录在其他逆转录病毒中观察到的早期逆转录的可能存在。使用实时定量 PCR，我们直接研究了泡沫病毒感染期间 DNA 合成的动力学。病毒 DNA 合成的早期阶段持续到感染后 3 小时，然后进入第二阶段，在感染后 10 小时达到顶峰。两个阶段均被逆转录酶抑制剂 3'-azido-3'-deoxythymidine 消除。与其他逆转录病毒类似，含有两个长末端重复序列的环状病毒DNA主要存在于受感染细胞的细胞核中。有趣的是，在细胞质和细胞外病毒粒子中检测到了这些圆形形式的一部分，这是嗜肝DNA病毒共有的特征。结合病毒体中病毒 DNA 和 RNA 基因组的包装，早期和晚期逆转录可能使 spumavirus 能够最大限度地复制其基因组。
Spumaviruses are complex retroviruses whose replication cycle resembles that of hepadnaviruses, especially by a late-occurring reverse transcription step. The possible existence of an early reverse transcription as observed in other retroviruses was not documented. Using real-time quantitative PCR, we addressed directly the kinetics of DNA synthesis during spumavirus infection. An early phase of viral DNA synthesis developed until 3 h postinfection, followed by a second phase, culminating 10 h postinfection. Both phases were abolished by the reverse transcriptase inhibitor 3'-azido-3'-deoxythymidine. Similar to other retroviruses, circular forms of viral DNA harboring two long terminal repeats were mainly found in the nucleus of infected cells. Interestingly, a fraction of these circular forms were detected in the cytoplasm and in extracellular virions, a feature shared with hepadnaviruses. Combined with packaging of both viral DNA and RNA genomes in virions, early and late reverse transcription might allow spumavirus to maximize its genome replication.