The AcMNPV pp31 gene is not essential for productive AcMNPV replication or late gene transcription but appears to increase levels of most viral transcripts.
The AcMNPV pp31 gene is not essential for productive AcMNPV replication or late gene transcription but appears to increase levels of most viral transcripts.
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DOI：
10.1016/j.virol.2007.02.034
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发表时间：
2007-08
期刊：
影响因子：
3.7
通讯作者：
J. Yamagishi;E. Burnett;S. H. Harwood;G. Blissard
中科院分区：
文献类型：
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作者：
J. Yamagishi;E. Burnett;S. H. Harwood;G. Blissard
苜蓿银纹夜蛾核型多角体病毒（Autographa californica multicapsid nucleopolyhedrovirus，AcMNPV）的pp 31基因编码一种磷酸化的DNA结合蛋白，与感染细胞核内的病毒发生基质相关。先前通过瞬时晚期表达测定对pp 31的研究表明pp 31可能在AcMNPV晚期基因的转录中起重要作用[托德，J.W.，Passarelli，A. L.，和米勒，L. K.（1995年）。18个杆状病毒基因，包括lef-11、p35、39 K和p47，支持晚期基因表达。J. Virol. 69，968-974]，尽管对密切相关的BmNPV pp 31基因的遗传研究表明pp 31可能是缺失的[Gomi，S.，Zhou C.，中国青冈C. E、Yih，W.，Majima，K.，和Maeda，S.（1997年）。杆状病毒BmNPV的18个晚期基因表达因子基因同源物中的4个的缺失分析。Virology 230（1），35-47]。在目前的研究中，我们研究了pp 31基因在感染AcMNPV基因组的背景下的作用。我们使用基于BACmid-based系统在AcMNPV基因组中产生pp 31敲除。随后通过将pp 31基因重新插入到相同病毒基因组的多角体蛋白基因座中来拯救pp 31敲除。我们发现pp 31对于病毒复制不是必需的，尽管pp 31的缺失导致较低的病毒滴度。在没有pp 31的情况下病毒DNA复制的分析表明，病毒DNA复制的动力学不受影响。AcMNPV寡核苷酸微阵列用于比较pp 31存在或不存在下所有AcMNPV基因的基因表达。在没有pp 31的情况下，检测到许多病毒基因（99个基因）的转录物适度减少，而没有观察到43个基因的显著增加或减少。与从对照病毒检测到的水平相比，来自6个基因（p6.9、ORF 97、ORF 60、ORF 98、ORF 102和几丁质酶）的转录物降低了66%或更多。通过所选基因的qPCR分析进一步检查微阵列结果。总之，这些数据表明pp 31基因的缺失不是致死性的，并且似乎不影响病毒DNA复制，但导致包括早期和晚期基因的AcMNPV基因亚组的明显适度下调。
The pp31 gene of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) encodes a phosphorylated DNA binding protein that associates with virogenic stroma in the nuclei of infected cells. Prior studies of pp31 by transient late expression assays suggested that pp31 may play an important role in transcription of AcMNPV late genes [Todd, J. W., Passarelli, A. L., and Miller, L. K. (1995). Eighteen baculovirus genes, including lef-11, p35, 39K, and p47, support late gene expression. J. Virol. 69, 968–974] although genetic studies of the closely related BmNPV pp31 gene suggested that pp31 may be dispensable [Gomi, S., Zhou, C. E., Yih, W., Majima, K., and Maeda, S. (1997). Deletion analysis of four of eighteen late gene expression factor gene homologues of the baculovirus, BmNPV. Virology 230 (1), 35–47]. In the current study, we examined the role of the pp31 gene in the context of the AcMNPV genome during infection. We used a BACmid-based system to generate a pp31 knockout in the AcMNPV genome. The pp31 knockout was subsequently rescued by reinserting the pp31 gene into the polyhedrin locus of the same virus genome. We found that pp31 was not essential for viral replication although the absence of pp31 resulted in a lower viral titer. Analysis of viral DNA replication in the absence of pp31 showed that the kinetics of viral DNA replication were unaffected. An AcMNPV oligonucleotide microarray was used to compare gene expression from all AcMNPV genes in the presence or absence of pp31. In the absence of pp31, a modest reduction in transcripts was detected for many viral genes (99 genes) while no substantial increase or decrease was observed for 43 genes. Transcripts from 6 genes (p6.9, ORF 97, ORF 60, ORF 98, ORF 102 and chitinase) were reduced by 66% or more compared to the levels detected from the control virus. Microarray results were further examined by qPCR analysis of selected genes. In combination, these data show that deletion of the pp31 gene was not lethal and did not appear to affect viral DNA replication but resulted in an apparent modest down-regulation of a subset of AcMNPV genes that included both early and late genes.