Parvovirus RNA Processing

描述（由申请人提供）：在上一个授权期内，我们几乎完成了对细小病毒亚科所有五个属的代表性成员的转录谱的表征，我们的分析揭示了比以前认为的更大的多样性或遗传策略。我们的工作清楚地表明，五个细小病毒属中的三个成员，即红病毒属、安多病毒属和可能还有博卡病毒属，在它们的左手端只使用一个启动子，因此它们的表达调控必须完全是转录后的。我们的工作还表明，除了红病毒，依赖病毒属、安多病毒属和博卡病毒属的成员也在基因组中心的位点使用替代性多腺苷酸化。因此，替代内部聚腺苷酸化作为一种手段来管理细小病毒基因的表达已经出现的规则，而不是例外。此外，现在清楚的是，细小病毒比以前认识到的更多地使用替代翻译策略来表达它们的结构和非结构蛋白-这也许并不奇怪，因为它们需要从如此紧凑的基因组表达复杂的基因表达模式。细小病毒表达策略的变化的发现也强调了许多蛋白质的潜在重要性，这些蛋白质未从对原型MVM、AAV和B19的研究中预测。例如，GPV大Rep 1蛋白充当其衣壳蛋白编码基因的转录激活因子，但其作用模式似乎与AAV 2 Rep蛋白或MVM NS 1不同。此外，博卡病毒NP 1蛋白在牛细小病毒BPV和人博卡病毒HBoV中都大量表达，这表明它可能是由许多细小病毒基因组中心的ORF编码的细小病毒蛋白的原型。在本申请中，我们建议I.）完成所有细小病毒亚科属的代表性实例的转录谱的确定; II.表征由新鉴定的遗传谱授权的新表达策略;和III.确定新的细小病毒蛋白质的功能，这些新的配置文件的重要性清楚。这些研究将大大推进我们对这组重要病毒的理解，为理解细小病毒亚科成员之间的进化关系提供一个框架，并像过去一样，继续揭示有吸引力的，易于处理的模型来检查基本的细胞功能。

DESCRIPTION (provided by applicant): Over the last granting period we have nearly completed characterization of the transcription profiles of representative members of all five genera of the Parvovirinae, and our analyses have revealed a much greater variety or genetic strategies than previously thought. Our work makes clear that members of three of the five parvovirus genera, the Erythrovirus, Amdovirus, and probably Bocavirus groups use only a single promoter in their left hand end, and so regulation of their expression must be exclusively posttranscriptional. Our work has also shown that in addition to the Erythroviruses, members of the Dependovirus, Amdovirus and Bocavirus genera also use alternative polyadenylation at a site within the center of the genome. Thus, alternative internal polyadenylation as a means to govern parvovirus gene expression has emerged as the rule rather than the exception. In addition, it is now clear that the parvoviruses make greater use of alternative translation strategies for their expression than previously appreciated, both for their structural and nonstructural proteins - which is perhaps not surprising, given their need to express complex patterns of gene expression from such compact genomes. Discovery of the variation in parvovirus expression strategies has also underscored the potential importance of a number of proteins not predicted from studies on the prototypes MVM, AAV and B19. For example, the GPV large Rep 1 protein acts as a transcriptional activator of its capsid protein-encoding gene, yet seems to be distinct in its mode of action from either the AAV2 Rep protein or MVM NS1. Additionally, the Bocavirus NP1 protein is abundantly expressed by both bovine parvovirus BPV and the human bocavirus HBoV, suggesting it may be a prototype of parvovirus proteins encoded by an ORF in the center of many parvovirus genomes. In this application we propose to I.) complete the determination of the transcription profiles of representative examples of all the Parvovirinae genera; II. characterize new expression strategies mandated by the newly identified genetic profiles; and III. determine the function of novel parvoviral proteins whose importance these new profiles make clear. These studies will significantly advance our understanding of this important group of viruses, provide a framework for understanding the evolutionary relationships between members of the Parvovirinae, and as has been the case in the past, continue to reveal attractive, tractable models to examine basic cellular functions.