Insights into Polyomaviridae MicroRNA Function Derived from Study of the Bandicoot Papillomatosis Carcinomatosis Viruses
Insights into Polyomaviridae MicroRNA Function Derived from Study of the Bandicoot Papillomatosis Carcinomatosis Viruses
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DOI：
10.1128/jvi.02557-10
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发表时间：
2011-05-01
影响因子：
5.4
通讯作者：
Sullivan, Christopher S.
中科院分区：
文献类型：
--
作者：
Chen, Chun Jung;Kincaid, Rodney P.;Sullivan, Christopher S.
多瘤病毒科的几种不同成员，包括一些人类病原体，编码相对于早期基因产物肿瘤（T）抗原反义的微小RNA（miRNA）。这些miRNAs通过引导小干扰RNA（siRNA）样切割早期转录物来负调节T抗原表达。多瘤病毒科的一些成员的miRNA突变体病毒在裂解感染期间表达增加水平的早期蛋白。然而，miRNA介导的T抗原负调控的重要性仍然不确定。袋狸乳头状瘤病癌病病毒1型（BPCV 1）与濒危有袋类动物西部条纹袋狸（Perameles bougainville）的乳头状瘤和癌有关。BPCV 1是一组新病毒的创始成员，这些病毒与多瘤病毒和乳头瘤病毒家族具有显著的共同特性。在这里，我们表明，BPCV 1编码，在相同的方向作为乳头瘤病毒样转录，位于基因组的一个长的非编码区（NCR）的miRNA。此外，该NCR充当产生miRNA的初级转录物的启动子和模板两者的功能。与多瘤病毒miRNA不同，BPCV 1 miRNA不是编码T抗原转录物的反义，而是位于基因组的一个单独的近端区域。我们已经定位了BPCV 1大T抗原早期转录物的3'非翻译区（UTR），并鉴定了与BPCV 1 miRNA不完全互补的功能性miRNA靶位点。当与BPCV 1 miRNA共表达时，含有整个BPCV 1 T抗原3' UTR的嵌合报告基因经历负调控。值得注意的是，所观察到的负调控程度相当于经工程改造以完全互补性结合BPCV 1 miRNA的相同报告基因的程度。我们还表明，这种miRNA和这种新的早期基因调控模式与相关的BPCV 2是保守的。最后，西方有斑袋狸的乳头瘤病变表达了易于检测水平的这种miRNA，强调了其在体内可能的重要性。总之，BPCV和多瘤病毒之间T抗原表达负调节的替代机制支持了miRNA介导的自身调节在一些不同的多瘤病毒和多瘤病毒样病毒的生命周期中的重要性。
Several different members of the Polyomaviridae, including some human pathogens, encode microRNAs (miRNAs) that lie antisense with respect to the early gene products, the tumor (T) antigens. These miRNAs negatively regulate T antigen expression by directing small interfering RNA (siRNA)-like cleavage of the early transcripts. miRNA mutant viruses of some members of the Polyomaviridae express increased levels of early proteins during lytic infection. However, the importance of miRNA-mediated negative regulation of the T antigens remains uncertain. Bandicoot papillomatosis carcinomatosis virus type 1 (BPCV1) is associated with papillomas and carcinomas in the endangered marsupial the western barred bandicoot (Perameles bougainville). BPCV1 is the founding member of a new group of viruses that remarkably share distinct properties in common with both the polyomavirus and papillomavirus families. Here, we show that BPCV1 encodes, in the same orientation as the papillomavirus-like transcripts, a miRNA located within a long noncoding region (NCR) of the genome. Furthermore, this NCR serves the function of both promoter and template for the primary transcript that gives rise to the miRNA. Unlike the polyomavirus miRNAs, the BPCV1 miRNA is not encoded antisense to the T antigen transcripts but rather lies in a separate, proximal region of the genome. We have mapped the 3' untranslated region (UTR) of the BPCV1 large T antigen early transcript and identified a functional miRNA target site that is imperfectly complementary to the BPCV1 miRNA. Chimeric reporters containing the entire BPCV1 T antigen 3' UTR undergo negative regulation when coexpressed with the BPCV1 miRNA. Notably, the degree of negative regulation observed is equivalent to that of an identical reporter that is engineered to bind to the BPCV1 miRNA with perfect complementarity. We also show that this miRNA and this novel mode of early gene regulation are conserved with the related BPCV2. Finally, papillomatous lesions from a western barred bandicoot express readily detectable levels of this miRNA, stressing its likely importance in vivo. Combined, the alternative mechanisms of negative regulation of T antigen expression between the BPCVs and the polyomaviruses support the importance of miRNA-mediated autoregulation in the life cycles of some divergent polyomaviruses and polyomavirus-like viruses.