Division of Infectious Diseases, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, ROC.
Arch Virol. 2011 Feb;156(2):285-94. doi: 10.1007/s00705-010-0858-y. Epub 2010 Nov 26.
A type III Trichomonas vaginalis virus, which may be involved in transcriptional regulation of the major surface protein gene P270 of the protozoan pathogen Trichomonas vaginalis, was purified and characterized in the present study. The complete 4844-base-pair complementary DNA sequence of the viral genome reveals overlapping cap and pol genes with a putative ribosomal frame-shifting signal within the overlap region. The type III virus is related more closely to the type II virus than to the type I virus in the sequence of its ribosomal frameshift signal and in its capsid protein. Phylogenetic analysis revealed that these viruses could be grouped in the same clade as a genus distantly related to other genera in the family Totiviridae. Virus-induced P270 gene expression was only evident in Trichomonas vaginalis cells infected with either a type II or type III virus, but not with a type I virus. These findings suggest that transcription of the P270 gene is likely regulated by viral factors common to type II and type III viruses and thus provides important information for future investigation of virus-host interactions.
本研究纯化并鉴定了一种可能参与原生动物病原体阴道毛滴虫主要表面蛋白基因 P270 转录调控的 III 型阴道毛滴虫病毒。病毒基因组的完整 4844 个碱基对 cDNA 序列揭示了重叠的帽和 pol 基因，在重叠区域内存在一个假定的核糖体移码信号。在核糖体移码信号和衣壳蛋白的序列中，III 型病毒与 II 型病毒的关系比与 I 型病毒的关系更为密切。系统发育分析表明，这些病毒可以与家族 Totiviridae 中与其他属关系较远的属归为同一进化枝。只有感染 II 型或 III 型病毒的阴道毛滴虫细胞中才可见到病毒诱导的 P270 基因表达，而感染 I 型病毒的细胞中则不可见。这些发现表明，P270 基因的转录可能受到 II 型和 III 型病毒共有的病毒因子的调节，因此为进一步研究病毒-宿主相互作用提供了重要信息。
