The second open reading frame of the avian reovirus S1 gene encodes a transcription-dependent and CRM1-independent nucleocytoplasmic shuttling protein
The second open reading frame of the avian reovirus S1 gene encodes a transcription-dependent and CRM1-independent nucleocytoplasmic shuttling protein
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DOI：
10.1128/jvi.79.4.2141-2150.2005
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发表时间：
2005-02-01
影响因子：
5.4
通讯作者：
Benavente, J
中科院分区：
文献类型：
--
作者：
Costas, C;Martínez-Costas, J;Benavente, J
以前的研究表明，禽呼肠孤病毒S1基因的第二个开放阅读框编码一个146个氨基酸的非结构蛋白，命名为p17，它没有已知的功能，也没有与其他已知蛋白的序列相似性。本报告中提出的结果表明，p17积累在感染和转染细胞的核质中。p17的推导的氨基酸序列的检查揭示了一个假定的monopartite核定位信号（NLS）之间的残基119和128的存在。突变分析表明，这一序列确实是一个功能性的NLS和它的两个基本的残基是至关重要的正常核分布的p17。种间异核体分析进一步表明，p17穿梭细胞核和细胞质之间的连续，这种活动是有限的，其NLS含有C-末端尾巴。最后，在RNA聚合酶II和CRM 1抑制剂存在下对p17的细胞内分布的分析进一步揭示了p17的核质分布与转录活性相关，并且病毒蛋白通过CRM 1非依赖性途径离开细胞核。
It was previously shown that the second open reading frame of the avian reovirus S1 gene encodes a 146-amino-acid nonstructural protein, designated p17, which has no known function and no sequence similarity to other known proteins. The results presented in this report demonstrate that p17 accumulates in the nucleoplasm of infected and transfected cells. An examination of the deduced amino acid sequence of p17 revealed the presence of a putative monopartite nuclear localization signal (NLS) between residues 119 and 128. Mutagenesis analysis revealed both that this sequence is indeed a functional NLS and that two of its basic residues are critical for the normal nuclear distribution of p17. An interspecies heterokaryon assay further showed that p17 shuttles continuously between the nucleus and the cytoplasm and that this activity is restricted to its NLS-containing C-terminal tail. Finally, an analysis of the intracellular distribution of p17 in the presence of inhibitors of both RNA polymerase II and CRM1 further revealed that the nucleocytoplasmic distribution of p17 is coupled to transcriptional activity and that the viral protein exits the nucleus via a CRM1-independent pathway.