Alves Carolina, Freitas Natália, Cunha Celso
Unidade de Biologia Molecular, Centro de Malária e Outras Doenças Tropicais, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira, 96 1349-008 Lisboa, Portugal.
Virology. 2008 Jan 5;370(1):12-21. doi: 10.1016/j.virol.2007.07.034. Epub 2007 Sep 25.
The delta antigen (HDAg) is the only protein encoded by the hepatitis delta virus (HDV) RNA genome. The HDAg contains an RNA binding domain, a dimerization domain, and a nuclear localization signal (NLS). The nuclear import of HDV RNPs is thought to be one of the first tasks of the HDAg during the HDV replication cycle. Using c-myc-PK fusions with several regions of the HDAg in transfection assays in Huh7 cells, we found that the HDAg NLS consists of a single stretch of 10 amino acids, EGAPPAKRAR, located in positions 66-75. Deletion and mutation analysis of this region showed that both the acidic glutamic acid residue at position 66 and the basic arginine residue at position 75 are essential for promoting nuclear import.
δ抗原（HDAg）是丁型肝炎病毒（HDV）RNA基因组编码的唯一蛋白质。HDAg包含一个RNA结合结构域、一个二聚化结构域和一个核定位信号（NLS）。HDV核糖核蛋白（RNP）的核输入被认为是HDAg在HDV复制周期中的首要任务之一。在Huh7细胞的转染实验中，通过将c-myc-PK与HDAg的几个区域进行融合，我们发现HDAg NLS由位于第66-75位的一段10个氨基酸的序列EGAPPAKRAR组成。对该区域的缺失和突变分析表明，第66位的酸性谷氨酸残基和第75位的碱性精氨酸残基对于促进核输入都是必不可少的。
