猪瘟病毒衣壳蛋白核仁定位信号鉴定

Characterization of nucleolar localization signals in the capsid protein of classical swine fever virus

为鉴定猪瘟病毒(CSFV)衣壳蛋白(C)在细胞中的核仁定位信号(No LS),本研究采用截短表达的方法将含有C基因不同片段的真核表达重组质粒转染猪睾丸细胞(ST)。结果表明,瞬时表达的截短C蛋白的aa51-aa71多肽定位于ST细胞核仁中。而将C蛋白的aa51-aa71缺失突变后,C蛋白则丧失了其核仁定位的能力。此外,将C蛋白的51KKK53突变为51AAA53,也同样导致C蛋白丧失核仁定位能力,表明该序列为核仁定位的核心基序。本研究为进一步分析C蛋白在CSFV复制过程中的功能提供了实验依据。

To identify the nucleolar localization signals （NoLS） of classical swine fever vires （CSFV） capsid （C） protein in the infected cells, the recombinant eukaryotic expression plasmids containing a set of overlapping DNA fragments of truncated C gene were transfected into the swine testicle （ST） cells, respectively. The results showed that aa51-aa71 peptide of C protein was localized in the nucleolus of ST cells; Whereas, the aa51-aaT1 deletion resulted in the C protein losing the ability of the nucleolar localization, which indicated that the peptide of aa51-aa71 in the C protein was the NoLS for nucleolar localization. Moreover, the C protein was also loss the nucleolar localization ability when the ^51KKK^53 was mutated to ^51AAA^53 in C protein, indicating the ^51KKK^53 was the crucial domain of the NoLS. These results provided the basis for further function studies of C protein in CSFV replication.