中文摘要：

为进一步研究血清抑制相关基因（Si1）的生物学功能,用绿色荧光蛋白EGFP融合的EGFP/Si1重组蛋白在HeLa细胞中成功表达.结果显示该蛋白定位在细胞核中,这一结果与生物信息学预测结果相符合.通过构建不同长度的EGFP/Si1基因突变体观察其核定位信号所在区段,发现核定位信号区在465～531氨基酸残基之间.Si1基因编码框中肿瘤相关1639位点的改变,虽然并不在入核信号相关结构区,但影响Si1基因表达蛋白的细胞核迁移,进而影响基因功能.

英文摘要：

A serum inhibited gene Sil （GenBank acession number： AY050169） was previously cloned and identified by differential expression of genes in U251 cells. For the further study of biological function of Sil, prediction procedure was performed to predict its subcelluar-localization. Relative experiments were carried out at the same time. The expression of EGFP/Sil recombinant in HeLa cells showed Sil protein located in nuclear which corroborated the prediction results of Psort Ⅱ, Proloc, Cello version2, Subnuclear compartments prediction system, NUCLEO and NUCPRED. According to the PredictNLS prediction, twelve different fragments of EGFP/Sil recombinants were constructed to identify precise NLS regulation sequence. Findings proved that the real NLS regulation sequence was not the same as the software predicted（1 206 bp-1 239 bp on Sil ORF）, but located on 1 395 bp- 1 594 bp of Sil. A tumor relatived mutation/EGFP recombinant localization result showed though the mutation site （1 639bp on Sil ORF） does not located in NLS regulation sequence, it did affect wildtype Sil protein divert to nuclear and may affect its natural function in cell, perhaps it is the main reason for highly mutation rate of Si 1 in tumor.