中文摘要：

PSF（polypyrimidine tract binding protein-associated splicing factor）蛋白是一种多功能的DNA／RNA结合蛋白，能够抑制原癌基因的表达，在人和小鼠中具有肿瘤抑制的作用。以人成纤维细胞总RNA为材料，利用PSF特异性引物通过RT-PCR的方法扩增得到PSF蛋白的编码序列，将其克隆到原核表达载体pET-28a（＋）中构建重组表达质粒pET-28-PSF，转化大肠杆菌BL21（DE3）并诱导表达。SDS-PAGE及免疫印记分析表明PSF能够在大肠杆茵中以可溶性形式表达。凝胶阻滞分析显示，原核表达的PSF融合蛋白在体外条件下能够与mVL30-1RNA结合，表明PSF的原核表达产物很可能具有完整的生物学活性。为进一步研究PSF蛋白的生物学功能奠定了基础。

英文摘要：

Polypyrimidine tract binding protein-associated splicing factor （PSF）, a muhifunctional RNA/ DNA-binding protein, can suppress the expression of proto-oncogene and function as tumor suppressor protein （TSP） in human and mouse. Using total RNA extracted from human fibroblasts, PSF-encoding cDNA was synthesized and inserted into vector pET-28a（ ＋ ） to construct the recombinant plasmid pET-28-PSF. The PSF fused with His-tag was expressed in E. coli BL21 （DE3） by IPTG induction and then purified by affinity chromatography. SDS-PAGE and Western blotting results indicated the soluble His-tagged PSF could be produced with a prokaryotic expression system. Finally, the RNA-binding capacity of recombinant PSF to mVL30-1 RNA was determined by Gel-shift assay. The results indicate that recombinant PSF produced with a prokaryotic expression system can be biologically active and will therefore allow us to investigate the function of PSF in the future.