【摘要】 目的:观察转录结构因子高迁移率蛋白I(HMGI)与血小板源生长因子B链(PDGF-B)基因上游序列的结合并初步鉴定HMGI的结合序列。方法:应用凝胶迁移率改变法(EMSA)观察重组人HMGI蛋白与PDGF-B基因上游-1758/+43bp片段的结合,并逐步确定与其结合的AT富含序列。结果:重组人HMGI蛋白能较特异地与PDGF-B链基因上游-1758/+43bp片段结合,分离到的两个HMGI结合片段,-1393/-1181bp和-190/+43bp,均含有AT富含序列TTTATAAA(-1333/-1326bp,-1314/-1307bp和-30/23bp)。HMGI能与含TT-TATAAA的合成寡核苷酸结合,并能促进转录因子NF-κB与拼接于旁侧的PDGF-B基因的切应力反应元件结合。结论:HMGI在体外能与PDGF-B链基因上游的TTTATAAA序列结合,可能参与PDGF-B基因的转录调控。更多还原

【Abstract】 AIM: To determine whether the high mobility group protein I (HMGI) is able to bind to the upstream sequence of platelet-derived growth factor B-chain gene and to characterize the HMGI-binding AT-rich regions. METHODS: Recombinant human HMGI (rhHMGI) protein was prepared and electrophoresis mobility shift assay (EMSA) was used. RESULTS: The binding of rhHMGI to PDGF-B (-1 758 / +43 bp) was observed in vitro. Two major HMGI-binding fragments -1 392 / -1 180 bp and -188 / +43 bp were identified, which contained the same AT-rich sequence TTTATAAA (-1 333 / -1 326 bp, -1 314 / -1 307 bp and -30 / -23 bp). An oligonucleotide bound to the TTTATAAA and the GAGACC, the core sequence of the shear stress response element of the PDGF-B, could also bind to the HMGI. Furthermore, HMGI facilitated the binding of NF-κB to the GAGACC in the oligonucleotide. CONCLUSION: The HMGI could bind to the upstream sequence of the PDGF-B gene via the AT-rich sequence TTTATAAA, which may play a role in the transcriptional regulation of the PDGF-B gene.更多还原