【作者】 向志明；

【导师】 李永青； 吴秀山；

【作者基本信息】 湖南师范大学 ， 发育生物学， 2006， 硕士

【摘要】 在心血管发病机理中，转录因子对基因表达调控起重要的作用。确定对心血管系统中起作用的调控基因对于了解先天性心脏病和其它心血管疾病的发病机理非常必要。Cys2／His2型锌指蛋白基因是一类很大的转录调控因子家族基因，已发现很多Cys2／His2型锌指蛋白参与了心脏发育和心血管疾病。ZNF540就是本文作者在利用生物信息学方法筛选人类心脏发育候选基因的过程中发现的一个人类新基因。ZNF540 cDNA全长3335个碱基，ORF全长1983个碱基，编码一个长661个氨基酸残基的蛋白质。该蛋白包含一个KRAB结构域和17个锌指结构域。Northern结果显示ZNF540在6个月胚胎中有广泛表达。ZNF540的COS-7亚细胞定位于细胞核，转录活性分析表明，ZNF540-BD通过KRAB框抑制VP-16基因的转录活性，COS-7细胞中过表达ZNF540蛋白可以使MAPK信号途径的两个下游转录因子ELK-1和SRE的转录抑制活性。综合目前的研究结果来看，ZNF540可能通过MAPK信号途径参与对细胞生命活动的调控过程。利用酵母双杂交实验筛选ZNF540的相互作用蛋白，得到96个蓝斑，测序发现其中一个为MVP。免疫共沉淀实验和细胞信号报告基因活性分析都初步证明了ZNF540和MVP可能存在相互作用。更多还原

【Abstract】 Transcription factors play an essential role in controlling gene expression during cardiac and vascular pathogenesis. Identification of regulatory genes in the cardiovascular system is a necessary toward an understanding of the pathogenesis of congenital heart disease (CHD) and acquired cardiovascular diseases. The Cys2/His2 type zinc finger genes are the single largest class of transcription factors in the human genome and many numbers of the kr(u|¨)pple-like zinc finger genes have been found to be involved in cardiac development or cardiovascular diseases.In the present study, we report the identification and characterization of a novel KRAB-containing zinc-finger protein, ZNF540, from a human embryonic heart cDNA library. ZNF540 encodes a putative protein of 661amino acids. Northern analysis and Northern blot indicate that ZNF540 is expressed in various tissues at the six months embryonic development stage.In COS-7 cells, ZNF540 protein is localized to nucleus. ZNF540 is a transcription repressor by KRAB motif and zinc finger motif when fused to Gal-4 DNA-binding domain and cotranfected with VP-16. Overexpression of ZNF540 in COS-7 cells inhibits the transcriptional activities of SRE and ELK-1, suggesting that the ZNF540 protein may act as a transcriptional repressor in mitogen-activated protein kinase (MAPK) signaling pathway to mediate cellular functions. Its intereaction proteins were screened by yeast two-hybrid system and 96 blue colones were obtained. The results of sequence indicated that one of the clones is MVP. Co-immunoprecipitation experiment showed that MVP may intereact with ZNF540.更多还原