Structure and Expression of Hepatocyte Growth Factor (HGF)

肝细胞生长因子 (HGF) 的结构和表达

• 批准号: 03833004
• 负责人: TASHIRO Kosuke
• 金额: $ 1.15万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03833004/
• 关键词: Hepatocyte Growth Factor; Gene Structure; induction of expression

1) Structure of the rat hepatocyte growth factor geneWe isolated the rat genomic clones coding the whole region of HGF from rat genomic library. The rat HGF is encoded in about 70 kbp genomic region and divided into 18 exons. The complete nucleotide sequences of its promoter region and the flanking regions between each exons and introns were determined. In the promoter region, the TATA and GC box sequences are not observed so that the promoter of rat HGF may has unique characters. There are some consensus sequences of various enhancer, such as AP1 and Sp1 binding site, APRF, and NF-1. Especially, the existence of APRF elements suggest that the expression of HGF are regulated by cytokines.By S1-protection and primer-extension analysis, it is found that there are at least four transcription start sites in HGF promoter region. When hepatitis was induced by CC14, the transcription from the 3rd start site (site B) increased dramatically, indicating that the transcriptional regulation from site B is an important for the expression of HGF in the injury.2) Development of the assay systems for HGF expressionTo establish the assay systems of HGF induction mechanisms, we try to culture the non-parenchymal cells. Until now, we have developed the method for the separation and the culture of the non-parenchymal livercells.

1)大鼠肝细胞生长因子基因的结构我们从大鼠基因组文库中分离了编码HGF全长的大鼠基因组克隆。大鼠肝细胞生长因子基因编码区约70kbp，分为18个外显子。测定了其启动子区域及各外显子和内含子之间的侧翼区的全序列。在启动子区域没有观察到TATA和GC盒序列，因此大鼠肝细胞生长因子的启动子可能具有独特的特性。各种增强子有一些共同的序列，如AP1和Sp1结合位点、APRF和NF-1。特别是APRF元件的存在，提示HGF的表达受细胞因子的调控。通过S1保护和引物延伸分析，发现HGF启动子区域至少有4个转录起始点。CC14诱导肝炎时，第3个起始位点(B位点)的转录显著增加，提示B位点的转录调控对HGF在损伤中的表达起重要作用。2)HGF表达检测体系的建立为了建立HGF诱导机制的检测体系，我们尝试了非实质细胞的培养。到目前为止，我们已经建立了分离和培养非实质肝细胞的方法。