权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Transcriptional Regulatory Mechanism for Ca^<2+>-Signaling Regulatory Protein Regucalcin Gene Which Is Expressed Specifically in Liver Cells

肝细胞特异表达的Ca^2信号调节蛋白Reguccalcin基因的转录调控机制

基本信息

批准号：
10672048
负责人：
YAMAGUCHI Masayoshi
金额：
$ 2.11万
依托单位：
University of Shizuoka
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10672048/
关键词：
Intracellular signal transduction Regucalcin Calcium Gene expression Transcriptional factor Liver cells 転写・因子

项目摘要

Regucalcin (RC) is a regulatory protein in Ca^<2+> signaling in cells, and it is mainly expressed in liver cells. This study was undertaken to clarify the transcriptional mechanism for the regucalcin gene in liver cells. Firstly, the involvement of signaling factors, which are related to serum component, on the regucalcin mRNA expression in the cloned rat hepatoma cells (H4-II-E) was examined. The regucalcin mRNA expression was found to be mediated through signaling pathway which are partly involved in Ca^<2+>-dependent protein kinase and tyrosine kinase in H4-II-E hepatoma cells. To understand the mechanism underlying the regulation of the regucalcin gene was the 5'-flanking region of the rat regucalcin gene was characterized, and it was found that nuclear proteins from H4-II-E cells specifically bind to the 5'-flanking region of the rat regucalcin gene. Then, the characterization of the binding of nuclear protein on the 5'-flanking resion of the rat regucalcin gene was investigated. It was found of that the specific nuclear factor binds to the NFI-like sequence, which can stimulate the transcriptional activity in the promoter region of regucalcin gene in liver cells. Moreover, it was demonstrated that hepatic nuclear protein can specifically bind to the TTGGC sequence in rat regucalcin gene promoter resion, and that this binding is enhanced by inttacellular signaling factors which are pathway mediated through protein phosphorylation. Liver nuclear proteins which can bind to the TTGGC sequence were clonining with one-hybrid method. It was found that two nuclear proteins can specifically bind to the TTGGC in the promoter region of regucalcin gene in liver cells. One was NFI (a2), and other was a novel protein.

Regucalcin（RC）是细胞内Ca^2+信号转导的调节蛋白，主要在肝细胞中表达。本研究旨在阐明regucalcin基因在肝细胞中的转录机制。首先，研究了与血清成分相关的信号传导因子对大鼠肝癌细胞株（H4-II-E）regucalcin mRNA表达的影响。在H4-II-E肝癌细胞中regucalcin mRNA的表达是通过Ca^<2+>依赖性蛋白激酶和酪氨酸激酶介导的。为了理解调节regucalcin基因的潜在机制，对大鼠regucalcin基因的5 '侧翼区进行了表征，并且发现来自H4-II-E细胞的核蛋白特异性结合至大鼠regucalcin基因的5'侧翼区。在此基础上，研究了大鼠regucalcin基因5 ′-侧翼区核蛋白的结合特性。在肝细胞中，发现特异性核因子与NFI样序列结合，可刺激regucalcin基因启动子区的转录活性。此外，研究表明，肝核蛋白可以特异性地与大鼠regucalcin基因启动子区域的TTGGC序列结合，并且这种结合通过蛋白磷酸化途径介导的细胞内信号传导因子增强。用单杂交方法克隆了能与TTGGC序列结合的肝细胞核蛋白。发现两种核蛋白可与regucalcin基因启动子区的TTGGC特异性结合。一个是NFI（a2），另一个是新蛋白。