Ca2+ administration stimulates the binding of AP-1 factor to the 5′-flanking region of the rat gene for the Ca2+-binding protein regucalcin
Ca2+ administration stimulates the binding of AP-1 factor to the 5′-flanking region of the rat gene for the Ca2+-binding protein regucalcin
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DOI：
10.1042/bj3290157
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发表时间：
1998-01-01
影响因子：
4.1
通讯作者：
Yamaguchi, M
中科院分区：
文献类型：
--
作者：
Murata, T;Yamaguchi, M
Ca 2+结合蛋白regucalcin的mRNA主要在肝脏中表达，在肾脏中仅少量表达，并且肝脏regucalcin mRNA的表达被Ga 2+施用显著刺激[Shimokawa和Yamaguchi（1992）FEBS Lett. 305，151-154]。研究了与大鼠regucalcin基因的5 '侧翼区结合的核因子的存在。当从各种大鼠组织中获得的核蛋白用于凝胶迁移率变化测定时，在肝脏和肾脏中发现了蛋白质-DNA复合物的组织特异性形成。一个额外的新的蛋白质-DNA复合物形成时，肝细胞核提取物从钙给药大鼠（10毫克的Ca 2 +/100克体重）使用。竞争凝胶迁移率移动实验，使用共识和突变的寡核苷酸AP-I因子表明，额外的新的复合物形成的AP-I因子regucalcin基因的结合。钙诱导的AP-1因子与regucalcin基因的结合被同时给予钙调素拮抗剂trifluoperazine完全抑制，这表明核AP-1蛋白的激活部分是通过钙/钙调素依赖性途径介导的。此外，大鼠regucalcin基因的5 '侧翼区连接到荧光素酶报告基因具有启动子活性在H4-II-E肝癌细胞。该启动子活性通过用Ca 2+通道激动剂Bay K 8644处理而增强。本研究表明，钙响应序列位于大鼠regucalcin基因的5 '侧翼区。
mRNA of the Ca2+-binding protein, regucalcin, is mainly expressed in the liver and only to a small extent in the kidney, and the expression of hepatic regucalcin mRNA is markedly stimulated by Ga2+ administration [Shimokawa and Yamaguchi (1992) FEBS Lett. 305, 151-154]. The existence of nuclear factors that bind to the 5'-flanking region of the rat regucalcin gene was investigated. When nuclear proteins obtained from various rat tissues were used in gel mobility-shift assays, tissue-specific formation of a protein-DNA complex was found in the liver and kidney. An additional novel protein-DNA complex was formed when liver nuclear extracts obtained from Ca2+-administered rats (10 mg of Ca2+/100 g body weight) were used. Competition gel mobility-shift experiments using consensus and mutant oligonucleotides for AP-I factor showed that the additional novel complex was formed from binding of the AP-I factor to the regucalcin gene. Ca2+-induced binding of the AP-1 factor to the regucalcin gene was completely inhibited by simultaneous administration of trifluoperazine, an antagonist of calmodulin, suggesting that the activation of nuclear AP-1 protein is partly mediated through a Ca2+/calmodulin-dependent pathway. Moreover, the 5'-flanking region of the rat regucalcin gene ligated to a luciferase reporter gene possessed the promoter activity in H4-II-E hepatoma cells. This promoter activity was enhanced by treatment with Bay K 8644, a Ca2+-channel agonist. The present study demonstrates that the Ca2+-response sequences are located within the 5'-flanking region of the rat regucalcin gene.