Expression of a novel Ca^<2+>-binding protein regucalcin and rlation to its physiologic role

研究了一种新的钙结合蛋白regucalcin的表达及其与生理作用的关系。获得以下结果.大鼠regucalcin基因由7个外显子组成。用直接R显带荧光原位杂交法对该基因进行了鉴定。regucalcin基因定位于大鼠染色体Xq11.1-12近端. Regucalcin基因在人、猴、大鼠、小鼠、狗、牛、兔和鸡等高等动物中具有广泛的保守性。在酵母中没有发现该基因。Regucalcin mRNA主要在大鼠和小鼠中表达，在人、牛和鸡中也有表达.禁食大鼠再喂食后，肝脏regucalcin mRNA的表达增加。这种表达与胰岛素和/或钙作为刺激因子的作用有关。苯巴比妥可降低大鼠肝脏regucalcin mRNA的表达.大鼠再生肝regucalcin mRNA表达增强，提示regucalcin对肝细胞增殖有促进作用; 7.1移植性Morris肝癌细胞regucalcin mRNA表达明显，而白蛋白mRNA表达较弱。

The expression of a novel calcium-binding protein regucalcin and relation to its physiologic role was investigated. The follwing results were obtained.1. Rat regucalcin gene consisted in 7 exons. The gene was determined by direct R-banding fluorescence in situ hybridization method with the 19.9 kb clone containing four exons. The regucalcin gene was localized on rat chromosome Xq11.1-12 proximal end.2. Regucalcin gene was widely conserved among higher animals including human, monkey, rat, mouse, dog, bovine, rabbit and chicken. The gene was not found in yeast. Regucalcin mRNA was predominantly expressed in rat and mouse, although the expression was also seen in human, bovine and chicken.3. The expression of regucalcin mRNA in the liver was elevated by refeeding of fasted rats. This expression was involved in the action of insulin and/or calcium as stimulating factors.4. The expression of hepatic regucalcin mRNA was decreased by phenobarbital administration in rats.5. The concentraition of regucalcin in the liver was clearly increased by calcium administration in rats.6.The expression of hepatic regucalcin mRNA was enhanced in regenerating rat liver, suggesting that regucalcin plays a role in proliferation of liver cells.7.1n the transplantable Morris hepatoma cells, the regucalcin mRNA was markedly expressed, while the albumin mRNA was expressed only slightly.