Ishihara T, Ichihara Y, Hayano T, Katsura I, Sogawa K, Fujii-Kuriyama Y, Takahashi K
Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Japan.
J Biol Chem. 1989 Jun 15;264(17):10193-9.
The entire rat pepsinogen C gene has been isolated from a rat genomic library, using the rat pepsinogen C cDNA as a probe. Southern blot analysis showed that there exists at least two rat pepsinogen C genes. The nucleotide sequences of the coding regions and the 5'- and 3'-flanking regions of one of the rat pepsinogen C genes have been determined. This gene is split into 9 exons interrupted by eight intervening sequences. The 5'-flanking region is similar to that of the human pepsinogen C gene, but only the former has the core sequence of the Sp1 binding site. The amount of transcripts of the rat pepsinogen C genes was found to increase during development, and a similar increase was shown to be induced by injection of hydrocortisone. As a candidate of a factor which regulates the transcription, we found a 25-kDa protein by Southwestern blotting. It binds to a specific site in the 5'-flanking region of the gene only in the presence of Mg2+ ion, and it is present in the nuclear fraction of the gastric mucosa but not of the liver.
利用大鼠胃蛋白酶原C cDNA作为探针，从大鼠基因组文库中分离出了完整的大鼠胃蛋白酶原C基因。Southern印迹分析表明，大鼠至少存在两个胃蛋白酶原C基因。已确定了其中一个大鼠胃蛋白酶原C基因编码区以及5'和3'侧翼区的核苷酸序列。该基因被8个间隔序列打断，分为9个外显子。其5'侧翼区与人胃蛋白酶原C基因的相似，但只有前者具有Sp1结合位点的核心序列。发现大鼠胃蛋白酶原C基因的转录本数量在发育过程中增加，注射氢化可的松也能诱导类似的增加。作为调节转录的一个因子的候选物，我们通过蛋白质印迹法发现了一种25 kDa的蛋白质。它仅在Mg2+离子存在的情况下与该基因5'侧翼区的一个特定位点结合，并且存在于胃黏膜的核组分中，而不存在于肝脏的核组分中。
