| 摘要: |
| 利用RACE技术获得了斑鳜胃蛋白酶原A(PG A1、PG A2)、胃质子泵α和β亚基cDNA序列。结果表明, PG A1、PG A2 cDNA序列全长分别为1361bp、1348bp, 其编码的前肽中均包含信号肽、激活肽和胃蛋白酶3个部分, 成熟肽中含有2个天冬氨酸残基和6个半胱氨酸残基。PG A1与PG A2在氨基酸序列组成、理化性质、功能位点、空间结构上存在明显差异, 暗示它们可能具有不同的生理功能。PG A1、PG A2的DNA序列均由9个外显子和8个内含子组成。胃质子泵α和β亚基cDNA全长序列分别为3531bp、1742bp, α亚基具有高度保守性, 而β亚基具有相对变异性。斑鳜成体组织中PG A1、PG A2和胃质子泵α、β亚基的RT-PCR检测显示, 它们均一致在食道和胃中大量表达, 推测PG A1、PG A2与胃质子泵间的表达关系可能存在一定的协同性。 |
| 关键词: 斑鳜 胃蛋白酶原A 胃质子泵 序列特征 组织表达 |
| DOI：10.11693/hyhz201303012012 |
| 分类号: |
| 基金项目:上海市科委基础研究重点项目, 09JC1406900 号; 上海市重点学科建设项目, Y1101 号; 上海海洋大学博士启动基金, 07274号。 |
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| CLONING AND TISSUE EXPRESSION ANALYSIS OF THE PEPSINOGEN A AND GASTRIC PROTON PUMP GENES FROM SINIPERCA SCHERZERI |
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DENG Yan-Fei1,2, XUE Yang1, ZHAO Jin-Liang1, QIAN Ye-Zhou3, WU Chao3, QIAN De3
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1.Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University;2.Freshwater Fisheries Research Institute of Jiangsu Province;3.Chizhou Institute of Special Aquaculture, Anhui Province
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| Abstract: |
| Pepsinogens (PG), precursors of pepsins, are activated into mature pepsins in gastric acid, which are secreted by the gastric proton pump (Gastric H+/K+-ATPase). In this study, the complete cDNA sequences and genomic DNA sequences of PG A1 and PG A2 were obtained by Rapid Amplification of cDNA Ends (RACE) from the stomach of Siniperca scherzeri. Both PG A1 and PG A2 genes were deduced to have nine exons and eight introns. The full length of PG A1 cDNA was 1361bp, which contained an open reading frame (ORF) of 1137bp and encoded a peptide of 378 amino acids; the full length of PG A2 cDNA was 1348bp, which contained an ORF of 1131bp and encoded a peptide of 376 amino acids. Three regions were identified in PG A1 and PG A2 amino acid sequence: the signal peptide, the activation segment and the pepsin moiety, the pepsin moiety had two aspartates functioned as catalytic residues and three disulfide bonds. There were significant differences in sequence composition, physical and chemical properties, functional sites and spatial structure between pepsin A1 and pepsin A2, suggesting that they may be encoded by different genes and have divergent functions. Both α and β subunits of the gastric proton pump were also isolated and cloned, with a length of 3531bp and 1742bp, respectively. Higher conservative sequence was revealed in α subunits which had multiple functional sites, while moderate variability existed in β subunits. The PG A1, PG A2, together with gastric proton pump α and β subunits mRNA were mainly expressed in stomach and esophagus detected by RT-PCR, which indicated gastric proton pump were expressed in a coordinate pattern with PG A1 and PG A2. |
| Key words: Siniperca scherzeri Pepsinogen A Gastric proton pump Sequence characterization Tissue expression |
