Department of Biology, Faculty of Education, Utsunomiya University, 350 Mine, Utsunomiya, Tochigi, 321-8505, Japan.
Comp Biochem Physiol B Biochem Mol Biol. 2013 Aug;165(4):226-35. doi: 10.1016/j.cbpb.2013.05.003. Epub 2013 May 20.
The full-length cDNAs of three pepsinogens (Pgs) were cloned from the stomach of newt, Cynops pyrrhogaster, and nucleotide sequences of the full-length cDNAs were determined. Molecular phylogenetic analysis showed that two Pgs, named PgC1 and PgC2, belong to the pepsinogen C group, and one Pg, named PgA, belongs to the pepsinogen A group. The sequences contain an open reading frame (ORF) encoding 385 amino acid residues for PgC1, 383 amino acid residues for PgC2 and 377 amino acid residues for PgA. In addition, all of the three amino acid sequences conserve some unique characteristics such as six cysteine residues and putative active site two aspartic acid residues. All of the pepsinogen mRNAs were detected in the stomach by RT-PCR but not in other organs. Although a slight difference at the time of the start of expression was seen among the three pepsinogen genes, all of them were expressed in the larval stage after hatching. This is the first report on cloning of pepsinogens from urodele stomach.
从中国大鲵（Cynops pyrrhogaster）胃中克隆了三种胃蛋白酶原（Pgs）全长 cDNA，并测定了全长 cDNA 的核苷酸序列。分子系统发育分析表明，两种 Pgs，命名为 PgC1 和 PgC2，属于胃蛋白酶原 C 组，一种 Pg，命名为 PgA，属于胃蛋白酶原 A 组。这些序列包含一个开放阅读框（ORF），编码 PgC1 的 385 个氨基酸残基、PgC2 的 383 个氨基酸残基和 PgA 的 377 个氨基酸残基。此外，这三种氨基酸序列都保守一些独特的特征，如 6 个半胱氨酸残基和假定的活性部位两个天冬氨酸残基。通过 RT-PCR 在胃中检测到所有三种胃蛋白酶原 mRNA，但在其他器官中未检测到。尽管这三种胃蛋白酶原基因在表达开始时略有差异，但它们在孵化后的幼体阶段都有表达。这是首次从有尾两栖动物胃中克隆胃蛋白酶原的报道。
