Ide H, Itoh H, Tomita M, Murakumo Y, Kobayashi T, Maruyama H, Osada Y, Nawa Y
Department of Parasitology, Miyazaki Medical College.
J Biochem. 1995 Jul;118(1):210-5. doi: 10.1093/oxfordjournals.jbchem.a124880.
A cDNA encoding rat mast cell tryptase (rMCT) was successfully cloned, and sequenced, from peritoneal cells of Lewis rats infected with Nippostrongylus brasiliensis by the reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends methods. The cDNA was 1,097 base-pairs long, and included 822 base-pairs of an open reading frame. As judged from the deduced amino acid sequence, rMCT is highly homologous to mouse mast cell protease-6, and is considered to be translated as a prepro-enzyme with a 19-amino acid signal peptide, a 10-amino acid activation peptide, and a 245-amino acid mature enzyme. The rMCT mRNA was not detected in peritoneal cells of mast cell-deficient Ws/Ws rats, though it was strongly detected in ones of littermate +/+ and Lewis rats. In addition to in peritoneal mast cells, the rMCT mRNA was detected in the tongue. However, mRNA signals were not detected in the small intestine regardless of N. brasiliensis infection. Nor were mRNA signals detected in RBL2H3 rat basophilic leukemia cells. In the lung, the rMCT mRNA was strongly detected after infection with N. brasiliensis, though it was only faintly detected before infection. These results suggest that the rMCT is basically specific for connective tissue mast cells, but not for mucosal mast cells and that it is up-regulated in the lung during the inflammatory process of a parasitic infection.
通过逆转录-聚合酶链反应和cDNA末端快速扩增方法，从感染巴西日圆线虫的Lewis大鼠腹膜细胞中成功克隆并测序了编码大鼠肥大细胞类胰蛋白酶（rMCT）的cDNA。该cDNA长1097个碱基对，包含一个822个碱基对的开放阅读框。根据推导的氨基酸序列判断，rMCT与小鼠肥大细胞蛋白酶-6高度同源，被认为是以一种前体酶的形式进行翻译，其包含一个19个氨基酸的信号肽、一个10个氨基酸的激活肽和一个245个氨基酸的成熟酶。在肥大细胞缺陷的Ws/Ws大鼠的腹膜细胞中未检测到rMCT mRNA，而在同窝的+/+大鼠和Lewis大鼠的腹膜细胞中则强烈检测到。除了腹膜肥大细胞外，在舌中也检测到了rMCT mRNA。然而，无论是否感染巴西日圆线虫，在小肠中均未检测到mRNA信号。在RBL2H3大鼠嗜碱性白血病细胞中也未检测到mRNA信号。在肺中，感染巴西日圆线虫后强烈检测到rMCT mRNA，而在感染前仅微弱检测到。这些结果表明，rMCT基本上对结缔组织肥大细胞具有特异性，而对黏膜肥大细胞不具有特异性，并且在寄生虫感染的炎症过程中，它在肺中上调表达。
