Cercarial Elastase Is Encoded by a Functionally Conserved Gene Family across Multiple Species of Schistosomes*
Cercarial Elastase Is Encoded by a Functionally Conserved Gene Family across Multiple Species of Schistosomes*
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DOI：
10.1074/jbc.m202364200
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发表时间：
2002-07
期刊：
影响因子：
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通讯作者：
Jason P. Salter;Youngchool Choe;H. Albrecht;C. Franklin;K. Lim;C. Craik;J. McKerrow
中科院分区：
文献类型：
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作者：
Jason P. Salter;Youngchool Choe;H. Albrecht;C. Franklin;K. Lim;C. Craik;J. McKerrow
血吸虫属的水媒尾蚴能迅速穿透宿主皮肤.一个单一的丝氨酸蛋白酶活性，尾蚴弹性蛋白酶，沉积在入侵的寄生虫通过空泡从十个大的髋臼腺细胞。尾蚴弹性蛋白酶活性是多种亚型的复合物。根据氨基酸和启动子序列的同源性，可以将编码同种型的基因分为两类。在曼氏血吸虫中鉴定的五个基因中的两个占释放的活性和蛋白质的90%以上。其余的基因几乎不产生蛋白质或沉默。位置扫描合成组合底物库表明，两种主要的异构体具有相似的底物特异性，因此是同工酶。密切相关的血吸虫hematobium和远亲Schistosomatium douthitti也包含多个orthopathicerecarial弹性蛋白酶基因，这表明在血吸虫进化的物种形成后可能发生了基因重复，并且这种重复是保守的。
Water borne cercaria(ae) of the trematode genusSchistosoma rapidly penetrate host skin. A single serine protease activity, cercarial elastase, is deposited in advance of the invading parasite by holocytosis of vesicles from ten large acetabular gland cells. Cercarial elastase activity is a composite of multiple isoforms. Genes coding for the isoforms can be divided into two classes by amino acid and promoter sequence homology. Two of the five genes identified in Schistosoma mansoni account for over 90% of the activity and protein released. The remaining genes produce little protein or are silent. Positional scanning synthetic combinatorial substrate libraries demonstrate that the two major isoforms have similar substrate specificities and are, therefore, isoenzymes. The closely related Schistosoma hematobium and the distantly related Schistosomatium douthitti also contain multiple orthologous cercarial elastase genes suggesting that gene duplication may have occurred after speciation in Schistosoma evolution and that this duplication has been conserved.