Characterization of a juvenile hormone-regulated chymotrypsin-like serine protease gene in Aedes aegypti mosquito
Characterization of a juvenile hormone-regulated chymotrypsin-like serine protease gene in Aedes aegypti mosquito
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DOI：
10.1016/j.ibmb.2007.10.008
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发表时间：
2008-02-01
影响因子：
3.8
通讯作者：
Zhu, Jinsong
中科院分区：
文献类型：
--
作者：
Bian, Guowu;Ralkhel, Alexander S.;Zhu, Jinsong
雌性蚊子从脊椎动物宿主摄取血液后，需要外肽酶和内肽酶将中肠中的血液蛋白消化成氨基酸，雌性蚊子使用氨基酸来构建蛋黄蛋白。这些蛋白酶并不总是存在于中肠中，它们的不同表达模式表明，这些酶的产生受到高度调节，以满足不同阶段的特定生理需求。在这里，我们报告鉴定的丝氨酸型蛋白酶，JHA 15，在黄热病蚊子埃及伊蚊。该蛋白与胰凝乳蛋白酶具有高度的序列同源性，并且确实表现出特异性胰凝乳蛋白酶酶促活性。JHA15基因主要在成年雌性蚊子的中肠中表达。我们的研究结果表明，它的转录激活保幼激素在新出现的女性成年人。虽然它的mRNA分布是类似的早期胰蛋白酶基因，我们发现，JHA15蛋白很容易检测到中肠上皮细胞的非吸血和吸血蚊子。多核糖体RNA的分析进一步证实了JHA15的合成发生在吸血之前和之后不久。敲低JHA 15的表达没有导致明显的表型变化，这意味着这些蛋白水解酶之间存在功能冗余。(C)2007爱思唯尔有限公司保留所有权利。
After female mosquitoes ingest blood from vertebrate hosts, exopeptidases and endopeptidases are required for digesting blood proteins in the midgut into amino acids, which female mosquitoes use to build yolk proteins. These proteases are not always present in the midgut, and their diverse expression patterns suggest that production of these enzymes is highly regulated in order to meet specific physiological demands at various stages. Here we report identification of a serine-type protease, JHA15, in the yellow fever mosquito Aedes aegypti. This protein shares high sequence homology with chymotrypsins, and indeed exhibits specific chymotrypsin enzymatic activity. The JHA15 gene is expressed primarily in the midgut of adult female mosquitoes. Our results indicate that its transcription is activated by juvenile hormone in the newly emerged female adults. Although its mRNA profile is similar to that of the early trypsin gene, we found that JHA15 proteins were readily detected in the midgut epithelium cells of both non-blood-fed and blood-fed mosquitoes. Analysis of polysomal RNA further substantiated that synthesis of JHA15 occurs before and shortly after blood feeding. Knocking down expression of JHA15 resulted in no evident phenotypic changes, implying that functional redundancy exists among those proteolytic enzymes. (C) 2007 Elsevier Ltd. All rights reserved.