Cloning and characterization of four Anopheles gambiae serpin isoforms, differentially induced in the midgut by Plasmodium berghei invasion
Cloning and characterization of four Anopheles gambiae serpin isoforms, differentially induced in the midgut by Plasmodium berghei invasion
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DOI：
10.1074/jbc.m208187200
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发表时间：
2003-02-07
影响因子：
4.8
通讯作者：
Loukeris, TG
中科院分区：
文献类型：
--
作者：
Danielli, A;Kafatos, FC;Loukeris, TG
疟疾载体冈比亚按蚊的基因组位点SRPN 10编码丝氨酸蛋白酶抑制剂超家族的四种可变剪接丝氨酸蛋白酶抑制剂。这四种40- 42-kDa的异构体仅在它们的C末端不同，C末端具有反应位点环，并且表现出与卵清蛋白家族的其他昆虫丝氨酸蛋白酶抑制剂和哺乳动物丝氨酸蛋白酶抑制剂的蛋白质序列相似性。重组纯化的SRPN 10丝氨酸蛋白酶抑制剂的抑制实验揭示了三种亚型对不同蛋白酶的不同和特异性抑制活性。所有亚型主要在蚊子的中肠中表达，但也在心包细胞和血细胞中表达。SRPN 10丝氨酸蛋白酶抑制剂的细胞定位在心包细胞、血细胞和血细胞样蚊子细胞系中是核质的，但在肠道中，蛋白质主要定位在细胞核中。虽然所有SRPN 10亚型的转录水平受到细菌攻击的轻微影响，但两种亚型（KRAL和RCM）的转录物在雌性蚊子中诱导，以响应伯氏疟原虫动合子的中肠入侵。KRAL和RCM SRPN 10亚型代表了研究按蚊中动合子中肠入侵过程的新的潜在标记。
The genomic locus SRPN10 of the malaria vector Anopheles gambiae codes for four alternatively spliced serine protease inhibitors of the serpin superfamily. The four 40- to 42-kDa isoforms differ only at their C terminus, which bears the reactive site loop, and exhibit protein sequence similarity with other insect serpins and mammalian serpins of the ovalbumin family. Inhibition experiments with recombinant purified SRPN10 serpins reveal distinct and specific inhibitory activity of three isoforms toward different proteases. All isoforms are mainly expressed in the midgut but also in pericardial cells and hemocytes of the mosquito. The cellular localization of SRPN10 serpins is nucleocytoplasmic in pericardial cells, in hemocytes and in a hemocyte-like mosquito cell line, but in the gut the proteins are mostly localized in the nucleus. Although the transcript levels of all SRPN10 isoforms are marginally affected by bacterial challenge, the transcripts of two isoforms (KRAL and RCM) are induced in female mosquitoes in response to midgut invasion by Plasmodium berghei ookinetes. The KRAL and RCM SRPN10 isoforms represent new potential markers to study the ookinete midgut invasion process in anopheline mosquitoes.