The role of the Aedes aegypti Epsilon glutathione transferases in conferring resistance to DDT and pyrethroid insecticides
The role of the Aedes aegypti Epsilon glutathione transferases in conferring resistance to DDT and pyrethroid insecticides
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DOI：
10.1016/j.ibmb.2010.12.005
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发表时间：
2011-03-01
影响因子：
3.8
通讯作者：
Ranson, Hilary
中科院分区：
文献类型：
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作者：
Lumjuan, Nongkran;Rajatileka, Shavanthi;Ranson, Hilary
登革热载体埃及伊蚊中的表型谷胱甘肽转移酶（GST）类由8个连续排列的基因组成，其在超级重叠群1.291上跨越53，645 bp，其定位于染色体2。一种Epidermal GST，GSTE 2，以前被认为与赋予对DDT的抗性有关。GSTE 2的氨基酸序列在杀虫剂敏感和滴滴涕抗性菌株不同的5个残基，其中两个发生在推定的滴滴涕结合位点。各自的重组酶的表征表明，这两种变体具有可比的DDT脱氯化氢酶活性，虽然从抗性菌株的异构体具有较高的亲和力的杀虫剂。GSTe 2和另外两个Epidemic GST基因GSTe 5和GSTe 7在抗性群体中以升高的水平表达，并且重组同二聚体GSTE 5 -5也表现出低水平的DDT脱氢氯酶活性。通过RNA干扰部分沉默GSTe 7或GSTe 2导致对拟除虫菊酯、溴氰菊酯的敏感性增加，表明这些GST酶也可能在对拟除虫菊酯杀虫剂的抗性中发挥作用。(C)2010爱思唯尔有限公司保留所有权利。
The Epsilon glutathione transferase (GST) class in the dengue vector Aedes aegypti consists of eight sequentially arranged genes spanning 53,645 bp on super contig 1.291, which maps to chromosome 2. One Epsilon GST, GSTE2, has previously been implicated in conferring resistance to DDT. The amino acid sequence of GSTE2 in an insecticide susceptible and a DDT resistant strain differs at five residues two of which occur in the putative DDT binding site. Characterization of the respective recombinant enzymes revealed that both variants have comparable DDT dehydrochlorinase activity although the isoform from the resistant strain has higher affinity for the insecticide. GSTe2 and two additional Epsilon GST genes, GSTe5 and GSTe7, are expressed at elevated levels in the resistant population and the recombinant homodimer GSTE5-5 also exhibits low levels of DDT dehydrochlorinase activity. Partial silencing of either GSTe7 or GSTe2 by RNA interference resulted in an increased susceptibility to the pyrethroid, deltamethrin suggesting that these GST enzymes may also play a role in resistance to pyrethroid insecticides. (C) 2010 Elsevier Ltd. All rights reserved.