ε类谷胱甘肽转移酶的活性升高赋予登革热媒介埃及伊蚊对滴滴涕的抗性。

Elevated activity of an Epsilon class glutathione transferase confers DDT resistance in the dengue vector, Aedes aegypti.

作者信息

Lumjuan Nongkran, McCarroll Lynn, Prapanthadara La-aied, Hemingway Janet, Ranson Hilary

机构信息

Vector Research Group, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK.

出版信息

Insect Biochem Mol Biol. 2005 Aug;35(8):861-71. doi: 10.1016/j.ibmb.2005.03.008.

DOI:10.1016/j.ibmb.2005.03.008

PMID:15944082

Abstract

Glutathione transferases (GSTs) play a central role in the detoxification of xenobiotics such as insecticides and elevated GST expression is an important mechanism of insecticide resistance. In the mosquito, Anopheles gambiae, increased expression of an Epsilon class GST, GSTE2, confers resistance to DDT. We have identified eight GST genes in the dengue vector, Aedes aegypti. Four of these belong to the insect specific GST classes Delta and Epsilon and three are from the more ubiquitously distributed Theta and Sigma classes. The expression levels of the two Epsilon genes, a Theta GST and a previously identified Ae. aegypti GST [Grant and Hammock, 1992. Molecular and General Genetics 234, 169-176] were established for an insecticide susceptible and a resistant strain. We show that the putative ortholog of GSTe2 in Ae. aegypti (AaGSTe2) is over expressed in mosquitoes that are resistant to the insecticides DDT and permethrin. Characterisation of recombinant AaGSTE2-2 confirmed the role of this enzyme in DDT metabolism. In addition, unlike its Anopheles ortholog, AaGSTE2-2 also exhibited glutathione peroxidase activity.

摘要

谷胱甘肽转移酶（GSTs）在杀虫剂等外源性物质的解毒过程中发挥着核心作用，GST表达升高是昆虫产生抗药性的重要机制。在冈比亚按蚊中，ε类GST（GSTE2）表达增加赋予了对滴滴涕的抗性。我们在登革热传播媒介埃及伊蚊中鉴定出了8个GST基因。其中4个属于昆虫特有的GST类，即δ类和ε类，3个来自分布更为广泛的θ类和σ类。我们测定了两个ε基因、一个θ类GST以及一个先前鉴定出的埃及伊蚊GST [Grant和Hammock，1992年。《分子与普通遗传学》234，169 - 176] 在一个杀虫剂敏感品系和一个抗性品系中的表达水平。我们发现埃及伊蚊中GSTe2的假定直系同源基因（AaGSTe2）在对杀虫剂滴滴涕和氯菊酯具有抗性的蚊子中过度表达。重组AaGSTE2 - 2的特性鉴定证实了该酶在滴滴涕代谢中的作用。此外，与它在按蚊中的直系同源基因不同，AaGSTE2 - 2还表现出谷胱甘肽过氧化物酶活性。