TY - JOUR
T1 - The role of the Aedes aegypti Epsilon glutathione transferases in conferring resistance to DDT and pyrethroid insecticides
AU - Lumjuan, Nongkran
AU - Rajatileka, Shavanthi
AU - Changsom, Donch
AU - Wicheer, Jureeporn
AU - Leelapat, Posri
AU - Prapanthadara, La aied
AU - Somboon, Pradya
AU - Lycett, Gareth
AU - Ranson, Hilary
PY - 2011/3/1
Y1 - 2011/3/1
N2 - 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.
AB - 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.
KW - Aedes aegypti
KW - DDT dehydrochlorinase
KW - Glutathione transferase
KW - Insecticide resistance
KW - Permethrin
KW - RNA interference
UR - http://www.scopus.com/inward/record.url?scp=79951516803&partnerID=8YFLogxK
U2 - 10.1016/j.ibmb.2010.12.005
DO - 10.1016/j.ibmb.2010.12.005
M3 - Article (Academic Journal)
C2 - 21195177
AN - SCOPUS:79951516803
SN - 0965-1748
VL - 41
SP - 203
EP - 209
JO - Insect Biochemistry and Molecular Biology
JF - Insect Biochemistry and Molecular Biology
IS - 3
ER -
