Transcription factors CncC/Maf and AhR/ARNT coordinately regulate the expression of multiple GSTs conferring resistance to chlorpyrifos and cypermethrin inSpodoptera exigua

Abstract

BACKGROUND: Glutathione S-transferases (GSTs) are a superfamily of multifunctional dimeric proteins existing in both prokaryotic and eukaryotic organisms. They are involved in the detoxification of both endogenous and exogenous electrophiles, including insecticides. However, the molecular mechanisms underlying the regulation of GST genes in insects are poorly understood. RESULTS:We first identified at least three GST genes involved in resistance to the insecticides chlorpyrifos and cypermethrin. Analysis of upstream sequences revealed that three GSTs (SeGSTo2, SeGSTe6 and SeGSTd3) harbor the same cap 'n' collar C/muscle aponeurosis fibromatosis (CncC/Maf) binding site, and SeGSTo2 and SeGSTe6 contain the aryl hydrocarbon receptor/aryl hydrocarbon receptor nuclear translocator (AhR/ARNT) binding site. Luciferase reporter assay showed co-transfection of reporter plasmid containing the SeGSTe6 promoter with CncC and/or Maf expressing constructs significantly boosted transcription. Similarly, AhR and/or ARNT expressing constructs also significantly increased the promoter activities. The co-transfection of mutated reporter plasmid with CncC/Maf or AhR/ARNT did not increase transcription activity anymore. Constitutive over-expression of CncC, Maf and AhR was also found in the HZ16 strain, which might be the molecular mechanism for up-regulated expression of multiple detoxification genes conferring resistance to insecticides. CONCLUSION: These results suggest that CncC/Maf and AhR/ARNT coordinately regulate the expression of multiple GST genes involved in insecticide resistance in Spodoptera exigua.

Characterization of the Cap ‘n’ Collar Isoform C gene in Spodoptera frugiperda and its Association with Superoxide Dismutase

“…Promoters of GSTo2, GSTe6, and GSTd3 of S. exigua harbor the same CncC/Maf binding site, and were found to be regulated by CncC/Maf and confer resistance to chlorpyrifos and cypermethrin [28]. Some oxidative stress responses in GST, P450, UGT, and NAD(P)H: quinone oxidoreductase have been confirmed to be regulated by Nrf2/CncC [17,18,20,27,[29][30][31][32]. The regulatory cascades that provide xenobiotic chemical inducibility still remain largely unknown.…”

“…Hence, we can ensure the involvement of Sf CncC in the Keap1-Nrf2-ARE pathway acted the same as the transcript factor of Nrf2 in vertebrate, and plays a role for host cell defense. The Keap1-Nrf2-ARE signaling pathway also exists in the D. melanogaster, and can be activated by oxidants, induces antioxidant and detoxification responses, and confers increased tolerance to oxidative stress [20,21,[29][30][31][32]. Importantly, Keap1 loss-of-function mutations extend the lifespan of Drosophila males, supporting a role for Nrf2 signaling in the regulation of longevity [21].…”

Peer Review #2 of "SMRT sequencing of the full-length transcriptome of the Rhynchophorus ferrugineus (Coleoptera: Curculionidae) (v0.1)"

“…For example, GATA and FoxA transcription factors play an important role in the differentiation and maintenance of different tissues by controlling gene expression (Boyle & Seaver, 2010;Zaret & Carroll, 2011). In some insects, AhR / ARNT may regulate the overexpression of multiple detoxification genes related to pesticide resistance (Hu et al, 2019). Transcription factor limpet has an impact on fungus-free insect survival, and these transcription factors have a direct effect on protecting Triatoma infestans from conditions of pathogenic pathogens, and these transcription factors are part of the primary immune response of other insects (Altincicek, Knorr & Vilcinskas, 2008;Jin et al, 2008;Mannino, Paixão & Pedrini, 2019).…”

Aryl hydrocarbon receptor regulates the expression of LmGSTd7 and is associated with chlorpyrifos susceptibility in Locusta migratoria

“…The AhR signaling pathway is responsible for the regulation of gossypol and spirotetramat tolerance‐related cytochrome P450 CYP6DA2 in Aphis gossypii Glover . AhR also regulates the expression of GST family genes that mediate resistance to cypermethrin and chlorpyrifos in Spodoptera exigua . The AhR downstream target enzymes, GST and NAD(P)H:quinone oxidoreductase 1 (NQO1), are also known to play key roles in cellular defense against reactive oxygen species.…”