The insect repellent DEET (N,N-diethyl-3-methylbenzamide) increases the synthesis of glutathione S-transferase in cultured mosquito cells.
DEET (N,N-diethyl-3-methylbenzamide) is the active ingredient used in many commonly used insect repellents, but its mode of action remains poorly understood. Efforts to identify properties that could lead to the development of more effective active ingredients have distinguished among DEET's repellent, deterrent, and insecticidal activities. We used an Aedes albopictus mosquito cell line to evaluate DEET's toxicological properties in the absence of sensory input mediated by the olfactory system. When cells were treated with DEET and labeled with [(35)S]methionine/cysteine, a single 25-kDa protein was induced, relative to other proteins, on SDS-polyacrylamide gels. The 25-kDa band from DEET-treated cells was enriched in peptides corresponding to glutathione S-transferase D10 and/or theta in the Aedes aegypti genome. Consistent with the increased expression of the labeled protein, DEET-treated cells had increased glutathione S-transferase activity, and the radiolabeled band bound to Sepharose 4B containing reduced glutathione. By analyzing partial tryptic digests, we established that DEET induces the homolog of A. aegypti glutathione S-transferase, class theta, corresponding to protein XP_001658009.1 in the NCBI database. This specific effect of DEET at the subcellular level suggests that DEET induces physiological responses that extend beyond recognition by the peripheral olfactory system.
Department of Entomology, University of Minnesota, 1980 Folwell Ave., St. Paul, MN 55108, USA.
Vanessa J
VJ
Hellestad
Bruce A
BA
Witthuhn
Ann M
AM
Fallon
D000595:Amino Acid Sequence; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D009033:Culicidae / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D003671:DEET / Q000633:toxicity*; D004591:Electrophoresis, Polyacrylamide Gel; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000096:biosynthesis* / Q000737:chemistry; D007302:Insect Repellents / Q000633:toxicity*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D014176:Protein Biosynthesis / Q000187:drug effects*; D012685:Sepharose; D016415:Sequence Alignment
D007302:Insect Repellents; D003671:DEET; D012685:Sepharose; D005982:Glutathione Transferase; D005978:Glutathione