Molecular cloning and functional characterization of the dopamine transporter from Eloria noyesi, a caterpillar pest of cocaine-rich coca plants
Chen R, Wu X, Wei H, Han DD, Gu HH.
Department of Pharmacology,
College of Medicine and Public Health,
The Ohio State University,
Columbus, OH 43210, United States.
Gene. 2005 Nov 23


Cocaine is produced by coca plants as a chemical defense to deter feeding by insects. It has been shown that cocaine sprayed on tomato leaves reduces insect feeding, causes abnormal behaviors at low doses and kills feeding insects at doses equivalent to that in coca leaves [Nathanson, J.A., Hunnicutt, E.J., Kantham, L., Scavone, C., 1993. Cocaine as a naturally occurring insecticide. Proc. Natl. Acad. Sci. U. S. A. 90, 9645-9648.]. Most insects avoid coca leaves except the larvae of Eloria noyesi, a caterpillar pest of coca plants, which feeds preferentially on coca leaves. In the current study, we cloned and characterized the dopamine transporters (DATs) from caterpillars of E. noyesi (enDAT) and the silkworm, Bombyx mori (B. mori, bmDAT). The two insect DATs shared 88% amino acid sequence homology and functional similarity. Although enDAT and bmDAT showed the highest affinity for dopamine among endogenous amines, they were more sensitive to mammalian NET-selective inhibitors than to mammalian DAT-selective inhibitors. Despite a high cocaine content in the food source for E. noyesi, cocaine sensitivity of enDAT was similar to that of bmDAT, suggesting that mechanisms other than DAT insensitivity to cocaine, such as cocaine sequestration, might be responsible for cocaine resistance in this species. Given the significant differences in pharmacological profile from mammalian DATs, invertebrate DATs provide excellent tools for identifying regions and residues in the transporters that contribute to high-affinity binding of psychostimulants and antidepressants.

Dopaminergic flies?
Dopaminergic agents
Cocaine immunization
The coke-craving brain
Cocaine and the lonely rat
Freebasing flies go hyperkinetic

01 02 03 04 05 06 07 08 09 10 11 12
13 14 15 16 17 18 19 20 21 22 23 24

Future Opioids
BLTC Research
Utopian Surgery?
Wirehead Hedonism
The Hedonistic Imperative
Ecstasy: Utopian Pharmacology
When Is It Best to Take Crack Cocaine?

swan image
The Good Drug Guide
The Responsible Parent's Guide To
Healthy Mood Boosters For All The Family