Is acetyl/butyrylcholine specificity a marker for insecticide-resistance mutations in insect acetylcholinesterase ?

Substrate specificity has been widely studied in vertebrate cholinesterases and it has been shown that two phenylalanines in the acyl pocket of acetylcholinesterase govern the acceptance of the acetyl/butyryl moiety of the choline esters. As an insecticide-resistance mutation has been evidenced in the acyl pocket of Drosophila melanogaster and Musca domestica acetylcholinesterase we investigated the possibility of linking changes in acetyl/butyrylthiocholine specificity with mutations in insect acetylcholinesterase. We thus analyzed the effect of 28 mutations in Drosophila enzyme on acetyl/butyrylthiocholine, N-methyl/N-propyl-carbamates and ethyl/methyl-paraoxon preference. It appeared that the highest changes on acetyl/butyrylthiocholine and N-propyl/N-methyl-carbamates preference were due to mutations in the acyl pocket. Nevertheless, other insecticide-resistance mutations, not located in the acyl pocket, also modified these substrate preferences. Moreover, the effect of mutations in the acyl pocket was hidden when some other insecticide-resistance mutations were combined in the enzyme. Consequently, acetyl/butyrylthiocholine preference alteration cannot be used as a marker to localize a mutation in the insect AChE.

Bibliographic Details

Main Authors:	Villatte, F., Ziliani, Philippe, Estrada-Mondaca, Sandino, Menozzi, Philippe, Fournier, Didier
Format:	article biblioteca
Language:	eng
Subjects:	H10 - Ravageurs des plantes, résistance aux produits chimiques, insecticide, mutation, choline, Drosophila melanogaster, Musca domestica, acétylcholinestérase, http://aims.fao.org/aos/agrovoc/c_5736, http://aims.fao.org/aos/agrovoc/c_3887, http://aims.fao.org/aos/agrovoc/c_5014, http://aims.fao.org/aos/agrovoc/c_1585, http://aims.fao.org/aos/agrovoc/c_30543, http://aims.fao.org/aos/agrovoc/c_30566, http://aims.fao.org/aos/agrovoc/c_85,
Online Access:	http://agritrop.cirad.fr/486151/ http://agritrop.cirad.fr/486151/1/ID486151.pdf
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