Molecular basis for the behavioral effects of the odorant degrading enzyme Esterase 6 in Drosophila

Sci Rep. 2017 Apr 10:7:46188. doi: 10.1038/srep46188.

Abstract

Previous electrophysiological and behavioural studies implicate esterase 6 in the processing of the pheromone cis-vaccenyl acetate and various food odorants that affect aggregation and reproductive behaviours. Here we show esterase 6 has relatively high activity against many of the short-mid chain food esters, but negligible activity against cis-vaccenyl acetate. The crystal structure of esterase 6 confirms its substrate-binding site can accommodate many short-mid chain food esters but not cis-vaccenyl acetate. Immunohistochemical assays show esterase 6 is expressed in non-neuronal cells in the third antennal segment that could be accessory or epidermal cells surrounding numerous olfactory sensilla, including basiconics involved in food odorant detection. Esterase 6 is also produced in trichoid sensilla, but not in the same cell types as the cis-vaccenyl acetate binding protein LUSH. Our data support a model in which esterase 6 acts as a direct odorant degrading enzyme for many bioactive food esters, but not cis-vaccenyl acetate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arthropod Antennae / enzymology
  • Behavior, Animal / physiology*
  • Carboxylesterase / chemistry
  • Carboxylesterase / metabolism*
  • Catalytic Domain
  • Drosophila Proteins / chemistry
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / enzymology*
  • Drosophila melanogaster / physiology*
  • Kinetics
  • Models, Molecular
  • Odorants*
  • Receptors, Odorant / metabolism
  • Structural Homology, Protein
  • Substrate Specificity

Substances

  • Drosophila Proteins
  • Orco protein, Drosophila
  • Receptors, Odorant
  • Carboxylesterase
  • Est-6 protein, Drosophila