Heteromeric Anopheline odorant receptors exhibit distinct channel properties

PLoS One. 2011;6(12):e28774. doi: 10.1371/journal.pone.0028774. Epub 2011 Dec 9.


Background: Insect odorant receptors (ORs) function as odorant-gated ion channels consisting of a conventional, odorant-binding OR and the Orco coreceptor. While Orco can function as a homomeric ion channel, the role(s) of the conventional OR in heteromeric OR complexes has largely focused only on odorant recognition.

Results: To investigate other roles of odorant-binding ORs, we have employed patch clamp electrophysiology to investigate the properties of the channel pore of several OR complexes formed by a range of different odorant-specific Anopheles gambiae ORs (AgOrs) each paired with AgOrco. These studies reveal significant differences in cation permeability and ruthenium red susceptibility among different AgOr complexes.

Conclusions: With observable differences in channel function, the data support a model in which the odorant-binding OR also affects the channel pore. The variable effect contributed by the conventional OR on the conductive properties of odorant-gated sensory channels adds additional complexity to insect olfactory signaling, with differences in odor coding beginning with ORs on the periphery of the olfactory system.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Anopheles / metabolism*
  • Cations, Divalent / metabolism
  • Cations, Monovalent / metabolism
  • Cell Line
  • Ion Channels / metabolism*
  • Odorants
  • Permeability
  • Protein Multimerization*
  • Receptors, Odorant / agonists
  • Receptors, Odorant / metabolism*
  • Ruthenium Red / metabolism


  • Cations, Divalent
  • Cations, Monovalent
  • Ion Channels
  • Receptors, Odorant
  • Ruthenium Red