Functional analysis of a mammalian odorant receptor subfamily

J Neurochem. 2006 Jun;97(5):1506-18. doi: 10.1111/j.1471-4159.2006.03859.x. Epub 2006 Apr 5.


Phylogenetic analysis groups mammalian odorant receptors into two broad classes and numerous subfamilies. These subfamilies are proposed to reflect functional organization. Testing this idea requires an assay allowing detailed functional characterization of odorant receptors. Here we show that a variety of Class I and Class II mouse odorant receptors can be functionally expressed in Xenopus laevis oocytes. Receptor constructs included the N-terminal 20 residues of human rhodopsin and were co-expressed with Galphaolf and the cystic fibrosis transmembrane regulator to allow electrophysiological measurement of receptor responses. For most mouse odorant receptors tested, these conditions were sufficient for functional expression. Co-expression of accessory proteins was required to allow functional surface expression of some mouse odorant receptors. We used this assay to examine the receptive ranges of all members of the mouse odorant receptor 42 (MOR42) subfamily. MOR42-1 responded to dicarboxylic acids, preferring a 10-12 carbon chain length. MOR42-2 responded to monocarboxylic acids (7-10 carbons). MOR42-3 responded to dicarboxylic acids (8-10 carbons) and monocarboxylic acids (10-12 carbons). Thus, the receptive range of each receptor was unique. However, overlap between the individual receptive ranges suggests that the members of this subfamily form one contiguous subfamily receptive range, suggesting that odorant receptor subfamilies do constitute functional units.

Publication types

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

MeSH terms

  • Animals
  • Biological Assay / methods
  • Cell Membrane / drug effects
  • Cell Membrane / genetics
  • Cell Membrane / metabolism*
  • Cystic Fibrosis Transmembrane Conductance Regulator / drug effects
  • Cystic Fibrosis Transmembrane Conductance Regulator / genetics
  • Cystic Fibrosis Transmembrane Conductance Regulator / metabolism
  • Dicarboxylic Acids / chemistry
  • Dicarboxylic Acids / pharmacology
  • Female
  • Gene Expression / physiology*
  • Mammals / genetics
  • Mammals / metabolism*
  • Membrane Potentials / drug effects
  • Membrane Potentials / genetics
  • Mice
  • Molecular Structure
  • Molecular Weight
  • Multigene Family
  • Oocytes
  • Patch-Clamp Techniques
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Messenger / pharmacology
  • Receptors, G-Protein-Coupled / drug effects
  • Receptors, G-Protein-Coupled / genetics
  • Receptors, G-Protein-Coupled / metabolism
  • Receptors, Odorant / drug effects
  • Receptors, Odorant / genetics
  • Receptors, Odorant / physiology*
  • Smell / drug effects
  • Smell / genetics*
  • Transfection / methods
  • Xenopus laevis


  • Dicarboxylic Acids
  • RNA, Messenger
  • Receptors, G-Protein-Coupled
  • Receptors, Odorant
  • Cystic Fibrosis Transmembrane Conductance Regulator