Evidence that a Gq-protein mediates excitatory odor transduction in lobster olfactory receptor neurons.
Non-hydrolysable analogs of GTP and GDP alter odor-evoked inward and outward currents in voltage-clamped cultured lobster olfactory receptor neurons. Currents of both polarities are pertussis and cholera toxin-insensitive. Antibodies directed against the alpha subunits of G(olf), G(o), G11, an internal Gq sequence, the common carboxyl terminal sequence of Gq and G11 (anti-Gq/11), and the transducin beta subunit, fail to perturb the outward current, but anti-G(o) and anti-Gq/11 selectively block the inward current. Anti-Gq/11 immunolabels a band of approximately 45 kDa by Western blot analysis, but the anti-G(o) immunolabeling is non-specific. These results suggest that the excitatory olfactory signalling pathway that leads to an odor-evoked inward current may be coupled via a member of the Gq family, while the odor-evoked outward current is transduced by a different G protein.
Fadool
D A
DA
Whitney Laboratory, University of Florida, St Augustine 32086, USA.
Estey
S J
SJ
Ache
B W
BW
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D046508:Culture Techniques; D003712:Dendrites / Q000378:metabolism / Q000502:physiology; D004591:Electrophoresis, Polyacrylamide Gel; D004594:Electrophysiology; D019204:GTP-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D008969:Molecular Sequence Data; D008121:Nephropidae / Q000502:physiology*; D018034:Olfactory Receptor Neurons / Q000378:metabolism / Q000502:physiology*; D018408:Patch-Clamp Techniques; D012679:Sense Organs / Q000166:cytology; D015398:Signal Transduction / Q000502:physiology*; D012903:Smell / Q000502:physiology*
D019204:GTP-Binding Proteins