Physiological and pharmacological evidence for odor stimulated phosphatidylinositol
3-kinase in lobster olfactory receptor cells.
Zhainazarov, Asylbek B., Richard Doolin, John-David Herlih and Barry W. Ache.
1Whitney Laboratory, University of Florida, St. Augustine, FL 32086; Departments
of 2Zoology and 3Neuroscience, and 4Center for Smell and Taste, University of Florida,
Gainesville, FL 32610
APStracts 8:0126J, 2001.
Two antagonists of phosphoinositide 3-OH kinases (PI3Ks), LY294002 and Wortmannin,
reduced the magnitude of the receptor potential in lobster olfactory receptor neurons
(ORNs) recorded by patch-clamping the cells in vivo. An antibody directed against the
c-terminus of human PI3K-P110ß detected a molecule of predicted size in the outer
dendrites of the ORNs. Two 3-phosphoinositides, PI(3,4)P2 (1-4 ?M) and PI(3,4,5)P3
(1-4 µM) applied to the cytoplasmic side of inside-out patches taken from cultured
lobster ORNs reversibly activated a Na+-gated channel previously implicated in the
transduction cascade in these cells. 3-phosphoinositides were the most effective
phosphoinositide (1 ?M) in enhancing the open probability of the channel. Collectively,
these results implicate 3-phosphoinositides in lobster olfactory transduction, and raise the
need to consider the 3-phosphoinositide pathway in olfactory transduction.
Received 27 November 2000; accepted in final form 14 March 2001
APS Manuscript Number J847-0.
Article publication pending Am J Physiol
ISSN 1080-4757 Copyright 2001 The American Physiological Society.
Published in APStracts on 14 May 2001