Molecular cloning of a lobster G alpha(q) protein expressed in neurons of olfactory organ and brain

Abstract

We have isolated from an American lobster (Homarus americanus) olfactory organ cDNA library a clone, hG alpha(q), with >80% identity to mammalian and arthropod G alpha(q) sequences. In brain and olfactory organ, hG alpha(q) mRNA was expressed predominantly in neurons, including virtually all the neuronal cell body clusters of the brain. G alpha(q) protein was also expressed broadly, appearing on western blots as a single band of 46 kDa in brain, eyestalk, pereiopod, dactyl, tail muscle, olfactory organ, and aesthetasc hairs. These results suggest that hG alpha(q) plays a role in a wide variety of signal transduction events. Its presence in the olfactory aesthetasc hairs, which are almost pure preparations of the outer dendrites of the olfactory receptor neurons, the expression of a single hG alpha(q) mRNA species (6 kb) in the olfactory organ, and the localization of hG alpha(q) mRNA predominantly in the olfactory receptor neurons of the olfactory organ strongly suggest that one function of hG alpha(q) is to mediate olfactory transduction.