Spatially restricted expression of regulators of G-protein signaling in primary olfactory neurons.

The intracellular signal transduction machinery of heterotrimeric G-protein coupled odorant and putative pheromone receptors converts odorous information into a cellular response. We have investigated for the presence of 18 members of the family termed "regulators of G-protein signaling" (RGS) in primary olfactory sensory neurons of the main as well as the accessory (vomeronasal) system of the mouse. Unexpectedly, expression of a few RGS members show spatial restrictions correlating with the patterns described for G-protein coupled receptors in these two types of olfactory neurons. RGS3 was selectively coexpressed with the Galphai2 G-protein subunit in a subpopulation of vomeronasal neurons. The mutually exclusive spatial extents of RGS9 and RGSZ1 expression in main olfactory neurons corresponded precisely to that of certain odorant receptor zones. This renders these RGS members the first described intracellular signal transduction components with a potential role in the spatially organized sensory coding in the main olfactory system.