A possible role for caveolin as a signaling organizer in olfactory sensory membranes.

Fast kinetics and sensitivity of olfactory signaling raise the question of whether the participating proteins may be associated in supramolecular transduction complexes. We found evidence that caveolin proteins could play an important role in organizing signaling elements in olfactory sensory neurons. Western blot analysis indicated that caveolins are highly enriched in olfactory sensory membranes, where they co-localize in detergent-insoluble complexes with key components of the signaling pathways. Furthermore, the results of immunoprecipitation experiments suggest that G proteins and effector enzyme form preassembled subcellular complexes with caveolins. Since anti-caveolin antibodies and synthetic peptides derived from the scaffolding domains of caveolin-1 and caveolin-2 effectively attenuated second messenger responses in sensory cilia preparations in a characteristic manner, the data led to the suggestion that caveolins could mediate the assembly of signaling complexes within specialized membrane microdomains of olfactory sensory neurons.