VOMEROMODULIN, A PUTATIVE PHEROMONE TRANSPORTER - CLONING, CHARACTERIZATION, AND CELLULAR-LOCALIZATION OF A NOVEL GLYCOPROTEIN OF LATERAL NASAL GLAND

Vomeromodulin, a novel glycoprotein of lateral nasal gland, has been cloned by differential hybridization from nasal/olfactory tissue. The 2.2-kb mRNA directs the in vitro synthesis of a 60-kDa primary translation product in reticulocyte lysates. Differential sensitivity to endoglycosidases indicates that vomeromodulin is posttranslationally modified in vivo by N-glycosylation to form a 70-kDa glycoprotein of the complex type. Immunocytochemical localization with two different antipeptide antisera demonstrates that vomeromodulin is abundant in the lateral nasal glands and is also present in the posterior septal and vomeronasal glands. Most striking is the observation that it is highly concentrated in the mucus of the vomeronasal organ of Jacobson but is not detectable in the mucus of the main olfactory neuroepithelium. Evaluation of mRNA and protein distribution by Northern and Western analyses, respectively, indicates that vomeromodulin is absent from 15 other tissues. The glandular and mucosal distribution of this glycoprotein implies a transport function that may be related to the mechanisms by which pheromones of low volatility gain access to their receptors in the vomeronasal organ. These observations support our hypothesis that vomeromodulin participates in perireceptor events that facilitate the process of pheromone access and detection.