Attenuation of the production of inositol 1,4,5-trisphosphate in the mouse vomeronasal organ by antibodies against the αq/11 subfamily of G-proteins

Abstract

The social and reproductive behaviors of most mammals are modulated by pheromones, which are perceived by the vomeronasal organ (VNO). Vomeronasal transduction in vertebrates is activated through G-protein-coupled receptors, which in turn leads to the generation of inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) by the activity of phospholipase C. DAG has been shown to gate the transient receptor potential channel 2, whereas IP3 may play a role in stimulating the release of calcium from the endoplasmic reticulum store. To investigate the role of the alpha subunits of Gq/11 in the transduction process, microvillar membranes from female mice VNO were preincubated with a selective C-terminal peptide antibody against Gαq/11 and then stimulated with adult male urine. Incubation of VNO membranes with antibodies against Gαq/11 blocked the production of IP3 in a dose-dependent manner. We were also able to impair the production of IP3 when we stimulated with 2-heptanone or 2,5-dimethylpyrazine in the presence of antibodies against the alpha subunit of Gq/11. 2-Heptanone is a known pheromone that has been linked to VIR receptors. Thus, our observations indicate that the alpha subunits of Gq/11 play a role in pheromonal signaling in the VNO. © 2006 Oxford University Press.