Attenuation of the Production of Inositol 1,4,5-Trisphosphate in the Mouse Vomeronasal Organ by Antibodies Against the α_q/11 Subfamily of G-Proteins

摘要

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 G_q/11 in the transduction process, microvillar membranes from female mice VNO were preincubated with a selective C-terminal peptide antibody against Gα_q/11 and then stimulated with adult male urine. Incubation of VNO membranes with antibodies against Gα_q/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 G_q/11. 2-Heptanone is a known pheromone that has been linked to VIR receptors. Thus, our observations indicate that the alpha subunits of G_q/11 play a role in pheromonal signaling in the VNO.