Involvement of G(q/11) in signal transduction in the mammalian vomeronasal organ.
Social behaviors of most mammals are profoundly affected by pheromones. Pheromones are detected by G-protein coupled receptors in the vomeronasal organ (VNO). To investigate the role of G alpha(q/11) in vomeronasal signal transduction pathways, microvillar membranes from murine VNO were prepared. Incubation of such membranes from prepubertal females with adult male urine results in an increase in production of inositol-(1,4,5)-trisphosphate (IP(3)). This stimulation is mimicked by GTP gamma S, blocked by GDP beta S and is tissue specific. Furthermore, use of bacterial toxins such as pertussis that lead to ADP-ribosylation of the G-protein alpha subunits of G(o) and G(i2) do not block the increase in IP(3) levels but U-73122, a PLC inhibitor, blocks the production of IP(3). Studies with monospecific antibodies revealed the presence of three G-proteins, G alpha(o), G alpha(i2) and G alpha(q/11)-related protein, in vomeronasal neurons, concentrated on their microvilli. Our observations indicate that pheromones in male urine act on vomeronasal neurons in the female VNO via a receptor-mediated, G alpha(q/11)-protein-dependent increase in IP(3) levels.
Wekesa
Kennedy S
KS
Alabama State University, Biomedical Research and Training Programs, Montgomery, AL 36104-0271, USA. kwekesa@asunset.alasu.edu
Miller
Stephanie
S
Napier
Audrey
A
D000818:Animals; D015153:Blotting, Western; D004963:Estrenes / Q000494:pharmacology; D005260:Female; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000096:biosynthesis; D008297:Male; D051379:Mice; D037342:Pertussis Toxin / Q000378:metabolism; D010675:Pheromones / Q000378:metabolism; D011760:Pyrrolidinones / Q000494:pharmacology; D015398:Signal Transduction; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors; D014556:Urine / Q000502:physiology; D019147:Vomeronasal Organ / Q000378:metabolism*
D004963:Estrenes; D010675:Pheromones; D011760:Pyrrolidinones; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D015544:Inositol 1,4,5-Trisphosphate; D037342:Pertussis Toxin; D010738:Type C Phospholipases; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020962:Heterotrimeric GTP-Binding Proteins