Disabling Gβγ SNARE interaction in transgenic mice disrupts GPCR-mediated presynaptic inhibition leading to physiological and behavioral phenotypes.
Gi/o-coupled G-protein coupled receptors modulate neurotransmission presynaptically through inhibition of exocytosis. Release of G{beta}{gamma} subunits decreases the activity of voltage-gated calcium channels (VGCC), decreasing excitability. A less understood G{beta}{gamma}-mediated mechanism downstream of calcium entry is the binding of G{beta}{gamma} to SNARE complexes. Here, we create a mouse partially deficient in this interaction. SNAP25{Delta}3 homozygote animals are developmentally normalbut impaired gait and supraspinal nociception. They also have elevated stress-induced hyperthermia and impaired inhibitory postsynaptic responses to 2A-AR, but normal inhibitory postsynaptic responses to Gi/o-coupled GABAB receptor activation. SNAP25{Delta}3 homozygotes have deficits in inhibition of hippocampal postsynaptic responses to 5 HT1b agonists that affect hippocampal learning. These data suggest that Gi/o-coupled GPCR inhibition of exocytosis through the G{beta}{gamma}-SNARE interaction is a crucial component of numerous physiological and behavioral processes.