G protein signaling (in phagocytes) Signal amplification GEF Downstream effectors Ga-GDP GaGTP PLC-B PI-3 kinase Sre GAP MAPK Ca2 Signal integration CAMP Nuclear Membrane Small Cytoskeleton Phoaphatase translocation Phosphorylation translocation GTPase reorganization Suppression NF-xB,AP-1 NADPH Granule Cell shape change oxidase release Adhesion Cytokine production Bacterial killing Chemotaxis Binding of one ligand to two receptors Ligand-gated ion (Na)channel found in autonomic ganglions,adrenal medulla. neuromuscular junction. Binds both acetylcholine and nicotine Pentameric receptor comprised of 4 different subunits:a(2),B,y,8 M2 G protein-coupled receptor with typical "cardiac" 7-membrane span structure The acetylcholine effect is mimicked by muscarine M1 and M3 couple to Gaq:M2 couples to Gai GiG protein signaling (in phagocytes) Gα•GDP GAP GEF Gα•GTP βγ βγ Pi Downstream effectors PLC-β PI-3 kinase Src MAPK Ca2+ Signal amplification Signal integration Small GTPase Cytoskeleton reorganization Membrane translocation cAMP Phoaphatase Phosphorylation Nuclear translocation Cell shape change Chemotaxis Adhesion Cytokine production Bacterial killing NF-κB, AP-1 Granule release NADPH oxidase Suppression • G protein-coupled receptor with typical 7-membrane span structure • The acetylcholine effect is mimicked by muscarine • M1 and M3 couple to Gαq; M2 couples to Gαi M2 “cardiac” Gi • Ligand-gated ion (Na+) channel found in autonomic ganglions, adrenal medulla, neuromuscular junction. • Binds both acetylcholine and nicotine • Pentameric receptor comprised of 4 different subunits: α(2), β, γ, δ Binding of one ligand to two receptors