title: Muscarinic agonists acting through M2 acetylcholine receptors stimulate the migration of an NO-sensitive guanylyl cyclase to the plasma membrane of bovine tracheal smooth muscle.
abstract: Muscarinic agonists acting on bovine tracheal smooth muscle (BTSM) induce two separate cGMP signals, one at 20 sec associated with NO-sensitive-soluble-guanylyl-cyclase (NO-sGC) and another at 60 sec, linked to natriuretic-peptide-GC. The 20-sec-cGMP novel cascade starts with mAChRs, via unknown components, activates an NO-sGC. To unravel this cascade, in crude membranes isolated from intact BTSM strips exposed to muscarinic agonists, we detected GC activities increments at 20 sec and 60 sec. The 20-sec-GC is a NO-sensitive-GC, identified as alpha(1)beta(1)-heterodimer. In reconstitution experiments with purified plasma membranes and cytosol, muscarinic agonists induced an NO-sGC migration in a dose-dependent manner, being inhibited by muscarinic antagonists displaying an M(2)AChR profile and blocked by PTX, suggesting the involvement of G(o)/G(i) proteins. The NO-sGC related to migration was isolated and identified as an alpha(1)beta(1)-heterodimer. This work shows that muscarinic agonists in BTSM induce a massive and selective alpha(1)beta(1)-NO-sGC migration from cytoplasm to plasma membranes being responsible for the 20-sec-cGMP signal.
authors.affiliation: Sección de Biomembranas, Instituto de Medicina Experimental, Cátedra de Patología General y Fisiopatología, Escuela Luís Razetti, Facultad de Medicina. Universidad Central de Venezuela, Caracas, Venezuela.
authors.forename: Fabiola Pláceres
authors.initials: FP
authors.lastname: Uray
authors.forename: Ramona González
authors.initials: RG
authors.lastname: de Alfonzo
authors.forename: Itala Lippo
authors.initials: IL
authors.lastname: de Becemberg
authors.forename: Marcelo J
authors.initials: MJ
authors.lastname: Alfonzo
mesh_terms: D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000201:enzymology*; D000242:Cyclic AMP / Q000378:metabolism; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D006162:Guanylate Cyclase / Q000378:metabolism*; D015151:Immunoblotting; D018721:Muscarinic Agonists / Q000494:pharmacology*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000201:enzymology; D009569:Nitric Oxide / Q000378:metabolism*; D037342:Pertussis Toxin / Q000494:pharmacology; D043585:Receptor, Muscarinic M2 / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D000071756:Soluble Guanylyl Cyclase; D013347:Subcellular Fractions; D014132:Trachea / Q000187:drug effects* / Q000201:enzymology
chemical_list: D018721:Muscarinic Agonists; D043585:Receptor, Muscarinic M2; D018160:Receptors, Cytoplasmic and Nuclear; D043562:Receptors, G-Protein-Coupled; D009569:Nitric Oxide; D000242:Cyclic AMP; D037342:Pertussis Toxin; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase