Characterization of a G protein-coupled guanylyl cyclase-B receptor from bovine tracheal smooth muscle.
A G protein-coupled natriuretic peptide-guanylyl cyclase receptor-B (NPR-B) located in plasma membranes from bovine tracheal smooth muscle shows complex kinetics and regulation. NPR-B was activated by natriuretic peptides (CNP-53 > ANP-28) at the ligand extracellular domain, stimulated by Gq-protein activators, such as mastoparan, and inhibited by Gi-sensitive chloride, interacting at the juxtamembrane domain. The kinase homology domain was evaluated by the ATP inhibition of Mn2+-activated NPR-B, which was partially reversed by mastoparan. The catalytic domain was studied by kinetics of Mn2+/Mg2+ and GTP, and the catalytic effect with GTP analogues with modifications of the /gamma phosphates and ribose moieties. Most NPR-B biochemical properties remained after detergent solubilization but the mastoparan activation and chloride inhibition of NPR-B disappeared. Our results indicate that NPR-B is a highly regulated nano-machinery with domains acting at cross-talk points with other signal transducing cascades initiated by G protein-coupled receptors and affected by intracellular ligands such as chloride, Mn2+, Mg2+, ATP, and GTP.
Alfonzo
Marcelo J
MJ
Sección de Biomembranas, Instituto de Medicina Experimental, Facultad de Medicina. Universidad Central de Venezuela, Caracas, Venezuela. hmag5@hotmail.com
de Aguilar
Esther Peña
EP
de Murillo
Alba Guevara
AG
de Villarroel
Sinaí Sánchez
SS
de Alfonzo
Ramona Gonzalez
RG
Borges
Adolfo
A
de Becemberg
Itala Lippo
IL
D000255:Adenosine Triphosphate / Q000737:chemistry / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D006162:Guanylate Cyclase / Q000737:chemistry*; D036341:Intercellular Signaling Peptides and Proteins; D008954:Models, Biological; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000378:metabolism*; D045265:Natriuretic Peptides / Q000737:chemistry; D010455:Peptides / Q000494:pharmacology; D017461:Receptors, Atrial Natriuretic Factor / Q000737:chemistry*; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D014132:Trachea / Q000378:metabolism*; D014862:Wasp Venoms / Q000494:pharmacology; D000099242:Atrial Natriuretic Factor Receptor B
D000255:Adenosine Triphosphate; D006162:Guanylate Cyclase; D036341:Intercellular Signaling Peptides and Proteins; D045265:Natriuretic Peptides; D010455:Peptides; D017461:Receptors, Atrial Natriuretic Factor; D043562:Receptors, G-Protein-Coupled; D014862:Wasp Venoms; D000099242:Atrial Natriuretic Factor Receptor B; C037500:mastoparan