Coupling of adenosine A1 receptors to a G-protein in coated vesicles isolated from bovine brain: presence of pertussis and cholera toxin substrates.
Adenosine A1 receptors have been described in coated vesicles isolated from bovine brain (Gonzalez-Calero et al., J. Neurochem. 1990, 55, 106-113). Addition of non hydrolyzable GTP analogue (guanyl-5-yl-imidodiphosphate) caused a transition of the receptor from the high- to the low-affinity state, without any significant change in the total binding sites. The presence of G-proteins has been investigated by pertussis and cholera toxins catalyzed ADP-ribosylation. A band of Mr = 41,000 D, similar to the alpha Gi subunit, was specifically labeled in the presence of preactivated pertussis toxin. Bands of Mr = 42,000 D and Mr = 47,000 D were specifically labeled in the presence of preactivated cholera toxin. These results confirm the presence of GTP binding proteins (alpha Gi and alpha Gs) in coated vesicles isolated from bovine brain.
Ros
M
M
Departamento de Química, Facultad de Químicas, Universidad de Castilla-La Mancha, Spain.
Gonzalez-Calero
G
G
Martín
M
M
Cubero
A
A
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002417:Cattle; D002772:Cholera Toxin / Q000378:metabolism*; D003034:Coated Pits, Cell-Membrane / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007700:Kinetics; D009243:NAD / Q000378:metabolism; D037342:Pertussis Toxin; D011983:Receptors, Purinergic / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D012265:Ribonucleotides / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000378:metabolism*
D011983:Receptors, Purinergic; D012265:Ribonucleotides; D010566:Virulence Factors, Bordetella; D009243:NAD; D006165:Guanylyl Imidodiphosphate; D002772:Cholera Toxin; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins