Presence of phospholipase C in coated vesicles from bovine brain. Dual regulatory effects of GTP-analogs.
Bovine brain coated vesicles display free calcium-dependent phospholipase C activity. Gpp(NH)p and GTP gamma S inhibited phospholipase C at nanomolar concentrations. Increasing concentrations of Gpp(NH)p and GTP gamma S reversed the inhibitory effects and stimulated phospholipase C activity. Preincubation of coated vesicles with pertussis toxin blocked the poorly-hydrolyzable GTP-analogs' inhibitory effects on phospholipase C. These data indicate that guanine nucleotides exert a dual regulatory control of phospholipase C in coated vesicles and that the inhibitory pathway is mediated by a pertussis toxin-sensitive G-protein.
Martin
M
M
Departamento de Inorgánica, Orgánica y Bioquímica, Facultad de Químicas, Universidad de Castilla-La Mancha, Ciudad Real, Spain.
Ros
M
M
González-Calero
G
G
Cubero
A
A
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D002462:Cell Membrane / Q000201:enzymology; D003034:Coated Pits, Cell-Membrane / Q000201:enzymology*; D019204:GTP-Binding Proteins / Q000502:physiology*; D006150:Guanine Nucleotides / Q000494:pharmacology*; D066298:In Vitro Techniques; D037342:Pertussis Toxin; D015398:Signal Transduction; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000502:physiology*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D006150:Guanine Nucleotides; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins