title: GTP-binding proteins Gi and Go transplanted onto Xenopus oocyte by rat brain messenger RNA.
abstract: After injection with messenger RNA (mRNA) isolated from rat brain, Xenopus laevis oocytes acquired electrophysiological responsiveness to externally perfused acetylcholine (ACh) or serotonin (5-HT), and elevated responsiveness to internally applied guanosine 5'-(3-O-thio)triphosphate (GTP gamma S). Compared with the membranes of native oocytes, those of mRNA-injected oocytes contained increased amounts of 39 and 41 kDa proteins, which could be [32P]ADP-ribosylated by pertussis toxin (PTX). The amplitude of the GTP gamma S response and the amounts of the 39 and 41 kDa proteins increased in a parallel manner for at least 3 days following mRNA injection. Current responses to internally applied GTP gamma S showed properties common to those of responses to ACh or 5-HT perfusion: both responses had reversal potentials close to the Cl- potential, were mimicked by intracellular injection of IP3, desensitized by a large dose of IP3, and inhibited by a simultaneous injection of neomycin or EGTA. Incubation of mRNA-injected cells with PTX inhibited both the 5-HT response and the [32P]ADP-ribosylation of the 39 and 41 kDa proteins in a parallel, dose-dependent manner. After pretreatment of oocytes with PTX followed by mRNA injection, the levels of the 39 and kDa proteins and the 5-HT response appeared to be similar to those of non-treated cells injected with mRNA, whereas no detectable amounts of these proteins were induced when PTX-pretreated cells were analyzed under the same conditions without mRNA injection.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D007267:Injections; D009865:Oocytes / Q000378:metabolism*; D037342:Pertussis Toxin; D010758:Phosphorus / Q000037:antagonists & inhibitors / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats / Q000235:genetics* / Q000378:metabolism; D011919:Rats, Inbred Strains; D013873:Thionucleotides / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D014982:Xenopus laevis / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D013873:Thionucleotides; D010566:Virulence Factors, Bordetella; D010758:Phosphorus; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins