[Identification and isolation of GTP-binding regulator protein from plasma membranes of oocytes from the starfish Asterias amurensis].
A method for isolating a GTP-binding regulatory protein from starfish oocytes is described. The protein consists of three subunits with molecular weights of 40, 37, and about 8 kDa. It is shown that the 40-kDa subunit has a high GTPase activity and is susceptible to ADP-ribosylation by pertussis toxin. The latter property of this subunit proved to decrease upon its incubation with nonhydrolyzable GTP analogues. These data provide evidence that the plasma membrane of starfish oocytes contains a 40-kDa GTP-binding protein with properties characteristic of the alpha subunit of the inhibitory Gi protein. The role of this protein in the transmembrane signal transmission from the 1-methyladenine receptor to intracellular effectors is discussed.
Lamash
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Institute of Marine Biology, Far East Division, Russian Academy of Sciences, ul. Pal'chevskogo 17, Vladivostok, 690041 Russia.
D000244:Adenosine Diphosphate / Q000737:chemistry; D000818:Animals; D002462:Cell Membrane / Q000737:chemistry; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification*; D008970:Molecular Weight; D009865:Oocytes / Q000737:chemistry* / Q000648:ultrastructure; D037342:Pertussis Toxin; D013215:Starfish / Q000737:chemistry* / Q000166:cytology; D010566:Virulence Factors, Bordetella / Q000737:chemistry
D008565:Membrane Proteins; D010566:Virulence Factors, Bordetella; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D000244:Adenosine Diphosphate; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins