The effects of hydrostatic pressure on pertussis toxin-catalyzed ribosylation of G proteins from deep-living macrourid fishes.

摘要: Abstract To test the effects of hydrostatic pressure on coupling receptors to guanyl nucleotide binding reglatory proteins (G proteins) in transmembrane signaling, pertussis toxin (PTX)-catalyzed [ 32 P]ADP-ribosylation was used probe nucleotide-binding G i and o brain membranes from four marine teleosts. These macrourids, Coryphaenoides pectoralis , cinereus filifer armatus span depths 200 5400 m. Pertussis specifically labelled 39–41 kDa. The PTX-catalyzed reaction linear for 7 h. Added nucleotides (guanosine 5′-diphosphate (GDP) guanosine 5′- O -(3-thiotriphosphate)(GTP[S])) at concentrations up 1000 μM did not affect ribosylation atmospheric pressure. Under basal conditions /G protein population appears be uncoupled bound with GDP. Pressures 476 atm were tested absence presence added nucleotides, 100 GDP GTP[S]. deeper-occurring C. inhibited by increased Increasing decreased . In GTP[S], all species. Pressure enhance efficacy GTP[S] dissociating heterotrimeric holoprotein.