Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Enhancement of endogenous kinase-dependent in vitro protein phosphorylation of subcellular fractions from brains and spinal cords of hens paralyzed 3 weeks after intoxication with tri-o-cresyl phosphate was correlated with the development of organophosphorus compound-induced delayed neurotoxicity (OPIDN). This was documented by showing: parallel dose-dependence curves for both responses, phosphorylation enhancement in proteins from hens treated with OPIDN-producing O-4-bromo-2,5-dichlorophenyl-O-methyl phenylphosphonothioates, but not in those treated with non-OPIDN-producing O,O-diethyl-O-4-nitrophenyl phosphorothioate or tri-p-cresyl phosphate, and shared age and species selectivities for both effects. These results strengthen our earlier observation of a close temporal relationship between protein phosphorylation enhancement and OPIDN. Further studies suggest that the proximate cause of the enhanced phosphorylation is not related to an alteration in protein phosphatase activity or to the preservation of a rate-limiting pool of [gamma-32P]ATP by adenosine triphosphatase inhibition. Therefore, it is most likely related either to altered protein kinase activity or amount (due to chemically originated physical disruption of the neuron). These data support the hypothesis that increased protein phosphorylation may be involved in the development of OPIDN.
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PMID:Relationship of tri-O-cresyl phosphate-induced delayed neurotoxicity to enhancement of in vitro phosphorylation of hen brain and spinal cord proteins. 377 11

Ca(2+)-mobilizing and cAMP-dependent hormones rapidly increase sodium, potassium-dependent adenosine triphosphatase (Na+/K(+)-ATPase)-mediated transport in rat hepatocytes. To explore the possible role of protein phosphatases in these responses we used a protein phosphatase inhibitor, okadaic acid. Okadaic acid stimulation of ouabain-sensitive 86Rb(+)-uptake was maximal between two and three minutes and displayed an EC50 of 41 +/- 1 nM. Inhibition of Na+/H+ exchange with an amiloride analog abolished the response to insulin, but had no effect on okadaic acid-mediated stimulation of Na+/K(+)-ATPase transport. In hepatocytes metabolically-radiolabeled with 32Pi, okadaic acid stimulated the incorporation of radioactivity into several 95 kDa peptides, one of which reacted with anti-LEAVE peptide antisera, that recognizes Na+/K(+)-ATPase alpha-subunits. In other experiments Na+/K(+)-ATPase was immunoprecipitated from detergent-solubilized membrane fractions of metabolically-radiolabeled cells with an antisera to purified rat kidney Na+/K(+)-ATPase. A 95 kDa phosphoprotein was immunoprecipitated using anti-Na+/K(+)-ATPase antisera, but not by preimmune serum. Okadaic acid stimulated incorporation of radioactivity into this band by 220 +/- 28%. These findings provide support for the hypothesis that rapid stimulation of hepatic Na+/K(+)-ATPase by hormones may be related to protein kinase/phosphatase-mediated changes in the phosphorylation state of the Na+/K(+)-ATPase alpha-subunit.
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PMID:Okadaic acid stimulates ouabain-sensitive 86Rb(+)-uptake and phosphorylation of the Na+/K(+)-ATPase alpha-subunit in rat hepatocytes. 798 91