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)

The Ca2+-sensitive ATPase (adenosine triphosphatase) of human erythrocyte membranes is activated, not only by Ca2+ ions, but also by a series of other bivalent metal ions including Sr2+, Ba2+, Mn2+, Ni2+, Co2+, Cd2+, Cu2+, Zn2+ and Pb2+. The degree of activation is dependent on the radius of the ion rather than on its nature, in contrast with the dissociation constant of the enzyme--metal ion complex.
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PMID:Activation of membrane-bound high-affinity calcium ion-sensitive adenosine triphosphatase of human erythrocytes by bivalent metal ions. 12 84

The proteins of sarcoplasmic reticulum were cross-linked by rapid oxidation of thiol groups with I2. About two-thirds of the thiols were oxidized without any significant cross-linking, implying an extensive formation of intramolecular disulphide bonds. When the thiols were completely oxidized at room temperature a series of oligomers containing up to five molecules were observed, as well as large aggregates which were excluded from the gels. Complete oxidation at -10 degrees C left most of the ATPase (adenosine triphosphatase) as monomer. Similar results were obtained when copper-phenanthroline complexes or dimethyl suberimidate were used as cross-linking reagents. We conclude that most of the cross-linked species arise by linking of randomly colliding ATPase molecules which are present in the membrane at very high concentration.
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PMID:Cross-linking experiments with the adenosine triphosphatase of sarcoplasmic reticulum. 15 36

1. The origin of the limiting membranes of autophagic vacuoles (AVs) in mouse pancreatic acinar cells was studied in vinblastine-induced autophagocytosis. 2. The marker enzymes used were adenosine triphosphatase, lipase, inosine diphosphatase and thiamine pyrophosphatase. The following impregnation techniques were used: unbuffered osmium tetroxide impregnation, imidazole-buffered osmium tetroxide impregnation and uranyl-lead-copper impregnation. 3. Only a weak lipase activity was observed between the limiting membranes of a few AVs. The AV membranes were stained heavily with all impregnation techniques used. 4. The origin of AV membranes seems to be same in mouse liver and exocrine pancreas in vinblastine-induced autophagocytosis.
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PMID:Cytochemical studies on induced autophagocytosis in mouse exocrine pancreas. 245 89

The effect of regucalcin, a calcium-binding protein isolated from rat liver cytosol, on Ca2+-adenosine triphosphatase (ATPase) activity in hepatic microsomes was investigated. Mg2+-ATPase activity was clearly increased by the presence of 50 microM Ca2+. Regucalcin (1.0-4.0 microM) caused a remarkable elevation (about 3-fold) of Ca2+-ATPase activity. Also, Mg2+-ATPase activity was increased (about 1.6-fold) by the presence of regucalcin (2.0 and 4.0 microM). Guanosine-5'-O-(3-thiotriphosphate) (GTPrs; 10(-5) and 10(-4) M) and nicotinamide adenine dinucleotide phosphate oxidized form (NADP+; 10(-5) to 10(-3) M) or reduced form (NADPH; 10(-4) and 10(-3) M) significantly increased Ca2+-ATPase activity. These increases were not enhanced by the presence of regucalcin (2.0 microM). Of various metal ions, a comparatively low concentration of V5+ (10(-5) M) or Cd2+ (10(-6) M) significantly increased Ca2+-ATPase activity, while Hg2+, Zn2+, Cu2+ and Mn2+ did not have such an effect. Regucalcin (2.0 microM) did not enhance the effect of V5+ and Cd2+ on Ca2+-ATPase activity. The present finding, that regucalcin activates hepatic microsomal Ca2+-ATPase, suggests a cell physiological role of regucalcin as an activator in the microsomal Ca2+-pump activity. This action of regucalcin may not be influenced by other regulators.
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PMID:Activation of hepatic microsomal Ca2+-adenosine triphosphatase by calcium-binding protein regucalcin. 252 22

Quercetin is a naturally occurring flavonoid, chemically related to cromolyn. Quercetin has been shown to inhibit antigen- and mitogen-induced histamine release from rat mast cells and basophils of subjects with hay fever, to increase cyclic adenosine monophosphate (AMP) in Ehrlich ascites tumor cells and to inhibit phosphodiesterase and certain adenosine triphosphatase (ATPase) systems. We have studied the effect of quercetin on mouse T cell responses. When 5 x 10(-6) to 5 x 10(-5) M quercetin is present throughout either allogeneic mixed leukocyte culture (MLC) or cytotoxic T lymphocyte (CTL) assay culture, inhibition of in vitro CTL generation or effector function results, respectively (inhibition is 75-100% at 2 x 10(-5) M and 100% at 5 x 10(-5) M). Quercetin also inhibits concanavalin A-induced DNA synthesis. Addition of Cu2+ strongly blocks the effects of quercetin in all systems tested, in a concentration dependent fashion, while Mg2+ and Ca2+ have little or no effect and Mn2+ and Co2+ have a significant but slight blocking effect on quercetin-mediated inhibition of both CTL generation and function. In kinetic studies, evidence was obtained for the existence of a major quercetin-sensitive step in CTL induction, between 3 and 24 hr of the MLC.
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PMID:Quercetin inhibition of the induction and function of cytotoxic T lymphocytes. 621 17

In previous studies we had demonstrated that in the presence of 0.25 mM Cu2+ and 1.25 mM o-phenanthroline, cross-linking of the alpha-subunits of Na+ + K+)-dependent adenosine triphosphatase was induced by the addition of Na+ + ATP, and that the formation of the alpha,alpha-dimer was preceded by that of phosphoenzyme. The purpose of the present studies was the further evaluation of the role of phosphoenzyme in the process of cross-linking. Na+ + UTP did not induce cross-linking unless Mg2+ was also added. In contrast, Na+ + ATP-induced cross-linking did not require the addition of Mg2+. The different effects of ATP and UTP in the absence of added Mg2+ could be accounted for by the presence in the enzyme preparation of bound Mg2+ which supported enzyme phosphorylation by ATP but not by UTP. When the enzyme was phosphorylated by Pi, in the presence of Mg2 and ouabain, and the exposed to Cu2+ and o-phenanthroline, the alpha,alpha-dimer was obtained. Under these conditions, Na+ blocked both phosphorylation and cross-linking. These results indicate that it is the formation of phosphoenzyme per se that leads to conformational transitions favorable to cross-linking. They also suggest that Cu2+ and o-phenanthroline participate in the cross-linking reaction, but not in the phosphorylation reactions. In the digitonin-treated enzyme, Na+ and ATP induced the formation of phosphoenzyme, but not that of alpha,alpha-dimer. These findings indicate that in addition to phosphorylation, a proper orientation o alpha-subunits in an oligomer is also necessary for cross-linking.
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PMID:(Na+ + K+)-ATPase : phosphorylation-dependent cross-linking of the alpha-subunits in the presence of Ca2+ and o-phenanthroline. 626 75

Rats were coexposed to lead (Pb) and Copper (Cu) through drinking water and intraperitoneally, respectively, for a period of 21 days. Neurochemical studies in these rats showed significant reduction in the activity of adenosine triphosphatase, cytochrome-c-oxidase, diaphorase and in the levels of biogenic amines in the rats simultaneously exposed to the two metals compared to either of the metal alone. These neurotoxic effects were not related to the contents of either of the metals in the brain since their accumulation after combined exposure was much less than observed after individual exposure to Pb or Cu.
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PMID:Neurochemical changes in rats coexposed to lead and copper. 628 90

The CtpA protein from pathogenic Listeria monocytogenes, is a P-type adenosine triphosphatase involved in copper homeostasis. To establish a role in pathogenicity for CtpA, a mutant strain was constructed by insertion of an antibiotic resistance cartridge into the ctpA gene. This mutant was then compared to the wild-type in tissue culture invasion assays and mouse infection studies. Mutants in CtpA, were unaltered for intracellular growth in J774 and HeLa cell lines. However, recovery of mutants from tissue of infected mice was dramatically reduced compared with the wild-type, and a significant impairment in terms of in vivo persistence in mixed-infection competition experiments was observed. These results demonstrate the significance of CtpA in establishing an in vivo infection by L. monocytogenes, and highlight some inadequacies of in vitro tissue culture monolayer assays for determining invasion and intracellular growth of a pathogen.
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PMID:Mutants in the CtpA copper transporting P-type ATPase reduce virulence of Listeria monocytogenes. 904 96

Wilson's disease is a rare autosomal recessive inherited disorder of copper metabolism. Hepatic excretion of copper is impaired due to mutation of the gene for a copper-transporting adenosine triphosphatase, ATP7B. Copper accumulation in liver, brain, and other tissues may cause a wide spectrum of hepatic, neuropsychiatric, and other clinical manifestations. The diagnosis may be supported by measurement of serum ceruloplasmin, urinary copper excretion, and hepatic copper content as well as by detection of Kayser-Fleischer rings. Several treatments are available to increase urinary excretion and decrease intestinal absorption of copper.
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PMID:Wilson's disease: copper unfettered. 1040 26

An isoleucine/valine polymorphism was observed at codon 1464 of the ATP7A gene, which is thought to encode a copper transporting adenosine triphosphatase (ATPase). The frequency of Val1464 was estimated to be 5.7% in the Japanese population. This polymorphism may be useful in genetic studies of Menkes disease.
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PMID:An Ile/Val polymorphism at codon 1464 of the ATP7A gene. 1057 Sep 20


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