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)

Proximal convoluted tubules were dissected from rabbit kidneys and perfused in vitro in order to determine the effect of monovalent ions on fluid absorption and transepithelial voltage. Replacement of sodium in the perfusate and bath by lithium, tetramethyl ammonium or choline caused the rate of fluid absorption and voltage to fall to near zero. Replacement of potassium in the bath by sodium had the identical effect. Replacement of chloride by nitrate or perchlorate had comparatively little effect. The results are consistent with the generally held view that active sodium transport (mediated by a Na- and K- activated adenosine triphosphatase) is the primary process responsible for the absorption of the fluid and the voltage. Replacement of bicarbonate in the perfusate and bath by chloride caused the rate of fluid absorption to decrease by 33%. The possible relation between sodium transport and bicarbonate is discussed.
Kidney Int 1976 Sep
PMID:Role of monovalent ions in the reabsorption of fluid by isolated perfused proximal renal tubules of the rabbit. 97 42

Chromaffin granules suspended in C1-containing media release catecholamine and protein when ATP is added. This phenomenon is inhibited in hyperosmotic media and in the presence of uncouplers of oxidative phosphorylation. Release requires a permeant anion in the medium, but is independent of the cation. The release process appears to be driven by an inwardly directed proton-translocating adenosine triphosphatase. The resulting proton-anion influx causes osmotic lysis of the chromaffin granules.
Biochem J 1976 Sep 15
PMID:Adenosine triphosphate-evoked catecholamine release in chromatin granules. Osmotic lysis as a consequence of proton translocation. 98 50

The presence of autoimmune gastritis was investigated in 54 women with postpartum thyroiditis. Parietal cell antibodies (PCA) specific against H+, K(+)-adenosine triphosphatase (EC 3.6.1.36) were found in 18 women during pregnancy; in 10 of them, a 2-9-fold increase in the PCA level was observed in the postpartum period. At a 5-year follow-up, the initially PCA-positive women still had elevated antibody levels. Hypergastrinemia and low pepsinogen levels were noted in 4 women. In 2 of these women low serum vitamin B12 levels had developed. In 6 of 9 PCA-positive women examined by gastroscopy, biopsy specimens from the gastric body mucosa contained mononuclear cells, mainly T lymphocytes (CD3+) and macrophages (Leu-M3+) combined with an aberrant epithelial expression of HLA-DR. In four patients with chronic gastritis, all parietal cells, as defined by a specific monoclonal antibody, were found to have immunoglobulin G (IgG) deposits by a double-immunostaining method. Three of them had microscopic evidence of atrophy, whereas in 1 patient the body mucosa was intact. In 1 further patient with intact glands at histological examination, the basolateral membrane of some oxyntic glands was coated with IgG. The selective in situ deposition of antibodies associated with histologically intact parietal cells may support the concept that specific autoantibodies participate in the early pathogenesis of parietal cell destruction.
Gastroenterology 1992 Sep
PMID:A study of autoimmune gastritis in the postpartum period and at a 5-year follow-up. 132

It is known that Na-K,adenosine triphosphatase (ATPase) in cell membranes represents an important consumer of cellular energy, eg, adenosine triphosphate (ATP), and that the concentration and activity of this enzyme change in a dose-dependent manner with serum thyroid hormone levels. To examine the hypothesis that low triiodothyronine (T3) syndrome represents a cellular adaptation in generalized severe illnesses that saves tissue energy expenditure, we measured the muscle Na-K,ATPase concentration and its activity in rats that led to low T3 syndrome induced by fasting. The Na-K,ATPase concentration was measured by 3H-ouabain binding to soleus muscle, and its activity was measured by 42K uptake in the contralateral soleus muscle. The effects of refeeding or T3 administration on Na-K,ATPase in soleus muscle in fasted rats were also examined. Na-K,ATPase concentration and activity were both increased in hyperthyroid rats and decreased in hypothyroid rats. In the fasting state, they were decreased to as low as the levels seen in hypothyroidism. Furthermore, with fasting + refeeding or fasting + T3 administration, Na-K,ATPase in soleus muscle returned to the normal level. These results suggest that tissue energy expenditure, as assessed by Na-K,ATPase, in skeletal muscles of fasted rats with low T3 syndrome is actually decreased to levels seen in hypothyroidism, due at least partly to the decrease in serum T3 concentrations, and that there exist some adaptation mechanisms in the peripheral tissues for the accommodation of energy metabolism in the body through decreased thyroxine (T4) to T3 conversion.
Metabolism 1992 Sep
PMID:Effects of fasting, refeeding, and fasting with T3 administration on Na-K,ATPase in rat skeletal muscle. 132 95

We studied the cellular membrane enzyme responsible for potassium transport in different Thai populations. We measured plasma and intraerythrocytic concentrations of sodium and potassium, activities of erythrocytic membrane Na, K-activated adenosine triphosphatase (Na, K-ATPase), ouabain-insensitive ATPase, total ATPase and the activity ratio of Na, K-ATPase/total ATPase in 25 healthy blood donors at Khon Kaen University Hospital, Khon Kaen (group 1), and in 32 donors at the National Blood Center, Thai Red Cross Society, Bangkok (group 2). Group 1 subjects had significantly higher concentrations of erythrocyte sodium (p < 0.001) and lower activity of Na, K-ATPase (p < 0.001) than group 2. When data of these 2 groups were combined, erythrocyte Na+ correlated inversely with Na, K-ATPase and the activity ratio of Na, K-ATPase/total ATPase. Our study suggests that there is a defect in membrane transport enzymes for sodium/potassium in certain northeast Thai populations.
Southeast Asian J Trop Med Public Health 1992 Sep
PMID:Abnormal erythrocyte Na, K-ATPase activity in a northeastern Thai population. 133 1

To clarify the damage site of complicated oxidative phosphorylation function after hemorrhagic shock in jaundiced liver mitochondria, the proton adenosine triphosphatase complex (H(+)-ATPase) activity of inside-out submitochondrial particles, mitochondrial membrane potential, and oxygen consumption in the presence of uncoupler were studied as indices of phosphorylation, membrane intactness, and oxidation, respectively. Hemorrhagic shock was induced according to the Wiggers' model (mean arterial blood pressure = 40 mm Hg) in rats made jaundiced by common bile duct ligation; rats that had undergone sham operations served as controls. After reinfusion of the shed blood, all of the control rats survived, but all of the jaundiced rats died. Liver mitochondria from jaundiced rats after 1 hour of hypotension demonstrated a 48% decrease in mitochondrial ATPase activity without remarkable changes in either oxidative activity or membrane potential of liver mitochondria. The reduction of ATPase activity appeared to be due to its release in the supernatants obtained from submitochondrial particles, because the ATPase activity of supernatants in jaundiced rats was significantly (p less than 0.001) higher than that of the controls. It is suggested that this enzyme plays a key role in energy restoration in recovery from shock.
J Lab Clin Med 1992 Sep
PMID:Alterations in the proton ATPase activity of rat liver mitochondria after hemorrhagic shock. 138 75

Prior studies have demonstrated the importance of hemodynamic loading in mediating thyroxine (T4)-induced cardiac hypertrophy. Direct cellular effects of thyroid hormone have been implicated in modulating the expression of the myosin heavy chain (MHC) genes and the slow sarcoplasmic reticulum calcium adenosine triphosphatase (SR Ca(2+)-ATPase) gene. In the present report, administration of T4 for 72 h did not stimulate growth of the hemodynamically unloaded heterotopic isograft. The synthetic rates of total cardiac proteins and MHC in the isograft remained significantly lower at 64 and 53% of the respective rates measured simultaneously in the in situ working heart. Although total left ventricle RNA content in the isograft was unchanged by T4, alpha-MHC and SR Ca(2+)-ATPase mRNA concentrations were increased 181 and 208%, respectively, and the previously observed beta-MHC expression was completely prevented. These data indicate that, although T4 requires an increased hemodynamic load to stimulate cardiac protein synthesis, it is capable of directly altering the expression of at least two myocyte-specific genes. Therefore some of the phenotypic alterations observed with thyroid hormone treatment are the result of direct effects of the hormones on specific cardiac genes and independent of changes in cardiac growth.
Am J Physiol 1992 Sep
PMID:Thyroid hormone effects on cardiac gene expression independent of cardiac growth and protein synthesis. 141 33

The effects of chemical modifications of myosin's reactive cysteines on actomyosin adenosine triphosphatase (ATPase) activities and sliding velocities in the in vitro motility assays were examined in this work. The three types of modifications studied were 4-[N-[(iodoacetoxy)ethyl]-N-methylamino]-7-nitrobenz-2-oxa-1,3- diazole labeling of SH2 (based on Ajtai and Burghart. 1989. Biochemistry. 28:2204-2210.), phenylmaleimide labeling of SH1, and phenylmaleimide labeling of myosin in myofibrils under rigor conditions. Each type of modified myosin inhibited the sliding of actin in motility assays. The sliding velocities of actin over copolymers of modified and unmodified myosins in the motility assay were slowest with rigor-modified myosin and most rapid with SH2-labeled myosin. The actin-activated ATPase activities of similarly copolymerized myosins were lowest with SH2-labeled myosin and highest with rigor-modified myosin. The actin-activated ATPase activities of myosin subfragment-1 obtained from these modified myosins decreased in the same linear manner with the fraction of modified heads. These results are interpreted using a model in which the sliding of actin filaments over myosin filaments decreases the probability of myosin activation by actin. The sliding velocity of actin over monomeric rigor-modified myosin exceeded that over the filamentous form, which suggests for this myosin that filament structure is important for the inhibition of actin sliding in motility assays. The fact that all cysteine modifications examined inhibited the actomyosin ATPase activities and sliding velocities of actin over myosin poses questions concerning the information about the activated crossbridge obtained from probes attached to SH1 or SH2 on myosin.
Biophys J 1992 Sep
PMID:Cooperativity of thiol-modified myosin filaments. ATPase and motility assays of myosin function. 142 Sep 10

Saponin-permeabilized polymorphonuclear leukocytes (PMNs) released beta-glucuronidase, a lysosomal enzyme, dose-dependently in response to cupric phenanthroline (CuPh), a mild oxidant, which catalyzes the formation of disulfide bridges. The beta-glucuronidase release induced by CuPh was inhibited by ethylene glycol bis(beta-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA). Both dithiothreitol (DTT) and N-(6-aminohexyl)-5-chloro-naphthalene sulfonamide (W-7) also inhibited the beta-glucuronidase release induced by CuPh. CuPh elicited a decrease in protein-bound free sulfhydryls simultaneously, and this decrease was not restored by EGTA treatment. CuPh inhibited Ca2+ uptake into Ca2+ store sites, and promoted a Ca2+ efflux from Ca2+ store sites. It also inhibited Ca(2+)-adenosine triphosphatase (ATPase) activity in permeable PMNs. DTT, a sulfhydryl reducing agent, suppressed both the beta-glucuronidase release and the Ca2+ uptake in CuPh-treated permeable PMNs. On the other hand, chloromercuriphenylsulfonic acid (CMPS), a sulfhydryl modifier, decreased the amount of free sulfhydryls in protein and released beta-glucuronidase in permeable PMNs dose-dependently, but EGTA did not inhibit either reaction. Neither CuPh nor CMPS released beta-glucuronidase from intact PMNs. These results indicate that both CuPh and CMPS act on intra-PMN target molecules to exert their influence, but the involved mechanisms are different in nature. Alteration in calcium movement is responsible for the beta-glucuronidase release in the CuPh-treated permeable PMNs.
Chem Pharm Bull (Tokyo) 1991 Sep
PMID:Study on the cupric phenanthroline-induced beta-glucuronidase release in saponin-permeabilized polymorphonuclear leukocytes. 180 54

We have shown previously that treatment of the coated vesicle proton-translocating adenosine triphosphatase (H(+)-ATPase) with chaotropic agents results in the release of a set of peripheral polypeptides which includes the 73-, 58-, 40-, 34-, and 33-kDa subunits (Adachi, I., Puopolo, K., Marquez-Sterling, N., Arai, H., and Forgac, M. (1990) J. Biol. Chem. 265, 967-973), with a coordinate loss of H(+)-ATPase activity. In the present paper we report the functional reassembly of the coated vesicle proton pump following dissociation of the peripheral subunits. Reassembly was demonstrated by restoration of ATP-driven proton transport using both native membranes and reconstituted vesicles and by Western blot analysis using a monoclonal antibody specific for the 73-kDa subunit. Reassembly occurs by attachment of a peripheral subcomplex containing the 73-, 58-, 34-, and 33-kDa subunits together with the 40-kDa polypeptide. The reassembled H(+)-ATPase, like the native proton pump, is inhibited by N-ethylmaleimide, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole, and N,N'-dicyclohexylcarbodiimide. Reassociation shows a biphasic time dependence, with restoration of 50-60% of the starting proton transport activity in the 1st h followed by recovery of a further 20-30% of the activity after 24 h. Reassembly also shows a marked dependence on protein concentration but, unlike solubilization of the intact H(+)-ATPase complex, does not require the presence of glycerol. Despite the ability of nucleotides to promote dissociation of the peripheral complex by chaotropic agents, reassociation is not blocked by the presence of 1 mM ATP. These results thus provide the first evidence for functional reassembly of a vacuolar H(+)-ATPase complex and should be useful in further analysis of the role of individual subunits in the assembly and activity of these ATP-driven proton pumps.
J Biol Chem 1990 Sep 05
PMID:Functional reassembly of the coated vesicle proton pump. 197 87


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