Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of intradermal injection of interferon alpha-2 beta on normal human skin were studied in 12 healthy adult volunteers using 500,000 international units recombinant human interferon alpha-2 beta, 3 times a week for five injections (n = 6) and nine injections (n = 6). Saline injections served as control sites. Lymphocytic infiltrates and the population of epidermal Langerhans' cells in the injection areas were observed. The results showed that epidermal Langerhans' cells (both adenosine triphosphatase positive and CD-1+) decreased significantly whereas human leukocyte antigen-DR expression in keratinocytes was enhanced. Dermal CD-3+ (Pan T cells), CD-4+ (T helper cells) and human leukocyte antigen DR+ cells increased. No significant differences in the number of CD-19+ (B cells) and CD-57+ (NK cells) were observed. There were no significant differences between the five-injection and nine-injection groups.
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PMID:Normal human skin lymphocytic and Langerhans' cell responses to intradermal interferon alpha-2 beta injections. 768 94

NaCl regulation of plasma membrane H(+)-ATPase gene expression in the glycophyte tobacco (Nicotiana tabacum L. var Wisconsin 38) and the halophyte Atriplex nummularia L. was evaluated by comparison of organ-specific mRNA abundance using homologous cDNA probes encoding the ATPases of the respective plants. Accumulation of mRNA was induced by NaCl in fully expanded leaves and in roots but not in expanding leaves or stems. The NaCl responsiveness of the halophyte to accumulate plasma membrane H(+)-ATPase mRNA in roots was substantially greater than that of the glycophyte. Salt-induced transcript accumulation in A. nummularia roots was localized by in situ hybridization predominantly to the elongation zone, but mRNA levels also increased in the zone of differentiation. Increased message accumulation in A. nummularia roots could be detected within 8 h after NaCl (400 mM) treatment, and maximal levels were severalfold greater than in roots of untreated control plants. NaCl-induced plasma membrane H(+)-ATPase gene expression in expanded leaves and roots presumably indicates that these organs require increased H(+)-electrochemical potential gradients for the maintenance of plant ion homeostasis for salt adaptation. The greater capacity of the halophyte to induce plasma membrane H(+)-ATPase gene expression in response to NaCl may be a salt-tolerance determinant.
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PMID:NaCl regulation of plasma membrane H(+)-ATPase gene expression in a glycophyte and a halophyte. 802 33

More than 80 studies have reported lowered blood pressure after dietary calcium enrichment in experimental models of hypertension. The evidence presented here suggests that dietary calcium may act concurrently through a number of physiological mechanisms to influence blood pressure. The importance of any given mechanism may vary depending on the experimental model under consideration. Supplemental dietary calcium is associated with reduced membrane permeability, increased Ca(2+)-ATPase and Na,K-ATPase, and reduced intracellular calcium. These results suggest that supplemental calcium may limit calcium influx into the cell and improve the ability of the VSMC to extrude calcium. This could be a direct effect of calcium on the VSMC or an indirect effect mediated hormonally. The calcium-regulating hormones have all been found to have vasoactive properties and therefore may influence blood pressure. Furthermore, CGRP and the proposed parathyroid hypertensive factor are both vasoactive substances that are responsive to dietary calcium. Therefore, diet-induced variations in calcium-regulating hormones may influence blood pressure. Modulation of the sympathetic nervous system is another important way that dietary calcium can influence blood pressure. There is evidence of altered norepinephrine levels in the hypothalamus as a consequence of manipulations of dietary calcium as well as changes in central sympathetic nervous system outflow. Dietary calcium has also been shown to specifically modify alpha 1-adrenergic receptor activity in the periphery. In some experimental models of hypertension, dietary calcium may alter blood pressure by changing the metabolism of other electrolytes. For example, the ability of calcium to prevent sodium chloride-induced elevations in blood pressure may be attributed to natriuresis. However, natriuresis does not account for all of the interactive effects of calcium and sodium chloride on blood pressure. Sodium chloride-induced hypertension may be due in part to calcium wasting and subsequent elevation of calcium-regulating hormones. Chloride is an important mediator of this effect because it appears that sodium does not cause calcium wasting when it is not combined with chloride. More attention to the central nervous system effects of dietary calcium is needed. Not only can calcium itself influence neural function, but many of the calcium-regulating hormones appear to affect the central nervous system. The influence of calcium and calcium-regulating hormones on central nervous system activity may have important implications for blood pressure regulation and also may extend to other aspects of physiology and behavior.
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PMID:Dietary calcium and blood pressure in experimental models of hypertension. A review. 814 21

The yeast PMR2/ENA1 gene encodes an ATPase involved in sodium extrusion and induced by NaCl. At low salt concentrations (0.3 M) induction is mediated by the HOG-MAP kinase pathway, a system activated by non-specific osmotic stress. At high salt concentrations (0.8 M) induction is mediated by the protein phosphatase calcineurin and is specific for sodium. Protein kinase A and Sis2p/Hal3p modulate PMR2/ENA1 expression as negative and positive factors, respectively but Sis2p/Hal3p does not participate in the transduction of the salt signal. Salt stress decreases the level of cAMP and the resulting decrease in protein kinase A activity may contribute to HOG-mediated induction.
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PMID:Multiple transduction pathways regulate the sodium-extrusion gene PMR2/ENA1 during salt stress in yeast. 861 70

The salt-sensitive phenotype of yeast cells deficient in the phosphoprotein phosphatase, calcineurin, was used to identify genes from the higher plant Arabidopsis thaliana that complement this phenotype. cDNA clones corresponding to two different sequences, designated STO (salt tolerance) and STZ (salt tolerance zinc finger), were found to increased tolerance of calcineurin mutants and of wild-type yeast to both Li+ and Na+ ions. STZ is related to Cys2/His2-type zinc-finger proteins found in higher plants, and STO is similar to the Arabidopsis CONSTANS protein in regions that may also be zinc fingers. Although neither protein has sequence similarity to any protein phosphatase, STO was able to at least partially compensate for all tested additional phenotypic effects of calcineurin deficiency, and STZ compensated for a subset of these effects. Salt tolerance produced by STZ appeared to be partially dependent on ENA1/PMR2, a P-type ATPase required for Li+ and Na+ efflux in yeast, whereas the effect of STO on salt tolerance was independent of ENA1/PMR2. STZ and STO were found to be expressed in Arabidopsis roots and leaves, whereas only STO message was detectable in flowers. An apparent increase in the level of STZ mRNA was observed in response NaCl exposure in Arabidopsis seedlings, but the level of STO mRNA was not altered by this treatment.
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PMID:Two classes of plant cDNA clones differentially complement yeast calcineurin mutants and increase salt tolerance of wild-type yeast. 866 38

The effect of thyrotropin-releasing hormone (TRH) on spinal cord Na(+)-K(+-adenosine triphosphatase (Na+-K+-ATPase) activity after spinal cord injury was evaluated in rats. The rats were injured by compression of the cord at T-10 for 1 minute with a 50-g clip. Saline in the placebo group (n = 8) and TRH (0.6 mg per dose) in the TRH group (n = 9) were administered intraperitoneally as bolus injections in two doses, at 45 and 120 minutes after the injury. The Na(+)-K(+)-ATPase activity level in the TRH group was significantly higher (p = 0.024) than in placebo group. These results indicate a possible role for TRH treatment in spinal cord injury.
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PMID:Effect of thyrotropin-releasing hormone on Na(+)-K(+)-Adenosine triphosphatase activity following experimental spinal cord trauma. 871 51

Isolated membranes of the moderate halophilic bacterium Haloferax volcanii are able to hydrolyze ATP via an ATPase, which needs the presence of Mg2+ or Mn2+, high concentrations of NaCl, a pH value of 9, and high temperatures with an optimum at 60 degrees C. We have not found any phosphatase activity in the preparations. We developed a purification method for the isolated enzyme with an enrichment factor of 90. SDS-gel electrophoresis of the partially purified enzyme of Haloferax volcanii showed putative ATPase subunits of 63, 51, 37, and 12 kDa. N-ethylmaleimide (NEM) a specific inhibitor for V-ATPases, which alkylates cyteines, inhibited the enzyme slightly. Binding of tritiated NEM to the isolated ATPase fractions resulted in labelling of the 63 and 51 kDa peptides. Using PCR with degenerate oligonucleotides, we could clone and sequence a gene cluster encoding the A1 part of the halophilic ATPase. The described genes are organized in an operon in the order D, C, E, B, A, named alphabetically according to their decreasing size. The deduced products of 64.5, 52, 38.7, 22, and 11.6 kDa confirm the results of the partial purification of the ATPase. Biochemical characterization of the Haloferax volcanii ATPase gave the following results: In presence of Mn2+ higher rates of ATP hydrolysis could be observed than in presence of Mg2+, but free manganese ions inhibited the enzyme activity of the ATPase. Calculation of the true concentrations of the complex between ATP and the respective divalent metal ion led to determination of Michaelis-Menten constants for ATP in the hydrolysis direction of 1 mM in presence of MgCl2 and 0.24 mM in presence of MnCl2. Sodium chloride concentrations in the molar range induce changes in KM by a factor of about 10. The enzyme is specific for ATP; other nucleotides including GTP and ADP are competitive inhibitors of ATP hydrolysis.
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PMID:Isolation, characterization, and substrate specificity of the plasma membrane ATPase of the hlophilic achaeon Haloferax volcanii. 872 Dec 12

Salt tolerance of crops could be improved by genetic engineering if basic questions on mechanisms of salt toxicity and defense responses could be solved at the molecular level. Mutant plants accumulating proline and transgenic plants engineered to accumulate mannitol or fructans exhibit improved salt tolerance. A target of salt toxicity has been identified in Saccharomyces cerevisiae: it is a sodium-sensitive nucleotidase involved in sulfate activation and encoded by the HAL2 gene. The major sodium-extrusion system of S. cerevisiae is a P-ATPase encoded by the ENA1 gene. The regulatory system of ENA1 expression includes the protein phosphatase calcineurin and the product of the HAL3 gene. In Escherichia coli, the Na(+)-H+ antiporter encoded by the nhaA gene is essential for salt tolerance. No sodium transport system has been identified at the molecular level in plants. Ion transport at the vacuole is of crucial importance for salt accumulation in this compartment, a conspicuous feature of halophytic plants. The primary sensors of osmotic stress have been identified only in E. coli. In S. cerevisiae, a protein kinase cascade (the HOG pathway) mediates the osmotic induction of many, but not all, stress-responsive genes. In plants, the hormone abscisic acid mediates many stress responses and both a protein phosphatase and a transcription factor (encoded by the ABI1 and ABI3 genes, respectively) participate in its action.
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PMID:Salt tolerance in plants and microorganisms: toxicity targets and defense responses. 890 Sep 56

To determine how the effect of insulin is related to the development of salt-induced hypertension, and whether a hyporesponse to insulin exists in the peripheral sympathetic nerves of a hypertensive model rat, we measured norepinephrine overflow from the periarterial nerve of isolated mesenteric arteries exposed to insulin in spontaneously hypertensive rats (SHR) as well as Wistar-Kyoto rats (WKY) fed diets that were high and low in salt. Salt loading (diet containing 8% salt for 4 weeks) accelerated the development of hypertension in young, spontaneously hypertensive rats (SHR) (157 +/- 5 mm Hg v 198 +/- 4 mm Hg, P < .01) but did not affect the blood pressure of Wistar-Kyoto rats (WKY) (102 +/- 7 mm Hg v 104 +/- 6 mm Hg, P = NS). Basal norepinephrine overflow did not differ in the SHR and WKY rats, but the overflow of norepinephrine after periarterial electrical stimulation (8 Hz 1 min.) was significantly greater in SHR (0.806 +/- 0.079 ng/g) than in WKY (0.723 +/- 0.022 ng/g; P < .01). Although insulin reduced the norepinephrine overflow by periarterial nerve stimulation in both WKY and SHR, the decrease with insulin was significantly greater in the SHR than in WKY (-18.4% +/- 4.0% v -32.0% +/- 4.6%, P < .05). The inhibitory effect of insulin on norepinephrine overflow was reduced by salt loading in SHR (-8.8% +/- 4.0%, P < .05), but not in WKY (-32.5% +/- 4.7%, P = NS). Cocaine and ouabain completely blocked the effect of insulin in all four groups. In contrast to insulin, direct stimulation of Na(+)-K+ ATPase with a high-potassium buffer (12 mmol/L) reduced NE overflow to the same extent among the four groups. These findings show that SHR have a blunted response to the suppression by insulin of norepinephrine overflow. Salt loading reduced the insulin response at peripheral sympathetic nerves of young SHR, but did not affect that of age-matched WKY. Thus, hyporeactivity to insulin may play a role in the development of salt-induced hypertension in young SHR, possibly through a reduced suppression of norepinephrine overflow from sympathetic nerve endings.
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PMID:Effect of insulin on norepinephrine overflow at peripheral sympathetic nerve endings in young spontaneously hypertensive rats. 893 38

Polymerization caused by defective folding of heat-denatured ovalbumin was examined. A compactly misfolded ovalbumin that was produced by cooling heat-denatured protein rapidly tended to aggregate in the presence of salt. Two different forms of aggregates were observed as the concentration of salt was varied: a linear polymer at a physiological concentration and a massive agglomerate at a higher concentration. Salt-induced polymerization depended on the species of anion and the order of effectiveness followed the lyotropic series of Hofmeister. Defective folding of heat-denatured ovalbumin induced the exposure of cysteine residues in sequences located in the interior of the native protein. The misfolded ovalbumin, but not the native protein, bound to bovine BiP and stimulated its ATPase activity with the K(m) of 64 microM and the V(max) of 0.5 nmol/min per milligram. Measurement of surface plasmon resonance revealed that only the misfolded ovalbumin was recognized with the K(d) of 4.12 X 10(-8) M by the Fab fragment of a monoclonal antibody raised against hen ovalbumin, and its epitope was determined to be a hydrophobic segment in the beta-strand of central sheet A. Transmission electron microscopy showed that the linear polymerization was inhibited by the addition of bovine BiP and the Fab fragment. These results demonstrated that the compactly misfolded ovalbumin polymerized through hydrophobic interaction occurring among the areas exposed as a result of defective folding of the heat-denatured protein. Exposure of the region of, or adjacent to, the central beta-sheet A was required for axial contact among the misfolded molecules, suggesting that this process may be explained by reference to the mechanism proposed for loop-sheet polymerization in the Z type variant of a serpin alpha1-antitrypsin.
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PMID:Linear polymerization caused by the defective folding of a non-inhibitory serpin ovalbumin. 916 32


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