scholarly journals Evidence that Mg2+- or Ca2+-activated adenosine triphosphatase in rat pancreas is a plasma-membrane ecto-enzyme

1983 ◽  
Vol 214 (1) ◽  
pp. 59-68 ◽  
Author(s):  
J M Hamlyn ◽  
A E Senior
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Active Site ◽  
Adenosine Triphosphatase ◽  
Hydrolytic Activity ◽  
Intact Cells ◽  
Rat Pancreas ◽  
Pancreatic Cells ◽  
Nucleoside Triphosphates ◽  
Specific Inhibitors

Preparations of enzymically dispersed rat pancreatic cells hydrolyse externally added nucleoside triphosphates and diphosphates at high rates in the presence of Mg2+ or Ca2+. The lack of response to specific inhibitors and activators differentiates this hydrolytic activity from that of other well-characterized ion-transporting ATPases. Studies based on inactivation of this hydrolytic activity by the covalently reacting, slowly permeating probe diazotized sulphanilic acid indicated that this nucleoside tri- and di-phosphatase is primarily a plasma-membrane ecto-enzyme. It is the major ATPase activity associated with intact cells, homogenates and isolated plasma-membrane fractions. Concanavalin A stimulates this ATPase activity of intact cells and isolated plasma-membrane fractions. The insensitivity of this ATPase activity to univalent ions and inhibitors of pancreatic electrolyte secretion, taken together with the evidence that the active site is externally located, suggests that this enzyme is not directly involved in HCO3- secretion in the pancreas. Its actual function remains unknown.

scholarly journals Mixed anhydrides of nucleotides and mesitylenecarboxylic acid as new specific inhibitors of mitochondrial adenosien triphosphatase

1979 ◽  
Vol 178 (2) ◽  
pp. 339-343 ◽  
Author(s):  
I A Kozlov ◽  
M V Shalamberidze ◽  
I Y Novikova ◽  
N I Sokolova ◽  
Z A Shabarova
Keyword(s):  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Covalent Binding ◽  
Mitochondrial Atpase ◽  
Mixed Anhydride ◽  
Submitochondrial Particles ◽  
Nucleoside Triphosphates ◽  
Mixed Anhydrides ◽  
Nucleotide Residue ◽  
Specific Inhibitors

Mixed anhydrides of nucleoside triphosphates and mesitylenecarboxylic acid inhibit soluble mitochondrial ATPase (adenosine triphosphatase), but do not inhibit ATPase of submitochondrial particles. Inhibition of soluble mitochondrial ATPase by the mixed anhydride of epsilon-ATP and mesitylenecarboxylic acid is followed by the covalent binding of one nucleotide residue to a molecule of the protein. It is suggested that this covalent binding occurs in the catalytic site of the mitochondrial ATPase. The mixed anhydride of ADP and mesitylenecarboxylic acid inhibits the ATPase activity of submitochondrial particles and has no effect on the activity of soluble mitochondrial ATPase. After separation of the submitochondrial particles from the mixed anhydride of ADP and mesitylenecarboxylic acid, their ATPase activity is restored to its original value (half-time of reactivation 3–4 min). Incubation of submitochondrial particles or soluble mitochondrial ATPase with the mixed anhydride of ADP and mesitylenecarboxylic acid results in AMP formation.

Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

1972 ◽  
Vol 30 ◽  
pp. 230-231
Author(s):  
James Cronshaw ◽  
Jamison E. Gilder
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Higher Plants ◽  
High Surface ◽  
Root Tip ◽  
Animal Cells ◽  
Physiological Processes ◽  
Tip Cells ◽  
Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

Tonoplast and plasma membrane ATPases from maize lines of high or low vigour

1992 ◽  
Vol 2 (2) ◽  
pp. 105-111 ◽  
Author(s):  
S. Sánchez-Nieto ◽  
R. Rodríguez-Sotres ◽  
P. González-Romo ◽  
I. Bernal-Lugo ◽  
M. Gavilanes-Ruíz
Keyword(s):  
Zea Mays ◽  
Plasma Membrane ◽  
Acid Phosphatase ◽  
Atpase Activity ◽  
Kinetic Analysis ◽  
Atp Hydrolysis ◽  
Membrane Atpases ◽  
Substrate Concentrations ◽  
Tonoplast Atpase ◽  
Specific Inhibitors

AbstractThe effectiveness of ATPase in germinated seed may play an important role in the vigour of germination. The activities of tonoplast and plasma membrane ATPases in two maize (Zea mays L.) lines with different vigour of germination were determined. ATP hydrolysis was measured in microsomal fractions from coleoptiles along with the responses to specific inhibitors for the plasma membrane, tonoplast and mitochondrial ATPases as well as for acid phosphatase. Nitrate-sensitive ATPase activity was 1.5–3.0 times lower in the low-vigour line than in the high-vigour line. Kinetic analysis of ATP hydrolysis at different substrate concentrations revealed the existence of two enzymes in the microsomal fractions of the two lines. The Vmax of enzyme 1 in the low-vigour line was a third of that in the high-vigour line. This enzyme was identified as the nitrate-sensitive or tonoplast ATPase on the basis of measurements of ATP hydrolysis in the presence of specific inhibitors at high (8.12mm) and low (0.77mm) ATP concentrations.

scholarly journals LEAD ION AND PHOSPHATASE HISTOCHEMISTRY II. EFFECT OF ADENOSINE TRIPHOSPHATE HYDROLYSIS BY LEAD ION ON THE HISTOCHEMICAL LOCALIZATION OF ADENOSINE TRIPHOSPHATASE ACTIVITY

1966 ◽  
Vol 14 (10) ◽  
pp. 702-710 ◽  
Author(s):  
HAROLD L. MOSES ◽  
ALAN S. ROSENTHAL ◽  
DAVID L. BEAVER ◽  
SHIRLEY S. SCHUFFMAN
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Lead Nitrate ◽  
Histochemical Localization ◽  
Lead Ion ◽  
Membrane Localization ◽  
Fixed Tissue ◽  
Plasma Membrane Localization ◽  
Hydrolysis Of

The lead method of Wachstein and Meisel for the histochemical localization of adenosine triphosphatase (ATPase) involves the incubation of sections of fixed tissue in reaction mixtures containing ATP, lead nitrate, magnesium sulfate and a Tris-maleate buffer, pH 7.2. Both fixation and the presence of lead ion were shown to inhibit tissue ATPase activity markedly and to inactivate the sodium- plus potassium-dependent membrane ATPase. In addition, recent studies have demonstrated that lead ion, in the concentration used in the Wachstein-Meisel system, will catalyze the hydrolysis of ATP. Studies on the effect of this nonenzymatic reaction on the histochemical localization of ATPases demonstrated that plasma membrane localization occurred only with lead and ATP concentrations which gave significant nonenzymatic hydrolysis of ATP by lead. In addition, nuclear and mitochondrial localization without accompanying plasma membrane localization could be obtained in formalin-fixed tissue with decreased concentrations of lead or with increased concentrations of ATP in the reaction mixture. The amount of lead-catalyzed hydrolysis was in the same order of magnitude as fixed tissue ATPase activity and could quantitatively account for the amount of phosphate needed to give recognizable localization of lead salt deposits in sections of fixed tissue.

Thyroid hormone stimulates Na-K-ATPase activity and its plasma membrane insertion in rat alveolar epithelial cells

2003 ◽  
Vol 285 (3) ◽  
pp. L762-L772 ◽  
Author(s):  
Jianxun Lei ◽  
Sogol Nowbar ◽  
Cary N. Mariash ◽  
David H. Ingbar
Keyword(s):  
Plasma Membrane ◽  
Thyroid Hormone ◽  
Atpase Activity ◽  
Cell Lines ◽  
Surface Expression ◽  
Hydrolytic Activity ◽  
Alveolar Epithelial Cells ◽  
Cell Surface Expression ◽  
Alveolar Epithelial ◽  
Adult Rat

Na-K-ATPase protein is critical for maintaining cellular ion gradients and volume and for transepithelial ion transport in kidney and lung. Thyroid hormone, 3,3′,5-triiodo-l-thyronine (T3), given for 2 days to adult rats, increases alveolar fluid resorption by 65%, but the mechanism is undefined. We tested the hypothesis that T3 stimulates Na-K-ATPase in adult rat alveolar epithelial cells (AEC), including primary rat alveolar type II (ATII) cells, and determined mechanisms of the T3 effect on the Na-KATPase enzyme using two adult rat AEC cell lines (MP48 and RLE-6TN). T3 at 10-8 and 10-5 M increased significantly hydrolytic activity of Na-K-ATPase in primary ATII cells and both AEC cell lines. The increased activity was dose dependent in the cell lines (10-9-10-4 M) and was detected within 30 min and peaked at 6 h. Maximal increases in Na-K-ATPase activity were twofold in MP48 and RLE-6TN cells at pharmacological T3 of 10-5 and 10-4 M, respectively, but increases were statistically significant at physiological T3 as low as 10-9 M. This effect was T3 specific, because reverse T3 (3,3′,5′-triiodo-l-thyronine) at 10-9-10-4 M had no effect. The T3-induced increase in Na-K-ATPase hydrolytic activity was not blocked by actinomycin D. No significant change in mRNA and total cell protein levels of Na-K-ATPase were detected with 10-9-10-5 M T3 at 6 h. However, T3 increased cell surface expression of Na-K-ATPase α1- or β1-subunit proteins by 1.7- and 2-fold, respectively, and increases in Na-K-ATPase activity and cell surface expression were abolished by brefeldin A. These data indicate that T3 specifically stimulates Na-K-ATPase activity in adult rat AEC. The upregulation involves translocation of Na-K-ATPase to plasma membrane, not increased gene transcription. These results suggest a novel nontranscriptional mechanism for regulation of Na-K-ATPase by thyroid hormone.

Populus euphratica remorin 6.5 activates plasma membrane H+-ATPases to mediate salt tolerance

2020 ◽  
Vol 40 (6) ◽  
pp. 731-745
Author(s):  
Huilong Zhang ◽  
Chen Deng ◽  
Xia Wu ◽  
Jun Yao ◽  
Yanli Zhang ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Salt Tolerance ◽  
Transgenic Plants ◽  
Recombinant Protein ◽  
Atpase Activity ◽  
Populus Euphratica ◽  
Hydrolytic Activity ◽  
In Vitro Assays

Abstract Remorins (REMs) play an important role in the ability of plants to adapt to adverse environments. PeREM6.5, a protein of the REM family in Populus euphratica (salt-resistant poplar), was induced by NaCl stress in callus, roots and leaves. We cloned the full-length PeREM6.5 from P. euphratica and transformed it into Escherichia coli and Arabidopsis thaliana. PeREM6.5 recombinant protein significantly increased the H+-ATPase hydrolytic activity and H+ transport activity in P. euphratica plasma membrane (PM) vesicles. Yeast two-hybrid assay showed that P. euphratica REM6.5 interacted with RPM1-interacting protein 4 (PeRIN4). Notably, the PeREM6.5-induced increase in PM H+-ATPase activity was enhanced by PeRIN4 recombinant protein. Overexpression of PeREM6.5 in Arabidopsis significantly improved salt tolerance in transgenic plants in terms of survival rate, root growth, electrolyte leakage and malondialdehyde content. Arabidopsis plants overexpressing PeREM6.5 retained high PM H+-ATPase activity in both in vivo and in vitro assays. PeREM6.5-transgenic plants had reduced accumulation of Na+ due to the Na+ extrusion promoted by the H+-ATPases. Moreover, the H+ pumps caused hyperpolarization of the PM, which reduced the K+ loss mediated by the depolarization-activated channels in the PM of salinized roots. Therefore, we conclude that PeREM6.5 regulated H+-ATPase activity in the PM, thus enhancing the plant capacity to maintain ionic homeostasis under salinity.

scholarly journals Sterol Extraction from Isolated Plant Plasma Membrane Vesicles Affects H+-ATPase Activity and H+-Transport

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1891
Author(s):  
Nikita K. Lapshin ◽  
Michail S. Piotrovskii ◽  
Marina S. Trofimova
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Atp Hydrolysis ◽  
Membrane Vesicles ◽  
Hydrolytic Activity ◽  
Significant Inhibition ◽  
Plasma Membrane Vesicles ◽  
Kinetics Parameters ◽  
Hydrolytic Activities ◽  
Lipid Environment

Plasma membrane H+-ATPase is known to be detected in detergent-resistant sterol-enriched fractions, also called “raft” domains. Studies on H+-ATPase reconstituted in artificial or native membrane vesicles have shown both sterol-mediated stimulations and inhibitions of its activity. Here, using sealed isolated plasma membrane vesicles, we investigated the effects of sterol depletion in the presence of methyl-β-cyclodextrin (MβCD) on H+-ATPase activity. The rate of ATP-dependent ∆µH+ generation and the kinetic parameters of ATP hydrolysis were evaluated. We show that the relative sterols content in membrane vesicles decreased gradually after treatment with MβCD and reached approximately 40% of their initial level in 30 mM probe solution. However, changes in the hydrolytic and H+-transport activities of the enzyme were nonlinear. The extraction of up to 20% of the initial sterols was accompanied by strong stimulation of ATP-dependent H+-transport in comparison with the hydrolytic activity of enzymes. Further sterol depletion led to a significant inhibition of active proton transport with an increase in passive H+-leakage. The solubilization of control and sterol-depleted vesicles in the presence of dodecyl maltoside negated the differences in the kinetics parameters of ATP hydrolysis, and all samples demonstrated maximal hydrolytic activities. The mechanisms behind the sensitivity of ATP-dependent H+-transport to sterols in the lipid environment of plasma membrane H+-ATPase are discussed.

scholarly journals Ultrastructural localizations of adenosine triphosphatase activity in resting mammary gland.

1977 ◽  
Vol 25 (2) ◽  
pp. 135-148 ◽  
Author(s):  
J Russo ◽  
P Wells
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Plasma Membranes ◽  
Ultrastructural Level ◽  
Mammary Glands ◽  
Myoepithelial Cells ◽  
Mammary Tissue ◽  
Plasma Membrane Atpase ◽  
Membrane Atpase

Adenosine triphosphatase (ATPase) activity was localized at an ultrastructural level in the resting mammary glands of female BALB/c mice. A Mg++ dependent ATPase was localized in the plasma membranes of both the epithelial and myoepithelial cells of the mammary tubules. A second type of ATPase activity that was not Mg++-dependent but that was Na+ and K+ dependent was localized primarily in the plasma membranes of the myoepithelial cells. Preincubation with either ouabain or N-ethylmaleimide decreased the quantity of reaction product, indicating that both types of ATPase activity were sensitive to these inhibitors. Control media, containing adenosine triphosphate and Pb(NO3)2 without cations, demonstrated that the amount of nonezymatic hydrolysis was negligible. These differences in the cationic requirements for plasma membrane ATPase activity can be used to distinguish histochemically the epithelial from myoepithelial cells in mammary tissue.

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