scholarly journals Regulation of the H+ Pump Activity in the Plasma Membrane of Internally Perfused Chara corallina

2001 ◽  
Vol 42 (5) ◽  
pp. 531-537 ◽  
Author(s):  
Izuo Tsutsui ◽  
Taka-aki Ohkawa
Keyword(s):  
Plasma Membrane ◽  
Chara Corallina ◽  
Pump Activity

Ca transport by plasma membrane and intracellular stores of gastric cells

1993 ◽  
Vol 264 (4) ◽  
pp. C843-C851 ◽  
Author(s):  
P. A. Negulescu ◽  
T. E. Machen
Keyword(s):  
Plasma Membrane ◽  
Intracellular Pool ◽  
Intracellular Store ◽  
Membrane Pump ◽  
Gastric Cells ◽  
Resting Cell ◽  
Ca Transport ◽  
Pump Activity ◽  
Basolateral Plasma Membrane ◽  
Gastric Parietal Cells

The relative Ca transport activities (i.e., of both pumps and leaks) of carbachol-releasable intracellular stores and the basolateral plasma membrane of gastric parietal cells were studied using digital image processing of fura-2 fluorescence. Cells were treated with either carbachol (a cholinergic agonist) or thapsigargin (an inhibitor of microsomal Ca-adenosinetriphosphatase) or a combination of the two. Ca-free solutions were used to selectively investigate intracellular store release and plasma membrane pump activity, whereas Ca-containing solutions were used to investigate Ca influx and refilling of the intracellular pool. In the resting cell depletion of the intracellular pool in Ca-free solutions was 15-fold faster than control in the presence of thapsigargin, indicating the efficient (> 90%) recycling of leaked Ca by the store Ca pump. Stimulation with carbachol increased the rate of pool depletion by 70-fold, and this Ca flux out of the internal store was ten times larger than the flux across the plasma membrane. Thus the internal store has ten times greater fluxes (both leaks and pumps) than the plasma membrane during resting and stimulated conditions. After carbachol removal (i.e., reloading) the permeability of the internal store decreases, whereas increased influx across the plasma membrane persists until the store is refilled. Cytoplasmic Ca does not increase during refilling because the intracellular store pump operates eightfold faster than the plasma membrane pump, effectively sequestering Ca as quickly as it enters the cell.

scholarly journals Control of phosphate transport across the plasma membrane of Chara corallina

1998 ◽  
Vol 49 (318) ◽  
pp. 13-19 ◽  
Author(s):  
T. Mimura ◽  
R. J. Reid ◽  
F. A. Smith
Keyword(s):  
Plasma Membrane ◽  
Phosphate Transport ◽  
Chara Corallina

scholarly journals Ouabain enhances cell-cell adhesion mediated by β1-subunits of the Na+,K+-ATPase in CHO fibroblasts

2019 ◽  
Author(s):  
Claudia Andrea Vilchis-Nestor ◽  
María Luisa Roldán ◽  
Teresita Padilla-Benavides ◽  
Liora Shoshani
Keyword(s):  
Plasma Membrane ◽  
Cell Adhesion ◽  
Epithelial Cells ◽  
Signaling Pathways ◽  
Cell Adhesion Molecules ◽  
Basolateral Membrane ◽  
Adhesive Properties ◽  
Α Subunit ◽  
Cardiotonic Steroid ◽  
Pump Activity

AbstractAdhesion is an important characteristic of epithelial cells to provide a crucial barrier to pathogens and substances. In polarized epithelial cells, cell-adhesion depends on tight junctions, adherent junctions and the Na+,K+-ATPase. All these are located in the basolateral membrane of the cells. The hormone ouabain, a cardiotonic steroid, binds to the α subunit of the Na+,K+-ATPase, and inhibits the pump activity when used at above μM concentrations. At physiological nM concentrations, ouabain affects the adhesive properties of epithelial cells by inducing the expression of cell adhesion molecules through activation of signaling pathways associated to the α subunit. Our group showed that non-adherent CHO cells transfected with the canine β1subunit become adhesive, and that homotypic interactions between β1subunits of the Na+,K+-ATPase occur between neighboring epithelial cells. Therefore, in this study we investigated whether the adhesion between β1subunits was also affected by ouabain. We used CHO fibroblasts stably expressing the β1subunit of the Na+,K+-ATPase (CHO-β1) and studied the effect of ouabain on cell adhesion. Aggregation assays showed that ouabain increased the adhesion between CHO-β1cells. Immunofluorescence and biotinylation assays showed that ouabain (50 nM) increases the expression of the β1 subunit of the Na+,K+-ATPase at the cell membrane. We also screened the effect of ouabain on activation of signaling pathways in CHO-β1cells, and their effect on cell adhesion. We found that c-Src, is activated by ouabain and is therefore likely to regulate the adhesive properties of CHO-β1cells. Collectively, our findings suggest that the β1subunits adhesion is modulated by the levels of expression and activation of the Na+,K+-ATPase at the plasma membrane, which is regulated by ouabain.

scholarly journals Calcium pump activities in the kidneys of Oreochromis mossambicus

1995 ◽  
Vol 198 (6) ◽  
pp. 1351-1357
Author(s):  
M Bijvelds ◽  
A Heijden ◽  
G Flik ◽  
P Verbost ◽  
Z Kolar ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Fraction ◽  
Transport Mechanism ◽  
Physiological Role ◽  
Membrane Vesicles ◽  
Oreochromis Mossambicus ◽  
High Affinity ◽  
Pump Activity ◽  
Basolateral Plasma Membrane ◽  
Euryhaline Teleost

The mechanism that underlies transcellular Ca2+ reabsorption in the kidney of the euryhaline teleost Oreochromis mossambicus was studied. Preparations of membrane vesicles made from the kidneys of freshwater- and seawater-adapted fish were more than sevenfold enriched in the basolateral plasma membrane marker Na+/K+-ATPase. Significant recovery of NADH­ cytochrome c reductase enzyme activity and of oxalate-stimulated Ca2+ pump activities in the membrane preparations indicated that the membrane fraction was of endoplasmic reticular origin. Indeed, thapsigargin specifically inhibited Ca2+ pump activity that could be attributed to oxalate-permeable endoplasmic reticular fragments. Kinetic analysis of thapsigargin-insensitive Ca2+ pump activity indicated the existence of a homogeneous, high-affinity, ATP-driven Ca2+ pump. No Na+-driven Ca2+ transport mechanism could be demonstrated. Plasma membrane Ca2+ pump activity was 56 % lower in preparations from seawater-adapted fish than in preparations from freshwater-adapted fish, suggesting a physiological role for this Ca2+ pump activity in renal Ca2+ handling by euryhaline species, with an involvement in the regulation of Ca2+ reabsorption.

Aluminium-inhibited NO3– uptake is related to Al-increased H2O2 content and Al-decreased plasma membrane ATPase activity in the root tips of Al-sensitive black soybean

2017 ◽  
Vol 44 (2) ◽  
pp. 198 ◽  
Author(s):  
Dan Yang ◽  
Dongjie Chen ◽  
Ping Wang ◽  
Daihua Jiang ◽  
Huini Xu ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Treatment Time ◽  
Root Tips ◽  
Black Soybean ◽  
Soybean Root ◽  
H2o2 Content ◽  
Al Stress ◽  
Pump Activity ◽  
Al Treatment

In this study, Al-sensitive black soybean (Glycine max (L.) Merr.) specimens were treated in Hoagland solutions containing 50–400 µM Al for 1–4 days. The measurement for NO3– uptake showed that the NO3– uptake decreased gradually as the Al concentration and treatment time increased, suggesting that Al stress significantly reduced the NO3– uptake by soybean. Under 100-µM Al stress for 4 days, the plasma membrane (PM) ATPase activity (inorganic phosphate (Pi) release), H+ pump activity, phosphorylation of PM ATPase and its interaction with 14-3-3 protein in soybean root tips were all smaller than those in the root tips of control plants. The addition of 150 µM Mg2+ in Al treatment solutions significantly alleviated the Al inhibition of NO3– uptake in soybean. The presence of Mg2+ in a 100-µM Al solution pronouncedly enhanced PM ATPase activity, H+ pump activity, phosphorylation of PM ATPase and its interaction with 14-3-3 protein in soybean root tips. The application of 2 mM ascorbic acid (AsA, an H2O2 scavenger) in Al treatment solutions significantly decreased Al-inhibited NO3– uptake in soybean. The cotreatment of soybeans with 2 mM AsA and 100 µM Al significantly reduced H2O2 accumulation and increased the PM ATPase activity, H+ pump activity, phosphorylation of PM H+-ATPase and its interaction with 14-3-3 protein in soybean root tips. The evidence suggested that Al-inhibited NO3– uptake is related to Al-increased H2O2 content and Al-decreased phosphorylation of PM ATPase and its interaction with 14-3-3 protein as well as PM ATPase activity in the root tips of soybean.

EFFECT OF HALOTHANE IN MODULATION OF CALCIUMATPase PUMP ACTIVITY IN SYNAPTOSOMAL PLASMA MEMBRANE FROM MAJOR AREAS OF RAT BRAIN

1992 ◽  
Vol 77 (Supplement) ◽  
pp. A352 ◽  
Author(s):  
G Singh ◽  
J J Franks ◽  
BVR Sastry ◽  
J L Horn ◽  
V. Janson
Keyword(s):  
Plasma Membrane ◽  
Rat Brain ◽  
Pump Activity ◽  
Synaptosomal Plasma Membrane

scholarly journals Glutamate-induced protease-mediated loss of plasma membrane Ca2+ pump activity in rat hippocampal neurons

2006 ◽  
Vol 98 (5) ◽  
pp. 1646-1656 ◽  
Author(s):  
William J. Pottorf ◽  
Tanner M. Johanns ◽  
Stephen M. Derrington ◽  
Emanuel E. Strehler ◽  
Agnes Enyedi ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Hippocampal Neurons ◽  
Pump Activity
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