Stimulation of Protein Kinase C Rapidly Reduces Intracellular Na<sup>+</sup>Concentration via Activation of the Na<sup>+</sup>Pump in OK Cells

“…Transfection with the active and dominant-negative mutants of PP2A was performed as described above. Selection of stable clones expressing the GFP-tagged rat Na ϩ ,K ϩ -ATPase ␣-subunit was performed as described previously (34).…”

Section: Methodsmentioning

confidence: 99%

Relevance of Dopamine Signals Anchoring Dynamin-2 to the Plasma Membrane during Na+,K+-ATPase Endocytosis

Efendiev

Yudowski

Zwiller

et al. 2002

Journal of Biological Chemistry

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“…The effect of dopamine on Na ϩ ,K ϩ -ATPase activity as well as the signaling mechanisms involved is similar to type-II cells isolated from rat lung (Guerrero et al, 2001;Ridge et al, 2002). Selection of stable clones of A549 cells expressing the GFP-tagged rat Na ϩ ,K ϩ -ATPase ␣ 1 -subunit was performed as described previously (Pedemonte et al, 1997;Ogimoto et al, 2000). LysoTracker Green DND-26 (LTG) was purchased from Molecular Probes (Eugene, OR).…”

Section: Reagentsmentioning

confidence: 99%

“…Determination of Na ؉ ,K ؉ -ATPase Activity Na ϩ ,K ϩ -ATPase activity was determined in A549 cells as the rate of ouabain-sensitive [ 86 Rb ϩ ]RbCl transport (Pedemonte et al, 1997) in cells that had been previously incubated with 1 M DA (5 min) before the assay.…”

Section: Reagentsmentioning

confidence: 99%

Analysis of Na⁺,K⁺-ATPase Motion and Incorporation into the Plasma Membrane in Response to G Protein–coupled Receptor Signals in Living Cells

Bertorello

Komarova

Smith

et al. 2003

MBoC

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Dopamine (DA) increases Na+,K+-ATPase activity in lung alveolar epithelial cells. This effect is associated with an increase in Na+,K+-ATPase molecules within the plasma membrane ( Ridge et al., 2002 ). Analysis of Na+,K+-ATPase motion was performed in real-time in alveolar cells stably expressing Na+,K+-ATPase molecules carrying a fluorescent tag (green fluorescent protein) in the α-subunit. The data demonstrate a distinct (random walk) pattern of basal movement of Na+,K+-ATPase–containing vesicles in nontreated cells. DA increased the directional movement (by 3.5 fold) of the vesicles and an increase in their velocity (by 25%) that consequently promoted the incorporation of vesicles into the plasma membrane. The movement of Na+,K+-ATPase–containing vesicles and incorporation into the plasma membrane were microtubule dependent, and disruption of this network perturbed vesicle motion toward the plasma membrane and prevented the increase in the Na+,K+-ATPase activity induced by DA. Thus, recruitment of new Na+,K+-ATPase molecules into the plasma membrane appears to be a major mechanism by which dopamine increases total cell Na+,K+-ATPase activity.

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“…Experiments were performed in renal proximal convoluted tubule (PCT) cells obtained from Sprague-Dawley rats (11)(12)(13) and in opossum kidney (OK) cells transfected with either the full-length cDNA NKA ␣ 1 subunit or the Ser 18 3 Ala mutant (12)(13)(14) as previously reported. Microdissected PCTs were isolated from Sprague-Dawley rats as described (15).…”

Section: Methodsmentioning

confidence: 99%

G protein-coupled receptors regulate Na+,K+-ATPase activity and endocytosis by modulating the recruitment of adaptor protein 2 and clathrin

Ogimoto¹

2000

Proceedings of the National Academy of Sciences

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Inhibition of Na ؉ ,K ؉ -ATPase (NKA) activity in renal epithelial cells by activation of G protein-coupled receptors is mediated by phosphorylation of the catalytic ␣-subunit followed by endocytosis of active molecules. We examined whether agonists that counteract this effect do so by dephosphorylation of the ␣-subunit or by preventing its internalization through a direct interaction with the endocytic network. Oxymetazoline counteracted the action of dopamine on NKA activity, and this effect was achieved not by preventing ␣-subunit phosphorylation, but by impaired endocytosis of ␣-subunits into clathrin vesicles and early and late endosomes. Dopamine-induced inhibition of NKA activity and ␣-subunit endocytosis required the interaction of adaptor protein 2 (AP-2) with the catalytic ␣-subunit. Phosphorylation of the ␣-subunit is essential because dopamine failed to promote such interaction in cells lacking the protein kinase C phosphorylation residue (S18A). Confocal microscopy confirmed that oxymetazoline prevents incorporation of NKA molecules into clathrin vesicles by inhibiting the ability of dopamine to recruit clathrin to the plasma membrane. Dopamine decreased the basal levels of inositol hexakisphosphate (InsP 6), whereas oxymetazoline prevented this effect. Similar increments (above basal) in the concentration of InsP 6 induced by oxymetazoline prevented AP-2 binding to the NKA ␣-subunit in response to dopamine. In conclusion, inhibition of NKA activity can be reversed by preventing its endocytosis without altering the state of ␣-subunit phosphorylation; increased InsP6 in response to G protein-coupled receptor signals blocks the recruitment of AP-2 and thereby clathrin-dependent endocytosis of NKA.

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Stimulation of Protein Kinase C Rapidly Reduces Intracellular Na⁺Concentration via Activation of the Na⁺Pump in OK Cells

Cited by 38 publications

References 44 publications

Relevance of Dopamine Signals Anchoring Dynamin-2 to the Plasma Membrane during Na+,K+-ATPase Endocytosis

Relevance of Dopamine Signals Anchoring Dynamin-2 to the Plasma Membrane during Na+,K+-ATPase Endocytosis

Analysis of Na⁺,K⁺-ATPase Motion and Incorporation into the Plasma Membrane in Response to G Protein–coupled Receptor Signals in Living Cells

G protein-coupled receptors regulate Na+,K+-ATPase activity and endocytosis by modulating the recruitment of adaptor protein 2 and clathrin

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Stimulation of Protein Kinase C Rapidly Reduces Intracellular Na+Concentration via Activation of the Na+Pump in OK Cells

Cited by 38 publications

References 44 publications

Relevance of Dopamine Signals Anchoring Dynamin-2 to the Plasma Membrane during Na+,K+-ATPase Endocytosis

Relevance of Dopamine Signals Anchoring Dynamin-2 to the Plasma Membrane during Na+,K+-ATPase Endocytosis

Analysis of Na+,K+-ATPase Motion and Incorporation into the Plasma Membrane in Response to G Protein–coupled Receptor Signals in Living Cells

G protein-coupled receptors regulate Na+,K+-ATPase activity and endocytosis by modulating the recruitment of adaptor protein 2 and clathrin

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Product

Resources

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Stimulation of Protein Kinase C Rapidly Reduces Intracellular Na⁺Concentration via Activation of the Na⁺Pump in OK Cells

Analysis of Na⁺,K⁺-ATPase Motion and Incorporation into the Plasma Membrane in Response to G Protein–coupled Receptor Signals in Living Cells