Hormonal‐dependent recruitment of Na⁺,K⁺‐ATPase to the plasmalemma is mediated by PKC_β and modulated by [Na⁺]_i

Abstract

The present study demonstrates that stimulation of hormonal receptors of proximal tubule cells with the serotonin‐agonist 8‐hydroxy‐2‐(di‐n‐propylamino) tetraline (8‐OH‐DPAT) induces an augmentation of Na+,K+‐ATPase activity that results from the recruitment of enzyme molecules to the plasmalemma. Cells expressing the rodent wild‐type Na+,K+‐ATPase α‐subunit had the same basal Na+,K+‐ATPase activity as cells expressing the α‐subunit S11A or S18A mutants, but stimulation of Na+,K+‐ATPase activity was completely abolished in either mutant. 8‐OH‐DPAT treatment of OK cells led to PKCβ‐dependent phosphorylation of the α‐subunit Ser‐11 and Ser‐18 residues, and determination of enzyme activity with the S11A and S18A mutants indicated that both residues are essential for the agonist‐dependent stimulation of Na+,K+‐ATPase activity. When cells were treated with both dopamine and 8‐OH‐DPAT, an activation of Na+,K+‐ATPase was observed at basal intracellular sodium concentration (∼9 mM), and this activation was gradually reduced and became a significant inhibition as the concentration of intracellular sodium gradually increased from 9 to 19 mM. Thus, besides the antagonistic effects of dopamine and 8‐OH‐DPAT, intracellular sodium modulates whether an activation or an inhibition of Na+,K+‐ATPase is produced. British Journal of Pharmacology (2002) 137, 1380–1386. doi:

G-protein-coupled Receptor-mediated Traffic of Na,K-ATPase to the Plasma Membrane Requires the Binding of Adaptor Protein 1 to a Tyr-255-based Sequence in the α-Subunit

“…1A). We have previously demonstrated that 8-OH-DPAT, a serotonin 1A receptor agonist, and the phorbol ester PMA, an activator of protein kinase C, stimulate the same signaling pathway as Ang II to induce the plasma membrane recruitment of NKA molecules (32). Consistent with this observation, the substitution of Tyr-255 for phenylalanine in NKA ␣1 impairs the stimulation of NKA activity by either 8-OH-DPAT or PMA (Fig.…”

The 14-3-3 Protein Translates the NA+,K+-ATPase α1-Subunit Phosphorylation Signal into Binding and Activation of Phosphoinositide 3-Kinase during Endocytosis

“…A representative Western blot of five experiments is shown. B, co-immunoprecipitation of the Na ϩ ,K ϩ -ATPase with 14-3-3 protein was performed exactly as described above for A in OK cells stably transfected with the Na ϩ ,K ϩ -ATPase bearing the mutation Ser 11 3 Ala (S11A), Ser 18 3 Ala (S18A), or deletion of the first 26 amino acids (⌬26) in the ␣ 1 -subunit, as described by Chibalin et al (8) …”

“…In the rodent renal epithelia, phosphorylation of Na ϩ ,K ϩ -ATPase ␣ 1 -subunits (at that are present at the plasma membrane is necessary for dopamine (DA) 1 -induced endocytosis (6 -8) and (at Ser-11) for parathyroid hormoneinduced endocytosis (9). In contrast, recruitment of new molecules to the plasma membrane in response to angiotensin II (10) or serotonin (11) requires the phosphorylation of Na ϩ ,K ϩ -ATPase molecules (Ser-11/Ser-18) present within endosomes. DA-mediated phosphorylation of the ␣ 1 -subunit and Na ϩ ,K ϩ -ATPase endocytosis requires activation of the PKC-isoform, whereas serotonin-and angiotensin II-dependent increase in Na ϩ ,K ϩ -ATPase activity requires activation of the PKC-␤ isoform (11,12).…”

“…In contrast, recruitment of new molecules to the plasma membrane in response to angiotensin II (10) or serotonin (11) requires the phosphorylation of Na ϩ ,K ϩ -ATPase molecules (Ser-11/Ser-18) present within endosomes. DA-mediated phosphorylation of the ␣ 1 -subunit and Na ϩ ,K ϩ -ATPase endocytosis requires activation of the PKC-isoform, whereas serotonin-and angiotensin II-dependent increase in Na ϩ ,K ϩ -ATPase activity requires activation of the PKC-␤ isoform (11,12). Nonetheless, phosphorylation in either circumstance does not change the catalytic properties of the enzyme (7,13), but constitutes a triggering factor essential for initiating their recruitment into clathrin vesicles and traffic to their final destination.…”

Changes in the expression and current of the Na+/K+ pump in the snail nervous system after exposure to static magnetic field

“…the turnover rate) of the pumps already present at the plasma membrane, as well as by modulating Na + /K + pump expression at the cell surface (Therien and Blostein, 2000). The latter is accomplished by recruiting an intracellular protein pool of the pump to the plasma membrane, and by internalization of the plasma membrane-associated pool (Barlet-Bas et al, 1990;Chibalin et al, 1999;Gonin et al, 2001;Budu et al, 2002;Efendiev et al, 2003;Vinciguerra et al, 2003;Efendiev et al, 2007). Our previous findings (Nikolić et al, 2012) and results obtained in the present study indicate that the SMF-induced increase in Na + /K + pump activity can be mediated through short-term mechanisms of pump activity regulation.…”