Phosphorylation of Na,K-ATPase by Protein Kinases: Structure-Functions Relationship

Béguin, Pascal; Beggah, Ahmed T.; Chibalin, Alexander V.; Vasilets, Larisa A.; Rossier, Bernard C.; Jaisser, Frédéric; Geering, Käthi

doi:10.1007/978-3-642-72511-1_122

Cited by 19 publications

(29 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our results demonstrated enhanced Pi incorporation into the ec-subunit of Na+,K+-ATPase under specific PKA activation conditions. They are strengthened by the fact that several groups recently identified a single highly conserved PKA phosphorylation site on the a-subunit of Na+,K+-ATPase (Ser-943) [8,9]. Moreover, direct phosphorylation by PKA has been demonstrated in in vitro studies with purified [7] and reconstituted [11] Na+,K+-ATPase.…”

Section: Resultsmentioning

confidence: 99%

“…Recent studies suggest that the c~-subunit of Na+,K+-ATPase is a target for regulatory phosphorylation by protein kinase A: PKA phosphorylates Na+,K+-ATPase c~-subunit in vitro [7] and mutation of the single PKA-phosphorylation site abolished the PKA-mediated phosphorylation of Na+,K+-ATPase in transfected COS cells [8,9]. However, PKA-mediated phosphorylation of the renal Na+,K+-ATPase has not been demonstrated in non-transfected intact cells.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Stimulation of ouabain‐sensitive ⁸⁶Rb⁺ uptake and Na⁺,K⁺‐ATPase α‐subunit phosphorylation by a cAMP‐dependent signalling pathway in intact cells from rat kidney cortex

Carranza¹,

Féraille²,

Kiroytcheva

et al. 1996

FEBS Letters

View full text Add to dashboard Cite

We investigated in intact cortical kidney tubules the role of PKA-mediated phosphorylation in the short-term control of Na+,K+-ATPase activity. The phosphorylation level of Na+,K+-ATPase was evaluated after immunoprecipitation of the enzyme from 32p-labelled cortical tubules and the cation transport activity of Na+,K+-ATPase was measured by ouabainsensitive 86Rb + uptake. Incubation of cells with cAMP analogues (8-bromo-cAMP, dibutyryl-cAMP) or with forskolin plus 3-isobutyl-l-methylxanthine increased the phosphorylation level of the Na+,K+-ATPase ~-subunit and stimulated ouabain-sensitive S6Rb + uptake. Inhibition of PKA by H-89 blocked the effects of dibutyryl-cAMP on both phosphorylation and S6Rb + uptake processes. The results suggest that phosphorylation by PKA stimulates the Na+,K+-ATPase activity.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Stimulation of ouabain‐sensitive ⁸⁶Rb⁺ uptake and Na⁺,K⁺‐ATPase α‐subunit phosphorylation by a cAMP‐dependent signalling pathway in intact cells from rat kidney cortex

Carranza¹,

Féraille²,

Kiroytcheva

et al. 1996

FEBS Letters

View full text Add to dashboard Cite

show abstract

“…Further, PKC-mediated inhibition of the rat renal Na/P i cotransporter was not prevented by the removal of the protein kinase C consensus sequences (44). Similarly, a cryptic site for PKC has been identified at the amino terminus of the Na ϩ /K ϩ -ATPase (45).…”

Section: Discussionmentioning

confidence: 97%

A Protein-tyrosine Kinase-regulated, pH-dependent, Carrier-mediated Uptake System for Folate in Human Normal Colonic Epithelial Cell Line NCM460

Kumar

Moyer

Dudeja

et al. 1997

Journal of Biological Chemistry

View full text Add to dashboard Cite

A significant proportion of the bacterially synthesized folate in the large intestine exists in the form of folate monoglutamate. Recent studies in our laboratory using human colonic apical membrane vesicles have shown the existence of an efficient carrier-mediated system for folate uptake. Nothing, however, is known about the cellular regulation of the colonic uptake process. In this study, we used a recently established human normal colonic epithelial cell line NCM460 to address this issue. Uptake of folic acid by NCM460 cells was: 1) linear with time for 4 min of incubation and occurred with minimal metabolic alterations, 2) temperature-and pH-(but not Na ؉ ) dependent, 3) saturable as a function of concentration (apparent K m of 1.4 M), 4) inhibited by structural analogs and anion transport inhibitors, and 5) energydependent. These characteristics of folic acid uptake by NCM460 cells are similar to those seen with apical membrane vesicles derived from human native colonic tissue. Using these cells, we found that protein kinase Cand Ca 2؉ /calmodulin-mediated pathways have no role in regulating folic acid uptake. On the other hand, cAMP (through a mechanism independent of protein kinase A) and protein-tyrosine kinase-mediated pathways were found to play a role in the regulation of folic acid uptake by these cells. These results establish the suitability of NCM460 cells as an in vitro model system for investigating the details of the mechanism of colonic folate uptake and its regulation. Folic acid uptake by these cells appears to involve a carrier-mediated system, which is temperature-, pH-, and energy-dependent and appears to be under the regulation of cAMP and protein tyrosine kinase.Folate is an essential micronutrient, which acts as a coenzyme in the synthesis of DNA and RNA and the interconversion and degradation of several amino acids (1-4). An adequate supply of folate is therefore necessary for normal cellular function, growth, and development. Folate deficiency has been suggested as one of the most common vitamin deficiencies in the Western Hemisphere (5, 6). Humans and other mammals cannot synthesize folate and rely on exogenous sources to meet their metabolic requirements. Folates are presented to the host from the diet and are also synthesized in the large intestine by normal microflora. The mechanism of absorption of dietary folate has been intensively examined over the past two decades at the tissue, cellular, subcellular, and more recently, molecular levels (6 -15). Absorption of dietary folate has been shown to occur mainly in the proximal small intestine and involves a specialized, carrier-mediated system (6 -12).As to the bacterially synthesized folate in the large intestine, a significant amount of that folate exists in the monoglutamate, i.e. the absorbable form. Using [ 3 H]p-aminobenzoic acid to label the newly synthesized folate by the intestinal flora, Rong et al. (16) have shown that a portion of this folate is indeed absorbed by the rat and is incorporated into its various tissues. ...

show abstract

“…Several membrane proteins have been shown to be modulated by PKC activation via direct protein phosphorylation. These include the rat kidney minK [5] and the human hKv3.4 [10] K + channels, the Na + channel [27,28] the GABAA receptor [29,30], and the Na,K-ATPase a subunit [31]. We found that this is probably not the case with the RCK1 channel as phosphorylation of none of the classical potential PKC phosphorylation sites [17] on the RCK1 protein (six of which reside in the N-terminus) could account for the inhibitory effect by the PKC activation.…”

Section: The Inhibitory Effect Is Mediated Partially By the N-termiaumentioning

confidence: 99%

Modulation by protein kinase C activation of rat brain delayed‐rectifier K⁺ channel expressed in Xenopus oocytes

et al. 1996

View full text Add to dashboard Cite

The modulation by protein kinase C (PKC) of the RCKI K ÷ channel was investigated in Xenopus oocytes by integration of two-electrode voltage clamp, site-directed mutagenesis and SDS-PAGE analysis techniques. Upon application of ~-phorbol 12-myristate 13-acetate (PMA) the current was inhibited by 50-90%. No changes in the voltage sensitivity of the channel, changes in membrane surface area or selective elimination of RCKI protein from the plasma membrane could be detected. The inhibition was mimicked by l-oleoyl-2-acetylrac-glycerol (OAG) but not by c~PMA, and was blocked by staurosporine and calphostin C. Upon deletion of most of the Nterminus a preceding enhancement of about 40% of the current was prominent in response to PKC activation. Its physiological significance is discussed. The N-terminus deletion eliminated 50% of the inhibition. However, phosphorylation of none of the ten classical PKC phosphorylation sites on the channel molecule could account, by itself or in combination with others, for the inhibition. Thus, our results show that PKC activation can modulate the channel conductance in a bimodal fashion. The Nterminus is involved in the inhibition, however, not via its direct phosphorylation.Key words: K + channel; Protein kinase C; Xenopus oocyte; Phosphorylation; Biphasic modulation; Site-directed mutagenesis tion of channels by integrating electrophysiological analysi with molecular biology techniques. Thus, it was shown that the function of a slowly activating K + channel (minK) is modulated by PKC activation through phosphorylation of a serine residue on the channel molecule [5] and by PKA activation, but not through direct channel phosphorylation [6,7]. The Shaker D, Shaker B [8] and Kvl.2 [9] channels were shown to be modulated by PKA activation via phosphorylation of a specific serine residue in each molecule and the hKv3.4 channel was shown to be modulated by PKC phosphorylation of two serine residues [10].Recently, with the addition of a biochemical approach to the study of K + channels in oocytes, we could show that the rat brain RCK1 channel (Kvl.1; ref. [11]), that functions in oocytes as a delayed rectifier-type of K + channel [12], is modulated by PKA activation through two separate mechanisms, one via direct channel phosphorylation at Ser-446 on the C-terminus and the other involving enhanced synthesis of the channel protein [13,14]. In the present work we have extended the study of this channel and characterize its modulation by PKC activation. We also show that, in contrast to the PKA modulation, the N-terminus is probably involved in the PKC modulation and not through direct channel phosphorylation.

show abstract

Phosphorylation of Na,K-ATPase by Protein Kinases: Structure-Functions Relationship

Cited by 19 publications

References 8 publications

Stimulation of ouabain‐sensitive ⁸⁶Rb⁺ uptake and Na⁺,K⁺‐ATPase α‐subunit phosphorylation by a cAMP‐dependent signalling pathway in intact cells from rat kidney cortex

Stimulation of ouabain‐sensitive ⁸⁶Rb⁺ uptake and Na⁺,K⁺‐ATPase α‐subunit phosphorylation by a cAMP‐dependent signalling pathway in intact cells from rat kidney cortex

A Protein-tyrosine Kinase-regulated, pH-dependent, Carrier-mediated Uptake System for Folate in Human Normal Colonic Epithelial Cell Line NCM460

Modulation by protein kinase C activation of rat brain delayed‐rectifier K⁺ channel expressed in Xenopus oocytes

Contact Info

Product

Resources

About

Phosphorylation of Na,K-ATPase by Protein Kinases: Structure-Functions Relationship

Cited by 19 publications

References 8 publications

Stimulation of ouabain‐sensitive 86Rb+ uptake and Na+,K+‐ATPase α‐subunit phosphorylation by a cAMP‐dependent signalling pathway in intact cells from rat kidney cortex

Stimulation of ouabain‐sensitive 86Rb+ uptake and Na+,K+‐ATPase α‐subunit phosphorylation by a cAMP‐dependent signalling pathway in intact cells from rat kidney cortex

A Protein-tyrosine Kinase-regulated, pH-dependent, Carrier-mediated Uptake System for Folate in Human Normal Colonic Epithelial Cell Line NCM460

Modulation by protein kinase C activation of rat brain delayed‐rectifier K+ channel expressed in Xenopus oocytes

Contact Info

Product

Resources

About

Stimulation of ouabain‐sensitive ⁸⁶Rb⁺ uptake and Na⁺,K⁺‐ATPase α‐subunit phosphorylation by a cAMP‐dependent signalling pathway in intact cells from rat kidney cortex

Stimulation of ouabain‐sensitive ⁸⁶Rb⁺ uptake and Na⁺,K⁺‐ATPase α‐subunit phosphorylation by a cAMP‐dependent signalling pathway in intact cells from rat kidney cortex

Modulation by protein kinase C activation of rat brain delayed‐rectifier K⁺ channel expressed in Xenopus oocytes