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Regulation of the Epithelial Na(+) Channel by the Protein Kinase CK2

CK2 is a ubiquitous, pleiotropic, and constitutively active Ser/Thr protein kinase that controls protein expression, cell signaling, and ion channel activity. Phosphorylation sites for CK2 are located in the C terminus of both β- and γ-subunits of the epithelial Na(+) channel (ENaC). We examined the...

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Autores principales: Bachhuber, Tanja, Almaça, Joana, Aldehni, Fadi, Mehta, Anil, Amaral, Margarida D., Schreiber, Rainer, Kunzelmann, Karl
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Biochemistry and Molecular Biology 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259572/
https://www.ncbi.nlm.nih.gov/pubmed/18308722
http://dx.doi.org/10.1074/jbc.M704532200
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author Bachhuber, Tanja
Almaça, Joana
Aldehni, Fadi
Mehta, Anil
Amaral, Margarida D.
Schreiber, Rainer
Kunzelmann, Karl
author_facet Bachhuber, Tanja
Almaça, Joana
Aldehni, Fadi
Mehta, Anil
Amaral, Margarida D.
Schreiber, Rainer
Kunzelmann, Karl
author_sort Bachhuber, Tanja
collection PubMed
description CK2 is a ubiquitous, pleiotropic, and constitutively active Ser/Thr protein kinase that controls protein expression, cell signaling, and ion channel activity. Phosphorylation sites for CK2 are located in the C terminus of both β- and γ-subunits of the epithelial Na(+) channel (ENaC). We examined the role of CK2 on the regulation of both endogenous ENaC in native murine epithelia and in Xenopus oocytes expressing rENaC. In Ussing chamber experiments with mouse airways, colon, and cultured M1-collecting duct cells, amiloride-sensitive Na(+) transport was inhibited dose-dependently by the selective CK2 inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB). In oocytes, ENaC currents were also inhibited by TBB and by the structurally unrelated inhibitors heparin and poly(E:Y). Expression of a trimeric channel lacking both CK2 sites (αβ(S631A)γ(T599A)) produced a largely attenuated amiloride-sensitive whole cell conductance and rendered the mutant channel insensitive to CK2. In Xenopus oocytes, CK2 was translocated to the cell membrane upon expression of wt-ENaC but not of αβ(S631A)γ(T599A)-ENaC. Phosphorylation by CK2 is essential for ENaC activation, and to a lesser degree, it also controls membrane expression of αβγ-ENaC. Channels lacking the Nedd4-2 binding motif in β-ENaC (R561X, Y618A) no longer required the CK2 site for channel activity and siRNA-knockdown of Nedd4-2 eliminated the effects of TBB. This implies a role for CK2 in inhibiting the Nedd4-2 pathway. We propose that the C terminus of β-ENaC is targeted by this essential, conserved pleiotropic kinase that directs its constitutive activity toward many cellular protein complexes.
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spelling pubmed-32595722012-01-18 Regulation of the Epithelial Na(+) Channel by the Protein Kinase CK2 Bachhuber, Tanja Almaça, Joana Aldehni, Fadi Mehta, Anil Amaral, Margarida D. Schreiber, Rainer Kunzelmann, Karl J Biol Chem Membrane Transport, Structure, Function, and Biogenesis CK2 is a ubiquitous, pleiotropic, and constitutively active Ser/Thr protein kinase that controls protein expression, cell signaling, and ion channel activity. Phosphorylation sites for CK2 are located in the C terminus of both β- and γ-subunits of the epithelial Na(+) channel (ENaC). We examined the role of CK2 on the regulation of both endogenous ENaC in native murine epithelia and in Xenopus oocytes expressing rENaC. In Ussing chamber experiments with mouse airways, colon, and cultured M1-collecting duct cells, amiloride-sensitive Na(+) transport was inhibited dose-dependently by the selective CK2 inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB). In oocytes, ENaC currents were also inhibited by TBB and by the structurally unrelated inhibitors heparin and poly(E:Y). Expression of a trimeric channel lacking both CK2 sites (αβ(S631A)γ(T599A)) produced a largely attenuated amiloride-sensitive whole cell conductance and rendered the mutant channel insensitive to CK2. In Xenopus oocytes, CK2 was translocated to the cell membrane upon expression of wt-ENaC but not of αβ(S631A)γ(T599A)-ENaC. Phosphorylation by CK2 is essential for ENaC activation, and to a lesser degree, it also controls membrane expression of αβγ-ENaC. Channels lacking the Nedd4-2 binding motif in β-ENaC (R561X, Y618A) no longer required the CK2 site for channel activity and siRNA-knockdown of Nedd4-2 eliminated the effects of TBB. This implies a role for CK2 in inhibiting the Nedd4-2 pathway. We propose that the C terminus of β-ENaC is targeted by this essential, conserved pleiotropic kinase that directs its constitutive activity toward many cellular protein complexes. American Society for Biochemistry and Molecular Biology 2008-05-09 /pmc/articles/PMC3259572/ /pubmed/18308722 http://dx.doi.org/10.1074/jbc.M704532200 Text en Copyright © 2008, The American Society for Biochemistry and Molecular Biology, Inc. Author's Choice Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) applies to Author Choice Articles
spellingShingle Membrane Transport, Structure, Function, and Biogenesis
Bachhuber, Tanja
Almaça, Joana
Aldehni, Fadi
Mehta, Anil
Amaral, Margarida D.
Schreiber, Rainer
Kunzelmann, Karl
Regulation of the Epithelial Na(+) Channel by the Protein Kinase CK2
title Regulation of the Epithelial Na(+) Channel by the Protein Kinase CK2
title_full Regulation of the Epithelial Na(+) Channel by the Protein Kinase CK2
title_fullStr Regulation of the Epithelial Na(+) Channel by the Protein Kinase CK2
title_full_unstemmed Regulation of the Epithelial Na(+) Channel by the Protein Kinase CK2
title_short Regulation of the Epithelial Na(+) Channel by the Protein Kinase CK2
title_sort regulation of the epithelial na(+) channel by the protein kinase ck2
topic Membrane Transport, Structure, Function, and Biogenesis
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259572/
https://www.ncbi.nlm.nih.gov/pubmed/18308722
http://dx.doi.org/10.1074/jbc.M704532200
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