cAMP and serum and glucocorticoid-inducible kinase (SGK) regulate the epithelial Na+ channel through convergent phosphorylation of Nedd4-2

Peter M. Snyder, Diane R. Olson, Rajesh Kabra, Ruifeng Zhou, Jennifer C. Steines

Research output: Contribution to journalArticle

163 Citations (Scopus)

Abstract

The epithelial Na+ channel (ENaC) functions as a pathway for epithelial Na+ transport, contributing to Na+ homeostasis and blood pressure control. Vasopressin increases ENaC expression at the cell surface through a pathway that includes cAMP and cAMP-dependent protein kinase (PKA), but the mechanisms that link PKA to ENaC are unknown. Here we found that cAMP regulates Na+ transport in part by inhibiting the function of Nedd4-2, an E3 ubiquitin-protein ligase that targets ENaC for degradation. Consistent with this model, we found that cAMP inhibited Nedd4-2 by decreasing its binding to ENaC. Moreover, decreased Nedd4-2 expression (RNA interference) or overexpression of a dominant negative Nedd4-2 construct disrupted ENaC regulation by cAMP. Nedd4-2 was a substrate for phosphorylation by PKA in vitro and in cells; three Nedd4-2 residues were phosphorylated by PKA and were required for cAMP to inhibit Nedd4-2 (relative functional importance Ser-327 > Ser-221 > Thr-246). Previous work found that these residues are also phosphorylated by serum and glucocorticoid-inducible kinase (SGK), a downstream mediator by which aldosterone regulates epithelial Na+ transport. Consistent with a functional interaction between these pathways, overexpression of SGK blunted ENaC stimulation by cAMP, whereas inhibition of SGK increased stimulation. Conversely, cAMP agonists decreased ENaC stimulation by SGK. The data suggest that cAMP regulates ENaC in part by phosphorylation and inhibition of Nedd4-2. Moreover, Nedd4-2 is a central convergence point for kinase regulation of Na+ transport.

Original languageEnglish (US)
Pages (from-to)45753-45758
Number of pages6
JournalJournal of Biological Chemistry
Volume279
Issue number44
DOIs
StatePublished - Oct 29 2004

Fingerprint

Epithelial Sodium Channels
Phosphorylation
Glucocorticoids
Phosphotransferases
Protein Kinases
serum-inducible kinase
Ubiquitin-Protein Ligases
Pressure control
Blood pressure
RNA Interference
Cyclic AMP-Dependent Protein Kinases
Aldosterone
Vasopressins
Homeostasis
RNA
Blood Pressure
Degradation

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

cAMP and serum and glucocorticoid-inducible kinase (SGK) regulate the epithelial Na+ channel through convergent phosphorylation of Nedd4-2. / Snyder, Peter M.; Olson, Diane R.; Kabra, Rajesh; Zhou, Ruifeng; Steines, Jennifer C.

In: Journal of Biological Chemistry, Vol. 279, No. 44, 29.10.2004, p. 45753-45758.

Research output: Contribution to journalArticle

Snyder, Peter M. ; Olson, Diane R. ; Kabra, Rajesh ; Zhou, Ruifeng ; Steines, Jennifer C. / cAMP and serum and glucocorticoid-inducible kinase (SGK) regulate the epithelial Na+ channel through convergent phosphorylation of Nedd4-2. In: Journal of Biological Chemistry. 2004 ; Vol. 279, No. 44. pp. 45753-45758.
@article{2204ada452554eb5a537f93e058952c1,
title = "cAMP and serum and glucocorticoid-inducible kinase (SGK) regulate the epithelial Na+ channel through convergent phosphorylation of Nedd4-2",
abstract = "The epithelial Na+ channel (ENaC) functions as a pathway for epithelial Na+ transport, contributing to Na+ homeostasis and blood pressure control. Vasopressin increases ENaC expression at the cell surface through a pathway that includes cAMP and cAMP-dependent protein kinase (PKA), but the mechanisms that link PKA to ENaC are unknown. Here we found that cAMP regulates Na+ transport in part by inhibiting the function of Nedd4-2, an E3 ubiquitin-protein ligase that targets ENaC for degradation. Consistent with this model, we found that cAMP inhibited Nedd4-2 by decreasing its binding to ENaC. Moreover, decreased Nedd4-2 expression (RNA interference) or overexpression of a dominant negative Nedd4-2 construct disrupted ENaC regulation by cAMP. Nedd4-2 was a substrate for phosphorylation by PKA in vitro and in cells; three Nedd4-2 residues were phosphorylated by PKA and were required for cAMP to inhibit Nedd4-2 (relative functional importance Ser-327 > Ser-221 > Thr-246). Previous work found that these residues are also phosphorylated by serum and glucocorticoid-inducible kinase (SGK), a downstream mediator by which aldosterone regulates epithelial Na+ transport. Consistent with a functional interaction between these pathways, overexpression of SGK blunted ENaC stimulation by cAMP, whereas inhibition of SGK increased stimulation. Conversely, cAMP agonists decreased ENaC stimulation by SGK. The data suggest that cAMP regulates ENaC in part by phosphorylation and inhibition of Nedd4-2. Moreover, Nedd4-2 is a central convergence point for kinase regulation of Na+ transport.",
author = "Snyder, {Peter M.} and Olson, {Diane R.} and Rajesh Kabra and Ruifeng Zhou and Steines, {Jennifer C.}",
year = "2004",
month = "10",
day = "29",
doi = "10.1074/jbc.M407858200",
language = "English (US)",
volume = "279",
pages = "45753--45758",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "44",

}

TY - JOUR

T1 - cAMP and serum and glucocorticoid-inducible kinase (SGK) regulate the epithelial Na+ channel through convergent phosphorylation of Nedd4-2

AU - Snyder, Peter M.

AU - Olson, Diane R.

AU - Kabra, Rajesh

AU - Zhou, Ruifeng

AU - Steines, Jennifer C.

PY - 2004/10/29

Y1 - 2004/10/29

N2 - The epithelial Na+ channel (ENaC) functions as a pathway for epithelial Na+ transport, contributing to Na+ homeostasis and blood pressure control. Vasopressin increases ENaC expression at the cell surface through a pathway that includes cAMP and cAMP-dependent protein kinase (PKA), but the mechanisms that link PKA to ENaC are unknown. Here we found that cAMP regulates Na+ transport in part by inhibiting the function of Nedd4-2, an E3 ubiquitin-protein ligase that targets ENaC for degradation. Consistent with this model, we found that cAMP inhibited Nedd4-2 by decreasing its binding to ENaC. Moreover, decreased Nedd4-2 expression (RNA interference) or overexpression of a dominant negative Nedd4-2 construct disrupted ENaC regulation by cAMP. Nedd4-2 was a substrate for phosphorylation by PKA in vitro and in cells; three Nedd4-2 residues were phosphorylated by PKA and were required for cAMP to inhibit Nedd4-2 (relative functional importance Ser-327 > Ser-221 > Thr-246). Previous work found that these residues are also phosphorylated by serum and glucocorticoid-inducible kinase (SGK), a downstream mediator by which aldosterone regulates epithelial Na+ transport. Consistent with a functional interaction between these pathways, overexpression of SGK blunted ENaC stimulation by cAMP, whereas inhibition of SGK increased stimulation. Conversely, cAMP agonists decreased ENaC stimulation by SGK. The data suggest that cAMP regulates ENaC in part by phosphorylation and inhibition of Nedd4-2. Moreover, Nedd4-2 is a central convergence point for kinase regulation of Na+ transport.

AB - The epithelial Na+ channel (ENaC) functions as a pathway for epithelial Na+ transport, contributing to Na+ homeostasis and blood pressure control. Vasopressin increases ENaC expression at the cell surface through a pathway that includes cAMP and cAMP-dependent protein kinase (PKA), but the mechanisms that link PKA to ENaC are unknown. Here we found that cAMP regulates Na+ transport in part by inhibiting the function of Nedd4-2, an E3 ubiquitin-protein ligase that targets ENaC for degradation. Consistent with this model, we found that cAMP inhibited Nedd4-2 by decreasing its binding to ENaC. Moreover, decreased Nedd4-2 expression (RNA interference) or overexpression of a dominant negative Nedd4-2 construct disrupted ENaC regulation by cAMP. Nedd4-2 was a substrate for phosphorylation by PKA in vitro and in cells; three Nedd4-2 residues were phosphorylated by PKA and were required for cAMP to inhibit Nedd4-2 (relative functional importance Ser-327 > Ser-221 > Thr-246). Previous work found that these residues are also phosphorylated by serum and glucocorticoid-inducible kinase (SGK), a downstream mediator by which aldosterone regulates epithelial Na+ transport. Consistent with a functional interaction between these pathways, overexpression of SGK blunted ENaC stimulation by cAMP, whereas inhibition of SGK increased stimulation. Conversely, cAMP agonists decreased ENaC stimulation by SGK. The data suggest that cAMP regulates ENaC in part by phosphorylation and inhibition of Nedd4-2. Moreover, Nedd4-2 is a central convergence point for kinase regulation of Na+ transport.

UR - http://www.scopus.com/inward/record.url?scp=8544270944&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=8544270944&partnerID=8YFLogxK

U2 - 10.1074/jbc.M407858200

DO - 10.1074/jbc.M407858200

M3 - Article

C2 - 15328345

AN - SCOPUS:8544270944

VL - 279

SP - 45753

EP - 45758

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 44

ER -