Serum and Glucocorticoid Inducible Kinases Functionally Regulate ClC-2 Channels

Biochem Biophys Res Commun. 2004 Sep 3;321(4):1001-6. doi: 10.1016/j.bbrc.2004.07.064.

Abstract

ClC-2 participates in the regulation of neuronal excitability, chloride secretion, and cell volume. The ClC-2 sequence contains a consensus site (Ser82) for phosphorylation by the serum and glucocorticoid inducible kinase isoforms SGK1-3. Thus, the present study explored whether ClC-2 is regulated by those kinases. ClC-2 expression in Xenopus oocytes induced inwardly rectifying currents that increased upon coexpression of SGK1-3 and the related kinase PKB. The stimulatory effect was still present upon disruption of the SGK phosphorylation site. SGKs can phosphorylate the ubiquitin ligase Nedd4-2 and prevent Nedd4-2 from binding to its target. Therefore, the role of Nedd4-2 in ClC-2 modulation was investigated. ClC-2 activity decreased upon Nedd4-2 coexpression, an effect reversed by the kinases. According to chemiluminescence ClC-2 membrane abundance was enhanced by SGKs and diminished by Nedd4-2. These observations suggest that SGK1-3 and Nedd4-2 regulate ClC-2 at least in part by modulating ClC-2 abundance at the plasma membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Binding Sites
  • Cell Membrane / metabolism
  • Chloride Channels / genetics
  • Chloride Channels / metabolism*
  • DNA Primers / genetics
  • Endosomal Sorting Complexes Required for Transport
  • Female
  • Immediate-Early Proteins
  • In Vitro Techniques
  • Membrane Potentials
  • Mutagenesis, Site-Directed
  • Nedd4 Ubiquitin Protein Ligases
  • Nuclear Proteins*
  • Oocytes / metabolism
  • Patch-Clamp Techniques
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism
  • Xenopus Proteins
  • Xenopus laevis

Substances

  • Chloride Channels
  • DNA Primers
  • Endosomal Sorting Complexes Required for Transport
  • Immediate-Early Proteins
  • Nuclear Proteins
  • Proto-Oncogene Proteins
  • Recombinant Proteins
  • Xenopus Proteins
  • Nedd4 Ubiquitin Protein Ligases
  • Nedd4 protein, Xenopus
  • nedd4l protein, Xenopus
  • Ubiquitin-Protein Ligases
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • serum-glucocorticoid regulated kinase