Arrestins and spinophilin competitively regulate Na+,K+-ATPase trafficking through association with a large cytoplasmic loop of the Na+,K+-ATPase

Mol Biol Cell. 2007 Nov;18(11):4508-18. doi: 10.1091/mbc.e06-08-0711. Epub 2007 Sep 5.

Abstract

The activity and trafficking of the Na(+),K(+)-ATPase are regulated by several hormones, including dopamine, vasopressin, and adrenergic hormones through the action of G-protein-coupled receptors (GPCRs). Arrestins, GPCR kinases (GRKs), 14-3-3 proteins, and spinophilin interact with GPCRs and modulate the duration and magnitude of receptor signaling. We have found that arrestin 2 and 3, GRK 2 and 3, 14-3-3 epsilon, and spinophilin directly associate with the Na(+),K(+)-ATPase and that the associations with arrestins, GRKs, or 14-3-3 epsilon are blocked in the presence of spinophilin. In COS cells that overexpressed arrestin, the Na(+),K(+)-ATPase was redistributed to intracellular compartments. This effect was not seen in mock-transfected cells or in cells expressing spinophilin. Furthermore, expression of spinophilin appeared to slow, whereas overexpression of beta-arrestins accelerated internalization of the Na(+),K(+)-ATPase endocytosis. We also find that GRKs phosphorylate the Na(+),K(+)-ATPase in vitro on its large cytoplasmic loop. Taken together, it appears that association with arrestins, GRKs, 14-3-3 epsilon, and spinophilin may be important modulators of Na(+),K(+)-ATPase trafficking.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • 14-3-3 Proteins / metabolism
  • Animals
  • Arrestin / metabolism*
  • Binding, Competitive
  • Cell Line
  • Chlorocebus aethiops
  • Choroid Plexus / metabolism
  • Cytoplasm / metabolism*
  • G-Protein-Coupled Receptor Kinases / metabolism
  • Kidney / metabolism
  • Mice
  • Microfilament Proteins / metabolism*
  • Nerve Tissue Proteins / metabolism*
  • Phosphorylation
  • Protein Binding
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • Protein Transport
  • Rabbits
  • Sodium-Potassium-Exchanging ATPase / genetics
  • Sodium-Potassium-Exchanging ATPase / metabolism*

Substances

  • 14-3-3 Proteins
  • Arrestin
  • Microfilament Proteins
  • Nerve Tissue Proteins
  • Protein Subunits
  • neurabin
  • G-Protein-Coupled Receptor Kinases
  • Sodium-Potassium-Exchanging ATPase