Ubiquitin-dependent regulation of phospho-AKT dynamics by the ubiquitin E3 ligase, NEDD4-1, in the insulin-like growth factor-1 response

J Biol Chem. 2013 Jan 18;288(3):1674-84. doi: 10.1074/jbc.M112.416339. Epub 2012 Nov 29.

Abstract

AKT is a critical effector kinase downstream of the PI3K pathway that regulates a plethora of cellular processes including cell growth, death, differentiation, and migration. Mechanisms underlying activated phospho-AKT (pAKT) translocation to its action sites remain unclear. Here we show that NEDD4-1 is a novel E3 ligase that specifically regulates ubiquitin-dependent trafficking of pAKT in insulin-like growth factor (IGF)-1 signaling. NEDD4-1 physically interacts with AKT and promotes HECT domain-dependent ubiquitination of exogenous and endogenous AKT. NEDD4-1 catalyzes K63-type polyubiquitin chain formation on AKT in vitro. Plasma membrane binding is the key step for AKT ubiquitination by NEDD4-1 in vivo. Ubiquitinated pAKT translocates to perinuclear regions, where it is released into the cytoplasm, imported into the nucleus, or coupled with proteasomal degradation. IGF-1 signaling specifically stimulates NEDD4-1-mediated ubiquitination of pAKT, without altering total AKT ubiquitination. A cancer-derived plasma membrane-philic mutant AKT(E17K) is more effectively ubiquitinated by NEDD4-1 and more efficiently trafficked into the nucleus compared with wild type AKT. This study reveals a novel mechanism by which a specific E3 ligase is required for ubiquitin-dependent control of pAKT dynamics in a ligand-specific manner.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Membrane / metabolism*
  • Cell Nucleus / metabolism*
  • Cytoplasm / metabolism
  • Endosomal Sorting Complexes Required for Transport / deficiency
  • Endosomal Sorting Complexes Required for Transport / genetics*
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Gene Expression Regulation
  • Humans
  • Insulin-Like Growth Factor I / genetics
  • Insulin-Like Growth Factor I / metabolism*
  • Mice
  • Nedd4 Ubiquitin Protein Ligases
  • Phosphorylation
  • Proteasome Endopeptidase Complex / genetics
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Transport
  • Proto-Oncogene Proteins c-akt / genetics*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction
  • Transfection
  • Ubiquitin / genetics*
  • Ubiquitin / metabolism
  • Ubiquitin-Protein Ligases / deficiency
  • Ubiquitin-Protein Ligases / genetics*
  • Ubiquitination

Substances

  • Endosomal Sorting Complexes Required for Transport
  • Ubiquitin
  • Insulin-Like Growth Factor I
  • Nedd4 Ubiquitin Protein Ligases
  • Nedd4 protein, human
  • Nedd4l protein, mouse
  • Ubiquitin-Protein Ligases
  • Proto-Oncogene Proteins c-akt
  • Proteasome Endopeptidase Complex