Endosomal transport of ErbB-2: mechanism for nuclear entry of the cell surface receptor

Mol Cell Biol. 2005 Dec;25(24):11005-18. doi: 10.1128/MCB.25.24.11005-11018.2005.

Abstract

The cell membrane receptor ErbB-2 migrates to the nucleus. However, the mechanism of its nuclear translocation is unclear. Here, we report a novel mechanism of its nuclear localization that involves interaction with the transport receptor importin beta1, nuclear pore protein Nup358, and a host of players in endocytic internalization. Knocking down importin beta1 using small interfering RNA oligonucleotides or inactivation of small GTPase Ran by RanQ69L, a dominant-negative mutant of Ran, causes a nuclear transport defect of ErbB-2. Mutation of a putative nuclear localization signal in ErbB-2 destroys its interaction with importin beta1 and arrests nuclear translocation, while inactivation of nuclear export receptor piles up ErbB-2 within the nucleus. Additionally, blocking of internalization by a dominant-negative mutant of dynamin halts its nuclear localization. Thus, the cell membrane-embedded ErbB-2, through endocytosis using the endocytic vesicle as a vehicle, importin beta1 as a driver and Nup358 as a traffic light, migrates from the cell surface to the nucleus. This novel mechanism explains how a receptor tyrosine kinase on the cell surface can be translocated into the nucleus. This pathway may serve as a general mechanism to allow direct communication between cell surface receptors and the nucleus, and our findings thus open a new era in understanding direct trafficking between the cell membrane and nucleus.

Publication types

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

MeSH terms

  • Active Transport, Cell Nucleus
  • Cell Nucleus / chemistry
  • Cell Nucleus / metabolism*
  • Cells, Cultured
  • Clathrin / metabolism
  • Endocytosis*
  • Endosomes / metabolism
  • Exportin 1 Protein
  • Humans
  • Karyopherins / genetics
  • Karyopherins / metabolism
  • Molecular Chaperones / metabolism*
  • Mutation
  • Nuclear Localization Signals / genetics
  • Nuclear Localization Signals / metabolism
  • Nuclear Pore Complex Proteins / metabolism*
  • Receptor, ErbB-2 / analysis
  • Receptor, ErbB-2 / metabolism*
  • Receptors, Cell Surface / analysis
  • Receptors, Cell Surface / metabolism*
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • beta Karyopherins / analysis
  • beta Karyopherins / metabolism*
  • ran GTP-Binding Protein / genetics
  • ran GTP-Binding Protein / metabolism

Substances

  • Clathrin
  • KPNB1 protein, human
  • Karyopherins
  • Molecular Chaperones
  • Nuclear Localization Signals
  • Nuclear Pore Complex Proteins
  • Receptors, Cell Surface
  • Receptors, Cytoplasmic and Nuclear
  • beta Karyopherins
  • ran-binding protein 2
  • Receptor, ErbB-2
  • ran GTP-Binding Protein