Alpha2B-adrenergic receptor interaction with tubulin controls its transport from the endoplasmic reticulum to the cell surface

J Biol Chem. 2011 Apr 22;286(16):14080-9. doi: 10.1074/jbc.M111.222323. Epub 2011 Feb 28.

Abstract

It is well recognized that the C terminus (CT) plays a crucial role in modulating G protein-coupled receptor (GPCR) transport from the endoplasmic reticulum (ER) to the cell surface. However the molecular mechanisms that govern CT-dependent ER export remain elusive. To address this issue, we used α(2B)-adrenergic receptor (α(2B)-AR) as a model GPCR to search for proteins interacting with the CT. By using peptide-conjugated affinity matrix combined with proteomics and glutathione S-transferase fusion protein pull-down assays, we identified tubulin directly interacting with the α(2B)-AR CT. The interaction domains were mapped to the acidic CT of tubulin and the basic Arg residues in the α(2B)-AR CT, particularly Arg-437, Arg-441, and Arg-446. More importantly, mutation of these Arg residues to disrupt tubulin interaction markedly inhibited α(2B)-AR transport to the cell surface and strongly arrested the receptor in the ER. These data provide the first evidence indicating that the α(2B)-AR C-terminal Arg cluster mediates its association with tubulin to coordinate its ER-to-cell surface traffic and suggest a novel mechanism of GPCR export through physical contact with microtubules.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Membrane / metabolism*
  • Endoplasmic Reticulum / metabolism*
  • Glutathione Transferase / metabolism
  • Humans
  • Microtubules / metabolism
  • Molecular Sequence Data
  • Protein Binding
  • Protein Structure, Tertiary
  • Protein Transport
  • Rats
  • Receptors, Adrenergic, alpha-2 / metabolism*
  • Receptors, G-Protein-Coupled / metabolism
  • Sequence Homology, Amino Acid
  • Tubulin / chemistry*

Substances

  • Receptors, Adrenergic, alpha-2
  • Receptors, G-Protein-Coupled
  • Tubulin
  • Glutathione Transferase