α2B-Adrenergic Receptor Interaction with Tubulin Controls Its Transport from the Endoplasmic Reticulum to the Cell Surface

• Published in: The Journal of biological chemistry Vol. 286; no. 16; pp. 14080 - 14089
• Main Authors: Duvernay, Matthew T., Wang, Hong, Dong, Chunmin, Guidry, Jesse J., Sackett, Dan L., Wu, Guangyu
• Format: Journal Article
• Language: English
• Published: 9650 Rockville Pike, Bethesda, MD 20814, U.S.A Elsevier Inc 22.04.2011; American Society for Biochemistry and Molecular Biology
• Subjects: Adrenergic Receptor; Cell Biology; Cell Surface Transport; ER Export; G Protein-coupled Receptors (GPCR); Microtubules; Trafficking; Tubulin; ER Export; G Protein-coupled Receptors (GPCR); Tubulin; Adrenergic Receptor; Microtubules; Trafficking; Cell Surface Transport
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M111.222323

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 α2B-adrenergic receptor (α2B-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 α2B-AR CT. The interaction domains were mapped to the acidic CT of tubulin and the basic Arg residues in the α2B-AR CT, particularly Arg-437, Arg-441, and Arg-446. More importantly, mutation of these Arg residues to disrupt tubulin interaction markedly inhibited α2B-AR transport to the cell surface and strongly arrested the receptor in the ER. These data provide the first evidence indicating that the α2B-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.