A Role for ADP-ribosylation Factor 6 in the Processing of G-protein-coupled Receptors

• Published in: The Journal of biological chemistry 2006-04, Vol.281 (17), p.12178-12186
• Main Authors: Madziva, Michael T., Birnbaumer, Mariel
• Format: Article
• Language: English
• Subjects: ADP-Ribosylation Factors - metabolism; Cell Line; Cell Membrane - metabolism; Endocytosis; Endoplasmic Reticulum - metabolism; Golgi Apparatus - metabolism; Humans; Kidney - metabolism; Protein Processing, Post-Translational; Protein Transport; Receptor, Muscarinic M2 - metabolism; Receptors, G-Protein-Coupled - metabolism; Receptors, Vasopressin - genetics; Receptors, Vasopressin - metabolism; Vacuoles - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M601357200

After agonist-induced internalization, the vasopressin V2 receptor (V2R) does not recycle to the plasma membrane. The ADP-ribosylation factor (ARF) proteins initiate vesicular intracellular traffic by promoting the recruitment of adaptor proteins; thus, we sought to determine whether ARF6 could promote V2 R recycling. Neither the agonist-induced internalization nor the recycling of the V2 Rwas regulated by ARF6, but a constitutively active mutant of ARF6 reduced cell-surface V2Rs 10-fold in the absence of agonist treatment. Visualization of the ARF6 mutant-expressing cells revealed a vacuolar-staining pattern of the V2R instead of the normal plasmamembrane expression. Analysis of V2R maturation revealed that reduced cell-surface expression was due to the diminished ability of the newly synthesized receptor to migrate from the endoplasmic reticulum to the Golgi network. The same mechanism affected processing of the V1aR and acetylcholine M2 receptors. Therefore, ARF6 controls the exit of the V2 and other receptors from the endoplasmic reticulum in addition to its established role in the trafficking of plasma-membrane-derived vesicles.