title: VCP/p97 regulates β2AR quality control during receptor biosynthesis.
abstract: GPCRs form signalling complexes with other receptors as part of dimers, G proteins and effector partners. A proteomic screen to identify proteins that associate with the β2-adrenergic receptor (β2AR) identified many of components of the Endoplasmic-Reticulum-Associated Degradation (ERAD) quality control system [1], including the valosin-containing protein (VCP/p97). Here, we validated the interaction of VCP with co-expressed FLAG-β2AR, demonstrating, using an inducible expression system, that the interaction of FLAG-β2AR and VCP is not an artifact of overexpression of the β2AR per se. We knocked down VCP and noted that levels of FLAG-β2AR were increased in cells with lower VCP levels. This increase in the level of FLAG-β2AR did not lead to an increase in the level of functional receptor observed at the cell surface. Similarly, inhibition of the proteasome lead to a dramatic increase in the abundance of TAP-β2AR, while cellular responses again remained unchanged. Taken together, our data suggests that a substantial proportion of the β2AR produced is non-functional and VCP plays a key role in the maturation and trafficking of the β2AR as part of the ERAD quality control process.
authors.affiliation: Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Wargachuk
authors.affiliation: Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
authors.forename: Irina
authors.initials: I
authors.lastname: Glazkova
authors.affiliation: Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Audet
authors.affiliation: Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
authors.forename: Darlaine
authors.initials: D
authors.lastname: Pétrin
authors.affiliation: Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
authors.forename: Phan
authors.initials: P
authors.lastname: Trieu
authors.affiliation: Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada. Electronic address: terence.hebert@mcgill.ca.
authors.forename: Terence E
authors.initials: TE
authors.lastname: Hébert
mesh_terms: D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D006801:Humans; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects; D059748:Proteolysis / Q000187:drug effects; D018343:Receptors, Adrenergic, beta-2 / Q000096:biosynthesis*; D015203:Reproducibility of Results; D015398:Signal Transduction / Q000187:drug effects; D000074405:Valosin Containing Protein / Q000378:metabolism*
chemical_list: D061988:Proteasome Inhibitors; D018343:Receptors, Adrenergic, beta-2; D046988:Proteasome Endopeptidase Complex; D000074405:Valosin Containing Protein