VCP/p97 regulates β
2AR quality control during receptor biosynthesis.
Cell Signal 2016;
30:50-58. [PMID:
27887991 DOI:
10.1016/j.cellsig.2016.11.015]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 11/08/2016] [Accepted: 11/17/2016] [Indexed: 11/20/2022]
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.
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