Lackman, J. J., Markkanen, P. M. H., Hogue, M., Bouvier, M., & Petäjä-Repo, U. E. (2014). N-Glycan-dependent and -independent Quality Control of Human δ Opioid Receptor N-terminal Variants. Journal of Biological Chemistry, 289(25), 17830–17842. https://doi.org/10.1074/jbc.m114.566273
N-glycan-dependent and -independent quality control of human δ opioid receptor N-terminal variants
|Author:||Lackman, Jarkko J.1; Markkanen, Piia M. H.1; Hogue, Mireille2;|
1Department of Anatomy and Cell Biology and the Medical Research Center Oulu, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland
2Department of Biochemistry, Institute for Research in Immunology and Cancer and Groupe de Recherche Universitaire sur le Médicament, Université de Montréal, Montréal, Québec H3C 3J7, Canada
|Online Access:||PDF Full Text (PDF, 1.7 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2019120545771
American Society for Biochemistry and Molecular Biology,
|Publish Date:|| 2019-12-05
Quality control (QC) in the endoplasmic reticulum (ER) scrutinizes newly synthesized proteins and directs them either to ER export or ER-associated degradation (ERAD). Here, we demonstrate that the human δ-opioid receptor (hδOR) is subjected to ERQC in both N-glycan-dependent and -independent manners. This was shown by investigating the biosynthesis and trafficking of wild-type and non-N-glycosylated F27C variants in metabolic pulse-chase assays coupled with flow cytometry and cell surface biotinylation. Both QC mechanisms distinguished the minute one-amino acid difference between the variants, targeting a large fraction of hδOR-Cys²⁷ to ERAD. However, the N-glycan-independent QC was unable to compensate the N-glycan-dependent pathway, and some incompletely folded non-N-glycosylated hδOR-Cys²⁷ reached the cell surface in conformation incompatible with ligand binding. The turnover of receptors associating with the molecular chaperone calnexin (CNX) was significantly slower for the hδOR-Cys²⁷, pointing to an important role of CNX in the hδOR N-glycan-dependent QC. This was further supported by the fact that inhibiting the co-translational interaction of hδOR-Cys²⁷ precursors with CNX led to their ERAD. Opioid receptor pharmacological chaperones released the CNX-bound receptors to ER export and, furthermore, were able to rescue the Cys²⁷ variant from polyubiquitination and retrotranslocation to the cytosol whether carrying N-glycans or not. Taken together, the hδOR appears to rely primarily on the CNX-mediated N-glycan-dependent QC that has the capacity to assist in folding, whereas the N-glycan-independent mechanism constitutes an alternative, although less accurate, system for directing misfolded/incompletely folded receptors to ERAD, possibly in altered cellular conditions.
Journal of biological chemistry
|Pages:||17830 - 17842|
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
1182 Biochemistry, cell and molecular biology
This work was supported by the Sigrid Jusélius Foundation, the Medical Research Center Oulu and Grant 127199 from the Academy of Finland (to U. E. P.-R.). Jarkko J. Lackman was supported by the Finnish Cultural Foundation.
|Academy of Finland Grant Number:||
127199 (Academy of Finland Funding decision)
This research was originally published in the Journal of Biological Chemistry. Lackman, J. J., Markkanen, P. M. H., Hogue, M., Bouvier, M., & Petäjä-Repo, U. E.. N-Glycan-dependent and -independent Quality Control of Human δ Opioid Receptor N-terminal Variants. J. Biol. Chem. 2012; 289:17830-17842. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.