Evidence map›Paper›PMID 42752995›Full record

ArticlePharmacology research & perspectives2026

Naltrexone, Naloxone, Morphine, and Fentanyl Pharmacologically Chaperone a Mutant μ-Opioid Receptor via an Endoplasmic Reticulum Exit Site-Dependent Pathway.

Stephen N Grant, Matthew J Mulcahy, Henry A Lester

Abstract read
In one paragraph

Article in Pharmacology research & perspectives, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Stephen N GrantDivision of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA.ORCID https://orcid.org/0000-0003-0923-8886
Matthew J MulcahyDivision of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA.
Henry A LesterDivision of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA.

Funding

Beta2 nicotine receptor subunits: biomarkers for dependenceR01DA036061 · NIDA · CALIFORNIA INSTITUTE OF TECHNOLOGY · PI LESTER, HENRY A. · 2014 to 2018
$2.5M
Tools for inside-out pharmacology: nicotinic agentsR01DA037161 · NIDA · CALIFORNIA INSTITUTE OF TECHNOLOGY · PI LESTER, HENRY A. · 2013 to 2016
$1.3M
Menthol as a chaperone for nicotonic receptorsR21DA037743 · NIDA · CALIFORNIA INSTITUTE OF TECHNOLOGY · PI LESTER, HENRY A. · 2014 to 2015
$413k
Molecular dissection of acute and chronic menthol interactionsF31DA046122 · NIDA · CALIFORNIA INSTITUTE OF TECHNOLOGY · PI GRANT, STEPHEN NICHOLAS · 2019 to 2021
$119k
NIDA NIH HHS F31 DA046122NIDA NIH HHS R01 DA036061NIDA NIH HHS R01 DA037161NIDA NIH HHS R21 DA037743NIH HHS DA036061NIH HHS DA037161NIH HHS DA037743NIH HHS DA046122
6 · The paper itself

Abstract

Opioid receptor antagonists increase the plasma membrane density of μ-opioid receptors (MOR) in vivo, thereby inducing "supersensitivity" to opioid agonists. This phenomenon increases the risk of overdose in patients that were being treated with naltrexone (Ntx), a popular MOR antagonist. Although there are many studies on the effects of ligands on the plasma membrane density of MORs, their effects on MOR trafficking from the endoplasmic reticulum (ER) via endoplasmic reticulum exit sites (ERES) have not been investigated. Using fluorescently tagged Sec24 to visualize ERES and a highly ER-retained μ-opioid receptor (MOR) point mutant, MOR[N190K], we measured ERES levels after incubation in various opioid receptor ligands. Data from sensitized emission Förster resonance energy transfer (FRET) show that MOR[N190K] interacts with Sec24D. We observe that Ntx, naloxone, morphine, and fentanyl increase the fraction of the cytoplasm occupied by ERES. In contrast, buprenorphine, methadone, and two allosteric modulators have no substantial effect on ERES levels. Mutating S375, an important phosphorylation site for MOR internalization, decreased morphine and fentanyl's pharmacological chaperoning abilities but did not affect Ntx's pharmacological chaperoning abilities. Ntx did not change intracellular cyclic adenosine monophosphate (cAMP) concentrations, so global trafficking is not expected to change. We also find that antagonist-induced pharmacological chaperoning depends on retrotransport from the Golgi as brefeldin A (BFA) treatment prevented pharmacological chaperoning. These data reveal new understandings of how opioid ligands change MOR trafficking from the ER and can help us better understand the pathophysiology of opioid use disorder.

Indexed as

Endoplasmic ReticulumMorphineNaltrexoneNarcotic AntagonistsReceptors, Opioid, muAnimalsFentanylFluorescence Resonance Energy TransferHEK293 CellsHumansMutationNaloxoneProtein TransportVesicular Transport ProteinsFentanylMorphineNaloxoneNaltrexoneNarcotic AntagonistsReceptors, Opioid, muVesicular Transport Proteinsendoplasmic reticulummicroscopyopioidsμ‐Opioid receptor

Identifiers

PMID42752995
PMCPMC13585096

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.