Protein / target
Kappa-type opioid receptor
Protein at a glance
Biological role
G protein-coupled opioid receptor
Strongest disease association
Alcoholism
Therapeutic position
Established drug target
Derived from structured UniProt, Open Targets and literature data on this page.
Protein profile
Canonical identity and biological annotation from UniProt.
Function overview
G protein-coupled opioid receptor that functions as a receptor for endogenous alpha-neoendorphins and dynorphins, but has low affinity for beta-endorphins.
View complete UniProt function annotationHide complete annotation
G protein-coupled opioid receptor that functions as a receptor for endogenous alpha-neoendorphins and dynorphins, but has low affinity for beta-endorphins. Also functions as a receptor for various synthetic opioids and for the psychoactive diterpene salvinorin A. Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of down-stream effectors, such as adenylate cyclase. Signaling leads to the inhibition of adenylate cyclase activity. Inhibits neurotransmitter release by reducing calcium ion currents and increasing potassium ion conductance. Plays a role in the perception of pain. Plays a role in mediating reduced physical activity upon treatment with synthetic opioids. Plays a role in the regulation of salivation in response to synthetic opioids. May play a role in arousal and regulation of autonomic and neuroendocrine functions
Subcellular location
Domains and Gene Ontology detail (46)Hide
Gene Ontology
- Caxon terminus
- Cdendrite
- Cmembrane
- Cmitochondrion
- Cneuron projection
- Cperikaryon
- Cplasma membrane
- Cpostsynaptic membrane
- Cpresynaptic membrane
- Csarcoplasmic reticulum
- Csynaptic vesicle membrane
- CT-tubule
Biological roles
What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.
View supporting evidenceHide supporting evidence
Synaptic signalling
- ·postsynaptic membrane
- ·presynaptic membrane
- ·chemical synaptic transmission
Ion channel gating
- ·positive regulation of potassium ion transmembrane transport
G protein-coupled signalling
- ·G protein-coupled opioid receptor that functions as a receptor for endogenous alpha-neoe…
- ·G protein-coupled opioid receptor activity
- ·adenylate cyclase-inhibiting G protein-coupled receptor signaling pathway
- ·G protein-coupled opioid receptor signaling pathway
View underlying pathways (3)Hide underlying pathways
Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.
Approved medicines with mapped indications
Approved therapies targeting this protein, grouped by what they are approved to treat — the disease-first view of the medicines below. Relationships come from the canonical approved-indication graph (ChEMBL phase-4), the same source as the drug cards.
31 medicines meet Open Targets' target-level approved-medicine definition; the 2 shown here are those on this page with a canonical approved disease indication in the graph. Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.
Drugs targeting this protein
How approved and investigational drugs engage this protein — mechanism and action type, direct vs complex targeting, and how broadly each acts across other targets. A drug-first view (the section above groups the approved ones disease-first); direct binders with few recorded targets are listed first.
Kappa opioid receptor agonist
Indicated for Acute Pain, Chronic Pain, Drug Overdose, Opioid-Related Disorders
Kappa opioid receptor agonist
ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.
Translational evidence
Why this target matters therapeutically, strongest evidence first. Disease associations are gene-level (via the gene that encodes this protein) and open into the full confidence synthesis; the development universe, tractability and safety annotations are target-level, from Open Targets.
Strongest disease associations · via encoding gene OPRK1
Gene-level evidence surfaced through the gene OPRK1 that encodes this protein — not a direct protein–disease relationship. Ranked by Forefront's causal-directness weighting, so genetically- and clinically-evidenced diseases lead over ones that merely share the literature.
View evidence synthesis (5)Hide
The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the per-type scores above show the calculation.
Show all associationsHide all associations
Drug development
38 compounds recorded · 31 approved · 7 in clinical development
View all recorded compounds (10)Hide
Open Targets known-drugs universe. Drug name and highest clinical stage only — the disease relationship is NOT read from this slice (it carries trial-context noise); approved indications come from the canonical graph above.
Tractability
Small molecules — Strong
Antibodies — Emerging
Protein degraders — Emerging
Other modalities — Strong
View underlying tractability evidence (11)Hide
Raw Open Targets tractability assessment buckets, by modality.
Safety-related annotations
Terms indexed against this target in Open Targets' safety data, with their datasource. These are annotations, not causal claims: the direction of effect (whether activation or inhibition is implicated), species and evidence strength are not captured here, so an entry does not mean that modulating this target is known to cause that condition.
Clinical trials
Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein. Ranked by active status, then clinical phase and recency, and spread across the targeting drugs.
View all trials (26)Hide
ClinicalTrials.gov via the drug-target graph.
What's happening now
Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for 2 drugs that target this protein, plus publications where such a drug is a genuine subject. Every item is reached indirectly through the drug, not the protein itself; incidental mentions (a paper that merely measures a drug) and press items are excluded.
- Supplemental approval
Supplemental approval: BUPRENORPHINE (ANDA078633)
- Supplemental approval
Supplemental approval: BUPRENORPHINE (ANDA090819)
- Supplemental approval
Supplemental approval: BUPRENORPHINE (ANDA201760)
- Supplemental approval
Supplemental approval: BUPRENORPHINE (ANDA207276)
- Supplemental approval
Supplemental approval: BUPRENORPHINE (ANDA204937)
- Supplemental approval
Supplemental approval: BUPRENORPHINE (ANDA207490)
- Supplemental approval
Supplemental approval: BUPRENORPHINE (ANDA210162)
- Supplemental approval
Supplemental approval: BUPRENORPHINE (ANDA210272)
- New publicationOpioid use disorder: current trends and potential treatments.
- New publicationNaltrexone/bupropion for binge-eating disorder: A randomized, double-blind, placebo-controlled trial.
- New publicationOpen-label, rapid initiation pilot study for extended-release buprenorphine subcutaneous injection.
- New publicationNaltrexone vs Placebo for the Treatment of Alcohol Dependence: A Randomized Clinical Trial.
Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.