Protein / target

Orexin receptor type 2

HCRTR2O43614Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
4
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Neuropeptide receptor activity

Primary system

Nervous system

Strongest disease association

Abnormality of the skeletal system

Genetic evidence · score 0.69

Therapeutic maturity

Clinically validated target

4 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

4 approved · 5 in clinical development

30 linked trials

Derived from structured UniProt, Open Targets and literature data on this page.

Protein profile

UniProt 2026_02

Canonical identity and biological annotation from UniProt.

Function

G protein-coupled receptor that binds neuropeptides orexin-A and orexin-B, two neuropeptides derived from a common precursor, prepro-orexin (PubMed:26950369, PubMed:33547286, PubMed:35614071, PubMed:9491897). Upon neuropeptide ligand binding, HCRTR2 can couple with both G(q)/11 and G(i)/o heterotrimeric G proteins thereby initiating distinct downstream signaling cascades (PubMed:35614071). Involved in regulating the sleep-wake cycle (By similarity). Contributes to central regulation of glucose homeostasis (By similarity)

Subcellular location

Cell membrane
Domains and Gene Ontology detail (14)

Gene Ontology

  • Cplasma membrane
  • Csynapse
  • Fneuropeptide receptor activity
  • Forexin receptor activity
  • Fpeptide hormone binding
  • Pcellular response to hormone stimulus
  • Pchemical synaptic transmission
  • Pcircadian sleep/wake cycle process
  • Pfeeding behavior
  • Pglucose homeostasis
  • Plocomotion
  • Pneuropeptide signaling pathway

444 aa · 51 kDa

Biological roles

Reactome v97

What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.

Synaptic signallingGOG protein-coupled signallingUniProtMotor controlGO
View supporting evidence

Synaptic signalling

  • ·synapse
  • ·chemical synaptic transmission

G protein-coupled signalling

  • ·G protein-coupled receptor that binds neuropeptides orexin-A and orexin-B, two neuropept…

Motor control

  • ·locomotion
View underlying pathways (2)

Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.

Interaction neighbourhood

STRING v12.0

Proteins with the strongest functional or physical association. Node size and line weight reflect STRING confidence; hover or select a partner to inspect one association.

HCRTGNB1HCRTR1GNAI1GNASGNG2POMCOXR1GRK2GRK5HCRTR2

10 strongest partners — larger node and heavier line mean higher confidence

Functional and physical associations from STRING v12.0. Only associations with this protein are drawn — partner-to-partner links are not part of this evidence.

Drugs targeting this protein

1

Whether each drug engages this protein directly or through a complex, and how many other targets are recorded for it. Direct binders with few recorded targets are listed first.

suvorexant
ApprovedAntagonist

Orexin receptor antagonist

Appears in clinical studies involving insomnia, Alzheimer disease, cocaine use disorder, restless legs syndrome

Acts on a complex — shared with HCRTR1 · 1 of 2 recorded protein targets — narrow recorded profile

ChEMBL mechanism, action type and target identity. Open Targets clinical status and indications.

Translational evidence

Open Targets 26

Why this target matters therapeutically — disease associations, drugs in development, tractability and safety, from Open Targets.

Strongest genetic associations

Human genetic evidence — the most direct causal link between this target and a disease.

Abnormality of the skeletal system0.69

Genetic · overall 0.42

hyperuricemia0.63

Genetic · overall 0.38

circadian rhythm0.58

Genetic · overall 0.35

gout0.57

Genetic · overall 0.34

placental retention0.49

Genetic · overall 0.30

Highest-confidence therapeutic associations

Diseases where a drug acting on this target has already reached clinical development.

insomnia0.98

Clinical · overall 0.60

major depressive disorder0.63

Clinical · overall 0.38

Alzheimer disease0.48

Clinical · overall 0.31

alcohol dependence0.47

Clinical · overall 0.29

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

dislocation0.27

Genetic

Show all associations
insomnia0.60
Abnormality of the skeletal system0.42
major depressive disorder0.38
hyperuricemia0.38
circadian rhythm0.35
gout0.34
Alzheimer disease0.31
placental retention0.30
alcohol dependence0.29
dislocation0.27

Open Targets ranks 643 associations for this target and we store the top 10 by aggregated score. The long tail is largely literature co-mention and RNA-expression evidence, not evidence that this target drives those diseases.

Known drugs · 9 total

LEMBOREXANTApproval

insomnia · insomnia · alcohol dependence

ALMOREXANTPhase 3

insomnia · insomnia · sleep-wake disorder

FILOREXANTPhase 2

diabetic neuropathy · insomnia · major depressive disorder

SB-649868Phase 2

insomnia

SELTOREXANTPhase 3

major depressive disorder · insomnia · Alzheimer disease

DARIDOREXANT HYDROCHLORIDEApproval

insomnia

ORN-0829 HYDRATEPhase 3

insomnia

DARIDOREXANTApproval

insomnia · insomnia · post-traumatic stress disorder

SUVOREXANTApproval

insomnia · Alzheimer disease · cocaine use disorder

Tractability

SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · Druggable FamilyAB · UniProt loc high confAB · GO CC high confAB · UniProt SigP or TMHMMAB · Human Protein Atlas locPR · Small Molecule BinderOC · Advanced Clinical

Clinical trials

30

Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein.

Show remaining trials (24)

COMPLETED · via suvorexant · NCT03077620

RECRUITING · via suvorexant · NCT06484075

COMPLETED · via suvorexant · NCT02785406

COMPLETED · via suvorexant · NCT03789214

RECRUITING · via suvorexant · NCT06326684

COMPLETED · via suvorexant · NCT02593682

ClinicalTrials.gov via the drug-target graph.

Forefront confidence

Synthesis

Our own weighting of the evidence behind each disease association. Human genetics and clinical evidence count for most; literature co-mention counts for little, because two entities sharing an abstract is not evidence that one drives the other.

insomniaModerately supported
0.75
agreement 0.590.90
Clinical96%Literature4%

Open Targets aggregate 0.60 · 2 independent evidence families

Abnormality of the skeletal systemModerately supported
0.69
agreement 0.570.81
Genetic100%

Open Targets aggregate 0.42 · 1 independent evidence family

hyperuricemiaModerately supported
0.63
agreement 0.510.75
Genetic100%

Open Targets aggregate 0.38 · 1 independent evidence family

circadian rhythmModerately supported
0.58
agreement 0.460.70
Genetic100%

Open Targets aggregate 0.35 · 1 independent evidence family

goutModerately supported
0.57
agreement 0.430.70
Genetic100%Literature0%

Open Targets aggregate 0.34 · 2 independent evidence families

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 underlying per-type scores are shown above so the calculation can be checked.

What's happening now

5

Recent activity around this target, drawn from one canonical event stream. Every item is reached through a drug that targets this protein, so each event is news about that drug rather than about the protein directly.

  1. New publication2024-09-14
    Orexin receptor antagonists in the treatment of insomnia associated with psychiatric disorders: a systematic review.

    Translational psychiatry · 2024 · 12 citations · Europe PMC · via suvorexant

  2. New publication2024-08-01
    Suvorexant for Reduction of Delirium in Older Adults After Hospitalization: A Randomized Clinical Trial.

    JAMA network open · 2024 · 9 citations · Europe PMC · via suvorexant

  3. New publication2016-01-01
    Effects of Suvorexant, an Orexin Receptor Antagonist, on Respiration during Sleep In Patients with Obstructive Sleep Apnea.

    Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2016 · 58 citations · Europe PMC · via suvorexant

  4. New publication2015-01-05
    Effects of suvorexant, an orexin receptor antagonist, on breathing during sleep in patients with chronic obstructive pulmonary disease.

    Respiratory medicine · 2015 · 34 citations · Europe PMC · via suvorexant

  5. New publication2012-11-28
    Orexin receptor antagonism for treatment of insomnia: a randomized clinical trial of suvorexant.

    Neurology · 2012 · 239 citations · Europe PMC · via suvorexant

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.