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Protein / target

Prostacyclin receptor

Encoded byPTGIRP43119Homo sapiensSwiss-Prot
UniProt: P43119Ensembl: ENSG00000160013HGNC: HGNC:9602NCBI Gene: 5739
Clinically validated
Therapeutic maturity
7
Approved medicines
Open Targets target-level
View by indication →
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Guanyl-nucleotide exchange factor

Strongest disease association

Adverse effect

Via encoding gene PTGIR · Genetic evidence · score 0.52

Therapeutic position

Established drug target

Small molecules

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 overview

Receptor for prostacyclin (prostaglandin I2 or PGI2).

View complete UniProt function annotation

Receptor for prostacyclin (prostaglandin I2 or PGI2). The activity of this receptor is mediated by G(s) proteins which activate adenylate cyclase

Subcellular location

Cell membrane
Domains and Gene Ontology detail (11)

Gene Ontology

  • Ccytosol
  • Cplasma membrane
  • Fguanyl-nucleotide exchange factor activity
  • Fprostacyclin receptor activity
  • Padenylate cyclase-activating G protein-coupled receptor signaling pathway
  • Pcell-cell signaling
  • PG protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger
  • Pinflammatory response
  • Pnegative regulation of platelet-derived growth factor receptor signaling pathway
  • Pnegative regulation of smooth muscle cell proliferation
  • Ppositive regulation of cytosolic calcium ion concentration

386 aa · 41 kDa

Biological roles

Reactome v97

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

Growth-factor signallingGOG protein-coupled signallingGO
View supporting evidence

Growth-factor signalling

  • ·negative regulation of platelet-derived growth factor receptor signaling pathway

G protein-coupled signalling

  • ·adenylate cyclase-activating G protein-coupled receptor signaling pathway
  • ·G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messen…
View underlying pathways (3)
Prostanoid ligand receptors
Prostacyclin signalling through prostacyclin receptor
G alpha (s) signalling events

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.

GNASPTGISTBXA2RPTGS1GNG8PTGS2PDZK1SRCGNGT2CYSLTR2PTGIR

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.

Approved medicines with mapped indications

2 medicines · 3 areas

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.

Hypertension, Pulmonary2 medicines
iloprostselexipag
Thrombosis2 medicines
iloprostselexipag
Familial Primary Pulmonary Hypertension1 medicine
selexipag

7 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

2

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.

selexipag
Narrow target profileApprovedAgonist

Prostanoid IP receptor agonist

Indicated for Familial Primary Pulmonary Hypertension, Hypertension, Pulmonary, Thrombosis

Direct interaction with this protein · Only this protein recorded as a target

iloprost
Narrow target profileApprovedAgonist

Prostanoid IP receptor agonist

Indicated for Hypertension, Pulmonary, Thrombosis

Direct interaction with this protein · Only this protein recorded as a target

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

Translational evidence

Open Targets 26

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 PTGIR

Gene-level evidence surfaced through the gene PTGIRthat 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.

Pulmonary arterial hypertension
0.76Well supported

Clinical evidence dominant · Open Targets 0.61

Hypertension, Pulmonary
0.72Moderately supported

Clinical evidence dominant · Open Targets 0.58

Idiopathic pulmonary arterial hypertension
0.63Moderately supported

Clinical evidence dominant · Open Targets 0.51

Adverse effect
0.52Moderately supported

Genetic evidence dominant · Open Targets 0.31

Neurodegenerative Diseases
0.31Preliminary

Pathway evidence dominant · Open Targets 0.47 · no direct causal or clinical evidence

View evidence synthesis (5)
Pulmonary arterial hypertensionWell supported
0.76
agreement 0.60–0.91
Clinical94%Literature6%

Open Targets aggregate 0.61 · 2 independent evidence families

Hypertension, PulmonaryModerately supported
0.72
agreement 0.57–0.88
Clinical97%Literature3%

Open Targets aggregate 0.58 · 2 independent evidence families

Idiopathic pulmonary arterial hypertensionModerately supported
0.63
agreement 0.48–0.79
Clinical97%Literature3%

Open Targets aggregate 0.51 · 2 independent evidence families

Adverse effectModerately supported
0.52
agreement 0.40–0.64
Genetic100%

Open Targets aggregate 0.31 · 1 independent evidence family

Neurodegenerative DiseasesPreliminary
0.31
agreement 0.08–0.54
Pathway100%

Open Targets aggregate 0.47 · 1 independent evidence family · no direct causal or clinical evidence

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 associations
Pulmonary arterial hypertension0.61
Hypertension, Pulmonary0.58
Idiopathic pulmonary arterial hypertension0.51
Neurodegenerative Diseases0.47
Adverse effect0.31

Drug development

10 compounds recorded · 7 approved · 3 in clinical development

Open Targets' development universe — every compound recorded against the target at any stage, not all approved medicines. Distinct from the 2 drugs that target this protein in Forefront's canonical graph (2 with a mapped approved indication, shown above): these count different sets and are not a subset relation.

View all recorded compounds (10)
ESUBERAPROSTPhase 3
TREPROSTINILApproval
RALINEPAGPhase 3
ILOPROSTApproval
EPOPROSTENOLApproval
EPOPROSTENOL SODIUMApproval
TREPROSTINIL SODIUMApproval
TREPROSTINIL DIOLAMINEPhase 3
ILOPROST TROMETHAMINEApproval
SELEXIPAGApproval

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

Approved Drug and Structure with Ligand support this modality.

Antibodies — Emerging

Feasibility evidence (go cc high conf and uniprot loc med conf) — no clinical-stage drug of this modality recorded.

Protein degraders — Emerging

Feasibility evidence (small molecule binder) — no clinical-stage drug of this modality recorded.

View underlying tractability evidence (8)
SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · Druggable FamilyAB · GO CC high confAB · UniProt loc med confAB · UniProt SigP or TMHMMPR · Small Molecule Binder

Raw Open Targets tractability assessment buckets, by modality.

Safety-related annotations

aspirin-intolerant asthmaClinPGx

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

30

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.

A Multicentre Randomised Cross-over Trial of Disease Specific Therapy in Patients With Pulmonary Arterial Hypertension (PAH) Implanted With Pulmonary Artery Pressure and Cardiac Rhythm Monitoring Devices (CardioMEMS/ConfirmRx)PHASE4

RECRUITING · via selexipag · NCT05825417

Evaluation of the Efficacy of Iloprost in the Management of Vaso-occlusive Crises in Adult Patients With Sickle Cell Disease: Multicenter, Randomized, Double-blind, Placebo-controlled StudyPHASE3

NOT_YET_RECRUITING · via iloprost · NCT07498309

A Prospective, Open-label, Platform Study for Long-term Follow-up of Participants Using Study Intervention in Pulmonary Hypertension Parent StudiesPHASE3

RECRUITING · via selexipag · NCT05179876

A Randomized, Multicenter, Double-Blind, Placebo-Controlled, Parallel-Group Study With Open-Label Extension Period to Assess the Efficacy and Safety of Selexipag as Add-On Treatment to Standard of Care in Children Aged >=2 to <18 Years With Pulmonary Arterial HypertensionPHASE3

ACTIVE_NOT_RECRUITING · via selexipag · NCT04175600

View all trials (26)
Efficacy and Safety of 72-hour Infusion of Prostacyclin (1 ng/kg/Min) in Mechanically Ventilated Patients With Infectious Pulmonary Endotheliopathy - a Multicenter Randomized, Placebo-controlled, Blinded, Investigator-initiated TrialPHASE2

RECRUITING · via iloprost · NCT06319274

A Prospective, Multicenter, Open Label, Single Arm, Phase 2 Study to Investigate the Safety, Tolerability and Pharmacokinetics of Selexipag in Children With Pulmonary Arterial HypertensionPHASE2

ACTIVE_NOT_RECRUITING · via selexipag · NCT03492177

Inhaled Iloprost and Exercise Hemodynamics and Ventricular Performance in Heart Failure With Preserved Ejection Fraction - the ILO-HOPE Clinical TrialPHASE4

UNKNOWN · via iloprost · NCT03620526

A Multi-center, Double-blind, Placebo-controlled Phase 4 Study in Patients With Pulmonary Arterial Hypertension to Assess the Effect of Selexipag on Daily Life Physical Activity and Patient's Self-reported Symptoms and Their ImpactsPHASE4

COMPLETED · via selexipag · NCT03078907

Inhaled Iloprost for Sarcoidosis Associated Pulmonary HypertensionPHASE4

COMPLETED · via iloprost · NCT00403650

Optimization of Treatment in Patients With Severe Peripheral Ischemia (Fontaine Stage IIb), Unsuitable or Suitable to Surgical Revascularization / Endovascular With Reference to the Change of Pain-free Walking Distance and Other EndpointsPHASE4

COMPLETED · via iloprost · NCT01718288

A Multicenter, Single-arm, Open-label, Long-term Follow-up Safety Study of Selexipag in Participants Who Participated in a Previous Selexipag StudyPHASE3

COMPLETED · via selexipag · NCT04565990

Efficacy and Safety of 72-hour Infusion of Prostacyclin (1 Nanogram(ng)/Kilo(kg)/Minute(Min)) in Patients With Septic Shock Induced Endotheliopathy - a Multicentre Randomized, Placebo-controlled, Blinded, Investigator-initiated Trial"PHASE2/PHASE3

COMPLETED · via iloprost · NCT04123444

" ILOPROST for Treatment of Septic Shock With Persistent Microperfusion Defects ", a Double-blind, Randomized Controlled Trial:The I-MICRO TrialPHASE3

COMPLETED · via iloprost · NCT03788837

Therapeutic Iloprost for the Treatment of Acute Respiratory Distress Syndrome (ARDS) (the ThIlo-Trial)PHASE3

COMPLETED · via iloprost · NCT03111212

A Multicenter, Randomized, Double-blind, Placebo-controlled, Parallel-group, Group-sequential, Adaptive, Phase 3 Study With Open-label Extension Period to Assess the Efficacy and Safety of Selexipag as an add-on to Standard of Care Therapy in Subjects With Inoperable or Persistent/Recurrent After Surgical and/or Interventional Treatment Chronic Thromboembolic Pulmonary HypertensionPHASE3

TERMINATED · via selexipag · NCT03689244

A Multicenter, Open-label, Single-sequence Cross-over Study to Assess Safety, Tolerability, and Pharmacokinetics of Intravenous Selexipag in Subjects With Stable Pulmonary Arterial Hypertension Switching From an Oral Stable Dose of SelexipagPHASE3

COMPLETED · via selexipag · NCT03187678

The Efficacy and Safety of Initial Triple Versus Initial Dual Oral Combination Therapy in Patients With Newly Diagnosed Pulmonary Arterial Hypertension: A Multi-center, Double-blind, Placebo-controlled, Phase 3b StudyPHASE3

COMPLETED · via selexipag · NCT02558231

Multicenter, Open-label, Single-group Study to Assess the Tolerability and the Safety of the Transition From Inhaled Treprostinil to Oral Selexipag in Adult Patients With Pulmonary Arterial HypertensionPHASE3

COMPLETED · via selexipag · NCT02471183

Phase Ⅲ Study of the Initial Combination of Bosentan With Iloprost in the Treatment of Pulmonary Arterial Hypertension PatientsPHASE3

UNKNOWN · via iloprost · NCT01712997

A Multi-center, Non-randomized, Open Label, Single-arm Study to Evaluate the Efficacy, Safety, and Pharmacokinetics (PK) of BAY q 6256 (Iloprost) Inhalation in Patients With Pulmonary Arterial Hypertension (PAH)PHASE3

COMPLETED · via iloprost · NCT01469169

A Multicenter, Double-blind, Placebo-controlled Phase 3 Study Assessing the Safety and Efficacy of Selexipag on Morbidity and Mortality in Patients With Pulmonary Arterial HypertensionPHASE3

COMPLETED · via selexipag · NCT01106014

Effect of Iloprost Inhalation Before and During Extracorporeal Circulation (ECC) on Perioperative Morbidity and Outcome in High Risk Cardiac Surgical PatientsPHASE3

COMPLETED · via iloprost · NCT00927654

A Multicenter, Double-blind, Randomized Study Comparing the Safety and Tolerability of Iloprost Inhalation Solution Delivered by I-neb Utilizing Power Disc-15 and Power Disc-6 in Patients With Symptomatic Pulmonary Arterial HypertensionPHASE3

COMPLETED · via iloprost · NCT00709098

A Multicenter, Double-blind, Randomized, Placebo-controlled, Crossover Study to Assess the Effects of a Single Dose of Iloprost Power 15 on Exercise Capacity in Patients With Symptomatic Pulmonary Arterial HypertensionPHASE3

COMPLETED · via iloprost · NCT00709956

Iloprost for Prevention of Contrast-Mediated Nephropathy in High-Risk Patients With Preexisting Renal Dysfunction Undergoing a Coronary ProcedurePHASE2/PHASE3

COMPLETED · via iloprost · NCT00345501

Open-label, Uncontrolled, Long-term Surveillance Study of Iloprost Aerosol Inhalation Therapy in the Treatment of Patients With Primary or Secondary Pulmonary Hypertension. Follow-up Program for Patients Who Completed 12 Weeks in Study ME97218/300180.PHASE3

COMPLETED · via iloprost · NCT00185315

Phase III Randomized, Double-Blind, Placebo-Controlled Study of Oral Iloprost for Raynaud's Phenomenon Secondary to Systemic SclerosisPHASE3

COMPLETED · via iloprost · NCT00004786

Phase II Trial of Oral Iloprost for the Precision Chemoprevention of Lung CancerPHASE2

WITHDRAWN · via iloprost · NCT05411107

A Multicenter, Randomized, Double-Blind, Placebo-Controlled Study in Participants With Sarcoidosis-Associated Pulmonary Hypertension (SAPH) to Assess the Efficacy and Safety of Oral Selexipag.PHASE2

TERMINATED · via selexipag · NCT03942211

Selexipag for the Treatment of Schistosomiasis-Associated Pulmonary Arterial HypertensionPHASE2

UNKNOWN · via selexipag · NCT04589390

ClinicalTrials.gov via the drug-target graph.

What's happening now

5

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.

  1. Regulatory approval2026-07-10

    Approval: ILOPROST (ANDA214997)

    fda · regulatory · fda · via iloprost

  2. Regulatory approval2016-05-12

    Approval: Uptravi (EMA)

    ema · regulatory · ema · via selexipag

  3. New publication2015-12-01
    Selexipag for the Treatment of Pulmonary Arterial Hypertension.

    The New England journal of medicine · 2015 · 686 citations · Europe PMC · via selexipag

  4. New publication2011-06-01
    Oral iloprost improves endobronchial dysplasia in former smokers.

    Cancer prevention research (Philadelphia, Pa.) · 2011 · 84 citations · Europe PMC · via iloprost

  5. Regulatory approval2003-09-15

    Approval: Ventavis (EMA)

    ema · regulatory · ema · via iloprost

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.

Related family literature

1

Papers about “Receptors, Prostaglandin” — a broader family this protein belongs to. Shown as context; not counted as papers specifically about this protein.

Prostaglandins and inflammation.

Ricciotti E · Arteriosclerosis, thrombosis, and vascular biology · 2011

via Receptors, Prostaglandin

Europe PMC literature, reached through curated HGNC family membership. Membership is a taxonomic relationship — it does not imply this protein participates in every mechanism these papers discuss.