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Protein / target

Organic anion transporter 3

Encoded bySLC22A8Q8TCC7Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
1
Approved medicines
Open Targets target-level
View by indication →
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Prostaglandin transmembrane transporter

Strongest disease association

Enteritis

Via encoding gene SLC22A8 · Genetic evidence · score 0.23

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

Functions as an organic anion/dicarboxylate exchanger that couples organic anion uptake indirectly to the sodium gradient.

View complete UniProt function annotation

Functions as an organic anion/dicarboxylate exchanger that couples organic anion uptake indirectly to the sodium gradient (PubMed:14586168, PubMed:15644426, PubMed:15846473, PubMed:16455804, PubMed:31553721). Transports organic anions such as estrone 3-sulfate (E1S) and urate in exchange for dicarboxylates such as glutarate or ketoglutarate (2-oxoglutarate) (PubMed:14586168, PubMed:15846473, PubMed:15864504, PubMed:22108572, PubMed:23832370). Plays an important role in the excretion of endogenous and exogenous organic anions, especially from the kidney and the brain (PubMed:11306713, PubMed:14586168, PubMed:15846473). E1S transport is pH- and chloride-dependent and may also involve E1S/cGMP exchange (PubMed:26377792). Responsible for the transport of prostaglandin E2 (PGE2) and prostaglandin F2(alpha) (PGF2(alpha)) in the basolateral side of the renal tubule (PubMed:11907186). Involved in the transport of neuroactive tryptophan metabolites kynurenate and xanthurenate (PubMed:22108572, PubMed:23832370). Functions as a biopterin transporters involved in the uptake and the secretion of coenzymes tetrahydrobiopterin (BH4), dihydrobiopterin (BH2) and sepiapterin to urine, thereby determining baseline levels of blood biopterins (PubMed:28534121). May be involved in the basolateral transport of steviol, a metabolite of the popular sugar substitute stevioside (PubMed:15644426). May participate in the detoxification/ renal excretion of drugs and xenobiotics, such as the histamine H(2)-receptor antagonists fexofenadine and cimetidine, the antibiotic benzylpenicillin (PCG), the anionic herbicide 2,4-dichloro-phenoxyacetate (2,4-D), the diagnostic agent p-aminohippurate (PAH), the antiviral acyclovir (ACV), and the mycotoxin ochratoxin (OTA), by transporting these exogenous organic anions across the cell membrane in exchange for dicarboxylates such as 2-oxoglutarate (PubMed:11669456, PubMed:15846473, PubMed:16455804). Contributes to the renal uptake of potent uremic toxins (indoxyl sulfate (IS), indole acetate (IA), hippurate/N-benzoylglycine (HA) and 3-carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF)), pravastatin, PCG, E1S and dehydroepiandrosterone sulfate (DHEAS), and is partly involved in the renal uptake of temocaprilat (an angiotensin-converting enzyme (ACE) inhibitor) (PubMed:14675047). May contribute to the release of cortisol in the adrenals (PubMed:15864504). Involved in one of the detoxification systems on the choroid plexus (CP), removes substrates such as E1S or taurocholate (TC), PCG, 2,4-D and PAH, from the cerebrospinal fluid (CSF) to the blood for eventual excretion in urine and bile (By similarity). Also contributes to the uptake of several other organic compounds such as the prostanoids prostaglandin E(2) and prostaglandin F(2-alpha), L-carnitine, and the therapeutic drugs allopurinol, 6-mercaptopurine (6-MP) and 5-fluorouracil (5-FU) (By similarity). Mediates the transport of PAH, PCG, and the statins pravastatin and pitavastatin, from the cerebrum into the blood circulation across the blood-brain barrier (BBB). In summary, plays a role in the efflux of drugs and xenobiotics, helping reduce their undesired toxicological effects on the body (By similarity)

Subcellular location

Basolateral cell membrane
Domains and Gene Ontology detail (13)

Gene Ontology

  • Capical plasma membrane
  • Cbasolateral plasma membrane
  • Cextracellular exosome
  • Cplasma membrane
  • Fprostaglandin transmembrane transporter activity
  • Fsolute:inorganic anion antiporter activity
  • Ftransmembrane transporter activity
  • Fxenobiotic transmembrane transporter activity
  • Pmonoatomic ion transport
  • Porganic anion transport
  • Pprostaglandin transport
  • Presponse to toxic substance

542 aa · 60 kDa · 5 isoforms

Approved medicines with mapped indications

1 medicine · 1 area

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.

Gout1 medicine

Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.

Drugs targeting this protein

1

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.

probenecid
Narrow target profileApprovedInhibitor

Solute carrier family 22 member 8 inhibitor

Indicated for Gout

Direct interaction with this protein · 1 of 3 recorded protein targets — narrow recorded profile

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 SLC22A8

Gene-level evidence surfaced through the gene SLC22A8 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.

Gout
0.66Moderately supported

Clinical evidence dominant · Open Targets 0.53

Enteritis
0.23Preliminary

Genetic evidence dominant · Open Targets 0.14

Neurodegenerative Diseases
0.15Preliminary

Pathway evidence dominant · Open Targets 0.23 · no direct causal or clinical evidence

View evidence synthesis (3)
GoutModerately supported
0.66
agreement 0.500.81
Clinical97%Literature3%

Open Targets aggregate 0.53 · 2 independent evidence families

EnteritisPreliminary
0.23
agreement 0.110.35
Genetic100%

Open Targets aggregate 0.14 · 1 independent evidence family

Neurodegenerative DiseasesPreliminary
0.15
agreement 0.000.38
Pathway100%

Open Targets aggregate 0.23 · 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
Gout0.53
Neurodegenerative Diseases0.23
Enteritis0.14

Drug development

2 compounds recorded · 1 approved · 1 in clinical development

Open Targets' development universe — every compound recorded against the target at any stage, not all approved medicines. Distinct from the 1 drug that targets this protein in Forefront's canonical graph (1 with a mapped approved indication, shown above): these count different sets and are not a subset relation.

View all recorded compounds (2)
PROBENECIDApproval
PRATOSARTANPhase 3

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 moleculesStrong

Approved Drug and High-Quality Ligand support this modality.

AntibodiesEmerging

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

Protein degradersEmerging

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

View underlying tractability evidence (7)
SM · Approved DrugSM · High-Quality LigandSM · Druggable FamilyAB · UniProt loc high confAB · GO CC high confAB · UniProt SigP or TMHMMPR · Small Molecule Binder

Raw Open Targets tractability assessment buckets, by modality.

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.

View all trials (26)

COMPLETED · via probenecid · NCT03965351

COMPLETED · via probenecid · NCT00000894

COMPLETED · via probenecid · NCT00288158

COMPLETED · via probenecid · NCT02243631

ClinicalTrials.gov via the drug-target graph.

What's happening now

1

Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for a drug that targets 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. Trial status changed2026-09-03

    An Open-label, Phase 1 Study to Individually Characterize the Food Effect, the Drug-Drug Interaction Effect of OAT Inhibition, and the Drug-Drug Interaction Effect of P-glycoprotein Inhibition on the Pharmacokinetics of MK-8527 in Healthy Adult Participants

    Status changed to Active, not recruiting · ClinicalTrials.gov · via probenecid

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.