Protein / target

Small ribosomal subunit protein uS3

Encoded byRPS3P23396Homo sapiensSwiss-Prot

UniProt: P23396 Ensembl: ENSG00000149273 HGNC: HGNC:10420 NCBI Gene: 6188

Clinically validated

Therapeutic maturity

Approved medicines

Open Targets target-level

View by indication →

Clinical trials

Small-molecule tractable

Druggability

Approved Drug

Protein at a glance

Biological role

DNA-(apurinic or apyrimidinic site) endonuclease

Strongest disease association

Alcohol drinking

Via encoding gene RPS3 · Genetic evidence · score 0.35

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

Component of the small ribosomal subunit.

View complete UniProt function annotation

Component of the small ribosomal subunit (PubMed:23636399, PubMed:8706699). The ribosome is a large ribonucleoprotein complex responsible for the synthesis of proteins in the cell (PubMed:23636399, PubMed:8706699). Has endonuclease activity and plays a role in repair of damaged DNA (PubMed:7775413). Cleaves phosphodiester bonds of DNAs containing altered bases with broad specificity and cleaves supercoiled DNA more efficiently than relaxed DNA (PubMed:15707971). Displays high binding affinity for 7,8-dihydro-8-oxoguanine (8-oxoG), a common DNA lesion caused by reactive oxygen species (ROS) (PubMed:14706345). Has also been shown to bind with similar affinity to intact and damaged DNA (PubMed:18610840). Stimulates the N-glycosylase activity of the base excision protein OGG1 (PubMed:15518571). Enhances the uracil excision activity of UNG1 (PubMed:18973764). Also stimulates the cleavage of the phosphodiester backbone by APEX1 (PubMed:18973764). When located in the mitochondrion, reduces cellular ROS levels and mitochondrial DNA damage (PubMed:23911537). Has also been shown to negatively regulate DNA repair in cells exposed to hydrogen peroxide (PubMed:17049931). Plays a role in regulating transcription as part of the NF-kappa-B p65-p50 complex where it binds to the RELA/p65 subunit, enhances binding of the complex to DNA and promotes transcription of target genes (PubMed:18045535). Represses its own translation by binding to its cognate mRNA (PubMed:20217897). Binds to and protects TP53/p53 from MDM2-mediated ubiquitination (PubMed:19656744). Involved in spindle formation and chromosome movement during mitosis by regulating microtubule polymerization (PubMed:23131551). Involved in induction of apoptosis through its role in activation of CASP8 (PubMed:14988002). Induces neuronal apoptosis by interacting with the E2F1 transcription factor and acting synergistically with it to up-regulate pro-apoptotic proteins BCL2L11/BIM and HRK/Dp5 (PubMed:20605787). Interacts with TRADD following exposure to UV radiation and induces apoptosis by caspase-dependent JNK activation (PubMed:22510408)

Subcellular location

CytoplasmNucleusNucleus, nucleolusMitochondrion inner membraneCytoplasm, cytoskeleton, spindle

Domains and Gene Ontology detail (70)

Domains & features

KH type-2

Gene Ontology

Ccytoplasm
Ccytosol
Ccytosolic ribosome
Ccytosolic small ribosomal subunit
Cendoplasmic reticulum
Cextracellular exosome
Cfocal adhesion
Cmembrane
Cmitochondrial inner membrane
Cmitochondrial matrix
Cmitotic spindle
CNF-kappaB complex

243 aa · 27 kDa · 2 isoforms

Biological roles

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

Transcriptional regulationUniProt · GOApoptosis & cell deathUniProt · GO

View supporting evidence

Transcriptional regulation

·Component of the small ribosomal subunit (PubMed:23636399, PubMed:8706699). The ribosome…
·DNA-binding transcription activator activity, RNA polymerase II-specific
·DNA-binding transcription factor binding
·DNA-templated transcription

Apoptosis & cell death

·Component of the small ribosomal subunit (PubMed:23636399, PubMed:8706699). The ribosome…
·apoptotic process
·regulation of apoptotic process

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

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.

Muscular Dystrophy, Duchenne1 medicine

ataluren

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.

ataluren

ApprovedModulator

80S Ribosome modulator

Indicated for Muscular Dystrophy, Duchenne

Acts on a complex — shared with RPL24, RPL26, RPSA +74 more · 1 of 78 recorded protein targets — broad pharmacology

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 RPS3

Gene-level evidence surfaced through the gene RPS3 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.

Alcohol drinking

0.35Limited support

Genetic evidence dominant · Open Targets 0.21

Influenza, Human

0.30Preliminary

Pathway evidence dominant · Open Targets 0.46 · no direct causal or clinical evidence

COVID-19

0.25Preliminary

Pathway evidence dominant · Open Targets 0.37 · no direct causal or clinical evidence

Severe Acute Respiratory Syndrome

0.24Preliminary

Pathway evidence dominant · Open Targets 0.37 · no direct causal or clinical evidence

Neoplasms

0.13Preliminary

Literature evidence dominant · Open Targets 0.10 · no direct causal or clinical evidence

View evidence synthesis (5)

Alcohol drinkingLimited support

0.35

agreement 0.23–0.47

Genetic100%

Open Targets aggregate 0.21 · 1 independent evidence family

Influenza, HumanPreliminary

0.30

agreement 0.08–0.53

Pathway100%

Open Targets aggregate 0.46 · 1 independent evidence family · no direct causal or clinical evidence

COVID-19Preliminary

0.25

agreement 0.08–0.43

Pathway95%Literature5%

Open Targets aggregate 0.37 · 2 independent evidence families · no direct causal or clinical evidence

Severe Acute Respiratory SyndromePreliminary

0.24

agreement 0.01–0.47

Pathway100%

Open Targets aggregate 0.37 · 1 independent evidence family · no direct causal or clinical evidence

NeoplasmsPreliminary

0.13

agreement 0.00–0.40

Literature100%

Open Targets aggregate 0.10 · 1 independent evidence family · no direct causal or clinical evidence

This ranking differs from Open Targets' own: re-weighting moves genetically-evidenced diseases above more heavily co-mentioned ones. 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

Influenza, Human0.46

COVID-190.37

Severe Acute Respiratory Syndrome0.37

Alcohol drinking0.21

Neurodegenerative Diseases0.17

Neoplasms0.10

Drug development

5 compounds recorded · 1 approved · 4 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 (5)

ZOLIMOMAB ARITOXPhase 2

ATALURENApproval

ELX-02Phase 2

MT-3724Phase 2

CITATUZUMAB BOGATOXPhase 1

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

Protein degraders — Emerging

Feasibility evidence (uniprot ubiquitination and database ubiquitination) — no clinical-stage drug of this modality recorded.

Other modalities — Strong

Advanced Clinical support this modality.

View underlying tractability evidence (10)

SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandAB · UniProt loc high confAB · GO CC high confPR · UniProt UbiquitinationPR · Database UbiquitinationPR · Half-life DataPR · Small Molecule BinderOC · Advanced Clinical

Raw Open Targets tractability assessment buckets, by modality.

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.

An Open Label N of 1 Study to Evaluate the Study and Efficacy of Long-Term Treatment With Ivacaftor in Combination With Ataluren (PTC124) in Subjects With Nonsense Mutation Cystic FibrosisPHASE4

COMPLETED · via ataluren · NCT03256968

A Phase 3, Randomized, Double-blind, Placebo-controlled Efficacy and Safety Study of Ataluren in Patients With Nonsense Mutation Duchenne Muscular Dystrophy and Open-Label ExtensionPHASE3

COMPLETED · via ataluren · NCT03179631

Phase 3 Extension Study of Ataluren (PTC124) in Patients With Nonsense Mutation Cystic FibrosisPHASE3

TERMINATED · via ataluren · NCT02456103

A Phase 3 Efficacy and Safety Study of Ataluren (PTC124®) in Patients With Nonsense Mutation Cystic FibrosisPHASE3

COMPLETED · via ataluren · NCT02139306

View all trials (23)

An Open-Label Safety and Efficacy Study for Patients With Nonsense Mutation Cystic Fibrosis Previously Treated With Ataluren (PTC124)PHASE3

TERMINATED · via ataluren · NCT02107859

A Phase 3 Extension Study of Ataluren (PTC124) in Patients With Nonsense Mutation DystrophinopathyPHASE3

TERMINATED · via ataluren · NCT02090959

A Phase 3 Efficacy and Safety Study of Ataluren in Patients With Nonsense Mutation DystrophinopathyPHASE3

COMPLETED · via ataluren · NCT01826487

An Open-Label Study for Previously Treated Ataluren (PTC124®) Patients With Nonsense Mutation DystrophinopathyPHASE3

COMPLETED · via ataluren · NCT01557400

An Open-Label, Safety Study for Ataluren (PTC124) Patients With Nonsense Mutation DystrophinopathyPHASE3

COMPLETED · via ataluren · NCT01247207

A Phase 3 Extension Study of Ataluren (PTC124®) in Subjects With Nonsense-Mutation-Mediated Cystic FibrosisPHASE3

COMPLETED · via ataluren · NCT01140451

A Phase 3 Efficacy and Safety Study of PTC124 as an Oral Treatment for Nonsense-Mutation-Mediated Cystic FibrosisPHASE3

COMPLETED · via ataluren · NCT00803205

An Open-Label Study Evaluating the Safety and Pharmacokinetics of Ataluren in Children From ≥6 Months to <2 Years of Age With Nonsense Mutation Duchenne Muscular DystrophyPHASE2

COMPLETED · via ataluren · NCT04336826

Phase 2, Non-Interventional, Clinical Study to Assess Dystrophin Levels in Subjects With Nonsense Mutation Duchenne Muscular Dystrophy Who Have Been Treated With Ataluren for ≥9 MonthsPHASE2

COMPLETED · via ataluren · NCT03796637

Nonsense Mutation Aniridia: An Ataluren (PTC124) Phase 2 Extension StudyPHASE2

WITHDRAWN · via ataluren · NCT04117880

Phase 2 Clinical Pharmacology Study to Assess Dystrophin Levels in Subjects With nmDMD Before and After Treatment With AtalurenPHASE2

COMPLETED · via ataluren · NCT03648827

A Phase 2 Randomized, Double-Masked Placebo-Controlled Crossover Safety and Tolerability Study of Ataluren for Drug Resistant Epilepsy in Patients With Nonsense Mutation CDKL5 or Dravet SyndromePHASE2

COMPLETED · via ataluren · NCT02758626

A Phase 2 Study of the Safety, Pharmacokinetics, and Pharmacodynamics of Ataluren (PTC124®) in Patients Aged ≥2 to <5 Years Old With Nonsense Mutation DystrophinopathyPHASE2

COMPLETED · via ataluren · NCT02819557

A Phase 2, Multicenter, Randomized, Double-Masked, Placebo-Controlled Study of the Safety and Efficacy of Ataluren (PTC124) for the Treatment of Nonsense Mutation AniridiaPHASE2

COMPLETED · via ataluren · NCT02647359

A Phase 2 Study of Ataluren (PTC124®) as an Oral Treatment for Nonsense Mutation Methylmalonic AcidemiaPHASE2

TERMINATED · via ataluren · NCT01141075

A Phase 2a Study of Ataluren (PTC124) in Nonambulatory Patients With Nonsense-Mutation-Mediated Duchenne/Becker Muscular DystrophyPHASE2

TERMINATED · via ataluren · NCT01009294

A Phase 2a Study of Ataluren (PTC124) as an Oral Treatment for Nonsense-Mutation-Mediated Hemophilia A and BPHASE2

TERMINATED · via ataluren · NCT00947193

A Phase 2B Extension Study of PTC124 in Subjects With Nonsense-Mutation-Mediated Duchenne and Becker Muscular DystrophyPHASE2

TERMINATED · via ataluren · NCT00847379

A Phase 2a Extension Study of PTC124 in Subjects With Nonsense-Mutation-Mediated Duchenne Muscular DystrophyPHASE2

TERMINATED · via ataluren · NCT00759876

A Phase 2B Efficacy and Safety Study of PTC124 in Subjects With Nonsense-Mutation-Mediated Duchenne and Becker Muscular DystrophyPHASE2

COMPLETED · via ataluren · NCT00592553

A Phase 2 Study of PTC124 as an Oral Treatment for Nonsense-Mutation-Mediated Cystic FibrosisPHASE2

COMPLETED · via ataluren · NCT00458341

A Phase 2 Study of PTC124 as an Oral Treatment for Nonsense-Mutation-Mediated Cystic FibrosisPHASE2

COMPLETED · via ataluren · NCT00237380

A Phase I Study Assessing the Effects of Rifampin on the Pharmacokinetics of Ataluren in Healthy SubjectsPHASE1

COMPLETED · via ataluren · NCT02409004

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 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.

Withdrawn from market2025-03-28
Market withdrawal: Translarna (EMA)
ema · market · ema · via ataluren
New publication2021-02-04
Ataluren for drug-resistant epilepsy in nonsense variant-mediated Dravet syndrome and CDKL5 deficiency disorder.
Annals of clinical and translational neurology · 2021 · 29 citations · Europe PMC · via ataluren
New publication2014-05-15
Ataluren for the treatment of nonsense-mutation cystic fibrosis: a randomised, double-blind, placebo-controlled phase 3 trial.
The Lancet. Respiratory medicine · 2014 · 259 citations · Europe PMC · via ataluren

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.