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Protein / target

Protein mono-ADP-ribosyltransferase PARP3

Encoded byPARP3Q9Y6F1Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
4
Approved medicines
Open Targets target-level
View by indication →
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

NAD+-protein-aspartate ADP-ribosyltransferase

Strongest disease association

Ovarian Neoplasms

Via encoding gene PARP3 · Clinical evidence · score 0.58

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

Mono-ADP-ribosyltransferase that mediates mono-ADP-ribosylation of target proteins and plays a key role in the response to DNA damage.

View complete UniProt function annotation

Mono-ADP-ribosyltransferase that mediates mono-ADP-ribosylation of target proteins and plays a key role in the response to DNA damage (PubMed:16924674, PubMed:19354255, PubMed:20064938, PubMed:21211721, PubMed:21270334, PubMed:23742272, PubMed:24598253, PubMed:25043379, PubMed:28447610). Mediates mono-ADP-ribosylation of glutamate, aspartate or lysine residues on target proteins (PubMed:20064938, PubMed:25043379). In contrast to PARP1 and PARP2, it is not able to mediate poly-ADP-ribosylation (PubMed:25043379). Involved in DNA repair by mediating mono-ADP-ribosylation of a limited number of acceptor proteins involved in chromatin architecture and in DNA metabolism, such as histone H2B, XRCC5 and XRCC6 (PubMed:16924674, PubMed:24598253). ADP-ribosylation follows DNA damage and appears as an obligatory step in a detection/signaling pathway leading to the reparation of DNA strand breaks (PubMed:16924674, PubMed:21211721, PubMed:21270334). Involved in single-strand break repair by catalyzing mono-ADP-ribosylation of histone H2B on 'Glu-2' (H2BE2ADPr) of nucleosomes containing nicked DNA (PubMed:27530147). Cooperates with the XRCC5-XRCC6 (Ku80-Ku70) heterodimer to limit end-resection thereby promoting accurate NHEJ (PubMed:24598253). Suppresses G-quadruplex (G4) structures in response to DNA damage (PubMed:28447610). Associates with a number of DNA repair factors and is involved in the response to exogenous and endogenous DNA strand breaks (PubMed:16924674, PubMed:21211721, PubMed:21270334). Together with APLF, promotes the retention of the LIG4-XRCC4 complex on chromatin and accelerate DNA ligation during non-homologous end-joining (NHEJ) (PubMed:21211721). May link the DNA damage surveillance network to the mitotic fidelity checkpoint (PubMed:16924674). Acts as a negative regulator of immunoglobulin class switch recombination, probably by controlling the level of AICDA /AID on the chromatin (By similarity). In addition to proteins, also able to ADP-ribosylate DNA: mediates DNA mono-ADP-ribosylation of DNA strand break termini via covalent addition of a single ADP-ribose moiety to a 5'- or 3'-terminal phosphate residues in DNA containing multiple strand breaks (PubMed:29361132, PubMed:29520010)

Subcellular location

NucleusChromosomeCytoplasm, cytoskeleton, microtubule organizing center, centrosomeCytoplasm, cytoskeleton, microtubule organizing center, centrosome, centriole
Domains and Gene Ontology detail (27)

Domains & features

WGRPARP alpha-helicalPARP catalytic

Gene Ontology

  • Ccentriole
  • Ccentrosome
  • Cnuclear body
  • Cnucleolus
  • Cnucleoplasm
  • Csite of double-strand break
  • Fcatalytic activity
  • FNAD DNA ADP-ribosyltransferase activity
  • FNAD+ poly-ADP-ribosyltransferase activity
  • FNAD+-protein mono-ADP-ribosyltransferase activity
  • FNAD+-protein-aspartate ADP-ribosyltransferase activity
  • FNAD+-protein-glutamate ADP-ribosyltransferase activity

533 aa · 60 kDa · 2 isoforms

Biological roles

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

Metabolic enzyme activityGO
View supporting evidence

Metabolic enzyme activity

  • ·catalytic activity
  • ·NAD DNA ADP-ribosyltransferase activity
  • ·NAD+ poly-ADP-ribosyltransferase activity
  • ·NAD+-protein mono-ADP-ribosyltransferase activity

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.

CASP3CASP9CASP7GZMBAPLFPARGPARP16PARP10XRCC6PARP15PARP3

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 · 5 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.

Breast Neoplasms1 medicine
Ovarian Neoplasms1 medicine
Pancreatic Neoplasms1 medicine
Prostatic Neoplasms, Castration-Resistant1 medicine
Neoplasms2 medicines

4 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

3

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.

olaparib
ApprovedInhibitor

PARP 1, 2 and 3 inhibitor

Indicated for Breast Neoplasms, Ovarian Neoplasms, Pancreatic Neoplasms, Prostatic Neoplasms, Castration-Resistant

Acts on a complex — shared with PARP1, PARP2 · 1 of 3 recorded protein targets — narrow recorded profile

rucaparib
ApprovedInhibitor

PARP 1, 2 and 3 inhibitor

Indicated for Neoplasms

Acts on a complex — shared with PARP1, PARP2 · 1 of 3 recorded protein targets — narrow recorded profile

veliparib
ApprovedInhibitor

PARP 1, 2 and 3 inhibitor

Acts on a complex — shared with PARP1, PARP2 · 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 PARP3

Gene-level evidence surfaced through the gene PARP3that 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.

Ovarian Neoplasms
0.71Moderately supported

Clinical evidence dominant · Open Targets 0.58

Neoplasms
0.65Moderately supported

Clinical evidence dominant · Open Targets 0.52

Ovarian carcinoma
0.64Moderately supported

Clinical evidence dominant · Open Targets 0.52

Ovarian neoplasm
0.57Moderately supported

Clinical evidence dominant · Open Targets 0.46

Breast Neoplasms
0.56Moderately supported

Clinical evidence dominant · Open Targets 0.43

View evidence synthesis (5)
Ovarian NeoplasmsModerately supported
0.71
agreement 0.560.87
Clinical100%Literature0%

Open Targets aggregate 0.58 · 2 independent evidence families

NeoplasmsModerately supported
0.65
agreement 0.490.81
Clinical94%Literature6%

Open Targets aggregate 0.52 · 2 independent evidence families

Ovarian carcinomaModerately supported
0.64
agreement 0.490.80
Clinical100%Literature1%

Open Targets aggregate 0.52 · 2 independent evidence families

Ovarian neoplasmModerately supported
0.57
agreement 0.420.73
Clinical99%Literature1%

Open Targets aggregate 0.46 · 2 independent evidence families

Breast NeoplasmsModerately supported
0.56
agreement 0.400.71
Clinical81%Literature19%

Open Targets aggregate 0.43 · 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 per-type scores above show the calculation.

Show all associations
Ovarian Neoplasms0.58
Neoplasms0.52
Ovarian carcinoma0.52
Ovarian neoplasm0.46
Breast Neoplasms0.43
Prostatic Neoplasms0.40
Carcinoma, Non-Small-Cell Lung0.40

Drug development

5 compounds recorded · 4 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 3 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 (5)
VELIPARIBApproval
E-7016Phase 2
OLAPARIBApproval
RUCAPARIBApproval
RUCAPARIB CAMSYLATEApproval

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 Structure with Ligand support this modality.

Protein degradersEmerging

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

View underlying tractability evidence (7)
SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · Druggable FamilyPR · LiteraturePR · Database UbiquitinationPR · 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)

ClinicalTrials.gov via the drug-target graph.

What's happening now

12

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. Trial status changed2026-07-21

    A Phase 1, Open-Label, Multicenter Study of INCB123667 as Monotherapy and in Combination With Anticancer Therapies in Participants With Selected Advanced Solid Tumors

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

  2. Trial results posted2026-07-17

    Phase II Study of Rucaparib and Nivolumab in Patients With Leiomyosarcoma

    Results posted · ClinicalTrials.gov · via rucaparib

  3. New publication2025-01-31
    Results of a phase Ib study of olaparib with concomitant radiotherapy in soft-tissue sarcoma: a French sarcoma group study.

    Annals of oncology : official journal of the European Society for Medical Oncology · 2025 · 4 citations · Europe PMC · via olaparib

  4. New publication2023-11-14
    Olaparib for the Treatment of Patients With Metastatic Castration-Resistant Prostate Cancer and Alterations in <i>BRCA1</i> and/or <i>BRCA2</i> in the PROfound Trial.

    Journal of clinical oncology : official journal of the American Society of Clinical Oncology · 2024 · 76 citations · Europe PMC · via olaparib

  5. New publication2023-10-21
    Durvalumab Plus Carboplatin/Paclitaxel Followed by Maintenance Durvalumab With or Without Olaparib as First-Line Treatment for Advanced Endometrial Cancer: The Phase III DUO-E Trial.

    Journal of clinical oncology : official journal of the American Society of Clinical Oncology · 2024 · 259 citations · Europe PMC · via olaparib

  6. New publication2023-02-16
    Rucaparib or Physician's Choice in Metastatic Prostate Cancer.

    The New England journal of medicine · 2023 · 332 citations · Europe PMC · via rucaparib

  7. New publication2022-10-10
    Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high-risk, early breast cancer.

    Annals of oncology : official journal of the European Society for Medical Oncology · 2022 · 325 citations · Europe PMC · via olaparib

  8. Safety communication2022-09-26

    Drug Safety Update: Rucaparib (Rubraca▼): withdrawal of third-line treatment indication

    mhra · safety · mhra · via rucaparib

  9. New publication2021-06-03
    Adjuvant Olaparib for Patients with <i>BRCA1</i>- or <i>BRCA2</i>-Mutated Breast Cancer.

    The New England journal of medicine · 2021 · 1,225 citations · Europe PMC · via olaparib

  10. New publication2020-04-28
    Olaparib for Metastatic Castration-Resistant Prostate Cancer.

    The New England journal of medicine · 2020 · 1,688 citations · Europe PMC · via olaparib

  11. New publication2019-06-02
    Maintenance Olaparib for Germline <i>BRCA</i>-Mutated Metastatic Pancreatic Cancer.

    The New England journal of medicine · 2019 · 1,718 citations · Europe PMC · via olaparib

  12. Regulatory approval2014-12-16

    Approval: Lynparza (EMA)

    ema · regulatory · ema · via olaparib

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

4

Papers about “Poly(ADP-ribose) Polymerases” — a broader family this protein belongs to. Shown as context; not counted as papers specifically about this protein.

NAD<sup>+</sup> homeostasis in renal health and disease.

Ralto KM · Nature reviews. Nephrology · 2020

via Poly(ADP-ribose) Polymerases

PARP and PARG inhibitors in cancer treatment.

Slade D · Genes & development · 2020

via Poly(ADP-ribose) Polymerases

Circular RNA <i>TLK1</i> Aggravates Neuronal Injury and Neurological Deficits after Ischemic Stroke via miR-335-3p/TIPARP.

Wu F · The Journal of neuroscience : the official journal of the Society for Neuroscience · 2019

via Poly(ADP-ribose) Polymerases

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.