Protein / target

Cullin-4A

CUL4AQ13619Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
3
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Ubiquitin ligase complex scaffold activity

Primary system

Immune system

Strongest disease association

plasma cell myeloma

Clinical evidence · score 0.61

Therapeutic maturity

Clinically validated target

3 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

3 approved · 1 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

Core component of multiple cullin-RING-based E3 ubiquitin-protein ligase complexes which mediate the ubiquitination of target proteins (PubMed:14578910, PubMed:14739464, PubMed:15448697, PubMed:15548678, PubMed:15811626, PubMed:16678110, PubMed:17041588, PubMed:24209620, PubMed:30166453, PubMed:33854232, PubMed:33854239). As a scaffold protein may contribute to catalysis through positioning of the substrate and the ubiquitin-conjugating enzyme (PubMed:14578910, PubMed:14739464, PubMed:15448697, PubMed:15548678, PubMed:15811626, PubMed:16678110, PubMed:17041588, PubMed:24209620). The E3 ubiquitin-protein ligase activity of the complex is dependent on the neddylation of the cullin subunit and is inhibited by the association of the deneddylated cullin subunit with TIP120A/CAND1 (PubMed:14578910, PubMed:14739464, PubMed:15448697, PubMed:15548678, PubMed:15811626, PubMed:16678110, PubMed:17041588, PubMed:24209620). The functional specificity of the E3 ubiquitin-protein ligase complex depends on the variable substrate recognition component (PubMed:14578910, PubMed:14739464, PubMed:15448697, PubMed:15548678, PubMed:15811626, PubMed:16678110, PubMed:17041588, PubMed:24209620). DCX(DET1-COP1) directs ubiquitination of JUN (PubMed:14739464). DCX(DDB2) directs ubiquitination of XPC (PubMed:15811626). DCX(DDB2) ubiquitinates histones H3-H4 and is required for efficient histone deposition during replication-coupled (H3.1) and replication-independent (H3.3) nucleosome assembly, probably by facilitating the transfer of H3 from ASF1A/ASF1B to other chaperones involved in histone deposition (PubMed:16678110, PubMed:17041588, PubMed:24209620). DCX(DTL) plays a role in PCNA-dependent polyubiquitination of CDT1 and MDM2-dependent ubiquitination of p53/TP53 in response to radiation-induced DNA damage and during DNA replication (PubMed:14578910, PubMed:15448697, PubMed:15548678). DCX(DTL) directs autoubiquitination of DTL (PubMed:23478445). In association with DDB1 and SKP2 probably is involved in ubiquitination of CDKN1B/p27kip (PubMed:16537899). Is involved in ubiquitination of HOXA9 (PubMed:14609952). The DDB1-CUL4A-DTL E3 ligase complex regulates the circadian clock function by mediating the ubiquitination and degradation of CRY1 (PubMed:26431207). The DCX(ERCC8) complex (also named CSA complex) plays a role in transcription-coupled repair (TCR) (PubMed:12732143, PubMed:32355176, PubMed:38316879). A number of DCX complexes (containing either TRPC4AP or DCAF12 as substrate-recognition component) are part of the DesCEND (destruction via C-end degrons) pathway, which recognizes a C-degron located at the extreme C terminus of target proteins, leading to their ubiquitination and degradation (PubMed:29779948). The DCX(AMBRA1) complex is a master regulator of the transition from G1 to S cell phase by mediating ubiquitination of phosphorylated cyclin-D (CCND1, CCND2 and CCND3) (PubMed:33854232, PubMed:33854239). The DCX(AMBRA1) complex also acts as a regulator of Cul5-RING (CRL5) E3 ubiquitin-protein ligase complexes by mediating ubiquitination and degradation of Elongin-C (ELOC) component of CRL5 complexes (PubMed:30166453). With CUL4B, contributes to ribosome biogenesis (PubMed:26711351)

Domains and Gene Ontology detail (38)

Domains & features

Cullin neddylation

Gene Ontology

  • CCul4-RING E3 ubiquitin ligase complex
  • CCul4A-RING E3 ubiquitin ligase complex
  • Ccytoplasm
  • Cnucleoplasm
  • Cnucleus
  • Fubiquitin ligase complex scaffold activity
  • Fubiquitin protein ligase activity
  • Fubiquitin protein ligase binding
  • Pcell population proliferation
  • Pcellular response to UV
  • PDNA damage response
  • Pepigenetic regulation of gene expression

759 aa · 88 kDa · 2 isoforms

Biological roles

Reactome v97

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

Transcriptional regulationUniProt · GO · ReactomeImmune signallingGOApoptosis & cell deathGO
View supporting evidence

Transcriptional regulation

  • ·Core component of multiple cullin-RING-based E3 ubiquitin-protein ligase complexes which…
  • ·epigenetic regulation of gene expression
  • ·Transcription-Coupled Nucleotide Excision Repair (TC-NER)

Immune signalling

  • ·regulation of mitotic cytokinesis
  • ·T cell activation

Apoptosis & cell death

  • ·regulation of apoptotic process
View underlying pathways (10)

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.

ERCC8DCAF1DCAF11DDA1DDB2RBX1DDB1CUL4BDTLCRBNCUL4A

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

2

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.

Thalidomide
ApprovedInhibitor

CRL4(CRBN) E3 ubiquitin ligase inhibitor

Appears in clinical studies involving plasma cell myeloma, immune system disorder, prostate cancer, non-small cell lung carcinoma

Acts on a complex — shared with CRBN, DDB1, RBX1 · 1 of 4 recorded protein targets

lenalidomide
ApprovedInhibitor

CRL4(CRBN) E3 ubiquitin ligase inhibitor

Appears in clinical studies involving anemia, mantle cell lymphoma, myelodysplastic syndrome, plasma cell myeloma

Acts on a complex — shared with CRBN, DDB1, RBX1 · 1 of 4 recorded protein targets

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.

Highest-confidence therapeutic associations

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

plasma cell myeloma0.99

Clinical · overall 0.61

follicular lymphoma0.93

Clinical · overall 0.57

myelodysplastic syndrome0.93

Clinical · overall 0.56

mantle cell lymphoma0.90

Clinical · overall 0.55

immune system disorder0.83

Clinical · overall 0.50

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

anemia0.49

Clinical

diffuse large B-cell lymphoma0.41

Clinical

hepatocellular carcinoma0.40

Literature

marginal zone lymphoma0.40

Clinical

systemic sclerosis0.39

Clinical

Show all associations
plasma cell myeloma0.61
follicular lymphoma0.57
myelodysplastic syndrome0.56
mantle cell lymphoma0.55
immune system disorder0.50
anemia0.49
diffuse large B-cell lymphoma0.41
hepatocellular carcinoma0.40
marginal zone lymphoma0.40
systemic sclerosis0.39

Open Targets ranks 498 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 · 4 total

IBERDOMIDEPhase 3

plasma cell myeloma · sarcoidosis · systemic lupus erythematosus

POMALIDOMIDEApproval

plasma cell myeloma · systemic sclerosis · immune system disorder

LENALIDOMIDEApproval

anemia · mantle cell lymphoma · myelodysplastic syndrome

THALIDOMIDEApproval

plasma cell myeloma · immune system disorder · prostate cancer

Tractability

SM · Approved DrugSM · High-Quality LigandSM · High-Quality PocketPR · UniProt UbiquitinationPR · Database UbiquitinationPR · Half-life DataPR · Small Molecule Binder

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)

UNKNOWN · via lenalidomide · NCT04025593

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.

plasma cell myelomaWell supported
0.76
agreement 0.600.91
Clinical95%Literature6%

Open Targets aggregate 0.61 · 2 independent evidence families

follicular lymphomaModerately supported
0.70
agreement 0.530.86
Clinical100%

Open Targets aggregate 0.57 · 1 independent evidence family

myelodysplastic syndromeModerately supported
0.69
agreement 0.530.86
Clinical100%

Open Targets aggregate 0.56 · 1 independent evidence family

mantle cell lymphomaModerately supported
0.68
agreement 0.520.83
Clinical100%Literature0%

Open Targets aggregate 0.55 · 2 independent evidence families

immune system disorderModerately supported
0.62
agreement 0.460.79
Clinical100%

Open Targets aggregate 0.50 · 1 independent evidence family

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

60

Recent activity around this target, drawn from one canonical event stream. Every item is reached through 2 drugs that target this protein, so each event is news about that drug rather than about the protein directly.

  1. Label change2026-07-22

    Label change: LENALIDOMIDE (NDA021880)

    fda · regulatory · fda · via lenalidomide

  2. Industry development2026-06-29
    Advanced hierarchical ZnFe-LDH@MnO₂ nanostructures for sensitive voltammetric determination of lenalidomide

    Nature — Environmental Sciences · news · via lenalidomide

  3. Label change2026-06-15

    Label change: LENALIDOMIDE (ANDA201452)

    fda · regulatory · fda · via lenalidomide

  4. Label change2026-06-15

    Label change: LENALIDOMIDE (ANDA201452)

    fda · regulatory · fda · via lenalidomide

  5. Supplemental approval2026-04-27

    Supplemental approval: LENALIDOMIDE (ANDA201452)

    fda · regulatory · fda · via lenalidomide

  6. Supplemental approval2026-04-27

    Supplemental approval: LENALIDOMIDE (NDA021880)

    fda · regulatory · fda · via lenalidomide

  7. Supplemental approval2023-03-24

    Supplemental approval: LENALIDOMIDE (ANDA201452)

    fda · regulatory · fda · via lenalidomide

  8. Supplemental approval2023-03-24

    Supplemental approval: LENALIDOMIDE (NDA021880)

    fda · regulatory · fda · via lenalidomide

  9. Regulatory approval2023-03-06

    Approval: LENALIDOMIDE (ANDA201452)

    fda · regulatory · fda · via lenalidomide

  10. Regulatory approval2022-09-19

    Approval: Thalidomide Lipomed (EMA)

    ema · regulatory · ema · via Thalidomide

  11. Label change2022-05-24

    Label change: LENALIDOMIDE (NDA021880)

    fda · regulatory · fda · via lenalidomide

  12. Label change2021-08-31

    Label change: LENALIDOMIDE (NDA021880)

    fda · regulatory · fda · via lenalidomide

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.