Back to discover

Protein / target

Proto-oncogene tyrosine-protein kinase Src

Encoded bySRCP12931Homo 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

Non-membrane spanning protein tyrosine kinase

Strongest disease association

Rare hemorrhagic disorder due to a constitutional platelet anomaly

Via encoding gene SRC · Genetic evidence · score 0.59

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

Non-receptor protein tyrosine kinase which is activated following engagement of many different classes of cellular receptors including immune response receptors, integrins and other adhesion receptors, receptor protein tyrosine kinases, G protein-coupled receptors as well as cytokine receptors.

View complete UniProt function annotation

Non-receptor protein tyrosine kinase which is activated following engagement of many different classes of cellular receptors including immune response receptors, integrins and other adhesion receptors, receptor protein tyrosine kinases, G protein-coupled receptors as well as cytokine receptors (PubMed:34234773). Participates in signaling pathways that control a diverse spectrum of biological activities including gene transcription, immune response, cell adhesion, cell cycle progression, apoptosis, migration, and transformation. Due to functional redundancy between members of the SRC kinase family, identification of the specific role of each SRC kinase is very difficult. SRC appears to be one of the primary kinases activated following engagement of receptors and plays a role in the activation of other protein tyrosine kinase (PTK) families. Receptor clustering or dimerization leads to recruitment of SRC to the receptor complexes where it phosphorylates the tyrosine residues within the receptor cytoplasmic domains. Plays an important role in the regulation of cytoskeletal organization through phosphorylation of specific substrates such as AFAP1. Phosphorylation of AFAP1 allows the SRC SH2 domain to bind AFAP1 and to localize to actin filaments. Cytoskeletal reorganization is also controlled through the phosphorylation of cortactin (CTTN) (Probable). When cells adhere via focal adhesions to the extracellular matrix, signals are transmitted by integrins into the cell resulting in tyrosine phosphorylation of a number of focal adhesion proteins, including PTK2/FAK1 and paxillin (PXN) (PubMed:21411625). In addition to phosphorylating focal adhesion proteins, SRC is also active at the sites of cell-cell contact adherens junctions and phosphorylates substrates such as beta-catenin (CTNNB1), delta-catenin (CTNND1), and plakoglobin (JUP). Another type of cell-cell junction, the gap junction, is also a target for SRC, which phosphorylates connexin-43 (GJA1). SRC is implicated in regulation of pre-mRNA-processing and phosphorylates RNA-binding proteins such as KHDRBS1 (Probable). Phosphorylates PKP3 at 'Tyr-195' in response to reactive oxygen species, which may cause the release of PKP3 from desmosome cell junctions into the cytoplasm (PubMed:25501895). Also plays a role in PDGF-mediated tyrosine phosphorylation of both STAT1 and STAT3, leading to increased DNA binding activity of these transcription factors (By similarity). Involved in the RAS pathway through phosphorylation of RASA1 and RASGRF1 (PubMed:11389730). Plays a role in EGF-mediated calcium-activated chloride channel activation (PubMed:18586953). Required for epidermal growth factor receptor (EGFR) internalization through phosphorylation of clathrin heavy chain (CLTC and CLTCL1) at 'Tyr-1477'. Involved in beta-arrestin (ARRB1 and ARRB2) desensitization through phosphorylation and activation of GRK2, leading to beta-arrestin phosphorylation and internalization. Has a critical role in the stimulation of the CDK20/MAPK3 mitogen-activated protein kinase cascade by epidermal growth factor (Probable). Might be involved not only in mediating the transduction of mitogenic signals at the level of the plasma membrane but also in controlling progression through the cell cycle via interaction with regulatory proteins in the nucleus (PubMed:7853507). Plays an important role in osteoclastic bone resorption in conjunction with PTK2B/PYK2. Both the formation of a SRC-PTK2B/PYK2 complex and SRC kinase activity are necessary for this function. Recruited to activated integrins by PTK2B/PYK2, thereby phosphorylating CBL, which in turn induces the activation and recruitment of phosphatidylinositol 3-kinase to the cell membrane in a signaling pathway that is critical for osteoclast function (PubMed:14585963, PubMed:8755529). Upon activation of the G(q)-dependent KISS1/KISS1R signaling pathway, active SRC is recruited, together with the phosphatase DUSP18, to the KISS1R C-terminus (PubMed:38346942). This leads to DUSP18-mediated SRC dephosphorylation and inactivation, down-regulation of osteoclast differentiation and activity, and consequently suppression of bone resorption (By similarity). Promotes energy production in osteoclasts by activating mitochondrial cytochrome C oxidase (PubMed:12615910). Phosphorylates DDR2 on tyrosine residues, thereby promoting its subsequent autophosphorylation (PubMed:16186108). Phosphorylates RUNX3 and COX2 on tyrosine residues, TNK2 on 'Tyr-284' and CBL on 'Tyr-731' (PubMed:20100835, PubMed:21309750). Enhances RIGI-elicited antiviral signaling (PubMed:19419966). Phosphorylates PDPK1 at 'Tyr-9', 'Tyr-373' and 'Tyr-376' (PubMed:14585963). Phosphorylates BCAR1 at 'Tyr-128' (PubMed:22710723). Phosphorylates CBLC at multiple tyrosine residues, phosphorylation at 'Tyr-341' activates CBLC E3 activity (PubMed:20525694). Phosphorylates synaptic vesicle protein synaptophysin (SYP) (By similarity). Involved in anchorage-independent cell growth (PubMed:19307596). Required for podosome formation (By similarity). Mediates IL6 signaling by activating YAP1-NOTCH pathway to induce inflammation-induced epithelial regeneration (PubMed:25731159). Phosphorylates OTUB1, promoting deubiquitination of RPTOR (PubMed:35927303). Phosphorylates caspase CASP8 at 'Tyr-380' which negatively regulates CASP8 processing and activation, down-regulating CASP8 proapoptotic function (PubMed:16619028). Mediates laminin-induced activation of RAC1 signaling through phosphorylation of syntrophin (By similarity)

Subcellular location

Cell membraneMitochondrion inner membraneNucleusCytoplasm, cytoskeletonCytoplasm, perinuclear regionCell junction, focal adhesionCell junction
Domains and Gene Ontology detail (108)

Domains & features

SH3SH2Protein kinase

Gene Ontology

  • Cactin filament
  • Ccaveola
  • Ccell junction
  • Ccell-cell junction
  • Ccytoplasm
  • Ccytosol
  • Cextracellular exosome
  • Cfocal adhesion
  • Clate endosome
  • Clysosome
  • Cmembrane raft
  • Cmitochondrial inner membrane

536 aa · 60 kDa · 3 isoforms

Biological roles

Reactome v97

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

Receptor tyrosine kinase signallingUniProt · GO · ReactomeGrowth-factor signallingUniProt · GO · ReactomeCell migrationGOChloride transportUniProtCell proliferation & survivalReactomeOncogenic signallingReactome
View supporting evidence

Receptor tyrosine kinase signalling

  • ·Non-receptor protein tyrosine kinase which is activated following engagement of many dif…
  • ·ERBB2 signaling pathway
  • ·Signaling by ERBB2
  • ·Nuclear signaling by ERBB4

Growth-factor signalling

  • ·Non-receptor protein tyrosine kinase which is activated following engagement of many dif…
  • ·epidermal growth factor receptor signaling pathway
  • ·vascular endothelial growth factor receptor signaling pathway
  • ·Signaling by EGFR

Cell migration

  • ·positive regulation of epithelial cell migration
  • ·regulation of epithelial cell migration

Chloride transport

  • ·Non-receptor protein tyrosine kinase which is activated following engagement of many dif…

Cell proliferation & survival

  • ·PIP3 activates AKT signaling

Oncogenic signalling

  • ·Constitutive Signaling by Aberrant PI3K in Cancer
View underlying pathways (25)

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.

SHC1ESR1SYKBCAR1CAV1PTK2BPXNGRB2HSP90A…PDGFRBSRC

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

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.

Keratosis, Actinic1 medicine

4 medicines meet Open Targets' target-level approved-medicine definition; the 1 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.

tirbanibulin
Narrow target profileApprovedInhibitor

Tyrosine-protein kinase SRC inhibitor

Indicated for Keratosis, Actinic

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

bosutinib
ApprovedInhibitor

Tyrosine-protein kinase SRC inhibitor

Direct interaction with this protein · 1 of 4 recorded protein targets

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 SRC

Gene-level evidence surfaced through the gene SRCthat 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.

Neoplasms
0.81Well supported

Clinical evidence dominant · Open Targets 0.63

chronic myelogenous leukemia, BCR-ABL1 positive
0.72Moderately supported

Clinical evidence dominant · Open Targets 0.59

Actinic keratosis
0.71Moderately supported

Clinical evidence dominant · Open Targets 0.57

Precursor Cell Lymphoblastic Leukemia-Lymphoma
0.70Moderately supported

Clinical evidence dominant · Open Targets 0.56

Medullary thyroid gland carcinoma
0.68Moderately supported

Clinical evidence dominant · Open Targets 0.55

View evidence synthesis (5)
NeoplasmsWell supported
0.81
agreement 0.680.93
Clinical54%Pathway34%Literature13%

Open Targets aggregate 0.63 · 3 independent evidence families

chronic myelogenous leukemia, BCR-ABL1 positiveModerately supported
0.72
agreement 0.570.88
Clinical96%Literature4%

Open Targets aggregate 0.59 · 2 independent evidence families

Actinic keratosisModerately supported
0.71
agreement 0.550.86
Clinical99%Literature1%

Open Targets aggregate 0.57 · 2 independent evidence families

Precursor Cell Lymphoblastic Leukemia-LymphomaModerately supported
0.70
agreement 0.550.86
Clinical86%Literature14%

Open Targets aggregate 0.56 · 2 independent evidence families

Medullary thyroid gland carcinomaModerately supported
0.68
agreement 0.520.83
Clinical97%Literature3%

Open Targets aggregate 0.55 · 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
Neoplasms0.63
chronic myelogenous leukemia, BCR-ABL1 positive0.59
Actinic keratosis0.57
Precursor Cell Lymphoblastic Leukemia-Lymphoma0.56
Medullary thyroid gland carcinoma0.55
Noonan syndrome0.54
Costello syndrome0.51
Rare hemorrhagic disorder due to a constitutional platelet anomaly0.51
Cardiomyopathy, Hypertrophic0.50

Drug development

11 compounds recorded · 4 approved · 7 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 (1 with a mapped approved indication, shown above): these count different sets and are not a subset relation.

View all recorded compounds (10)
DASATINIB ANHYDROUSApproval
VANDETANIBApproval
ILORASERTIBPhase 2
XL-228Phase 1
SARACATINIBPhase 2 3
TIRBANIBULINApproval
BOSUTINIBApproval
ENMD-981693Phase 2
JNJ-26483327Phase 1
TG100-801Phase 2

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.

AntibodiesEmerging

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

Protein degradersEmerging

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

View underlying tractability evidence (13)
SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · High-Quality PocketSM · Druggable FamilyAB · UniProt loc high confAB · GO CC high confAB · Human Protein Atlas locPR · LiteraturePR · UniProt UbiquitinationPR · Database UbiquitinationPR · Half-life DataPR · Small Molecule Binder

Raw Open Targets tractability assessment buckets, by modality.

Safety-related annotations

cell hypertrophyBrennan et al. (2024)Abnormal behaviourBrennan et al. (2024)pulmonary arterial hypertensionBrennan et al. (2024)Pleural effusionBrennan et al. (2024)anxietyBrennan et al. (2024)cognitive disorderBrennan et al. (2024)pulmonary oedemaBrennan et al. (2024)regulation of catalytic activityToxCastthrombocytopeniaBrennan et al. (2024)bone disorderBrennan et al. (2024)deep vein thrombosisBrennan et al. (2024)platelet dysfunctionBrennan et al. (2024)

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.

View all trials (26)

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 approval2026-06-12

    Approval: BOSUTINIB (ANDA209624)

    fda · regulatory · fda · via bosutinib

  2. Regulatory approval2025-05-23

    Approval: BOSUTINIB (ANDA209543)

    fda · regulatory · fda · via bosutinib

  3. Regulatory approval2021-07-16

    Approval: Klisyri (EMA)

    ema · regulatory · ema · via tirbanibulin

  4. New publication2020-03-03
    European LeukemiaNet 2020 recommendations for treating chronic myeloid leukemia.

    Leukemia · 2020 · 1,035 citations · Europe PMC · via bosutinib

  5. Regulatory approval2013-03-27

    Approval: Bosulif (EMA)

    ema · regulatory · ema · via bosutinib

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.