Protein / target

Proto-oncogene tyrosine-protein kinase Src

SRCP12931Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
4
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Non-membrane spanning protein tyrosine kinase activity

Primary system

Immune system

Strongest disease association

Rare hemorrhagic disorder due to a constitutional platelet anomaly

Genetic evidence · score 0.59

Therapeutic maturity

Clinically validated target

4 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

4 approved · 7 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

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.

Kinase signallingUniProt · GOImmune signallingUniProt · GOCell adhesionUniProt · GOTranscriptional regulationUniProt · GOApoptosis & cell deathUniProt · GOMuscle contractionUniProt · GO
View supporting evidence

Kinase signalling

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

Immune signalling

  • ·Non-receptor protein tyrosine kinase which is activated following engagement of many dif…
  • ·interleukin-6-mediated signaling pathway
  • ·negative regulation of inflammatory response to antigenic stimulus
  • ·response to interleukin-1

Cell adhesion

  • ·Non-receptor protein tyrosine kinase which is activated following engagement of many dif…
  • ·Cell junction, focal adhesion
  • ·Cell junction
  • ·cell junction

Transcriptional regulation

  • ·Non-receptor protein tyrosine kinase which is activated following engagement of many dif…
  • ·negative regulation of transcription by RNA polymerase II

Apoptosis & cell death

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

Muscle contraction

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

Drugs targeting this protein

1

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.

bosutinib
ApprovedInhibitor

Tyrosine-protein kinase SRC inhibitor

Appears in clinical studies involving breast cancer, neoplasm, chronic myelogenous leukemia, BCR-ABL1 positive, chronic myelogenous leukemia, BCR-ABL1 positive

Direct interaction with this protein · 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.

Strongest genetic associations

Human genetic evidence — the most direct causal link between this target and a disease.

Rare hemorrhagic disorder due to a constitutional platelet anomaly0.59

Genetic · overall 0.51

Highest-confidence therapeutic associations

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

chronic myelogenous leukemia, BCR-ABL1 positive0.95

Clinical · overall 0.59

actinic keratosis0.94

Clinical · overall 0.57

medullary thyroid gland carcinoma0.89

Clinical · overall 0.55

acute lymphoblastic leukemia0.89

Clinical · overall 0.56

neoplasm0.84

Clinical · overall 0.54

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

cancer0.63

Pathway

Noonan syndrome0.54

Pathway

Costello syndrome0.51

Pathway

hypertrophic cardiomyopathy0.50

Pathway

Show all associations
cancer0.63
chronic myelogenous leukemia, BCR-ABL1 positive0.59
actinic keratosis0.57
acute lymphoblastic leukemia0.56
medullary thyroid gland carcinoma0.55
Noonan syndrome0.54
neoplasm0.54
Costello syndrome0.51
Rare hemorrhagic disorder due to a constitutional platelet anomaly0.51
hypertrophic cardiomyopathy0.50

Open Targets ranks 2,840 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 · 11 total

DASATINIB ANHYDROUSApproval

chronic myelogenous leukemia, BCR-ABL1 positive · acute lymphoblastic leukemia · chronic myelogenous leukemia, BCR-ABL1 positive

VANDETANIBApproval

thyroid gland carcinoma · medullary thyroid gland carcinoma · medullary thyroid gland carcinoma

ILORASERTIBPhase 2

juvenile myelomonocytic leukemia · acute myeloid leukemia · myelodysplastic syndrome

XL-228Phase 1

childhood leukemia · acute lymphoblastic leukemia · chronic myelogenous leukemia, BCR-ABL1 positive

SARACATINIBPhase 2 3

ovarian cancer · primary peritoneal carcinoma · fallopian tube cancer

TIRBANIBULINApproval

actinic keratosis · prostate cancer · basal cell carcinoma

BOSUTINIBApproval

breast cancer · neoplasm · chronic myelogenous leukemia, BCR-ABL1 positive

ENMD-981693Phase 2

colorectal carcinoma · breast carcinoma · exocrine pancreatic carcinoma

JNJ-26483327Phase 1
TG100-801Phase 2

macular degeneration · age-related macular degeneration

Tractability

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 Data

Safety liabilities

cell hypertrophyAbnormal behaviourpulmonary arterial hypertensionPleural effusionanxietycognitive disorderpulmonary oedemaregulation of catalytic activitythrombocytopeniabone disorderdeep vein thrombosisplatelet dysfunction

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)

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.

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

acute lymphoblastic leukemiaModerately supported
0.70
agreement 0.550.86
Clinical86%Literature14%

Open Targets aggregate 0.56 · 2 independent evidence families

neoplasmModerately supported
0.68
agreement 0.530.84
Clinical81%Literature19%

Open Targets aggregate 0.54 · 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 underlying per-type scores are shown above so the calculation can be checked.

What's happening now

4

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

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

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

  4. 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.