Protein / target
Tyrosine-protein kinase BTK
Protein at a glance
Biological role
Non-membrane spanning protein tyrosine kinase activity
Primary system
Immune system
Strongest disease association
X-linked agammaglobulinemia
Therapeutic maturity
Clinically validated target
Druggability
Small molecule
Clinical development
11 approved · 13 in clinical development
Derived from structured UniProt, Open Targets and literature data on this page.
Protein profile
Canonical identity and biological annotation from UniProt.
Function
Non-receptor tyrosine kinase indispensable for B lymphocyte development, differentiation and signaling (PubMed:19290921). Binding of antigen to the B-cell antigen receptor (BCR) triggers signaling that ultimately leads to B-cell activation (PubMed:19290921). After BCR engagement and activation at the plasma membrane, phosphorylates PLCG2 at several sites, igniting the downstream signaling pathway through calcium mobilization, followed by activation of the protein kinase C (PKC) family members (PubMed:11606584). PLCG2 phosphorylation is performed in close cooperation with the adapter protein B-cell linker protein BLNK (PubMed:11606584). BTK acts as a platform to bring together a diverse array of signaling proteins and is implicated in cytokine receptor signaling pathways (PubMed:16517732, PubMed:17932028). Plays an important role in the function of immune cells of innate as well as adaptive immunity, as a component of the Toll-like receptors (TLR) pathway (PubMed:16517732). The TLR pathway acts as a primary surveillance system for the detection of pathogens and are crucial to the activation of host defense (PubMed:16517732). Especially, is a critical molecule in regulating TLR9 activation in splenic B-cells (PubMed:16517732, PubMed:17932028). Within the TLR pathway, induces tyrosine phosphorylation of TIRAP which leads to TIRAP degradation (PubMed:16415872). BTK also plays a critical role in transcription regulation (PubMed:19290921). Induces the activity of NF-kappa-B, which is involved in regulating the expression of hundreds of genes (PubMed:19290921). BTK is involved on the signaling pathway linking TLR8 and TLR9 to NF-kappa-B (PubMed:19290921). Acts as an activator of NLRP3 inflammasome assembly by mediating phosphorylation of NLRP3 (PubMed:34554188). Transiently phosphorylates transcription factor GTF2I on tyrosine residues in response to BCR (PubMed:9012831). GTF2I then translocates to the nucleus to bind regulatory enhancer elements to modulate gene expression (PubMed:9012831). ARID3A and NFAT are other transcriptional target of BTK (PubMed:16738337). BTK is required for the formation of functional ARID3A DNA-binding complexes (PubMed:16738337). There is however no evidence that BTK itself binds directly to DNA (PubMed:16738337). BTK has a dual role in the regulation of apoptosis (PubMed:9751072). Plays a role in STING1-mediated induction of type I interferon (IFN) response by phosphorylating DDX41 (PubMed:25704810)
Subcellular location
Domains and Gene Ontology detail (58)Hide
Domains & features
Gene Ontology
- Ccytoplasm
- Ccytoplasmic vesicle
- Ccytosol
- Cmembrane raft
- Cnucleus
- Cperinuclear region of cytoplasm
- Cplasma membrane
- FATP binding
- Fidentical protein binding
- Fnon-membrane spanning protein tyrosine kinase activity
- Fphosphatidylinositol-3,4,5-trisphosphate binding
- Fphospholipase activator activity
Biological roles
What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.
View supporting evidenceHide supporting evidence
Immune signalling
- ·Non-receptor tyrosine kinase indispensable for B lymphocyte development, differentiation…
- ·adaptive immune response
- ·B cell activation
- ·B cell receptor signaling pathway
Kinase signalling
- ·Non-receptor tyrosine kinase indispensable for B lymphocyte development, differentiation…
- ·non-membrane spanning protein tyrosine kinase activity
- ·protein tyrosine kinase activity
- ·peptidyl-tyrosine phosphorylation
Transcriptional regulation
- ·Non-receptor tyrosine kinase indispensable for B lymphocyte development, differentiation…
- ·DNA-templated transcription
Apoptosis & cell death
- ·regulation of B cell apoptotic process
View underlying pathways (14)Hide underlying pathways
Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.
Interaction neighbourhood
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.
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
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.
Tyrosine-protein kinase BTK inhibitor
Appears in clinical studies involving macroglobulinemia, mantle cell lymphoma, B-cell chronic lymphocytic leukemia, B-cell chronic lymphocytic leukemia
ChEMBL mechanism, action type and target identity. Open Targets clinical status and indications.
Translational evidence
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.
Highest-confidence therapeutic associations
Diseases where a drug acting on this target has already reached clinical development.
Show all associationsHide all associations
Open Targets ranks 928 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 · 24 total
B-cell non-Hodgkin lymphoma · mantle cell lymphoma · follicular lymphoma
chronic progressive multiple sclerosis · multiple sclerosis · myasthenia gravis
mantle cell lymphoma · non-Hodgkin lymphoma · neoplasm
B-cell chronic lymphocytic leukemia · B-cell chronic lymphocytic leukemia · childhood leukemia
rheumatoid arthritis · systemic lupus erythematosus
mantle cell lymphoma · B-cell chronic lymphocytic leukemia · lymphoplasmacytic lymphoma
B-cell chronic lymphocytic leukemia · rheumatoid arthritis · non-Hodgkin lymphoma
non-small cell lung carcinoma · non-small cell lung carcinoma · prostate cancer
neoplasm · B-cell chronic lymphocytic leukemia · B-cell chronic lymphocytic leukemia
systemic lupus erythematosus
Tractability
Safety liabilities
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.
Show remaining trials (24)Hide
ClinicalTrials.gov via the drug-target graph.
Forefront confidence
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.
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
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.
- New publicationIbrutinib-Rituximab or Chemoimmunotherapy for Chronic Lymphocytic Leukemia.
- New publicationA head-to-head Phase III study comparing zanubrutinib versus ibrutinib in patients with Waldenström macroglobulinemia.
- Safety communication
Drug Safety Update: Ibrutinib (Imbruvica▼): reports of ventricular tachyarrhythmia; risk of hepatitis B reactivation and of opportunistic infections
- Regulatory approval
Approval: Imbruvica (EMA)
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.