Reactome: A Curated Pathway Database
THIS SITE IS USED FOR CURATION AND TESTING
IT IS NOT STABLE, IS LINKED TO AN INCOMPLETE DATA SET, AND IS NOT MONITORED FOR PERFORMANCE. WE STRONGLY RECOMMEND THE USE OF OUR PUBLIC SITE

Query author contributions in Reactome

Reactome depends on collaboration between our curation team and outside experts to assemble and peer-review its pathway modules. The integration of ORCID within Reactome enables us to meet a key challenge with authoring, curating and reviewing biological information by incentivizing and crediting the external experts that contribute their expertise and time to the Reactome curation process. More information is available at ORCID and Reactome.

If you have an ORCID ID that is not listed on this page, please forward this information to us and we will update your Reactome pathway records.

Name Email address

Details on Person UniProt:Q06187-1 BTK

Class:IdReferenceIsoform:8976901
_chainChangeLoginitiator methionine:1 added on Fri February 17 2017;chain:2-659 added on Fri February 17 2017;initiator methionine:1 for 8976901 removed on Fri Nov 03 2023;initiator methionine: for 8976901 added on Fri Nov 03 2023;initiator methionine: for 8976901 removed on Fri Aug 15 2025;initiator methionine:1 for 8976901 added on Fri Aug 15 2025
_displayNameUniProt:Q06187-1 BTK
_timestamp2026-02-20 22:19:29
chaininitiator methionine:1
chain:2-659
checksumDF06B5D1FEC257CC
commentFUNCTION 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).CATALYTIC ACTIVITY L-tyrosyl-[protein] + ATP = O-phospho-L-tyrosyl-[protein] + ADP + H(+)COFACTOR Binds 1 zinc ion per subunit.ACTIVITY REGULATION Activated by phosphorylation. In primary B lymphocytes, is almost always non-phosphorylated and is thus catalytically inactive. Stimulation of TLR8 and TLR9 causes BTK activation. As a negative feedback mechanism to fine-tune BCR signaling, activated PRKCB down-modulates BTK function via direct phosphorylation of BTK at Ser-180, resulting in translocation of BTK back to the cytoplasmic fraction. PIN1, SH3BP5, and IBTK were also identified as BTK activity inhibitors. Interaction with CAV1 leads to dramatic down-regulation of the kinase activity of BTK. LFM-13A is a specific inhibitor of BTK. Dasatinib, a cancer drug acting as a tyrosine kinase inhibitor, also blocks BTK activity.SUBUNIT Part of a complex composed of EEIG1, TNFRSF11A/RANK, PLCG2, GAB2, TEC and BTK; complex formation increases in the presence of TNFSF11/RANKL (By similarity). Binds GTF2I through the PH domain. Interacts with SH3BP5 via the SH3 domain. Interacts with IBTK via its PH domain. Interacts with ARID3A, CAV1, FASLG, PIN1, TLR8 and TLR9. Interacts with MPL/TPOR (PubMed:24607955).INTERACTION In steady state, BTK is predominantly cytosolic. Following B-cell receptor (BCR) engagement by antigen, translocates to the plasma membrane through its PH domain. Plasma membrane localization is a critical step in the activation of BTK. A fraction of BTK also shuttles between the nucleus and the cytoplasm, and nuclear export is mediated by the nuclear export receptor CRM1.ALTERNATIVE PRODUCTS Predominantly expressed in B-lymphocytes.DOMAIN The PH domain mediates the binding to inositol polyphosphate and phosphoinositides, leading to its targeting to the plasma membrane. It is extended in the BTK kinase family by a region designated the TH (Tec homology) domain, which consists of about 80 residues preceding the SH3 domain.PTM Following B-cell receptor (BCR) engagement, translocates to the plasma membrane where it gets phosphorylated at Tyr-551 by LYN and SYK. Phosphorylation at Tyr-551 is followed by autophosphorylation of Tyr-223 which may create a docking site for a SH2 containing protein. Phosphorylation at Ser-180 by PRKCB, leads in translocation of BTK back to the cytoplasmic fraction. Phosphorylation at Ser-21 and Ser-115 creates a binding site for PIN1 at these Ser-Pro motifs, and promotes its recruitment.DISEASE The disease is caused by variants affecting the gene represented in this entry.DISEASE The disease may be caused by variants affecting the gene represented in this entry.MISCELLANEOUS Produced by alternative promoter usage. Predominant form in many tumor cells where it may function as an anti-apoptotic cell survival factor.SIMILARITY Belongs to the protein kinase superfamily. Tyr protein kinase family. TEC subfamily.ONLINE INFORMATION BTK mutation db
created[InstanceEdit:8964659] Weiser, JD
descriptionrecommendedName: Tyrosine-protein kinase BTK ecNumber evidence="20 43"2.7.10.2 alternativeName: Agammaglobulinemia tyrosine kinase shortName: ATK alternativeName: B-cell progenitor kinase shortName: BPK alternativeName: Bruton tyrosine kinase
geneNameBTK
AGMX1
ATK
BPK
identifierQ06187
isoformParent
isSequenceChangedFALSE
keyword3D-structure
Acetylation
Adaptive immunity
Alternative promoter usage
Apoptosis
ATP-binding
Cell membrane
Cytoplasm
Direct protein sequencing
Disease variant
Dwarfism
Immunity
Innate immunity
Kinase
Lipid-binding
Membrane
Metal-binding
Nucleotide-binding
Nucleus
Phosphoprotein
Proteomics identification
Reference proteome
SH2 domain
SH3 domain
Transcription
Transcription regulation
Transferase
Tyrosine-protein kinase
Zinc
Zinc-finger
modified[InstanceEdit:9836292] Weiser, Joel, 2023-05-25
[InstanceEdit:9841277] Weiser, Joel
[InstanceEdit:9852000] Weiser, Joel, 2023-11-03
[InstanceEdit:9926675] Weiser, Joel, 2024-11-03
[InstanceEdit:9939033] Weiser, Joel, 2025-02-21
[InstanceEdit:9963647] Weiser, Joel, 2025-08-15
[InstanceEdit:9983091] Weiser, Joel, 2026-02-20
nameBTK
referenceDatabase[ReferenceDatabase:2] UniProt
referenceGene[ReferenceDNASequence:8989402] ENSEMBL:ENSG00000010671 BTK [Homo sapiens]
secondaryIdentifierBTK_HUMAN
B2RAW1
Q32ML5
sequenceLength659
species[Species:48887] Homo sapiens
variantIdentifierQ06187-1
[Change default viewing format]
No pathways have been reviewed or authored by UniProt:Q06187-1 BTK (8976901)