Rahul Sharma (Editor)

Bruton's tyrosine kinase

Updated on
Edit
Like
Comment
Share on FacebookTweet on TwitterShare on LinkedInShare on Reddit
Species
  
Human

Entrez
  
695

Human
  
Mouse

Ensembl
  
ENSG00000010671

Bruton's tyrosine kinase

Aliases
  
BTK, AGMX1, AT, ATK, BPK, IMD1, PSCTK1, XLA, Bruton tyrosine kinase

External IDs
  
OMIM: 300300 MGI: 88216 HomoloGene: 30953 GeneCards: BTK

Bruton's tyrosine kinase (abbreviated Btk or BTK) also known as tyrosine-protein kinase BTK is an enzyme that in humans is encoded by the BTK gene. BTK is a kinase that plays a crucial role in B-cell development.

Contents

Function

BTK plays a crucial role in B cell maturation as well as mast cell activation through the high-affinity IgE receptor.

Btk contains a PH domain that binds phosphatidylinositol (3,4,5)-trisphosphate (PIP3). PIP3 binding induces Btk to phosphorylate phospholipase C, which in turn hydrolyzes PIP2, a phosphatidylinositol, into two second messengers, inositol triphosphate (IP3) and diacylglycerol (DAG), which then go on to modulate the activity of downstream proteins during B-cell signalling.

Clinical significance

Mutations in the BTK gene are implicated in the primary immunodeficiency disease X-linked agammaglobulinemia (Bruton's agammaglobulinemia); sometimes abbreviated to XLA. Patients with XLA have normal pre-B cell populations in their bone marrow but these cells fail to mature and enter the circulation. The Btk gene is located on the X chromosome. At least 400 mutations of the BTK gene have been identified.

BTK inhibitors

Approved drugs that inhibit BTK :

  • Ibrutinib (PCI-32765), a selective Bruton's tyrosine kinase inhibitor.
  • Various drugs that inhibit BTK are in clinical trials:

  • Phase 3:
  • Acalabrutinib, for relapsed CLL, 95% overall remission reported.
  • Phase 2:
  • Phase 1:
  • ONO-4059 for Non-Hodgkin's Lymphoma and/or CLL. Renamed GS-4059 and now in trial NCT02457598.
  • spebrutinib (AVL-292, CC-292)
  • BGB-3111 for CLL. It can be taken orally.
  • Discovery

    Bruton's tyrosine kinase was discovered in 1993 and is named for Ogden Bruton, who first described XLA in 1952.

    Interactions

    Bruton's tyrosine kinase has been shown to interact with:

    References

    Bruton's tyrosine kinase Wikipedia