Biomaterial Database

The Btk subfamily of cytoplasmic tyrosine kinases: structure, regulation and function. 1995

D J Rawlings, and O N Witte

Department of Microbiology and Molecular Genetics, University of California, Los Angeles 90024-1662, USA.

The genetic defect associated with two closely related primary immunodeficiencies was recently identified as a deficiency of function of a new cytoplasmic tyrosine kinase, Bruton's tyrosine kinase (Btk). Btk and related genes expressed primarily in hematopoietic cells (Itk, Tec, Drsrc28C and Txk) comprise a new subfamily of cytoplasmic tyrosine kinases. These proteins share significant structural and sequence homology including an amino-terminal pleckstrin homology (PH) domain not present in other cytoplasmic tyrosine kinase subfamilies. This domain plays an essential role in regulation and function of the Btk subfamily proteins. Genetic evidence supports a critical role for Btk in B-lineage development. Additional studies demonstrate activation of these proteins in multiple hematopoietic signaling pathways including the B cell antigen receptor, several cytokine receptors, and a potential novel role in heterotrimeric G protein associated receptor signaling.

UI	MeSH Term	Description	Entries
D011505	Protein-Tyrosine Kinases	Protein kinases that catalyze the PHOSPHORYLATION of TYROSINE residues in proteins with ATP or other nucleotides as phosphate donors.	Tyrosine Protein Kinase,Tyrosine-Specific Protein Kinase,Protein-Tyrosine Kinase,Tyrosine Kinase,Tyrosine Protein Kinases,Tyrosine-Specific Protein Kinases,Tyrosylprotein Kinase,Kinase, Protein-Tyrosine,Kinase, Tyrosine,Kinase, Tyrosine Protein,Kinase, Tyrosine-Specific Protein,Kinase, Tyrosylprotein,Kinases, Protein-Tyrosine,Kinases, Tyrosine Protein,Kinases, Tyrosine-Specific Protein,Protein Kinase, Tyrosine-Specific,Protein Kinases, Tyrosine,Protein Kinases, Tyrosine-Specific,Protein Tyrosine Kinase,Protein Tyrosine Kinases,Tyrosine Specific Protein Kinase,Tyrosine Specific Protein Kinases
D002454	Cell Differentiation	Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.	Differentiation, Cell,Cell Differentiations,Differentiations, Cell
D003593	Cytoplasm	The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Protoplasm,Cytoplasms,Protoplasms
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000077329	Agammaglobulinaemia Tyrosine Kinase	A non-receptor tyrosine kinase that is essential for the development, maturation, and signaling of B-LYMPHOCYTES. It contains an N-terminal zinc finger motif and localizes primarily to the PLASMA MEMBRANE and nucleus of B-lymphocytes. Mutations in the gene that encode this kinase are associated with X-LINKED AGAMMAGLOBULINEMIA.	B Cell Progenitor Kinase,Bruton's Tyrosine Kinase,Bruton Tyrosine Kinase,Brutons Tyrosine Kinase,Kinase, Agammaglobulinaemia Tyrosine,Kinase, Bruton's Tyrosine,Tyrosine Kinase, Agammaglobulinaemia,Tyrosine Kinase, Bruton's
D000361	Agammaglobulinemia	An immunologic deficiency state characterized by an extremely low level of generally all classes of gamma-globulin in the blood.	Hypogammaglobulinemia,Agammaglobulinemias,Hypogammaglobulinemias
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001402	B-Lymphocytes	Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.	B-Cells, Lymphocyte,B-Lymphocyte,Bursa-Dependent Lymphocytes,B Cells, Lymphocyte,B Lymphocyte,B Lymphocytes,B-Cell, Lymphocyte,Bursa Dependent Lymphocytes,Bursa-Dependent Lymphocyte,Lymphocyte B-Cell,Lymphocyte B-Cells,Lymphocyte, Bursa-Dependent,Lymphocytes, Bursa-Dependent