BTK (Bruton agammaglobulinemia tyrosine kinase)
نویسندگان
چکیده
The BTK protein is a 77 kDa protein of 659 amino acids. Translation of the BTK transcript starts at the ATG site that is located in exon 2 and ends in exon 19. The BTK protein is composed of an N-terminal Pleckstrin homology (PH) domain followed three protein interacting domains: Tec homology (TH) region, Src homology 3 (SH3) domain and SH2 domain. A tyrosine-kinase catalytic domain is located at the C-terminal end. Two tyrosine phos-phorylation sites are located at the positions Y223 and Y551, which are located in the SH3 and kinase domain, respectively. Both phosphorylation sites play a pivotal role in the activation of BTK. Y551 is transphosphorylated by Syk (or Lyn) kinases which promotes the catalytic activity of BTK, with subsequent autophosphorylation at position Y223.
منابع مشابه
Female agammaglobulinemia due to the Bruton tyrosine kinase deficiency caused by extremely skewed X-chromosome inactivation.
We analyzed the cause of agammaglobulinemia in a girl whose father had been diagnosed as having X-linked agammaglobulinemia (XLA). Flow cytometric analysis revealed the lack of peripheral B cells with the block of B-cell differentiation in the stages between pro-B cells and pre-B cells in the bone marrow, and the defect of the Bruton tyrosine kinase (BTK) expression on monocytes. We found a BTK...
متن کاملDeficient Expression of Bruton's Tyrosine Kinase in Monocytes from X-Linked Agammaglobulinemia as Evaluated by a Flow Cytometric Analysis and its Clinical Application to Carrier Detection
Background: The B-cell defect in X-linked agammaglobulinemia (XLA) is caused by mutations in the gene for Bruton's tyrosine kinase (BTK). BTK mutations result in deficient expression of BTK protein in peripheral blood monocytes. Methods: Using the anti-BTK monoclonal antibody (48-2H), a flow cytometric analysis of intra cytoplasmic BTK protein expression in monocytes was performed to identify I...
متن کاملMolecular and biophysical analysis of the non-catalytic PH, TH, SH3 and SH2 domains of Bruton tyrosine kinase (Btk) protein
Academic dissertation To be presented for public criticism, with the permission of Abbreviations Abstract 1 Introduction 10 1.1 Primary immunodeficiencies (PIDs) 10 1.1.1 X-linked agammaglobulinemia (XLA) 12
متن کاملStructure and function of the SH3 domain from Bruton ́s tyrosine kinase
Mutations in the gene coding for Bruton ́s tyrosine kinase (Btk) lead to a lymphocyte differentiation block, which results in an extreme deficiency of B cells and plasma cells in the blood. These mutations are one cause of the hereditary immunodeficiency Xlinked agammaglobulinemia. Evolutionarily, Btk belongs to the Tec family of nonreceptor protein tyrosine kinases. Members of this family share...
متن کاملBruton tyrosine kinase (BTK) in X-linked agammaglobulinemia (XLA).
X-linked agammaglobulinemia (XLA) is a heritable immunodeficiency disorder that is caused by a differentiation block leading to almost complete absence of B lymphocytes and plasma cells. The affected protein is a cytoplasmic protein tyrosine kinase, Bruton's agammaglobulinemia tyrosine kinase (Btk). Btk along with Tec, Itk, Bmx and Txk belong to a distinct family of protein kinases. These prote...
متن کاملRegulation of Bruton tyrosine kinase by the peptidylprolyl isomerase Pin1.
Bruton tyrosine kinase (Btk) is expressed in B-lymphocytes. Mutations in Btk cause X-linked agammaglobulinemia in humans. However, the mechanism of activation and signaling of this enzyme has not been fully investigated. We have here shown that the peptidylprolyl cis/trans isomerase (PPIase) Pin1 is a negative regulator of Btk, controlling its expression level by reducing its half-life, whereas...
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