1. Activation of BTK by a phosphorylation mechanism initiated by SRC family kinases.
- Author
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Rawlings DJ, Scharenberg AM, Park H, Wahl MI, Lin S, Kato RM, Fluckiger AC, Witte ON, and Kinet JP
- Subjects
- 3T3 Cells, Agammaglobulinaemia Tyrosine Kinase, Animals, Cell Line, Transformed, Cell Membrane enzymology, Enzyme Activation, Immunoglobulin M immunology, Lymphocyte Activation, Mice, Mutation, Phosphopeptides analysis, Phosphorylation, Phosphotyrosine metabolism, Protein-Tyrosine Kinases chemistry, Protein-Tyrosine Kinases genetics, Receptors, Antigen, B-Cell metabolism, Signal Transduction, B-Lymphocytes enzymology, Protein-Tyrosine Kinases metabolism, src-Family Kinases metabolism
- Abstract
Bruton's tyrosine kinase (BTK) is pivotal in B cell activation and development through its participation in the signaling pathways of multiple hematopoietic receptors. The mechanisms controlling BTK activation were studied here by examination of the biochemical consequences of an interaction between BTK and SRC family kinases. This interaction of BTK with SRC kinases transphosphorylated BTK on tyrosine at residue 551, which led to BTK activation. BTK then autophosphorylated at a second site. The same two sites were phosphorylated upon B cell antigen receptor cross-linking. The activated BTK was predominantly membrane-associated, which suggests that BTK integrates distinct receptor signals resulting in SRC kinase activation and BTK membrane targeting.
- Published
- 1996
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