title: itk, a T-cell-specific tyrosine kinase gene inducible by interleukin 2.
abstract: T lymphocytes are activated by interactions with antigens, lymphokines, and cell adhesion molecules. Tyrosine phosphorylation has been implicated as important in signaling through each of these pathways, but except for p56lck, a member of the Src family that associates with CD4 and CD8, the protein-tyrosine kinases involved have not been defined. We describe here a tyrosine kinase gene that we have designated itk (for IL-2-inducible T-cell kinase). The itk gene specifies a 72-kDa protein-tyrosine kinase that is related to members of the Src family but lacks two features characteristic of Src kinases: an N-terminal myristoylation consensus sequence and a regulatory tyrosine residue near the C terminus. Analysis of mouse tissues and cell lines indicates that itk is specifically expressed in the T-cell lineage, suggesting that the tyrosine kinase encoded by itk functions in a signal transduction pathway unique to T lymphocytes. On addition of IL-2 to responsive T cells, itk RNA increases in parallel with that of IL-2R alpha, implicating itk in T-cell activation.
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004790:Enzyme Induction; D007376:Interleukin-2 / Q000494:pharmacology*; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D010766:Phosphorylation; D019000:Phosphotyrosine; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000201:enzymology*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D007376:Interleukin-2; D009838:Oligodeoxyribonucleotides; D019000:Phosphotyrosine; D014443:Tyrosine; D004247:DNA; D011505:Protein-Tyrosine Kinases