title: RIBP, a novel Rlk/Txk- and itk-binding adaptor protein that regulates T cell activation.
abstract: A novel T cell-specific adaptor protein, RIBP, was identified based on its ability to bind Rlk/Txk in a yeast two-hybrid screen of a mouse T cell lymphoma library. RIBP was also found to interact with a related member of the Tec family of tyrosine kinases, Itk. Expression of RIBP is restricted to T and natural killer cells and is upregulated substantially after T cell activation. RIBP-disrupted knockout mice displayed apparently normal T cell development. However, proliferation of RIBP-deficient T cells in response to T cell receptor (TCR)-mediated activation was significantly impaired. Furthermore, these activated T cells were defective in the production of interleukin (IL)-2 and interferon gamma, but not IL-4. These data suggest that RIBP plays an important role in TCR-mediated signal transduction pathways and that its binding to Itk and Rlk/Txk may regulate T cell differentiation.
authors.affiliation: Committee on Immunology, University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: K
authors.initials: K
authors.lastname: Rajagopal
authors.forename: C L
authors.initials: CL
authors.lastname: Sommers
authors.forename: D C
authors.initials: DC
authors.lastname: Decker
authors.forename: E O
authors.initials: EO
authors.lastname: Mitchell
authors.forename: U
authors.initials: U
authors.lastname: Korthauer
authors.forename: A I
authors.initials: AI
authors.lastname: Sperling
authors.forename: C A
authors.initials: CA
authors.lastname: Kozak
authors.forename: P E
authors.initials: PE
authors.lastname: Love
authors.forename: J A
authors.initials: JA
authors.lastname: Bluestone
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002460:Cell Line; D002478:Cells, Cultured; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D015723:Gene Library; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation; D016399:Lymphoma, T-Cell; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D009115:Muridae; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000276:immunology*; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D007376:Interleukin-2; D011994:Recombinant Proteins; C402726:Sh2d2a protein, mouse; C089848:Tec protein-tyrosine kinase; D011505:Protein-Tyrosine Kinases; C080813:emt protein-tyrosine kinase