Association of human NK cell surface receptors NKR-P1 and CD94 with Src-family protein kinases

Immunogenetics - Tập 46 - Trang 231-236 - 1997
J. Černý1, Anna Fišerová2, Ondrej Horváth2, Karel Bezouška3, Milan Pospíšil2, Václav Hořejší1
1Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague 4, Czech Republic,
2Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague 4, Czech Republic
3Faculty of Sciences, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic,

Tóm tắt

 Human natural killer (NK) cells express on their surface several members of the C-type lectin family such as NKR-P1, CD94, and NKG2 that are probably involved in recognition of target cells and delivery of signals modulating NK cell cytotoxicity. To elucidate the mechanisms involved in signaling via these receptors, we solubilized in vitro cultured human NK cells by a mild detergent, Brij-58, immunoprecipitated molecular complexes containing the NKR-P1 or CD94 molecules, respectively, by specific monoclonal antibodies, and performed in vitro kinase assays on the immunoprecipitates. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, autoradiography, and phospho-amino acid analysis revealed the presence of in vitro tyrosine phosphorylated proteins that were subsequently identified by re-precipitation (and/or by western blotting) as the respective C-type lectin molecules and Src family kinases Lck, Lyn, and Fyn. The NKR-P1 and the CD94-containing complexes were independent of each other and both very large, as judged by Sepharose 4B gel chromatography. Crosslinking of NKR-P1 on the cell surface induced transient in vivo tyrosine phosphorylation of cellular protein substrates. These results indicate involvement of the associated Src-family kinases in signaling via the NKR-P1 and CD94 receptors.