Tyrosine Phosphorylation-dependent Suppression of a Voltage-gated K+Channel in T Lymphocytes upon Fas Stimulation*

Autor: Szabò, Ildikò, Gulbins, Erich, Apfel, Horst, Zhang, Xinfeng, Barth, Petra, Busch, Andreas E., Schlottmann, Klaus, Pongs, Olaf, Lang, Florian
Zdroj: Journal of Biological Chemistry; August 1996, Vol. 271 Issue: 34 p20465-20469, 5p
Abstrakt: Selective cell death plays a critical role in the development of the immune system and in the elimination of target cells expressing foreign antigens. Most of programmed cell death occurs by apoptosis. Apoptotic cell death of lymphocytes can be triggered by ligation of APO-1/Fas (CD95) antigen (Suda, T., and Nagata, S. (1994) J. Exp. Med.179, 873-879; Nagata, S., and Golstein, P. (1995) Science267, 1449-1456). We find that activation of Fas leads to the inhibition of the voltage-dependent n-type K+channels (Kv1.3) studied by patch clamp technique in Jurkat T lymphocytes. Tyrosine kinases have been shown to be crucial in Fas-induced cell death (Eischen, C. M., Dick, C. J., and Leibson, P. J. (1994) J. Immunol.153, 1947-1954). The inhibition of the current is correlated with the tyrosine phosphorylation of immunoprecipitated and blotted K+channel protein. We show, that the Src-like protein-tyrosine kinase inhibitor herbimycin A and the deficiency of the p56lcktyrosine kinase in mutant Jurkat cells abolished the channel inhibition and phosphorylation by anti-Fas antibody, while reconstitution of the p56lckkinase partly restored these effects of Fas receptor triggering. These results suggest a regulation of n-type K+channels by tyrosine kinases upon Fas receptor triggering, which might be important for apoptosis.
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