APO-1(CD95)-mediated apoptosis in Jurkat cells does not involve src kinases or CD45.
Tyrosine phosphorylation has been reported to be an early event required for APO-1/Fas(CD95) signalling in lymphocytes [Eischen, C.M., Dick, C.J. and Leibson, P.J. (1994) J. Immunol. 153, 1947-1954]. We have compared two mutant Jurkat cells, one largely deficient in expression of CD-45 (J45.01) and a second one deficient in expression of p56lck (JCaM1.6) with wild type Jurkat cells for their ability to undergo APO-1-induced apoptosis. No significant difference was observed among the three cell lines. In the mutant Jurkat cells APO-1 triggering did not result in increased tyrosine phosphorylation of cytosolic proteins. Furthermore, herbimycin A did not inhibit but rather augmented apoptosis at concentrations which effectively degraded the src related kinases lck and fyn. The data suggest that APO-1-mediated signalling is independent from src kinases and CD45.
Schraven
B
B
Division of Applied Immunology, German Cancer Research Center, Heidelberg.
Peter
M E
ME
D000954:Antigens, Surface / Q000502:physiology*; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D016227:Benzoquinones; D006801:Humans; D047029:Lactams, Macrocyclic; D017493:Leukocyte Common Antigens / Q000502:physiology*; D015688:Oncogene Protein pp60(v-src) / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D011809:Quinones / Q000494:pharmacology; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D017828:Rifabutin / Q000031:analogs & derivatives; D013601:T-Lymphocytes / Q000502:physiology*; D014407:Tumor Cells, Cultured; D019014:fas Receptor
D000954:Antigens, Surface; D016227:Benzoquinones; D047029:Lactams, Macrocyclic; D011809:Quinones; D011948:Receptors, Antigen, T-Cell; D019014:fas Receptor; D017828:Rifabutin; C020754:herbimycin; D011505:Protein-Tyrosine Kinases; D015688:Oncogene Protein pp60(v-src); D017493:Leukocyte Common Antigens