Phosphorylation of a 15- to 17-kDa protein correlated with lytic function in cytotoxic T lymphocytes.
CTL are activated to lyse their targets through the interaction of the CTL-R and the appropriate Ag on the surface of the target cell. Experiments with tumor-promoting phorbol esters have suggested that the activation and translocation of protein kinase C (PKC) to the CTL membrane may be important in the activation process. We have studied the functional role of PKC in lytic signal transduction by correlating the phosphorylation of a set of CTL membrane proteins bound by the lectin Con A with lytic function in CTL clones. The data obtained indicate that the phosphorylation of a 15- to 17-kDa polypeptide in this subset is associated with the translocation of PKC to the membrane and the stimulation of lytic function. This suggests that the 15- to 17-kDa protein may be a physiologically relevant substrate for PKC translocated to the membrane as a result of Ag-specific perturbation of the CTL-R.
Filiaggi
M C
MC
Department of Pharmacology, Washington University Medical School, St. Louis, MO 63110.
McCulley
D E
DE
Russell
J H
JH
D003208:Concanavalin A / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects; D008565:Membrane Proteins / Q000378:metabolism*; D010703:Phorbol Esters / Q000494:pharmacology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism
D008565:Membrane Proteins; D010703:Phorbol Esters; D003208:Concanavalin A; D011493:Protein Kinase C