Pertussis toxin activates protein kinase C and a tyrosine protein kinase in the human T cell line Jurkat.

Pertussis toxin activates T lymphocytes by a mechanism that is independent of its ADP-ribosylation activity. The toxin stimulates increases in diacylglycerol and intracellular calcium apparently by interacting with a cell surface receptor. Consistent with the production of these second messengers we have found that pertussis toxin activates protein kinase C in the Jurkat cell line. The toxin was also found to activate a tyrosine protein kinase in these cells in a manner similar to that observed with phytohemagglutinin. These results provide evidence that the mechanism of activation of T cells by pertussis toxin involves stimulating the activity of protein kinase C and a tyrosine protein kinase.