Protein kinase C is not a downstream effector of p21^ras in activated T cells

The aim of this present study was to investigate the role of protein kinase C (PKC), downstream of p21^ras, in activating interleukin‐2 (IL‐2) gene expression. It has been reported that PKC is an effector of p21^ras in T cells. Data is presented, using the potent and selective PKC inhibitor Ro 31‐8425 and transient expression of a constitutively active ras mutant, which clearly shows that PKC is not downstream of p21^ras in the induction of NF‐AT and AP‐1 transcriptional activity and in the expression of IL‐2 in human Jurkat T cells. Reporter gene experiments demonstrated that NF‐χB transcriptional activity is not affected by expression of activated p21^ras. The signaling pathways involving PKC activation, calcium mobilization and ras activation combine to provide the necessary components for production of IL‐2 during T cell activation.