[Possible role of protein kinase C in the T-lymphocyte cell cycle]

Experimental results of induction of T-lymphocyte proliferation by means of tumor promotors-activators of protein kinase C (PKC) are reviewed. A hypothesis has been put forward that the discrepancy of the data so far available can be explained on the account of the difference in membrane-associated PKC activation patterns produced by tumor promotors and by interleukin 2. It is established that the former induce a permanent PKC activation, whereas the latter induces a transient one. Although enhancing DNA synthesis, the permanent (non-physiological) activation must induce an accumulation of cells in the cell cycle phases following the S-phase.