Synthesis of p34, the mammalian homolog of the yeast cdc2+/CDC28 protein kinase, is stimulated during adenovirus-induced proliferation of primary baby rat kidney cells.

The homolog of the cdc2+/CDC28+ encoded protein kinases has previously been identified in HeLa cells by immunological methods. Here we have studied the distribution and synthesis of this 34 kd protein in rat tissues and cell lines. p34 was found in a variety of organs, including some such as brain that are not highly active in cell division. Kidney has very low levels of p34. However, proliferative activation of baby rat kidney cells with adenovirus caused rapid induction of p34 synthesis. Induction was dependent on the E1A gene of the virus but not E1B, and was not prevented by inhibition of cellular DNA synthesis with hydroxyurea. Increased synthesis of p34 is due, at least in part, to an increase in abundance of translatable p34 mRNA. These data are consistent with the possibility that p34 plays a role in cell division in higher vertebrates.