Translational control of ADP-ribosylation in eucaryotic cells

Starvation of the mouse hepatoma cell line Hepa for an essential amino acid (Trp, His, Leu, Ile or Phe) stimulated the incorporation of [3H]adenosine as ADP-ribose monomer into an 80,000-Mr protein, P80. Two-dimensional electrophoresis of Hepa proteins showed that P80 was the only protein labeled under starvation conditions. Time course experiments showed that the ADP-ribosylation of P80 was a consequence rather than the cause of reduced translational activity. Cycloheximide treatment and incubation at reduced temperatures also reduced the rate of protein synthesis and stimulated the ADP-ribosylation of P80. Starvation-dependent ADP-ribosylation of P80 was shown to occur in three other cell lines (Chang, Neuro-2a, and chick comb fibroblasts).