Induced polypeptide synthesis during the development of bacterial bioluminescence.

The dramatic increase in bioluminescence observed during the later exponential growth of Beneckea harveyi is due to the induction of luciferase activity. The mechanism by which luciferase activity is induced and the possible existence of other induced proteins was investigated in a double-labelind experiment: [4,5-3H]leucine was incorporated into cellular proteins synthesized during the luminescence lag period in early growth; [14C]leucine was incorporated during the later period of luminescence induction. The protein of the cell-free extract were extensively fractionated and luciferase was purified to homogeneity. Analysis of the radioactivity incorporated into the alpha and beta subunits of luciferase showed a dramatic but equal decrease in the 3H/14C ratio for both subunits. This result proves that the synthesis of the alpha and beta chains of luciferase is subject to similar controls and that the regulatory mechanism is operative at the level of gene transcription, or translation at the time of bioluminescence induction, or both. Several additional polypeptides have been found which also show a marked decrease in their 3H/14C ratio indicating that their synthesis is induced during the same period as luciferase. In addition, one polypeptide that is synthesized specifically in the bioluminescence lag period was also detected. The function and role of these new polypeptides with respect to the bioluminescent system is presently under investigation.