Poising of the arginine pool and control of bioluminescence in Beneckea harveyi

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Abstract
Arginine dramatically stimulates bioluminescence in the marine bacterium B. harveyi growing in minimal media, an effect due to increases in synthesis and expression of luciferase. To elucidate the mechanism of this phenomenon, transport and metabolism of arginine in B. harveyi were studied. The transport of arginine and lysine involves 2 kinetically distinct transport systems for uptake of arginine and lysine. Ornithine is transported only by a system common to all 3 amino acids. Internal amino acid pools were measured in mutants that do not show stimulation of bioluminescence by arginine and in wild-type cells that do. In minimal media, internal arginine pools are undetectably low. Exogenously added labeled arginine is rapidly transported and converted to citrulline and argininosuccinate. The results can be accommodated by a model in which internal arginine is poised at a very low concentration; the stimulatory effect of exogenous arginine on luciferase biosynthesis occurs at the transcriptional level and the actual mediator can be arginine or argininyl tRNA.