Measurements of metabolites during cAMP oscillations of Dictyostelium discoideum.

During aggregation the cellular slime mold Dictyostelium discoideum synthesizes and releases pulses of cAMP about every five minutes. Current models proposed to explain this phenomenon postulate that oscillating levels of some key intracellular metabolite control the oscillatory synthesis of cAMP. We have assayed the levels of likely candidates for this metabolite during a cAMP oscillation, but have found them to remain constant. Compounds measured include ATP, GTP, glucose-1-phosphate, glucose-6-phosphate, isocitrate, alpha-ketoglutarate, amino acids, and other aminated metabolites. On the basis of this negative data, as well as results described elsewhere (Geller and Brenner, '78), we question whether the proposed models are correct, and discuss several alternatives.