Metabolic compartments in Dictyostelium discoideum

• Published in: The Journal of biological chemistry 1982-07, Vol.257 (13), p.7587-7594
• Main Authors: Wright, B E, Thomas, D A, Ingalls, D J
• Format: Article
• Language: English
• Subjects: Carbon Radioisotopes; Dictyostelium - growth & development; Dictyostelium - metabolism; Dictyostelium discoideum; fungi; Glucose - metabolism; Glycolysis; Kinetics; Radioisotope Dilution Technique
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)34420-X

D. discoideum was exposed to low levels of (U- super(14)C)glucose at various stages during the culmination process, and seven metabolites were isolated. Steady state models having 15 metabolite pools were constructed to intepret the data obtained. The analyses have led to the following conclusions. Metabolically, two cell types can be distinguished during sorocarp construction: presumptive spore and stalk cells and mature stalk cells. There are separate pools of glucose and hexose phosphates in the stalk cells and in the presumptive spore and stalk cells. After the glycogen and end product saccharides are synthesized in presumptive spore and stalk cells, they are distributed into spore or stalk cells where they are accumulated, degraded, or both. As glycogen levels fall during culmination, the amount which turns over is constant, thereby increasing from 3 to 9%. Metabolically, the presumptive cell types and stalk cells behave like two independent cell populations; stalk metabolites are not used as precursor material by prespore and prestalk cells. It was found that the models are highly constrained by the extensive data available; relatively few compensatory effects are possible among the parameters involved.