Difference in sensitivity to amino acid starvation between the wild type and sir2A-null mutant of Dictyostelium discoideum

抄録

Dictyostelium discoideum transits from growth phase to developmental phase when nutrients are depleted. D. discoideum under a starved condition aggregates and forms a cell mass called mound within 12 h and then forms a fruiting body. The nutrients critical for the transition are amino acids. Thus, D. discoideum is thought to have a mechanism for sensing amino acid starvation. We examined in the current study the function of Sir2A in the initiation of development. The wild type initiated development and formed mounds within 12 h even in the presence of 1 ~ 3 mg/ml amino acids, while the null mutant did not form mounds within 12 h in the presence of 2 mg/ml amino acid. These results suggest that the null mutant is less sensitive to starvation than is the wild type and that Sir2A plays an important role in the recognition of amino acid starvation.