Regulation of enzyme synthesis in an enucleate cell

Abstract

Acetabularia crenulata contains three phosphatases having pH optima 5.0, 8.5 and 12.0. The synthesis of these enzymes was studied during normal growth of the cells and during the period of regeneration which follows removal of the cap. A comparison was made between regenerating cells which contained a nucleus and similar cells from which the nucleus had been removed. Synthesis of all three enzymes took place in the enucleate cell. Synthesis of the pH 12 enzyme was found to be specifically associated with the formation of the cap. When the cap was re-formed after amputation, this enzyme was synthesized in similar amounts in the nucleate and the enucleate cell. These findings indicate not only that synthesis of specific enzymes can take place in the absence of the nucleus, but also that this synthesis can be regulated in the enucleate cell.