INVIVO ACTIVATION OF THE YEAST PLASMA-MEMBRANE ATPASE DURING NITROGEN STARVATION - IDENTIFICATION OF THE REGULATORY DOMAIN THAT CONTROLS ACTIVATION

Yeast plasma membrane ATPase is activated during nitrogen starvation when a fermentable substrate is present. This activation is due to changes in the V(max) and it is irreversible, independent of protein synthesis and apparently triggered by a decrease in the intracellular pH. It is shown that the ATPase regulatory domain implicated in the activation by fermentable carbon sources is also implicated in activation by nitrogen starvation and by external acidification.