Addition of basic amino acids prevents G-1 arrest of nitrogen-starved cultures of Saccharomyces cerevisiae.

Arginase-minus mutants of Saccharomyces cerevisiae were arrested in growth and accumulated at the unbudded G-1 stage of the cell cycle when starved for nitrogen. If, however, arginine was added to the culture medium at the time of starvation, growth ceased but the cells did not collect at the unbudded G-1 stage. We suggest that arginine addition prevented the cells from collecting at the G-1 stage by starving them for histidine and lysine, thereby inhibiting synthesis of proteins needed to complete the cell cycle.