Fig. 9: Model.
Under nitrogen starvation, autophagy allows yeast cells to retrieve nitrogen to support glutamate synthesis via a complex nexus of transamination and deamination reactions. This replenishes cellular nitrogen currency for subsequent nitrogen anabolism such as aspartate synthesis to support macromolecule synthesis. Although not specifically depicted here, amino acids derived directly from protein turnover may also participate in macromolecule synthesis under nitrogen starvation.
