Eukaryotic gene expression: metabolite control by amino acids.

Our understanding of the metabolite control in mammalian cells lags far behind that in prokaryotes. This is particularly true for amino-acid-dependent gene expression. Few proteins have been identified for which synthesis is selectively regulated by amino-acid availability, and the mechanisms for control of transcription and translation in response to changes in amino-acid availability have not yet been elucidated. The intimate relationship between amino-acid supply and the fundamental cellular process of protein synthesis makes amino-acid-dependent control of gene expression particularly important. Future studies should provide important insight into amino-acid and other nutrient signaling pathways, and their impact on cellular growth and metabolism.