Cellular responses to L-serine in Saccharomyces cerevisiae: roles of general amino acid control, compartmentalization, and aspartate synthesis.

In addition to its other roles, L-serine functions in one-carbon metabolism and is interconvertable with glycine via serine hydroxymethyltransferases. However, the transcriptional response by Saccharomyces cerevisiae to L-serine addition is markedly different from that to glycine, with L-serine acting as a nutrient source rather than one-carbon units. Following addition of excess L-serine, 743 genes showed significant expression changes.