Identification of a novel one-carbon metabolism regulon in Saccharomyces cerevisiae.
Glycine specifically induces genes encoding subunits of the glycine decarboxylase complex (GCV1, GCV2, and GCV3), and this is mediated by a fall in cytoplasmic levels of 5,10-methylenetetrahydrofolate caused by inhibition of cytoplasmic serine hydroxymethyltransferase. Here it is shown that this control system extends to genes for other enzymes of one-carbon metabolism and de novo purine biosynthesis. Northern analysis of the response to glycine demonstrated that the induction of the GCV genes and the induction of other amino acid metabolism genes are temporally distinct. The genome-wide response to glycine revealed that several other genes are rapidly co-induced with the GCV genes, including SHM2, which encodes cytoplasmic serine hydroxymethyltransferase. These results were refined by examining transcript levels in an shm2Delta strain (in which cytoplasmic 5,10-methylenetetrahydrofolate levels are reduced) and a met13Delta strain, which lacks the main methylenetetrahydrofolate reductase activity of yeast and is effectively blocked at consumption of 5,10-methylene tetrahydrofolate for methionine synthesis. Glycine addition also caused a substantial transient disturbance to metabolism, including a sequence of changes in induction of amino acid biosynthesis and respiratory chain genes. Analysis of the glycine response in the shm2Delta strain demonstrated that apart from the one-carbon regulon, most of these transient responses were not contingent on a disturbance to one-carbon metabolism. The one-carbon response is distinct from the Bas1p purine biosynthesis regulon and thus represents the first example of transcriptional regulation in response to activated one-carbon status.
Gelling
Cristy L
CL
Ramaciotti Centre for Gene Function Analysis and School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
Piper
Matthew D W
MD
Hong
Seung-Pyo
SP
Kornfeld
Geoffrey D
GD
Dawes
Ian W
IW
D020816:Amino Acid Motifs; D000594:Amino Acid Oxidoreductases / Q000502:physiology; D015152:Blotting, Northern; D002244:Carbon / Q000737:chemistry / Q000378:metabolism*; D002455:Cell Division; D003593:Cytoplasm / Q000201:enzymology / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005998:Glycine / Q000737:chemistry; D050959:Glycine Decarboxylase Complex; D050841:Glycine Dehydrogenase (Decarboxylating); D012696:Glycine Hydroxymethyltransferase / Q000037:antagonists & inhibitors; D008954:Models, Biological; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D011687:Purines / Q000737:chemistry; D012313:RNA / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D013997:Time Factors; D014158:Transcription, Genetic
D018076:DNA, Complementary; D004791:Enzyme Inhibitors; D011687:Purines; D029701:Saccharomyces cerevisiae Proteins; D012313:RNA; D002244:Carbon; D004247:DNA; D000594:Amino Acid Oxidoreductases; C494237:GCV2 protein, S cerevisiae; D050959:Glycine Decarboxylase Complex; D050841:Glycine Dehydrogenase (Decarboxylating); D012696:Glycine Hydroxymethyltransferase; D005998:Glycine