Regulation of the balance of one-carbon metabolism in Saccharomyces cerevisiae

Matthew D. Piper, Seung Pyo Hong, Graham E. Ball, Ian W. Dawes

Research output: Contribution to journalArticleResearchpeer-review

62 Citations (Scopus)

Abstract

One-carbon metabolism in yeast is an essential process that relies on at least one of three one-carbon donor molecules: serine, glycine, or formate. By a combination of genetics and biochemistry we have shown how cells regulate the balance of one-carbon flow between the donors by regulating cytoplasmic serine hydroxymethyltransferase activity in a side reaction occurring in the presence of excess glycine. This control governs the level of 5,10-methylene tetrahydrofolate (5,10-CH2-H4folate) in the cytoplasm, which has a direct role in signaling transcriptional control of the expression of key genes, particularly those encoding the unique components of the glycine decarboxylase complex (GCV1, GCV2, and GCV3). Based on these and other observations, we propose a model for how cells balance the need to supplement their one-carbon pools when charged folares are limiting or when glycine is in excess. We also propose that under normal conditions, cytoplasmic 5,10-CH2-H4folate is mainly directed to generating methyl groups via methionine, whereas one-carbon units generated from glycine in mitochondria are more directed to purine biosynthesis. When glycine is in excess, 5,10-CH2-H4folate is decreased, and the regulation loop shifts the balance of generation of one-carbon units into the mitochondrion.

Original languageEnglish
Pages (from-to)30987-30995
Number of pages9
JournalJournal of Biological Chemistry
Volume275
Issue number40
Publication statusPublished - 6 Oct 2000
Externally publishedYes

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