Ramifications of impaired PRPP synthesis in Saccharomyces cerevisiae

The model eukaryote Saccharomyces cerevisiae is well suited to investigate the causes of metabolic disturbance. PRPP [5-phospho-D-ribosyl-1(α)-pyrophosphate] may be regarded as a junction of carbon and nitrogen metabolism. As a result of this central position, perturbations in its synthesis can give rise to many unexpected cellular events, such as impaired cell integrity. We have taken advantage of S. cerevisiae's genetic tractability to investigate the metabolic links responsible for connecting the biochemical intermediate PRPP to apparently unrelated cellular functions. This approach provides insight into the co-ordination of different biological processes.

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In Saccharomyces cerevisiae, impaired PRPP synthesis is accompanied by valproate and Li+ sensitivity

Biochemical Society Transactions ◽

10.1042/bst0331154 ◽

2005 ◽

Vol 33 (5) ◽

pp. 1154-1157 ◽

Cited By ~ 5

Author(s):

S. Vavassori ◽

K. Wang ◽

L.M. Schweizer ◽

M. Schweizer

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Wall ◽

Nitrogen Metabolism ◽

Phospholipid Metabolism ◽

Cell Wall Integrity ◽

Yeast Genome ◽

Carbon And Nitrogen ◽

Yeast Physiology ◽

Cellular Biochemistry ◽

Carbon And Nitrogen Metabolism

The biosynthetic intermediate PRPP (phosphoribosylpyrophosphate) has a central role in cellular biochemistry since it links carbon and nitrogen metabolism. Its importance may be reflected in the fact that, in the Saccharomyces cerevisiae (yeast) genome, there are five unlinked genes, PRS1–PRS5, each of which is theoretically capable of encoding the enzyme synthesizing PRPP. Interference with the complement of PRS genes in S. cerevisiae has far-reaching consequences for yeast physiology and has uncovered unexpected metabolic links including cell wall integrity and phospholipid metabolism.

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Disruption of MRG19 results in altered nitrogen metabolic status and defective pseudohyphal development in Saccharomyces cerevisiae

Microbiology ◽

10.1099/mic.0.27347-0 ◽

2005 ◽

Vol 151 (1) ◽

pp. 91-98 ◽

Cited By ~ 5

Author(s):

Maitreyi Das ◽

Paike Jayadeva Bhat

Keyword(s):

Saccharomyces Cerevisiae ◽

Nitrogen Metabolism ◽

Type Strain ◽

Wild Type Strain ◽

Glucose Repression ◽

Metabolic Status ◽

Wild Type ◽

Developmental Pathway ◽

Carbon And Nitrogen ◽

Carbon And Nitrogen Metabolism

It was previously shown that MRG19 downregulates carbon metabolism in Saccharomyces cerevisiae upon glucose exhaustion, and that the gene is glucose repressed. Here, it is shown that glucose repression of MRG19 is overcome upon nitrogen withdrawal, suggesting that MRG19 is a regulator of carbon and nitrogen metabolism. β-Galactosidase activity fostered by the promoter of GDH1/3, which encode anabolic enzymes of nitrogen metabolism, was altered in an MRG19 disruptant. As compared to the wild-type strain, the MRG19 disruptant showed a decrease in the ratio of 2-oxoglutarate to glutamate under nitrogen-limited conditions. MRG19 disruptants showed reduced pseudohyphal formation and enhanced sporulation, a phenomenon that occurs under conditions of both nitrogen and carbon withdrawal. These studies revealed that MRG19 regulates carbon and nitrogen metabolism, as well as morphogenetic changes, suggesting that MRG19 is a component of the link between the metabolic status of the cell and the corresponding developmental pathway.

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