Biosynthesis of hydroxymethylpyrimidine pyrophosphate in Saccharomyces cerevisiae

Kawasaki, Yuko; Onozuka, Mari; Mizote, Tomoko; Nosaka, Kazuto

doi:10.1007/s00294-004-0557-x

Cited by 22 publications

(28 citation statements)

References 19 publications

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“…THI4 encodes an enzyme required for the synthesis of HET (Praekelt et al 1994). THI20 and THI21 (and possibly THI22) encode enzymes with HMP kinase and HMP-P kinase activities (Llorente et al 1999;Kawasaki et al 2005). The THI5 family (THI5, THI11, THI12 and THI13) encodes enzymes for biosynthesis of HMP.…”

Section: Introductionmentioning

confidence: 99%

Pdc2 coordinates expression of the THI regulon in the yeast Saccharomyces cerevisiae

Mojžita

Hohmann

2006

Mol Genet Genomics

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Coordination of gene expression in response to different metabolic signals is crucial for cellular homeostasis. In this work, we addressed the role of Pdc2 in the coordinated control of biosynthesis and demand of an essential metabolic cofactor, thiaminediphosphate (ThDP). The DNA binding protein Pdc2 was initially identified as a regulator of the genes PDC1 and PDC5, which encode isoforms of the glycolytic enzyme pyruvate decarboxylase (Pdc). The Pdc2 has also been implicated as a regulator of genes encoding enzymes in ThDP metabolism. The ThDP is the cofactor of Pdc. Using global and gene-specific expression analysis, we show that Pdc2 is required for the upregulation of all genes controlled by thiamine availability. The Pdc2 seems to act together with Thi2, a known transcriptional regulator of THI genes. The requirement for these two factors differs in a gene-specific manner. While the Thi2, in conjunction with Thi3, seems to control expression of THI genes with respect to thiamine availability, the Pdc2 may link the ThDP demand to carbon source availability. Interestingly, the enzymes Pdc1 and Pdc5 are enriched in the nucleus. Both are known to affect gene expression in an autoregulatory mechanism and expression of both is regulated by glucose and Pdc2, further pointing to a role of Pdc2 in coordinating different metabolic signals. Our analysis helps to further define the THI regulon and hence the spectrum of genes/proteins involved in the ThDP homeostasis. In particular, we identify novel proteins putatively involved in thiamine and/or ThDP transport across the plasma and the mitochondrial membrane. In conclusion, the THI regulon is the most interesting system to study principles of genes expression and metabolic coordination and deserves further attention.

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Section: Introductionmentioning

confidence: 99%

Pdc2 coordinates expression of the THI regulon in the yeast Saccharomyces cerevisiae

Mojžita

Hohmann

2006

Mol Genet Genomics

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“…The single null strains for THI20 and THI21 grow at the same rate as the parental strain in medium lacking thiamin, but the simultaneous disruption of both genes leads to thiamin auxotrophy. Although THI20 and THI21 are functionally redundant in terms of de novo thiamin synthesis, Thi20p has higher ability to synthesize HMP‐PP from HMP than Thi21p (Kawasaki et al , 2005). The sequences of the C‐terminal parts of THI20/21/22 are similar to the sequence of the S. cerevisiae PET18 gene over its full length (about 20% aa identity).…”

Section: Introductionmentioning

confidence: 99%

Involvement of thiaminase II encoded by theTHI20gene in thiamin salvage ofSaccharomyces cerevisiae

Onozuka

Konno

Kawasaki

et al. 2008

FEMS Yeast Research

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The physiological significance of thiaminase II, which catalyzes the hydrolysis of thiamin, has remained elusive for several decades. The C-terminal domains of THI20 family proteins (THI20/21/22) and the whole region of PET18 gene product of Saccharomyces cerevisiae are homologous to bacterial thiaminase II. On the other hand, the N-terminal domains of THI20 and THI21 encode 2-methyl-4-amino-5-hydroxymethylpyrimidine kinase and 2-methyl-4-amino-5-hydroxymethylpyrimidine phosphate kinase involved in the thiamin synthetic pathway. In this study, it was first indicated that the C-terminal domains of the THI20 family and PET18 are not required for de novo thiamin synthesis in S. cerevisiae, using a quadruple deletion strain expressing the N-terminal domain of THI20. Biochemical analysis using cell-free extracts and recombinant proteins demonstrated that yeast thiaminase II activity is exclusively encoded by THI20. It appeared that Thi20p has an affinity for the pyrimidine moiety of thiamin, and HMP produced by the thiaminase II activity is immediately phosphorylated. Thi20p was found to participate in the formation of thiamin from two synthetic antagonists, pyrithiamin and oxythiamin, by hydrolyzing both antagonists and phosphorylating HMP to give HMP pyrophosphate. Furthermore, 2-methyl-4-amino-5-aminomethylpyrimidine, a presumed naturally occurring thiamin precursor, was effectively converted to HMP by incubation with Thi20p. It is proposed that the thiaminase II activity of Thi20p is involved in the thiamin salvage pathway by catalyzing the hydrolysis of HMP precursors in S. cerevisiae.

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“…The members of another gene family, THI20 and THI21, encode HMP-P kinases, which are actually trifunctional proteins, as they can also perform the salvage HMP phosphorylation, and contain an additional C-terminal domain with a thiamin degrading (thiaminase II) activity [14,20]. Interestingly, the C-terminal domain exhibits a high sequence similarity to PET18 [14]. The function of the third member of the same gene family, THI22, is unknown at present [21].…”

Section: The Genetic Control Of Thiamin Biosynthesis In Yeastsmentioning

confidence: 99%

“…Later steps of HMP-P synthesis up till the final HMP-P phosphorylation are controlled by genes of the THI5/THI11/THI12/THI13 family [19] and the PET18 gene, but the exact enzymatic functions of their protein products have not yet been recognized. The members of another gene family, THI20 and THI21, encode HMP-P kinases, which are actually trifunctional proteins, as they can also perform the salvage HMP phosphorylation, and contain an additional C-terminal domain with a thiamin degrading (thiaminase II) activity [14,20]. Interestingly, the C-terminal domain exhibits a high sequence similarity to PET18 [14].…”

Section: The Genetic Control Of Thiamin Biosynthesis In Yeastsmentioning

confidence: 99%

“…HMP-P is synthesized in yeast cells from histidine and pyridoxal-5-phosphate, the latter linking the thiamin and vitamin B 6 (pyridoxine) biosynthesis pathways [13]. Yeasts can also salvage HMP-P by an uptake of 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP) from the environment followed by its phosphorylation [14]. The next phosphorylation step yields HMP-PP ready for condensation with HET-P to produce TMP.…”

Section: Thiamin Biosynthesis Pathways In Yeastsmentioning

confidence: 99%

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The genes and enzymes involved in the biosynthesis of thiamin and thiamin diphosphate in yeasts

Kowalska

Kozik

2008

Cellular and Molecular Biology Letters

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Thiamin (vitamin B1) is an essential molecule for all living organisms. Its major biologically active derivative is thiamin diphosphate, which serves as a cofactor for several enzymes involved in carbohydrate and amino acid metabolism. Important new functions for thiamin and its phosphate esters have recently been suggested, e.g. in gene expression regulation by influencing mRNA structure, in DNA repair after UV illumination, and in the protection of some organelles against reactive oxygen species. Unlike higher animals, which rely on nutritional thiamin intake, yeasts can synthesize thiamin de novo. The biosynthesis pathways include the separate synthesis of two precursors, 4-amino -5-hydroxymethyl-2-methylpyrimidine diphosphate and 5-(2-hydroxyethyl)-4-methylthiazole phosphate, which are then condensed into thiamin monophosphate. Additionally, yeasts evolved salvage mechanisms to utilize thiamin and its dephosphorylated late precursors, 4-amino-5-hydroxymethyl-2-methylpyrimidine and 5-(2-hydroxyethyl)-4-methylthiazole, from the environment. The current state of knowledge on the discrete steps of thiamin biosynthesis in yeasts is far from satisfactory; many intermediates are postulated only by analogy to the much better understood biosynthesis process in bacteria. On the other hand, the genetic mechanisms regulating thiamin biosynthesis in yeasts are currently under extensive exploration. Only recently, the structures of some of the yeast enzymes involved in thiamin biosynthesis, such as thiamin diphosphokinase and thiazole synthase, were determined at the atomic resolution, and mechanistic proposals for the catalysis of particular biosynthetic steps started to emerge.

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Biosynthesis of hydroxymethylpyrimidine pyrophosphate in Saccharomyces cerevisiae

Cited by 22 publications

References 19 publications

Pdc2 coordinates expression of the THI regulon in the yeast Saccharomyces cerevisiae

Pdc2 coordinates expression of the THI regulon in the yeast Saccharomyces cerevisiae

Involvement of thiaminase II encoded by theTHI20gene in thiamin salvage ofSaccharomyces cerevisiae

The genes and enzymes involved in the biosynthesis of thiamin and thiamin diphosphate in yeasts

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