Regulation of purine nucleotide biosynthesis: in yeast and beyond

2006 ◽  
Vol 34 (5) ◽  
pp. 786-790 ◽  
Author(s):  
R.J. Rolfes
Keyword(s):  
Saccharomyces Cerevisiae ◽  
De Novo ◽  
Purine Nucleotide ◽  
De Novo Synthesis ◽  
Normal Functioning ◽  
Purine Nucleotides ◽  
Yeast Saccharomyces Cerevisiae ◽  
Nucleotide Biosynthesis ◽  
Salvage Pathways ◽  
Pool Sizes

Purine nucleotides are critically important for the normal functioning of cells due to their myriad of activities. It is important for cells to maintain a balance in the pool sizes of the adenine-containing and guanine-containing nucleotides, which occurs by a combination of de novo synthesis and salvage pathways that interconvert the purine nucleotides. This review describes the mechanism for regulation of the biosynthetic genes in the yeast Saccharomyces cerevisiae and compares this mechanism with that described in several microbial species.

scholarly journals De novo synthesis of serine and glycine fuels purine nucleotide biosynthesis in human lung cancer tissues

2019 ◽  
Vol 294 (36) ◽  
pp. 13464-13477 ◽  
Author(s):  
Teresa W. M. Fan ◽  
Ronald C. Bruntz ◽  
Ye Yang ◽  
Huan Song ◽  
Yelena Chernyavskaya ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Human Lung ◽  
De Novo ◽  
Human Lung Cancer ◽  
Purine Nucleotide ◽  
De Novo Synthesis ◽  
Nucleotide Biosynthesis ◽  
Cancer Tissues

Purine metabolism in cultured aortic and coronary endothelial cells

1989 ◽  
Vol 67 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Christine Des Rosiers ◽  
Stephan Nees ◽  
Eckehart Gerlach
Keyword(s):  
Endothelial Cells ◽  
Adrenergic Receptor ◽  
De Novo ◽  
De Novo Synthesis ◽  
Purine Nucleotides ◽  
Aortic Endothelial Cells ◽  
Purine Bases ◽  
Coronary Endothelial Cells ◽  
Salvage Pathways ◽  
Aortic Endothelial

Purine salvage pathways in cultured endothelial cells of macrovascular (pig aorta) and microvascular (guinea pig coronary system) origin were investigated by measuring the incorporation of radioactive purine bases (adenine or hypoxanthine) or nucleosides (adenosine or inosine) into purine nucleotides. These precursors were used at initial extracellular concentrations of 0.1, 5, and 500 μM. In both types of endothelial cells, purine nucleotide synthesis occurred with all four substrates. Aortic endothelial cells salvaged adenine best among purines and nucleosides when applied at 0.1 μM. At 5 and 500 μM, adenosine was the best precursor. In contrast, microvascular endothelial cells from the coronary system used adenosine most efficiently at all concentrations studied. The synthetic capacity of salvage pathways was greater than that of the de novo pathway. As measured using radioactive formate or glycine, de novo synthesis of purine nucleotides was barely detectable in aortic endothelial cells, whereas it readily occurred in coronary endothelial cells. Purine de novo synthesis in coronary endothelial cells was inhibited by physiological concentrations of purine bases and nucleosides, and by ribose or isoproterenol. The isoproterenol-induced inhibition was prevented by the β-adrenergic receptor antagonist propranolol. The end product of purine catabolism in aortic endothelial cells was found to be hypoxanthine, whereas coronary endothelial cells degraded hypoxanthine further to xanthine and uric acid, a reaction catalyzed by the enzyme xanthine dehydrogenase.Key words: purine metabolism, aortic endothelial cells, coronary endothelial cells, β-adrenergic receptor.

scholarly journals Disruption of de novo purine biosynthesis in Pseudomonas fluorescens Pf0-1 leads to reduced biofilm formation and a reduction in cell size of surface-attached but not planktonic cells

2015 ◽  
Author(s):  
Shiro Yoshioka ◽  
Peter D Newell
Keyword(s):  
Pseudomonas Fluorescens ◽  
Cell Size ◽  
Biofilm Formation ◽  
De Novo ◽  
Purine Biosynthesis ◽  
Model Organisms ◽  
Purine Nucleotides ◽  
Surface Attachment ◽  
Nucleotide Biosynthesis ◽  
Mutant Cells

Pseudomonas fluorescens Pf0-1 is one of the model organisms for biofilm research. Our previous transposon mutagenesis study suggested a requirement for the de novo purine nucleotide biosynthesis pathway for biofilm formation by this organism. This study was performed to verify that observation and investigate the basis for the defects in biofilm formation shown by purine biosynthesis mutants. Constructing deletion mutations in 8 genes in this pathway, we found that they all showed reductions in biofilm formation that could be partly or completely restored by nucleotide supplementation or genetic complementation. We demonstrated that, despite a reduction in biofilm formation, more viable mutant cells were recovered from the surface-attached population than from the planktonic phase under conditions of purine deprivation. Analyses using scanning electron microscopy revealed that the surface-attached mutant cells were 25~30% shorter in length than WT, which partly explains the reduced biomass in the mutant biofilms. The laser diffraction particle analyses confirmed this finding, and further indicated that the WT biofilm cells were smaller than their planktonic counterparts. The defects in biofilm formation and reductions in cell size shown by the mutants were fully recovered upon adenine or hypoxanthine supplementation, indicating that the purine shortages caused reductions in cell size. Our results are consistent with surface attachment serving as a survival strategy during nutrient deprivation, and indicate that changes in the cell size may be a natural response of P. fluorescens to growth on a surface. Finally, cell sizes in WT biofilms became slightly smaller in the presence of exogenous adenine than in its absence. Our findings suggest that purine nucleotides or related metabolites may influence the regulation of cell size in this bacterium.

[78] Some methods for the study of de Novo synthesis of purine nucleotides

1955 ◽  
pp. 504-519 ◽  
Author(s):  
David A. Goldthwait ◽  
G. Robert Greenberg
Keyword(s):  
De Novo ◽  
De Novo Synthesis ◽  
Purine Nucleotides

Molecular genetic analysis of Saccharomyces cerevisiae C1-tetrahydrofolate synthase mutants reveals a noncatalytic function of the ADE3 gene product and an additional folate-dependent enzyme

1990 ◽  
Vol 10 (11) ◽  
pp. 5679-5687
Author(s):  
C K Barlowe ◽  
D R Appling
Keyword(s):  
Saccharomyces Cerevisiae ◽  
De Novo ◽  
Point Mutations ◽  
Gene Replacement ◽  
Molecular Genetic Analysis ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Purine Synthesis

In eucaryotes, 10-formyltetrahydrofolate (formyl-THF) synthetase, 5,10-methenyl-THF cyclohydrolase, and NADP(+)-dependent 5,10-methylene-THF dehydrogenase activities are present on a single polypeptide termed C1-THF synthase. This trifunctional enzyme, encoded by the ADE3 gene in the yeast Saccharomyces cerevisiae, is thought to be responsible for the synthesis of the one-carbon donor 10-formyl-THF for de novo purine synthesis. Deletion of the ADE3 gene causes adenine auxotrophy, presumably as a result of the lack of cytoplasmic 10-formyl-THF. In this report, defined point mutations that affected one or more of the catalytic activities of yeast C1-THF synthase were generated in vitro and transferred to the chromosomal ADE3 locus by gene replacement. In contrast to ADE3 deletions, point mutations that inactivated all three activities of C1-THF synthase did not result in an adenine requirement. Heterologous expression of the Clostridium acidiurici gene encoding a monofunctional 10-formyl-THF synthetase in an ade3 deletion strain did not restore growth in the absence of adenine, even though the monofunctional synthetase was catalytically competent in vivo. These results indicate that adequate cytoplasmic 10-formyl-THF can be produced by an enzyme(s) other than C1-THF synthase, but efficient utilization of that 10-formyl-THF for purine synthesis requires a nonenzymatic function of C1-THF synthase. A monofunctional 5,10-methylene-THF dehydrogenase, dependent on NAD+ for catalysis, has been identified and purified from yeast cells (C. K. Barlowe and D. R. Appling, Biochemistry 29:7089-7094, 1990). We propose that the characteristics of strains expressing full-length but catalytically inactive C1-THF synthase could result from the formation of a purine-synthesizing multienzyme complex involving the structurally unchanged C1-THF synthase and that production of the necessary one-carbon units in these strains is accomplished by an NAD+ -dependent 5,10-methylene-THF dehydrogenase.

scholarly journals TMOD-38. PRODUCTION OF D-2-HYDROXYGLUTARATE IN SACCHAROMYCES CEREVISIAE LEADS TO GROWTH IMPAIRMENT AND DECREASED SURVIVAL

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi271-vi271
Author(s):  
Sophie Fiola ◽  
Eli Ganni ◽  
Rita Lo ◽  
Ka Yee Lok ◽  
Elena Kuzmin ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Gene Interactions ◽  
Low Grade ◽  
Yeast Saccharomyces Cerevisiae ◽  
Growth Impairment ◽  
Knockout Strain ◽  
Genomic Array ◽  
Negative Gene

Abstract High levels of D-2-hydroxyglutarate (D2HG) are found in several types of cancers, most notably low grade gliomas (LGGs). The accumulation of D-2HG contributes to tumorigenesis through a variety of mechanisms including decreased utilization of oxidative phosphorylation and histone hypermethylation. The use of the budding yeast Saccharomyces cerevisiae as a model system to study cancer allows for faster, more efficient elucidation of various molecular mechanisms, including functional genomics via genomic array screening. S. cerevisiae encodes two homologs of the human D-2HG dehydrogenase: the mitochondrial Dld2 and cytosolic Dld3. We detected an increase in the production of D-2HG in the dld3∆ knockout strain by LC-MS. In addition, the dld3∆ knockout strain shows decreased survival and a growth impairment in glucose-containing liquid media. However, this strain did not show a significant growth impairment on glucose or glycerol-containing solid media. Using publicly available Synthetic Genomic Array (SGA) analysis data from TheCellMap.org, we investigated the top negative gene interactions for our dld3 knockout strain. GO analysis of these negative gene interactions showed enrichment of targets locating to the mitochondria, suggesting that the increase of 2-HG leads to mitochondrial impairment, consistent with previous observations in other models of LGGs. The top two targets of the SGA screen were mdm35, a mitochondrial interspace membrane protein involved in assembly of the mitochondrial respiratory chain complex and cdc8, a component of the de novo pyrimidine biosynthesis pathway. Taken together, these results suggest that the dld3∆ knockout strain is an appropriate model in which to study the D-2HG-driven changes that occur during tumorigenesis.

Intrapulmonary catabolism of surfactant-saturated phosphatidylcholine in rabbits

1990 ◽  
Vol 69 (5) ◽  
pp. 1856-1862 ◽  
Author(s):  
E. D. Rider ◽  
M. Ikegami ◽  
A. H. Jobe
Keyword(s):  
Alveolar Macrophages ◽  
Secretory Pathway ◽  
De Novo ◽  
Turnover Time ◽  
Lung Homogenate ◽  
De Novo Synthesis ◽  
Phospholipase A1 ◽  
Pool Sizes

Intrapulmonary surfactant catabolism was investigated by use of a phospholipase A1- and A2-resistant analogue of dipalmitoylphosphatidylcholine (DPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPC ether). [14C]DPC ether, made into liposomes with [3H]DPC and associated with 32P-labeled rabbit surfactant, was given intratracheally to 1-kg rabbits, which were killed at preset times to 48 h. Recoveries of radiolabel as saturated phosphatidylcholine (Sat PC) isolated from alveolar wash (AW), postlavage lung homogenate (LH), and alveolar macrophages were measured. All groups had similar AW and LH Sat PC pool sizes, indicating no perturbation of endogenous Sat PC pools. Despite a nearly fivefold accumulation of [14C]DPC ether in the lung by 48 h (P less than 0.01), the three probes had similar alveolar clearance curves. Furthermore, the Sat PC reutilization efficiency (41.6%) and turnover time (5.9 h) calculated for DPC ether were not different from values for the DPC and rabbit surfactant. Of the DPC ether (0.7%) and DPC (9%) labels recovered as PC in organs outside the lung, greater than 85% was unsaturated, indicating de novo synthesis using precursors from degraded PC. DPC ether was a useful probe of intrapulmonary DPC catabolism, and after alveolar uptake there was no direct reentry of intact DPC from the catabolic compartment(s) into the secretory pathway.

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