Regulation of pyrimidine formation in Pseudomonas lundensis

2009 ◽  
Vol 55 (3) ◽  
pp. 261-268 ◽  
Author(s):  
Thomas P. West
Keyword(s):  
Carbon Source ◽  
Orotic Acid ◽  
De Novo ◽  
Enzyme Synthesis ◽  
Chemical Mutagenesis ◽  
Aspartate Transcarbamoylase ◽  
Food Spoilage ◽  
Orotate Phosphoribosyltransferase ◽  
Selection Procedures ◽  
Monophosphate Decarboxylase

The regulation of pyrimidine formation in the food spoilage agent Pseudomonas lundensis ATCC 49968 by pyrimidines was examined. In P. lundensis cells grown on glucose as a carbon source, the enzymes aspartate transcarbamoylase, dihydroorotase, and orotidine 5′-monophosphate decarboxylase were induced by orotic acid. Pyrimidine auxotrophs containing reduced transcarbamoylase or orotate phosphoribosyltransferase activity were isolated using chemical mutagenesis and selection procedures. Independent of carbon source, the maximum derepression of enzyme activity was observed for orotidine 5′-monophosphate decarboxylase after pyrimidine limitation of either auxotroph. In the glucose-grown cells of the transcarbamoylase mutant strain, orotic acid induced dihydroorotase and decarboxylase activities. Aspartate transcarbamoylase activity in succinate-grown P. lundensis cells was highly regulated by pyrophosphate as well as by pyrimidine and purine ribonucleotides. It was concluded that pyrimidine formation in P. lundensis was controlled both at the level of de novo pyrimidine biosynthetic enzyme synthesis and at the level of transcarbamoylase activity.

Control of pyrimidine formation in Pseudomonas putida ATCC 17536

2002 ◽  
Vol 48 (12) ◽  
pp. 1076-1081 ◽  
Author(s):  
Manuel F Santiago ◽  
Thomas P West
Keyword(s):  
Carbon Source ◽  
Pseudomonas Putida ◽  
Orotic Acid ◽  
De Novo ◽  
Enzyme Synthesis ◽  
Pyrimidine Biosynthesis ◽  
Transcriptional Level ◽  
Orotate Phosphoribosyltransferase ◽  
Biosynthesis Regulation ◽  
Uracil Auxotrophs

The regulation of de novo pyrimidine biosynthesis in Pseudomonas putida ATCC 17536 by pyrimidines was explored. The pathway enzyme activities were higher in glucose-grown cells than in succinate-grown cells, indicating catabolite repression by succinate. In P. putida cells grown on succinate as a carbon source, only aspartate transcarbamoylase activity was greatly diminished by uracil supplementation. When glucose was the carbon source, orotic acid supplementation significantly decreased orotate phosphoribosyltransferase and orotidine 5'-monophosphate (OMP) decarboxylase activities. Uracil auxotrophs, deficient for dihydroorotase activity or with reduced phosphoribosyltransferase activity, were isolated. After pyrimidine limitation of both auxotrophs, the greatest derepression of enzyme activity was observed for OMP decarboxylase independent of carbon source. Orotic acid induced both phosphoribosyltransferase and decarboxylase activities in glucose-grown cells of the dihydroorotase-deficient strain. Regulation at the transcriptional level of de novo pyrimidine biosynthetic enzyme synthesis in P. putida ATCC 17536 was observed, which contrasts with previous observations.Key words: pyrimidine biosynthesis, regulation, auxotrophs, induction, Pseudomonas.

Induction and repression of L-fucose dehydrogenase of Pullularia pullulans

1984 ◽  
Vol 30 (6) ◽  
pp. 753-757 ◽  
Author(s):  
P. F. Conter ◽  
M. F. Guimarães ◽  
L. A. Veiga
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
De Novo ◽  
Ring Structure ◽  
Enzyme Synthesis ◽  
De Novo Synthesis

The growth of Pullularia pullulans on L-fucose as the sole carbon source induces the synthesis of L-fucose dehydrogenase, a NAD-dependent enzyme that catalyzes the oxidation of L-fucose to L-fucono-δ-lactone, which spontaneously hydrolyzes to L-fuconic acid. The induction of the enzyme is inhibited by cycloheximide, suggesting de novo synthesis. D-Glucose, D-galactose, and glycerol at 0.5% concentration gave rise to 62, 54, 51, and 46% of repression of enzyme synthesis, respectively. No repression effect was detected with D-arabinose and L-rhamnose. L-Arabinose repressed only 20% of the enzyme synthesis. Among the sugars tested, only L-fucose and L-galactose were oxidized by the enzyme. L-Galactose, which shares a common ring structure with L-fucose, showed only 10% of the activity observed when L-fucose was used.

scholarly journals N-Acetylglucosamine Utilization by Saccharomyces cerevisiae Based on Expression of Candida albicans NAG Genes

2009 ◽  
Vol 75 (18) ◽  
pp. 5840-5845 ◽  
Author(s):  
Jürgen Wendland ◽  
Yvonne Schaub ◽  
Andrea Walther
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
De Novo ◽  
Biofuel Production ◽  
Bioethanol Production ◽  
Catabolic Pathway ◽  
Cellular Functions ◽  
Kinase A

ABSTRACT Synthesis of chitin de novo from glucose involves a linear pathway in Saccharomyces cerevisiae. Several of the pathway genes, including GNA1, are essential. Genes for chitin catabolism are absent in S. cerevisiae. Therefore, S. cerevisiae cannot use chitin as a carbon source. Chitin is the second most abundant polysaccharide after cellulose and consists of N-acetylglucosamine (GlcNAc) moieties. Here, we have generated S. cerevisiae strains that are able to use GlcNAc as a carbon source by expressing four Candida albicans genes (NAG3 or its NAG4 paralog, NAG5, NAG2, and NAG1) encoding a GlcNAc permease, a GlcNAc kinase, a GlcNAc-6-phosphate deacetylase, and a glucosamine-6-phosphate deaminase, respectively. Expression of NAG3 and NAG5 or NAG4 and NAG5 in S. cerevisiae resulted in strains in which the otherwise-essential ScGNA1 could be deleted. These strains required the presence of GlcNAc in the medium, indicating that uptake of GlcNAc and its phosphorylation were achieved. Expression of all four NAG genes produced strains that could use GlcNAc as the sole carbon source for growth. Utilization of a GlcNAc catabolic pathway for bioethanol production using these strains was tested. However, fermentation was slow and yielded only minor amounts of ethanol (approximately 3.0 g/liter), suggesting that fructose-6-phosphate produced from GlcNAc under these conditions is largely consumed to maintain cellular functions and promote growth. Our results present the first step toward tapping a novel, renewable carbon source for biofuel production.

scholarly journals ON THE NATURE OF SPOROGENESIS IN SOME AEROBIC BACTERIA

1952 ◽  
Vol 35 (6) ◽  
pp. 907-927 ◽  
Author(s):  
W. A. Hardwick ◽  
J. W. Foster
Keyword(s):  
De Novo ◽  
Enzyme Synthesis ◽  
Aerobic Bacteria ◽  
Low Molecular Weight ◽  
Inhibitory Effects ◽  
Nitrogenous Substances ◽  
Enzyme Formation ◽  
Spore Forming Bacteria ◽  
Endogenous Process ◽  
Exogenous Source

Washed vegetative cells of various species of aerobic spore-forming bacteria sporulate abundantly when shaken in distilled water in air. The spores thus formed possess the same heat resistance as spores formed in a complete growth medium. Various factors influencing sporogenesis in water are described. Glucose in low concentration completely suppresses sporogenesis under these conditions and the suppression is relieved by the presence of ammonia as an exogenous source of nitrogen. Various amino acid and purine antimetabolite analogues inhibit sporogenesis and their inhibitory effects are completely reversed by much smaller amounts of the corresponding metabolites. Sporogenesis is thus regarded as a de novo synthesis of spore proteins from preexisting endogenous (enzyme) proteins. Cells low in protein fail to sporulate and the capacity of the cell to adaptively attack maltose and trehalose is strongly interfered with after the cell is irreversibly committed to sporulation, but not before that. Evidence is advanced supporting the hypothesis that sporogenesis is an endogenous process which commences when the supply of exogenous energy and carbon is depleted. It utilizes low molecular weight nitrogenous substances liberated by the degradation of preexisting enzyme proteins of the vegetative cell. Sporogenesis and adaptive enzyme formation are regarded as competitive synthetic processes, both utilizing endogenous enzyme proteins. The events of sporogenesis suggest that this process may be an adaptive protein synthesis, analogous to adaptive enzyme synthesis.

XVII.—Utilization of Dietary Purines and Pyrimidines by Drosophila melanogaster

1957 ◽  
Vol 66 (4) ◽  
pp. 339-359 ◽  
Author(s):  
James H. Sang
Keyword(s):  
Drosophila Melanogaster ◽  
Orotic Acid ◽  
De Novo ◽  
Normal Growth ◽  
Energy Utilization ◽  
Good Growth ◽  
Response Curves ◽  
Adenylic Acid ◽  
Multicellular Organisms

SynopsisDrosophila melanogaster larvæ when cultured aseptically on a synthetic diet require exogenous ribose nucleic acid (RNA) for normal growth even though they can synthesize their own endogenous RNA from simple precursors. The optimum dietary supply lies between 0.4 and 0.7 per cent RNA. Individual bases, nucleosides and nucleotides which make up RNA cannot substitute for the whole polynucleotide, but adenine, adenosine, adenylic acid, guanosine and guanylic acid are used and stimulate growth to varying degrees. The pyrimidines and their nucleosides and nucleotides are not used when fed singly.It is shown that the de novo synthesis of purines may be more difficult than that of pyrimidines, and that if a source of purines is supplied (as adenylic acid), then the nucleosides and nucleotides of both cytosine and uracil are utilized by the larvæ, whereas the free bases are not. Cytidylic and uridylic acids seem to be interchangeable, and together with an adequate supply of adenylic acid give as good growth as RNA. Orotic acid and 2—6-diaminopurine are not used by the larvæ under the conditions described, but hypoxanthine and inosine are: xanthine and xanthosine can also be shown to have an effect on growth.Dose-response curves were determined for adenylic, guanylic, cytidylic and uridylic acids under conditions which allow the determination of the optimal supplies of each. These are found to be about 0.110, 0.080, 0.025 and 0.025 per cent, respectively. The requirement of RNA is therefore primarily a requirement of adenylic acid, since more than enough of the other nucleotides should be available when the supply of RNA is optimal. The optimal supply of adenine corresponds almost exactly with the optimal supply of adenylic acid, though a somewhat delayed larval development may be a result of energy utilization in the base-nucleoside-nucleotide conversion.These results are discussed in the light of our knowledge of purine and pyrimidine utilization in other multicellular organisms, particularly the rat, and possible applications of the findings are considered.

Orotic Acid, More Than Just an Intermediate of Pyrimidine de novo Synthesis

2015 ◽  
Vol 42 (5) ◽  
pp. 207-219 ◽  
Author(s):  
Monika Löffler ◽  
Elizabeth A. Carrey ◽  
Elke Zameitat
Keyword(s):  
Orotic Acid ◽  
De Novo ◽  
De Novo Synthesis

Enhanced orotate phosphoribosyltransferase activity in renal cell carcinoma and its prognostic significance

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 15590-15590
Author(s):  
Y. Mizutani ◽  
D. Toiyama ◽  
T. Shiraishi ◽  
T. Nakamura ◽  
K. Mikami ◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
De Novo ◽  
Prognostic Significance ◽  
Normal Kidney ◽  
Orotate Phosphoribosyltransferase ◽  
Synthetic Process ◽  
Dna And Rna ◽  
Fresh Frozen

15590 Background: 5-Fluorouracil ( 5-FU ) is an anticancer agent clinically used against various cancers including renal cell carcinoma ( RCC ). 5-FU is a prodrug and orotate phosphoribosyltransferase ( OPRT ) is the principal enzyme which directly converts 5-FU to an active anticancer metabolite, 5-fluoro-2’-deoxyuridine 5’-monophosphate. Furthermore, OPRT is the key enzyme in the de novo DNA and RNA synthetic process, which converts orotic acid to orotidine 5’-phosphate. Little is known about the significance of OPRT in a variety of cancers including RCC. We investigated OPRT activity in 83 RCC and evaluated the association between OPRT activity and the stage/grade of RCC. The relationship between OPRT activity in RCC cells and their sensitivity to 5-FU was also examined. Methods: OPRT activity in non-fixed fresh frozen RCC and normal kidney were determined enzymatically by the 5-FU phosphorylation assay. The sensitivity of RCC cells to 5-FU was assessed by the microculture tetrazolium dye assay. Results: OPRT activity was approximately 8.5-fold higher in RCC compared to normal kidney. OPRT activity in T3/4 RCC was 3-fold higher than that in T1/2 RCC. OPRT activity in M1 RCC was 2.5-fold higher than that in M0 RCC. In addition, OPRT activity in Stage III/IV RCC was 3-fold higher than that in Stage I/II RCC. The level of OPRT activity in Grade 3 RCC was 3-fold higher than that in Grade 1/2 cancer. Patients with RCC with low OPRT activity had a longer postoperative disease-specific survival than those with high activity in the 5-year follow-up. OPRT activity in RCC cells positively correlated with their sensitivity to 5-FU. Conclusions: The present study has demonstrated that OPRT activity in RCC was higher than that in normal kidney, and that OPRT activity positively correlated with the stage/grade of RCC. Moreover, higher OPRT activity in RCC predicted worse prognosis and higher sensitivity to 5-FU. These results suggest that OPRT activity may be used as both a prognostic parameter and a predictive indicator for 5-FU efficacy in RCC. No significant financial relationships to disclose.

scholarly journals Genomic Analysis of PIS1 Gene Expression

2005 ◽  
Vol 4 (3) ◽  
pp. 604-614 ◽  
Author(s):  
Mary E. Gardocki ◽  
Margaret Bakewell ◽  
Deepa Kamath ◽  
Kelly Robinson ◽  
Kathy Borovicka ◽  
...  
Keyword(s):  
Carbon Source ◽  
Cell Cycle Progression ◽  
De Novo ◽  
Essential Gene ◽  
Genomic Analysis ◽  
Anaerobic Growth ◽  
Regulatory Sequence ◽  
Database Mining ◽  
Biosynthetic Genes ◽  
Sequence Element

ABSTRACT The Saccharomyces cerevisiae PIS1 gene is essential and required for the final step in the de novo synthesis of phosphatidylinositol. Transcription of the PIS1 gene is uncoupled from the factors that regulate other yeast phospholipid biosynthetic genes. Most of the phospholipid biosynthetic genes are regulated in response to inositol and choline via a regulatory circuit that includes the Ino2p:Ino4p activator complex and the Opi1p repressor. PIS1 is regulated in response to carbon source and anaerobic growth conditions. Both of these regulatory responses are modest, which is not entirely surprising since PIS1 is essential. However, even modest regulation of PIS1 expression has been shown to affect phosphatidylinositol metabolism and to affect cell cycle progression. This prompted the present study, which employed a genomic screen, database mining, and more traditional promoter analysis to identify genes that affect PIS1 expression. A screen of the viable yeast deletion set identified 120 genes that affect expression of a PIS1-lacZ reporter. The gene set included several peroxisomal genes, silencing genes, and transcription factors. Factors suggested by database mining, such as Pho2 and Yfl044c, were also found to affect PIS1-lacZ expression. A PIS1 promoter deletion study identified an upstream regulatory sequence element that was required for carbon source regulation located downstream of three previously defined upstream activation sequence elements. Collectively, these studies demonstrate how a collection of genomic and traditional strategies can be implemented to identify a set of genes that affect the regulation of an essential gene.

Sign in / Sign up

Export Citation Format

Share Document