scholarly journals Complex Metabolic Phenotypes Caused by a Mutation in yjgF, Encoding a Member of the Highly Conserved YER057c/YjgF Family of Proteins

1998 ◽  
Vol 180 (24) ◽  
pp. 6519-6528 ◽  
Author(s):  
Jodi L. Enos-Berlage ◽  
Mark J. Langendorf ◽  
Diana M. Downs
Keyword(s):  
Pentose Phosphate Pathway ◽  
Biosynthetic Pathway ◽  
Genetic Characterization ◽  
Pentose Phosphate ◽  
Oxidative Pentose Phosphate Pathway ◽  
Phenotypic Characterization ◽  
Reading Frame ◽  
Wide Range ◽  
Isoleucine Biosynthesis

ABSTRACT The oxidative pentose phosphate pathway is required for function of the alternative pyrimidine biosynthetic pathway, a pathway that allows thiamine synthesis in the absence of the PurF enzyme inSalmonella typhimurium. Mutants that no longer required function of the oxidative pentose phosphate pathway for thiamine synthesis were isolated. Further phenotypic analyses of these mutants demonstrated that they were also sensitive to the presence of serine in the medium, suggesting a partial defect in isoleucine biosynthesis. Genetic characterization showed that these pleiotropic phenotypes were caused by null mutations in yjgF, a previously uncharacterized open reading frame encoding a hypothetical 13.5-kDa protein. The YjgF protein belongs to a class of proteins of unknown function that exhibit striking conservation across a wide range of organisms, from bacteria to humans. This work represents the first detailed phenotypic characterization of yjgF mutants in any organism and provides important clues as to the function of this highly conserved class of proteins. Results also suggest a connection between function of the isoleucine biosynthetic pathway and the requirement for the pentose phosphate pathway in thiamine synthesis.

Characterization of trophic changes and a functional oxidative pentose phosphate pathway in Synechocystis sp. PCC 6803

2009 ◽  
Vol 32 (3) ◽  
pp. 511-518 ◽  
Author(s):  
Tove Jansén ◽  
Dominic Kurian ◽  
Wuttinun Raksajit ◽  
Steve York ◽  
Michael L. Summers ◽  
...  
Keyword(s):  
Pentose Phosphate Pathway ◽  
Pentose Phosphate ◽  
Oxidative Pentose Phosphate Pathway ◽  
Trophic Changes ◽  
Synechocystis Sp ◽  
Pcc 6803

scholarly journals Targeting oxidative pentose phosphate pathway prevents recurrence in mutant Kras colorectal carcinomas

PLoS Biology ◽  
2019 ◽  
Vol 17 (8) ◽  
pp. e3000425 ◽  
Author(s):  
WenChao Gao ◽  
YuTing Xu ◽  
Tao Chen ◽  
ZunGuo Du ◽  
XiuJuan Liu ◽  
...  
Keyword(s):  
Pentose Phosphate Pathway ◽  
Pentose Phosphate ◽  
Oxidative Pentose Phosphate Pathway ◽  
Colorectal Carcinomas

scholarly journals Genetic Characterization of the Carotenoid Biosynthetic Pathway in Methylobacterium extorquens AM1 and Isolation of a Colorless Mutant

2003 ◽  
Vol 69 (12) ◽  
pp. 7563-7566 ◽  
Author(s):  
Stephen J. Van Dien ◽  
Christopher J. Marx ◽  
Brooke N. O'Brien ◽  
Mary E. Lidstrom
Keyword(s):  
Biosynthetic Pathway ◽  
Genetic Characterization ◽  
Carotenoid Biosynthesis ◽  
Biosynthesis Pathway ◽  
Wild Type ◽  
Methylobacterium Extorquens ◽  
Growth Properties ◽  
Carotenoid Biosynthesis Pathway ◽  
Free Strain

ABSTRACT Genomic searches were used to reconstruct the putative carotenoid biosynthesis pathway in the pink-pigmented facultative methylotroph Methylobacterium extorquens AM1. Four genes for putative phytoene desaturases were identified. A colorless mutant was obtained by transposon mutagenesis, and the insertion was shown to be in one of the putative phytoene desaturase genes. Mutations in the other three did not affect color. The tetracycline marker was removed from the original transposon mutant, resulting in a pigment-free strain with wild-type growth properties useful as a tool for future experiments.

Genetic characterization of Rhizobium sp. strain TAL1145 that nodulates tree legumes

1994 ◽  
Vol 40 (3) ◽  
pp. 208-215 ◽  
Author(s):  
M. L. C. George ◽  
J. P. W. Young ◽  
D. Borthakur
Keyword(s):  
Rhizobium Leguminosarum ◽  
Genetic Characterization ◽  
Rhizobium Meliloti ◽  
Wild Type ◽  
Tree Legumes ◽  
Wide Range ◽  
The Common ◽  
Rrna Sequences ◽  
Rhizobium Sp

Rhizobium sp. strain TALI 145 nodulates Leucaena ieucocephaia and Phaseolus vulgaris, in addition to a wide range of tropical tree legumes. Six overlapping clones that complemented nodulation defects in leucaena and bean rhizobia were isolated and a 40-kb map of the symbiosis region was constructed. The common nod and nifA genes were situated approximately 17 kb apart, with the nodlJ genes in between. These clones enabled a derivative of TAL1145 carrying a partially deleted pSym to form ineffective nodules on both leucaena and bean, and a similar derivative of Rhizobium etli TAL182 to form ineffective nodules on bean. When two representative clones, pUHR9 and pUHR114, were each transferred to wild-type rhizobial strains, they allowed ineffective nodulation by Rhizobium meliloti on both leucaena and bean and by Rhizobium leguminosarum bv. viciae on bean. Transconjugants of R. leguminosarum bv. trifolii formed effective nodules on leucaena and ineffective nodules on bean. Tn5 mutagenesis of the symbiosis region resulted in a variety of nodulation and fixation phenotypes on leucaena and bean. On the basis of 16S rRNA sequences, TAL1145 was found to be distinct from both R. tropici and NGR234, the two groups of leucaena symbionts that were previously described.Key words: Rhizobium, Leucaena leucocephala, nodulation, nitrogen fixation.

Significance of the Non-Oxidative Pentose Phosphate Pathway in Aspergillus oryzae Grown on Different Carbon Sources

1991 ◽  
Vol 46 (3-4) ◽  
pp. 223-227 ◽  
Author(s):  
Maria Luisa Peleato ◽  
Teresa Muiño-Blanco ◽  
José Alvaro Cebrian Pérez ◽  
Manuel José López-Pérez
Keyword(s):  
Aspergillus Oryzae ◽  
Pentose Phosphate Pathway ◽  
Enzyme Activities ◽  
Developmental Stages ◽  
Carbon Sources ◽  
Pentose Phosphate ◽  
Oxidative Pentose Phosphate Pathway ◽  
Pentose Pathway ◽  
Hexose Phosphates

Specific enzyme activities of the non-oxidative pentose phosphate pathway in Aspergillus oryzae mycelia grown on different carbon sources were determined. Mycelia grown on glucose, mannitol and ribose show the highest specific activities, ribose 5-phosphate isomerase being specially very enhanced. Moreover, transketolase, transaldolase, ribose 5-phosphate isomerase and ribulose 5-phosphate 3-epimerase were determined in different developmental stages of mycelia grown on glucose, mannitol and ribose. The non-oxidative pentose phosphate pathway is more active during conidiogenesis, except for ribulose 5-phosphate 3-epimerase, suggesting a fundamental role of this pathway during that stage to supply pentoses for nucleic acids biosynthesis. A general decrease of the enzyme activities was found in sporulated mycelia. Arabinose 5-phosphate was tested as metabolite of the pentose pathway. This pentose phosphate was not converted into hexose phosphates or triose phosphates and inhibits significantly the ribose 5-phosphate utilization, being therefore unappropriate to support the Aspergillus oryzae growth.

scholarly journals Roles of the hexosamine biosynthetic pathway and pentose phosphate pathway in bile acid‐induced cancer development

2019 ◽  
Vol 110 (8) ◽  
pp. 2408-2420 ◽  
Author(s):  
Masayoshi Munemoto ◽  
Ken‐ichi Mukaisho ◽  
Tomoharu Miyashita ◽  
Katsunobu Oyama ◽  
Yusuke Haba ◽  
...  
Keyword(s):  
Bile Acid ◽  
Pentose Phosphate Pathway ◽  
Biosynthetic Pathway ◽  
Pentose Phosphate ◽  
Cancer Development ◽  
Hexosamine Biosynthetic Pathway

scholarly journals Beneficial effects of acute inhibition of the oxidative pentose phosphate pathway in the failing heart

2014 ◽  
Vol 306 (5) ◽  
pp. H709-H717 ◽  
Author(s):  
Claudio Vimercati ◽  
Khaled Qanud ◽  
Gianfranco Mitacchione ◽  
Danuta Sosnowska ◽  
Zoltan Ungvari ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pentose Phosphate Pathway ◽  
Tissue Concentration ◽  
Glucose Consumption ◽  
Pentose Phosphate ◽  
Oxidative Pentose Phosphate Pathway ◽  
Stroke Work ◽  
Failing Heart

In vitro studies suggested that glucose metabolism through the oxidative pentose phosphate pathway (oxPPP) can paradoxically feed superoxide-generating enzymes in failing hearts. We therefore tested the hypothesis that acute inhibition of the oxPPP reduces oxidative stress and enhances function and metabolism of the failing heart, in vivo. In 10 chronically instrumented dogs, congestive heart failure (HF) was induced by high-frequency cardiac pacing. Myocardial glucose consumption was enhanced by raising arterial glycemia to levels mimicking postprandial peaks, before and after intravenous administration of the oxPPP inhibitor 6-aminonicotinamide (80 mg/kg). Myocardial energy substrate metabolism was measured with radiolabeled glucose and oleic acid, and cardiac 8-isoprostane output was used as an index of oxidative stress. A group of five chronically instrumented, normal dogs served as control. In HF, raising glycemic levels from ∼80 to ∼170 mg/dL increased cardiac isoprostane output by approximately twofold, whereas oxPPP inhibition normalized oxidative stress and enhanced cardiac oxygen consumption, glucose oxidation, and stroke work. In normal hearts glucose infusion did not induce significant changes in cardiac oxidative stress. Myocardial tissue concentration of 6P-gluconate, an intermediate metabolite of the oxPPP, was significantly reduced by ∼50% in treated versus nontreated failing hearts, supporting the inhibitory effect of 6-aminonicotinamide. Our study indicates an important contribution of the oxPPP activity to cardiac oxidative stress in HF, which is particularly pronounced during common physiological changes such as postprandial glycemic peaks.

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