Tags

Type your tag names separated by a space and hit enter

Yeast mutants of glucose metabolism with defects in the coordinate regulation of carbon assimilation.
Arch Biochem Biophys. 1999 May 15; 365(2):279-88.AB

Abstract

The enzymes of the glyoxylate cycle and gluconeogenesis are tightly regulated by transcriptional, posttranscriptional, and posttranslational mechanisms in Saccharomyces cerevisiae. We have previously identified four genes, ACN8, ACN9, ACN17, and ACN18, whose mutant phenotype includes two- to fourfold elevated levels of enzymes of the glyoxylate cycle, gluconeogenesis, and acetyl-CoA metabolism. The affected enzymes are elevated on nonfermentable carbon sources but are still fully repressed by glucose. Catabolite inactivation of the cytosolic malate dehydrogenase is not affected in the mutants. Instead, the phenotype appeared to be manifested primarily at the level of transcription. The ACN8, ACN17, and ACN18 genes were isolated by functional complementation of the respective mutant's inability to utilize acetate as a carbon and energy source, and these genes were shown to encode subunits of metabolic enzymes. ACN8 was identical to FBP1, which encodes the gluconeogenic enzyme, fructose 1,6-bisphosphatase, while ACN17 and ACN18 were identical to the SDH2 and SDH4 genes, respectively, that encode subunits of the respiratory chain and tricarboxylic acid cycle enzyme, succinate dehydrogenase. Mutants defective in other glyoxylate cycle and gluconeogenic enzymes also display the elevated enzyme phenotype, indicating that the enzyme superinduction is a general property of gluconeogenic dysfunction. Glucose 6-phosphate levels were diminished in the mutants, suggesting that endogenous glucose synthesis can regulate the expression of gluconeogenic enzymes.

Links

Publisher Full Text

Authors+Show Affiliations

Dennis RA
Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, 72205, USA.
Rhodey M
No affiliation info available
McCammon MT
No affiliation info available

MeSH

Acetyl Coenzyme AFructose-BisphosphataseGenes, FungalGenotypeGluconeogenesisGlucoseGlyoxylatesKineticsMutationPhenotypeSaccharomyces cerevisiaeSuccinate Dehydrogenase

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

10328823

Citation

Dennis, R A., et al. "Yeast Mutants of Glucose Metabolism With Defects in the Coordinate Regulation of Carbon Assimilation." Archives of Biochemistry and Biophysics, vol. 365, no. 2, 1999, pp. 279-88.
Dennis RA, Rhodey M, McCammon MT. Yeast mutants of glucose metabolism with defects in the coordinate regulation of carbon assimilation. Arch Biochem Biophys. 1999;365(2):279-88.
Dennis, R. A., Rhodey, M., & McCammon, M. T. (1999). Yeast mutants of glucose metabolism with defects in the coordinate regulation of carbon assimilation. Archives of Biochemistry and Biophysics, 365(2), 279-88.
Dennis RA, Rhodey M, McCammon MT. Yeast Mutants of Glucose Metabolism With Defects in the Coordinate Regulation of Carbon Assimilation. Arch Biochem Biophys. 1999 May 15;365(2):279-88. PubMed PMID: 10328823.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Yeast mutants of glucose metabolism with defects in the coordinate regulation of carbon assimilation. AU - Dennis,R A, AU - Rhodey,M, AU - McCammon,M T, PY - 1999/5/18/pubmed PY - 1999/5/18/medline PY - 1999/5/18/entrez SP - 279 EP - 88 JF - Archives of biochemistry and biophysics JO - Arch Biochem Biophys VL - 365 IS - 2 N2 - The enzymes of the glyoxylate cycle and gluconeogenesis are tightly regulated by transcriptional, posttranscriptional, and posttranslational mechanisms in Saccharomyces cerevisiae. We have previously identified four genes, ACN8, ACN9, ACN17, and ACN18, whose mutant phenotype includes two- to fourfold elevated levels of enzymes of the glyoxylate cycle, gluconeogenesis, and acetyl-CoA metabolism. The affected enzymes are elevated on nonfermentable carbon sources but are still fully repressed by glucose. Catabolite inactivation of the cytosolic malate dehydrogenase is not affected in the mutants. Instead, the phenotype appeared to be manifested primarily at the level of transcription. The ACN8, ACN17, and ACN18 genes were isolated by functional complementation of the respective mutant's inability to utilize acetate as a carbon and energy source, and these genes were shown to encode subunits of metabolic enzymes. ACN8 was identical to FBP1, which encodes the gluconeogenic enzyme, fructose 1,6-bisphosphatase, while ACN17 and ACN18 were identical to the SDH2 and SDH4 genes, respectively, that encode subunits of the respiratory chain and tricarboxylic acid cycle enzyme, succinate dehydrogenase. Mutants defective in other glyoxylate cycle and gluconeogenic enzymes also display the elevated enzyme phenotype, indicating that the enzyme superinduction is a general property of gluconeogenic dysfunction. Glucose 6-phosphate levels were diminished in the mutants, suggesting that endogenous glucose synthesis can regulate the expression of gluconeogenic enzymes. SN - 0003-9861 UR - https://www.unboundmedicine.com/medline/citation/10328823/Yeast_mutants_of_glucose_metabolism_with_defects_in_the_coordinate_regulation_of_carbon_assimilation_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0003-9861(99)91163-3 DB - PRIME DP - Unbound Medicine ER -