Characterization of a glucose-repressed pyruvate kinase (Pyk2p) in Saccharomyces cerevisiae that is catalytically insensitive to fructose-1,6-bisphosphate

• Published in: Journal of Bacteriology Vol. 179; no. 9; pp. 2987 - 2993
• Main Authors: Boles, E. (Heinrich-Heine-Universitat, Dusseldorf, Germany.), Schulte, F, Miosga, T, Freidel, K, Schluter, E, Zimmermann, F.K, Hollenberg, C.P, Heinisch, J.J
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01.05.1997
• Subjects: ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Allosteric Regulation; Amino Acid Sequence; amino acid sequences; Animals; ARN MENSAJERO; ARN MESSAGER; AZUCARES FOSFATOS; Bacteria; Bacteriology; Base Sequence; beta-Galactosidase; beta-Galactosidase - metabolism; biosynthesis; chemistry; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; enzyme activity; Enzymes; enzymology; Ethanol; Ethanol - metabolism; EXPRESION GENICA; EXPRESSION DES GENES; Fructosediphosphates; Fructosediphosphates - metabolism; GENE; Gene Deletion; gene expression; GENES; Genes, Fungal; GENETICA; genetics; GENETIQUE; Genotype; GLUCOSA; GLUCOSE; Glucose - metabolism; Glycolysis; Isoenzymes; Isoenzymes - chemistry; Isoenzymes - genetics; Isoenzymes - metabolism; Kidney; Kidney - enzymology; Kinetics; Liver; Liver - enzymology; messenger RNA; Metabolism; Molecular Sequence Data; Muscle, Skeletal; Muscle, Skeletal - enzymology; Mutation; Oligodeoxyribonucleotides; open reading frames; physiology; PIRUVATO QUINASA; PYRUVATE KINASE; Pyruvate Kinase - chemistry; Pyruvate Kinase - genetics; Pyruvate Kinase - metabolism; Rats; Recombinant Fusion Proteins; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - metabolism; SACCHAROMYCES CEREVISIAE; Saccharomyces cerevisiae - enzymology; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - physiology; SECUENCIA NUCLEOTIDICA; Sequence Homology, Amino Acid; SEQUENCE NUCLEOTIDIQUE; structural genes; Substrate Specificity; SUCRE PHOSPHATE; sugar phosphates; Yeast
• ISSN: 0021-9193; 1098-5530; 1067-8832
• DOI: 10.1128/jb.179.9.2987-2993.1997

We have characterized the gene YOR347c of Saccharomyces cerevisiae and shown that it encodes a second functional pyruvate kinase isoenzyme, Pyk2p. Overexpression of the YOR347c/PYK2 gene on a multicopy vector restored growth on glucose of a yeast pyruvate kinase 1 (pyk1) mutant strain and could completely substitute for the PYK1-encoded enzymatic activity. PYK2 gene expression is subject to glucose repression. A pyk2 deletion mutant had no obvious growth phenotypes under various conditions, but the growth defects of a pyk1 pyk2 double-deletion strain were even more pronounced than those of a pyk1 single-mutation strain. Pyk2p is active without fructose-1,6-bisphosphate. However, overexpression of PYK2 during growth on ethanol did not cause any of the deleterious effects expected from a futile cycling between pyruvate and phosphoenolpyruvate. The results indicate that the PYK2-encoded pyruvate kinase may be used under conditions of very low glycolytic flux