TY - JOUR
T1 - Glycolysis in Ustilago maydis
AU - Saavedra, Emma
AU - Ramos-Casillas, Laura E.
AU - Marín-Hernández, Alvaro
AU - Moreno-Sánchez, Rafael
AU - Guerra-Sánchez, Guadalupe
PY - 2008/12
Y1 - 2008/12
N2 - The kinetic parameters of the 10 glycolytic enzymes and glycolytic fluxes were determined for the first time in Ustilago maydis. Enzyme activities in yeast grown in minimal medium and harvested in the stationary stage were twofold higher than those from yeast grown in rich medium. In contrast, in yeast harvested in the exponential stage, the enzyme activities were higher in cells grown in rich medium. Phosphofructokinase activity was the lowest in the four culture conditions analyzed, suggesting that this enzyme is a flux-controlling step in U. maydis glycolysis. The Vmax and Km values of hexokinase and pyruvate kinase were similar under all conditions. The results revealed that U. maydis aldolase belongs to the class II type of metalo-aldolases. 3-Phosphoglycerate mutase (PGAM) activity was 2,3-bisphosphoglycerate cofactor independent, which contrasted with the cofactor dependency predicted by the amino acid sequence alignment analysis. Pyruvate was secreted by U. maydis yeast in the presence and absence of external glucose. The glycolytic enzyme activities in the U. maydis mycelial form were similar to those found in yeast, except for one order of magnitude higher phosphofructokinase and PGAM activities, thus suggesting differences in the glycolysis regulatory mechanisms between the two cellular forms.
AB - The kinetic parameters of the 10 glycolytic enzymes and glycolytic fluxes were determined for the first time in Ustilago maydis. Enzyme activities in yeast grown in minimal medium and harvested in the stationary stage were twofold higher than those from yeast grown in rich medium. In contrast, in yeast harvested in the exponential stage, the enzyme activities were higher in cells grown in rich medium. Phosphofructokinase activity was the lowest in the four culture conditions analyzed, suggesting that this enzyme is a flux-controlling step in U. maydis glycolysis. The Vmax and Km values of hexokinase and pyruvate kinase were similar under all conditions. The results revealed that U. maydis aldolase belongs to the class II type of metalo-aldolases. 3-Phosphoglycerate mutase (PGAM) activity was 2,3-bisphosphoglycerate cofactor independent, which contrasted with the cofactor dependency predicted by the amino acid sequence alignment analysis. Pyruvate was secreted by U. maydis yeast in the presence and absence of external glucose. The glycolytic enzyme activities in the U. maydis mycelial form were similar to those found in yeast, except for one order of magnitude higher phosphofructokinase and PGAM activities, thus suggesting differences in the glycolysis regulatory mechanisms between the two cellular forms.
KW - Basidiomycete metabolism
KW - Fungal glycolysis
KW - Ustilago maydis metabolism
UR - http://www.scopus.com/inward/record.url?scp=55349087280&partnerID=8YFLogxK
U2 - 10.1111/j.1567-1364.2008.00437.x
DO - 10.1111/j.1567-1364.2008.00437.x
M3 - Artículo
SN - 1567-1356
VL - 8
SP - 1313
EP - 1323
JO - FEMS Yeast Research
JF - FEMS Yeast Research
IS - 8
ER -