Stimulation of Phosphofructokinase from Phycomyces blakesleeanus and Some Other Fungi by Micromolar Concentrations of Fructose 2,6-bisphosphate

Laere, André J. Van

doi:10.1099/00221287-129-10-3281

Cited by 10 publications

(13 citation statements)

References 16 publications

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“…In contrast to reports on S. cereuisiae and P . blakesleeanus PFK, but in agreement with reports on the enzyme from several mammalian tissues (Bartrons et al, 1982;Van Laere, 1983;Van Schaftingen et al, 1981 ;Heylen et al, 1982), the presence of Fru 2,6-P2 did not increase V,,,,,. With Fru 6-P concentrations between 0.47 and 1 mM half maximum stimulation was obtained at 0.1-0.2 p~-F r u 2,6-P2 (Fig.…”

Section: R E S U L T Ssupporting

confidence: 89%

“…Effects of Fru 2,6-P2 that are similar, but not identical, to those that occur in higher eukaryotic systems have been demonstrated with purified PFK from Saccharomyces cerevisiae (Bartrons et al, 1982) and with crude extracts from Phycomyces blakesleeanus (Van Laere, 1983). In the present paper we report studies on the effect of Fru 2,6-P2 on partially purified PFK from A. niger.…”

Section: Introductionmentioning

confidence: 83%

“…We are investigating the regulation of glycolysis in the fungus Aspergillus niger in relation to its ability to accumulate high concentrations of citric acid, and have shown that PFK is a major control point (Habison et al, 1979;1983;Meixner-Monori et al, 1984;Schreferl et al, 1986). Several lines of evidence have led to the assumption that citrate accumulates in this fungus because the feedback control of PFK by citrate is relieved by high intracellular concentrations of NH,+ ions (Rohr & Kubicek, 1981 ; Kubicek & Rohr, 1986).…”

Section: Introductionmentioning

confidence: 99%

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Regulation of Phosphofructokinase from Aspergillus Niger: Effect of Fructose 2,6-Bisphosphate on the Action of Citrate, Ammonium Ions and AMP

1987

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The role of fructose 2,6-bisphosphate in the regulation of glycolysis in the citric acid accumulating fungus Aspergillus niger was investigated. Fructose 2,6-bisphosphate stimulated the activity of partially purified phosphofructokinase by increasing the affinity of the enzyme for fructose 6-phosphate and relieving inhibition by ATP. Fructose 2,6-bisphosphate acted synergistically with AMP, but not with NH,+ ions, which otherwise also activate phosphofructokinase. Fructose 2,6-bisphosphate also partially antagonized citrate inhibition of phosphofructokinase; complete deinhibition against high (5 mM) concentrations of citrate (as occur during citric acid accumulation), however, required the simultaneous presence of fructose 2,6bisphosphate (0.1 PM), AMP (0.1 mM) and NH,+ ions (20 mM).

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Section: R E S U L T Ssupporting

confidence: 89%

Section: Introductionmentioning

confidence: 83%

Section: Introductionmentioning

confidence: 99%

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Regulation of Phosphofructokinase from Aspergillus Niger: Effect of Fructose 2,6-Bisphosphate on the Action of Citrate, Ammonium Ions and AMP

1987

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“…Increased level of F2,6P after V 5+ addition, indicated by HPLC and 31 P NMR data, is in agreement with formation of F2,6P established in chicken liver [7] and rat adypocytes [9], where vanadate inhibited fructose 2,6 bisphosphatase (F2,6P 2 ), an enzyme which catalyses F6P synthesis through dephosphorilation of F2,6P [47]. Formation of F2,6P may also be a consequence of increased participation of glucose in glycolytic pathway caused by V 5+ and would be in accord with previous data obtained on P. blakesleeanus spores [21] and S. cerevisiae [48], where increase in glucose concentration was directly connected with the higher content of F2,6P. It should be mentioned that glucose is present in experimental medium, giving permanent glucose input in 31 P NMR experiments in vivo .…”

Section: Discussionsupporting

confidence: 91%

Vanadate Influence on Metabolism of Sugar Phosphates in Fungus Phycomyces blakesleeanus

et al. 2014

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The biological and chemical basis of vanadium action in fungi is relatively poorly understood. In the present study, we investigate the influence of vanadate (V5+) on phosphate metabolism of Phycomyces blakesleeanus. Addition of V5+ caused increase of sugar phosphates signal intensities in 31P NMR spectra in vivo. HPLC analysis of mycelial phosphate extracts demonstrated increased concentrations of glucose 6 phosphate, fructose 6 phosphate, fructose 1, 6 phosphate and glucose 1 phosphate after V5+ treatment. Influence of V5+ on the levels of fructose 2, 6 phosphate, glucosamine 6 phosphate and glucose 1, 6 phosphate (HPLC), and polyphosphates, UDPG and ATP (31P NMR) was also established. Increase of sugar phosphates content was not observed after addition of vanadyl (V4+), indicating that only vanadate influences its metabolism. Obtained results from in vivo experiments indicate catalytic/inhibitory vanadate action on enzymes involved in reactions of glycolysis and glycogenesis i.e., phosphoglucomutase, phosphofructokinase and glycogen phosphorylase in filamentous fungi.

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“…The third step is that glucose is formed from trehalose and can be converted to triose phosphates thanks to the presence of fructose 2,6-bisphosphate which stimulates 6-phosphofructo-1-kinase [17] and that triose phosphates are finally converted to glycerol as described in the preceding paragraph. Altogether, the result of these transformations is the conversion of part of the stores of trehalose in the spores to glycerol.…”

Section: The Sequence Of Events Following Spore Activationmentioning

confidence: 99%

Glycerol formation after the breaking of dormancy of Phycomyces blakesleeanus spores

Schaftingen

Laere

1985

European Journal of Biochemistry

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The breaking of dormancy of Phycomyces blakesleeanus spores by a heat shock was followed by a transient production of glycerol, which culminated within 5 -10 min and was terminated at 20 min. Extracts of spores contained a magnesium-dependent glycerol-3-phosphatase active on both L-glycerol 3-phosphate and dihydroxyacetone phosphate but having more affinity for the first substrate than for the second. In extracts from dormant spores, the phosphatase was profoundly inhibited by physiological concentrations of inorganic phosphate, which induced cooperativity for the substrate, whereas the enzyme from heat-activated spores was much less inhibited and this difference in kinetic properties persisted after gel filtration of the enzymic preparation. When measured at 1 mM phosphate and 0.1 mM glycerol 3-phosphate, the phosphatase activity was undetectable in dormant spores, increased sharply during the heat treatment and the following 5 min at 25"C, then fell again to a low value by 20 min. A similar transient activation of the enzyme was observed following the breaking of dormancy by incubation of the spores in the presence of 0.1 M ammonium acetate. Incubation of a cell-free extract or of the partially purified glycerol-3-phosphatase in the presence of ATP-Mg and the catalytic subunit of cyclic-AMP-dependent protein kinase released the enzyme from inhibition by phosphate and endowed it with the same kinetic properties as did the heat treatment of the spores. It appears therefore most likely that phosphorylation of glycerol-3-phosphatase by cyclic-AMP-dependent protein kinase causes its activation and that this transient process explains the equally transient formation of glycerol by the spores after the heat shock.The breaking of dormancy of Phycomyces blakesleeanus spores by a heat shock is directly followed by a 15 -30-min period, called the critical period [l], during which the spores need to be incubated in the presence of glucose or 6-deoxyglucose in order to germinate eventually. This period is characterized by several transient metabolic changes, including the activation of trehalase [2], the formation of hexose 6-phosphates and of fructose 2,6-bisphosphate [l], the formation of cyclic AMP [3] and the production of about 300 pmol glycerol/g spores [4]. On the other hand, a link between the transport of glucose, the formation of cyclic AMP as well as of fructose 2,6-bisphosphate and the activation of trehalase has been recently established in Saccharomyces cerevisiae [5] suggesting that all these metabolic transformations could be connected with cyclic AMP.The present work was undertaken in order to investigate the respective roles of cyclic AMP and of fructose 2,6-bisphosphate in the formation of glycerol which is known to occur during the first minutes after spore activation. It led to the discovery of an interconvertible glycerol-3-phosphatase, which is a substrate for cyclic-AMP-dependent protein kinase,

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Stimulation of Phosphofructokinase from Phycomyces blakesleeanus and Some Other Fungi by Micromolar Concentrations of Fructose 2,6-bisphosphate

Cited by 10 publications

References 16 publications

Regulation of Phosphofructokinase from Aspergillus Niger: Effect of Fructose 2,6-Bisphosphate on the Action of Citrate, Ammonium Ions and AMP

Regulation of Phosphofructokinase from Aspergillus Niger: Effect of Fructose 2,6-Bisphosphate on the Action of Citrate, Ammonium Ions and AMP

Vanadate Influence on Metabolism of Sugar Phosphates in Fungus Phycomyces blakesleeanus

Glycerol formation after the breaking of dormancy of Phycomyces blakesleeanus spores

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