Distribution of pyruvate kinase isozymes in adult and developing Xenopus laevis

Ibsen, Kenneth H.; Cardin, John P.; Chiu, Robert; Garratt, Kirk N.; Marles, Steven W.; Doty, James R.

doi:10.1016/0305-0491(80)90299-0

Cited by 4 publications

(5 citation statements)

References 21 publications

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“…These data are in good agreement with those reported by Ibsen et al [ 19] in Xenopus indicating a decrease of the specific activities expressed on a DNA basis (i.e. 6.5, 0.77, 0.19 and 0.15 U/pg of DNA for blastulae, gastrulae, neural crest stage and tadpoles, respectively).…”

Section: Resultssupporting

confidence: 82%

Changes in Activity of the Regulatory Glycolytic Enzymes and of the Pyruvate-Dehydrogenase Complex during the Development of <i>Xenopus laevis</i>

Raddatz

Løvtrup-Rein²

1986

Pathobiology

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In this study we investigated the variations of the maximal activities of the rate-controlling glycolytic enzymes (i.e., hexokinase, HK; phosphofructokinase, PFK; pyruvate kinase, PK) and of the pyruvate-dehydrogenase complex (PDHc) during the early embryogenesis of Xenopus laevis (from cleavage through hatching). All the enzymatic assays, using different coupled reactions, were performed spectrophotometrically on cytosolic and mitochondrial fractions. The maximal HK activity increases markedly from neurulation onwards, PFK activity presents a peak around gastrulation, PK activity remains relatively constant throughout the period studied and the highest PDHc activity is observed during cleavage. The specific activities display the same temporal pattern. Furthermore, in the sequence of reactions by which glucose is degraded to form acetyl-CoA, the maximal activities of PFK and PK are not limiting while those of HK and PDHc could be rate-limiting at relatively late developmental stages (hatching).

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Section: Resultssupporting

confidence: 82%

Changes in Activity of the Regulatory Glycolytic Enzymes and of the Pyruvate-Dehydrogenase Complex during the Development of <i>Xenopus laevis</i>

Raddatz

Løvtrup-Rein²

1986

Pathobiology

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“…Up to five forms separated either by electrophoresis or chromatography have been described in Rana and Xenopus eggs (Schloen et al, 1974;Ibsen, 1980;Dworkin et al, 1987). We have been able to sepa- Fig.…”

Section: Pyruvate Kinasementioning

confidence: 94%

“…The total pyruvate kinase activity of Xenopus eggs is relatively high, and the level stays fairly constant through gastrulation and neurulation in both Rana and Xenopus (Wallace, 1961;Raddatz and Lovtrup-Rein, 1986). Up to five forms separated either by electrophoresis or chromatography have been described in Rana and Xenopus eggs (Schloen et al, 1974;Ibsen, 1980;Dworkin et al, 1987). We have been able to sepa- the three panels cannot be quantitatively compared with each other (for quantitation see Table 1).…”

Section: Pyruvate Kinasementioning

confidence: 99%

Glycogen breakdown in cleaving xenopus embryos is limited by ADP

Dworkin¹,

Dworkin‐Rastl²

1992

Molecular Reproduction Devel

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Xenopus eggs contain large stores of glycogen, but this glycogen is not glycolytically processed during cleavage. The Embden-Meyerhof pathway is inhibited by the absence of pyruvate kinase activity in vivo, and lactate and pyruvate are present at relatively low levels. In the late blastula, just preceding gastrulation, lactate levels increase, indicating the onset of glycogen breakdown and glycolytic flux. Glycolysis from microinjected [14C]glucose-6-phosphate could be transiently activated, however, by the coinjection of ADP into fertilized eggs, and constitutively activated by the injection of the ATPase potato apyrase, indicating the presence of all enzymes necessary for glycolytic activity. The isozyme profiles of pyruvate kinase and malic enzyme, two enzymes involved in carbon metabolism during cleavage or in the subsequent activation of glycogen breakdown, do not change between the egg and gastrula stages. These data suggest that the activation of glycogen breakdown and glycolysis in the late blastula is probably not a result of new gene activity but may be the metabolic consequence of increased free ADP that is then able to support the pyruvate kinase reaction.

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MATERIALS AND METHODSOrganism and growth conditions. M. racemosus ATCC 1216B was grown in 10-liter carboys continuously sparged with either air (PK1) or CO2 (PK5) and incubated at room temperature (20 to 23°C).

…”

mentioning

confidence: 99%

“…The catalytic and regulatory properties of the L and M1 types are very different and appear well suited to the specialized tissues in which they occur (14,25 (7,13).…”

mentioning

confidence: 99%

Purification and properties of two isozymes of pyruvate kinase from Mucor racemosus

Höhn¹,

Paznokas²

1987

J Bacteriol

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The dimorphic phycomycete Mucor racemosus was found to contain up (7,13).In each of these systems the isozyme types could be generated in a variety of different ways, including multiple structural genes for pyruvate kinase, posttranscriptional modification of transcripts from a single gene, and posttranslational modification of the product from a single transcript.We report here on the purification and characterization of two forms of M. racemosus pyruvate kinase, PK1 and PK5, and provide evidence that these electrophoretic forms are isozymic homotetramers composed of unique subunits. MATERIALS AND METHODSOrganism and growth conditions. M. racemosus ATCC 1216B was grown in 10-liter carboys continuously sparged with either air (PK1) or CO2 (PK5) and incubated at room temperature (20 to 23°C). For PK1, the organism was grown on a defined medium containing 0.5% glutamate and adjusted to pH 5.0 with H2SO4. These

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Distribution of pyruvate kinase isozymes in adult and developing Xenopus laevis

Cited by 4 publications

References 21 publications

Changes in Activity of the Regulatory Glycolytic Enzymes and of the Pyruvate-Dehydrogenase Complex during the Development of <i>Xenopus laevis</i>

Changes in Activity of the Regulatory Glycolytic Enzymes and of the Pyruvate-Dehydrogenase Complex during the Development of <i>Xenopus laevis</i>

Glycogen breakdown in cleaving xenopus embryos is limited by ADP

Purification and properties of two isozymes of pyruvate kinase from Mucor racemosus

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