Regulation of the activity of phosphoenolypyruvate carboxylase by fructose diphosphate

Sanwal, B. D.; Maeba, P.

doi:10.1016/0006-291x(66)90431-1

Cited by 52 publications

(8 citation statements)

References 8 publications

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“…FBP is a known positive regulator of PEP carboxylase 17,18 , and its depletion could potentially decrease PEP carboxylase activity and thus cause PEP accumulation. Existing biochemical literature data suggested, however, that the observed change in FBP concentration would lead to only a five-fold decrease in PEP carboxylase activity 19,20 .…”

Section: Resultsmentioning

confidence: 99%

Ultrasensitive regulation of anapleurosis via allosteric activation of PEP carboxylase

Amador‐Noguez

Reaves

et al. 2012

Nat Chem Biol

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Anapleurosis is the filling of the TCA cycle with four-carbon units. The common substrate for both anapleurosis and glucose phosphorylation in bacteria is the terminal glycolytic metabolite, phosphoenolpyruvate (PEP). Here we show that E. coli quickly and almost completely turns off PEP consumption upon glucose removal. The resulting build-up of PEP is used to quickly import glucose if it becomes re-available. The switch-like termination of anapleurosis results from depletion of fructose-1,6-bisphosphate (FBP), an ultrasensitive allosteric activator of PEP carboxylase. E. coli expressing an FBP-insensitive point mutant of PEP carboxylase grow normally on steady glucose. However, they fail to build-up PEP upon glucose removal, grow poorly on oscillating glucose, and suffer from futile cycling at the PEP node on gluconeogenic substrates. Thus, bacterial central carbon metabolism is intrinsically programmed with ultrasensitive allosteric regulation to enable rapid adaptation to changing environmental conditions.

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Section: Resultsmentioning

confidence: 99%

Ultrasensitive regulation of anapleurosis via allosteric activation of PEP carboxylase

Amador‐Noguez

Reaves

et al. 2012

Nat Chem Biol

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“…The enzyme has a rather complex regulatory mechanism. It has at least two functionally welldefined allosteric activator sites (3,9,21,22,26), one allosteric inhibitor site (4), and binding sites for substrates. The enzyme is catalytically active both as a dimer and as a tetramer; however, the normal active form is believed to be the tetramer (25; Y.-B.…”

mentioning

confidence: 99%

Properties of an Escherichia coli mutant deficient in phosphoenolpyruvate carboxylase catalytic activity

Coomes¹,

Mitchell²,

Beezley³

et al. 1985

J Bacteriol

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A mutant Escherichia coli (Ppcc') which was unable to grow on glucose as a sole carbon source was isolated. This mutant had very low levels of phosphoenolpyruvate carboxylase activity (approximately 5% of the wild type). Goat immunoglobulin G prepared against wild-type phosphoenolypyruvate carboxylase cross-reacted with the Ppccenzyme. The amount of enzyme protein in the mutant cells was similar to that found in wild-type cells, but it had greatly diminished specific activity. The catalytically less active mutant enzyme retained the ability to interact with fructose 1,6-bisphosphate, but did not exhibit stabilization of the tetrameric form by aspartate. The pl of the mutant protein was lower (4.9) than that of the wild-type protein (5.1). After electrophoresis and immunoblotting of the partially purified protein, several immunostaining bands were seen in addition to the main enzyme band. A novel method for showing that these bands represented proteolytic fragments of phosphoenolpyruvate carboxylase was developed.

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“…The activity of phosphoenolpyruvate carboxylase of bacteria is dependent upon the presence of several activators like acetyl coenzyme A (3), fructose 1,6-bisphosphate (12,20), CDP (21), and several other compounds both of physiological (10, 25) and non-physiological (22) significance. The first metabolites shown to regulate the activity ofthis enzyme were acetyl coenzyme A and aspartate.…”

mentioning

confidence: 99%

Properties of a mutant Escherichia coli phosphoenolpyruvate carboxylase deficient in coregulation by intermediary metabolites

McAlister¹,

Evans²,

Smith³

1981

J Bacteriol

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Phosphoenolpyruvate carboxylase of Escherichia coli is activated by three different mechanisms: contiguous by acetyl coenzyme A, precursor by fructose 1,6-bisphosphate, and compensatory feedback by cytidine 5'-diphosphate (CDP). Even though each activator can interact independently with the enzyme, synergistic effects are observed with some combinations, namely, fructose 1,6-bisphosphate or CDP (coregulators), with acetyl coenzyme A. A mutant was isolated that has a phosphoenolpyruvate carboxylase which is refractory to activation by fructose, 1,6-bisphosphate and CDP. The mutant enzyme was shown to be active primarily as the dimer and to lack cooperativity in substrate binding. The binding of acetyl coenzyme A and substrate, however, was essentially the same as that of the wild-type enzyme. The mutant cells grew extremely slowly on glucose alone as the sole carbon source. The only defect in the mutant appeared to be the inability of this enzyme to be activated by the coregulators. These data are consistent with the thesis that coregulation by fructose 1,6-bisphosphate or CDP is an essential requirement for the activation in vivo of this enzyme.

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Regulation of the activity of phosphoenolypyruvate carboxylase by fructose diphosphate

Cited by 52 publications

References 8 publications

Ultrasensitive regulation of anapleurosis via allosteric activation of PEP carboxylase

Ultrasensitive regulation of anapleurosis via allosteric activation of PEP carboxylase

Properties of an Escherichia coli mutant deficient in phosphoenolpyruvate carboxylase catalytic activity

Properties of a mutant Escherichia coli phosphoenolpyruvate carboxylase deficient in coregulation by intermediary metabolites

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