Gene/Protein
Disease
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Drug
Enzyme
Compound
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Target Concepts:
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Query: EC:4.1.1.32 (
phosphoenolpyruvate carboxykinase
)
4,204
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The control of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (
PFK-2/FBPase-2
; EC 2.7.1.105/3.1.3.46) gene expression during liver regeneration was studied. The level of
PFK-2/FBPase-2
mRNA decreased to about 5% of the control value 6 hr after partial hepatectomy. Thereafter the mRNA increased to a maximum at 48 hr and returned to normal levels by 96 hr. In sham-operated animals, only a small increase was observed during the first 4 hr. The mRNA was recognized by a 299-base-pair liver-specific cDNA probe but not by a muscle-specific probe. The time course of mRNA modulation was well correlated with
PFK-2/FBPase-2
activity and with the amount of bifunctional enzyme protein determined by immunoblotting with an antibody raised against the N-terminal decapeptide of liver
PFK-2/FBPase-2
. No alteration in the degradation rate of
PFK-2/FBPase-2
mRNA was noted after partial hepatectomy. The modulation of
PFK-2/FBPase-2
gene expression during liver regeneration involved changes in the transcription rate. The rate decreased by 50% at 6 hr after liver resection. The rate increased thereafter to a maximum at 72 hr and then returned to control values by 96 hr. The transcription rate of albumin did not change, whereas that of
phosphoenolpyruvate carboxykinase
increased 12-fold at 6 hr. These results show that
PFK-2/FBPase-2
gene transcription is specifically regulated and that this regulation is in part responsible for the alterations in hepatic metabolism seen in regenerating liver.
...
PMID:Transcriptional and posttranscriptional regulation of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase during liver regeneration. 131 37
Incubation of fetal hepatocytes from 21-day-old rats with permeant derivatives of cyclic AMP (cAMP) or glucagon, increased the mRNA levels of 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase (
PFK-2/FBPase-2
), L-pyruvate kinase (L-PK) and
phosphoenolpyruvate carboxykinase
(
PEPCK
). Contrary to this behavior, adult hepatocytes exhibited a decrease in the
PFK-2/FBPase-2
and L-PK mRNA levels when incubated under equivalent experimental conditions. Dexamethasone also increased the
PFK-2/FBPase-2
mRNA levels and costimulation of fetal hepatocytes with dexamethasone and a permeant analogue of cyclic AMP enhanced the levels of
PFK-2/FBPase-2
mRNA, a situation opposite to that exhibited by adult hepatocytes. Treatment of the hepatocytes with transcriptional and translational inhibitors also produced differential responses in both types of cells. The
PFK-2/FBPase-2
mRNA in fetal hepatocytes was more stable than in the adult cells. These results suggest that specific transcriptional factors and regulatory pathways differentially operate in fetal and adult hepatocytes in the control of the responses of carbohydrate metabolism to cAMP.
...
PMID:Differential regulation of the expression of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase and pyruvate kinase by cyclic adenosine 3',5'-monophosphate in fetal and adult hepatocytes. 759 43
By screening suppressors of a respiratory mutant lacking a functional cytochrome pathway in the filamentous fungus Podospora anserina, we isolated a mutation located in the phosphatase domain of the bi-functional enzyme 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase (
PFK-2/FBPase-2
). We show that the inactivation of the phosphatase but not of the kinase domain is responsible for the suppressor effect that results from the activation of the RSEs transcription factors that control expression of AOX, an alternative oxidase able to bypass the mitochondria cytochrome pathway of respiration. Remarkably, activation of the RSEs also stimulates the expression of the gluconeogenic enzymes, fructose-1,6 bi-phosphatase (FBPase-1) and
phosphoenolpyruvate carboxykinase
(PCK-1). We thus reveal in P. anserina an apparently paradoxical situation where the inactivation of the phosphatase domain of
PFK-2/FBPase-2
, supposed to stimulate glycolysis, is correlated with the transcriptional induction of the gluconeogenic enzymes. Phylogenic analysis revealed the presence of multiple presumed
PFK-2/FBPase-2
isoforms in all the species of tested Ascomycetes.
...
PMID:Mutations in the phosphatase domain of the 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase result in the transcriptional activation of the alternative oxidase and gluconeogenic pathways in Podospora anserina. 3098 Sep 7
