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PubMed1978

Cytoplasmic malic enzyme from mouse kidneys.

NADP+-dependent cytoplasmic malic enzyme was purified to homogeneity from mouse kidneys by a two-step procedure involving 8-(6-aminohexyl)-amino-2', 5'-ADP-Sepharose affinity chromatography and DEAE-Sephadex ion exchange chromatography. The biochemical properties of the purified enzyme from DBA/2J mice were characterized. These include the determination of molecular weight and amino acid compositions, steady-state kinetics, thermal stability and inactivations by iodoacetate and urea. The native enzyme is a tetramer with a molecular weight of 270,000.Km's for NADP+, L-malate, NADPH and pyruvate were determined to be 3.3 micrometer, 50 micrometer, 10.5 micrometer respectively. Similar to the pigeon liver enzyme, the mouse enzyme exhibits an ordered kinetic mechanism proceeding with the binding of coenzyme first. The enzyme is only weakly inhibited by ATP and other cellular metabolites. A remarkable similarity in amino acid compositions was found between the mouse and rat liver malic enzymes.

Amino Acids↗
PubMed2005

Characterization of an archaeal malic enzyme from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1.

Although the interconversion between C4 and C3 compounds has an important role in overall metabolism, limited information is available on the properties and regulation of enzymes acting on these metabolites in hyperthermophilic archaea. Malic enzyme is one of the enzymes involved in this interconversion, catalyzing the oxidative decarboxylation of malate to pyruvate as well as the reductive carboxylation coupled with NAD(P)H. This study focused on the enzymatic properties and expression profile of an uncharacterized homolog of malic enzyme identified in the genome of a heterotrophic, hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 (Tk-Mae). The amino acid sequence of Tk-Mae was 52-58% identical to those of malic enzymes from bacteria, whereas the similarities to the eukaryotic homologs were lower. Several catalytically important regions and residues were conserved in the primary structure of Tk-Mae. The recombinant protein, which formed a homodimer, exhibited thermostable malic enzyme activity with strict divalent cation dependency. The enzyme preferred NADP(+) rather than NAD(+), but did not catalyze the decarboxylation of oxaloacetate, unlike the usual NADP-dependent malic enzymes. The apparent Michaelis constant (K(m)) of Tk-Mae for malate (16.9 mM) was much larger than those of known enzymes, leading to no strong preference for the reaction direction. Transcription of the gene encoding Tk-Mae and intracellular malic enzyme activity in T. kodakaraensis were constitutively weak, regardless of the growth substrates. Possible roles of Tk-Mae are discussed based on these results and the metabolic pathways of T. kodakaraensis deduced from the genome sequence.

Amino Acid Sequence↗
PubMed1964

EVIDENCE FOR THE PRESENCE OF CERTAIN TRICARBOXYLIC ACID CYCLE ENZYMES IN THIOBACILLUS THIOPARUS.

Cooper, Robert C. (Michigan State University, East Lansing). Evidence for the presence of certain tricarboxylic acid cycle enzymes in Thiobacillus thioparus. J. Bacteriol. 88:624-629. 1964.-Various tricarboxylic acid cycle enzymes appear to be present in Thiobacillus thioparus. Cell-free extracts of T. thioparus were active for a number of tricarboxylic acid cycle enzymes, including aconitase, isocitric dehydrogenase, and malic dehydrogenase. Tests for the presence of fumarase and the condensing enzyme, citrogenase, were inconclusive. Citrate was shown to be active in the metabolism of T. thioparus, but the actual mechanism involved in its formation was not clear. The enzyme, isocitratase, appeared to be absent. Evidence for the presence of succinic dehydrogenase was found in experiments with whole cells. From these results, it would appear that T. thioparus has a terminal respiration pathway similar to that found in many heterotrophic microorganisms.

Carbonic Anhydrases↗
PubMed2003

The age-related inverse relationship between ob and lipogenic enzymes genes expression in rat white adipose tissue.

To determine whether increase of serum leptin (the known natural inhibitor of lipogenic enzymes gene expression) concentration would account for the age-related decrease in lipogenesis (a) serum leptin concentration; (b) leptin mRNA abundance; (c) the rate of fatty acid synthesis in vivo; (d) lipogenic enzymes activity and (e) mRNA levels were assayed in white adipose tissue (WAT) of male young and old rats. We found that leptin mRNA abundance in WAT and serum leptin concentration was much lower in young than in old animals. In contrast, the rate of fatty acid synthesis in WAT was much higher in young animals. The old rats displayed much lower lipogenic enzymes activities (acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), ATP-citrate lyase (ACL), malic enzyme (ME), glucose 6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase 6PGDH) and mRNA abundance as compared to young rats. Considering the inverse relationship between serum leptin concentration and lipogenic enzymes genes expression and known inhibitory effect of leptin on lipogenic enzymes gene expression, one can conclude that the increase of ob gene expression could at least partly account for the reduced WAT lipogenic enzymes genes expression in old animals.

ATP Citrate (pro-S)-Lyase↗
PubMed1997

Isolation of cDNA for an NADP-malic enzyme from Aloe arborescens.

NADP-malic enzyme catalyzes the reaction of decarboxylation from malate. In CAM plants, functions of this enzyme diverged to include both photosynthetic and non-photosynthetic roles. A full length cDNA for an NADP-malic enzyme was isolated from an 'obligate' CAM plant aloe (Aloe arborescens). The cDNA contains an ORF encoding 592 amino acid residues, whose sequence is highly homologous to the known plant NADP-malic enzymes. This gene is constitutively expressed in all organs in a low level. The amount of the transcript exhibited no diurnal variation, suggesting that this gene is not involved in photosynthetic functions.

Aloe↗
PubMed1979

Response of rat hepatic fatty acid synthesis and activities of related enzymes to changes in level of dietary fat.

The rate of in vivo fatty acid synthesis as well as the levels of glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), malic enzyme (ME), citrate cleavage enzyme (CCE), acetyl-CoA carboxylase (ACX) and fatty acid synthetase (FAS) activities, have been studied in the liver of rats fed a fat-free diet for 7 days, followed by diets containing different amounts of soybean oil (0 to 24.79 kcal%) for 7 days. The dietary fat depressed activities of G6PD, 6PGD, ME, CCE, and FAS significantly at 1.24 or 2.48 kcal%. On the other hand, AC activity and the rate of fatty acid synthesis were decreased when the level of dietary fat was 12.39 kcal% or greater. These findings, as well as the pattern of decrement of enzyme activities and of lipogenesis, suggest a close correlation of fat feeding to ACX activity and fatty acid synthesis. The results also suggest that changes of G6PD, 6PGD, ME, CCE, and FAS activities may be largely independent of those modifications which occur in the substrate flux, concomitantly with the decrease of lipogenesis caused by the inclusion of fat in the diet.

ATP Citrate (pro-S)-Lyase↗
PubMed2006

Anaerobic central metabolic pathways in Shewanella oneidensis MR-1 reinterpreted in the light of isotopic metabolite labeling.

It has been proposed that during growth under anaerobic or oxygen-limited conditions, Shewanella oneidensis MR-1 uses the serine-isocitrate lyase pathway common to many methylotrophic anaerobes, in which formaldehyde produced from pyruvate is condensed with glycine to form serine. The serine is then transformed through hydroxypyruvate and glycerate to enter central metabolism at phosphoglycerate. To examine its use of the serine-isocitrate lyase pathway under anaerobic conditions, we grew S. oneidensis MR-1 on [1-13C]lactate as the sole carbon source, with either trimethylamine N-oxide (TMAO) or fumarate as an electron acceptor. Analysis of cellular metabolites indicated that a large percentage (>70%) of lactate was partially oxidized to either acetate or pyruvate. The 13C isotope distributions in amino acids and other key metabolites indicate that under anaerobic conditions, although glyoxylate synthesized from the isocitrate lyase reaction can be converted to glycine, a complete serine-isocitrate pathway is not present and serine/glycine is, in fact, oxidized via a highly reversible degradation pathway. The labeling data also suggest significant activity in the anapleurotic (malic enzyme and phosphoenolpyruvate carboxylase) reactions. Although the tricarboxylic acid (TCA) cycle is often observed to be incomplete in many other anaerobes (absence of 2-oxoglutarate dehydrogenase activity), isotopic labeling supports the existence of a complete TCA cycle in S. oneidensis MR-1 under certain anaerobic conditions, e.g., TMAO-reducing conditions.

Acetates↗
PubMed1993

Pre-translational regulation of lipid synthesizing enzymes and surfactant proteins in fetal rat lung in explant culture.

In hormone-free explant cultures of 18-day fetal rat lung the levels of the mRNAs for fatty acid synthase, ATP citrate lyase and surfactant proteins A, B, and C, increased as they do in vivo. Also CTP:phosphocholine cytidylyltransferase mRNA increased spontaneously. Unlike in vivo, malic enzyme mRNA increased drastically in cultured explants. Culture with dexamethasone increased the abundance of fatty acid synthase and surfactant protein mRNAs, but considerably depressed that of malic enzyme mRNA. Dexamethasone had little effect on CTP:phosphocholine cytidylyltransferase mRNA, supporting the concept that the increased activity of this enzyme caused by glucocorticoid is due to increased fatty acid synthesis.

ATP Citrate (pro-S)-Lyase↗
PubMed2004

Suppression of hepatic fatty acid synthase by feeding alpha-linolenic acid rich perilla oil lowers plasma triacylglycerol level in rats.

This study was performed to determine the effects of dietary perilla oil, a n-3 alpha-linolenic acid (ALA) source, on hepatic lipogenesis as a possible mechanism of lowering triacylglycerol (TG) levels. Male Sprague-Dawley rats were trained for a 3-hour feeding protocol and fed one of five semipurified diets as follows: 1% (w/w) corn oil control diet, or one of four diets supplemented with 10% each of beef tallow, corn oil, perilla oil, and fish oil. Two separate experiments were performed to compare the effects of feeding periods, 4 weeks and 4 days. Hepatic and plasma TG levels were decreased in rats fed perilla oil and fish oil diets, compared with corn oil and beef tallow diets. The activities of hepatic lipogenic enzymes such as fatty acid synthase (FAS), glucose-6-phosphate dehydrogenase, and malic enzyme were suppressed in the fish oil, perilla oil, and corn oil-fed groups, and the effect was the most significant in the fish oil-fed group. Also, the activities of glycolytic enzymes, glucokinase, and L-pyruvate kinase showed the similar trend as that of lipogenic enzymes. The activity of FAS, the key regulatory enzyme in lipogenesis, was positively correlated with hepatic and plasma TG levels and reduced significantly in the perilla oil-fed group compared with corn oil-fed group. In addition, the FAS activity was negatively correlated with the hepatic microsomal content of EPA and DHA. In conclusion, suppression of FAS plays a significant role in the hypolipidemic effects observed in rats fed ALA rich perilla oil and these effects were associated with the increase of hepatic microsomal EPA and DHA contents.

Animals↗
PubMed2005

Mammary lipid metabolism and milk fatty acid secretion in alpine goats fed vegetable lipids.

Fourteen Alpine goats at midlactation were fed a diet of hay and concentrate (55:45), without (control) or with formaldehyde-treated linseed (FLS) or oleic sunflower oil (OSO) at 11.2 or 3.5% of dry matter intake, respectively, in a 3 x 3 Latin Square design with three 3-wk periods. Milk yield was lower in goats fed FLS than control or OSO (2.13 vs. 2.32 kg/d). Milk fat content was higher with FLS or OSO than control (40.8 vs. 33.8 g/kg). Formaldehyde-treated linseed and OSO caused a significant decrease (23 and 18%, respectively) of C10 to C17 fatty acids secretion compared with control. The secretion of cis-9 C18:1 and cis-9, trans-11 C18:2 were increased 1.44- and 1.54-fold for FLS and 1.78- and 1.36-fold for OSO, compared with control. The C18:3 (n-3) secretion was increased 2.61-fold with FLS compared with control. Milk cis-9 C14:1/C14:0, cis-9 C16:1/C16:0, and cis-9 C18:1/C18:0 ratios decreased with the supplemented diets compared with control. Mammary stearoyl-CoA desaturase mRNA and activity were decreased by the lipid supplements, whereas no significant change was observed for acetyl-CoA carboxylase and fatty acid synthase. The activities of glucose-6-phosphate dehydrogenase, malic enzyme, and glycerol-3-phosphate dehydrogenase were not affected by the lipid supplements. Mammary lipoprotein lipase mRNA increased with OSO, whereas lipoprotein lipase activity tended to decrease with FLS compared with control. Milk lipoprotein lipase activity sharply decreased with lipid supplement (by 59 and 71%, for FLS and OSO, respectively). The changes in milk fatty acid profile due to FLS and OSO supplements were partly related to changes in the levels of mammary enzyme activities or mRNA.

Animal Feed↗
PubMed1983

The effect of starvation and refeeding on lipogenic enzymes in mammary glands and livers of lactating rats.

Lactating rats were starved for 48 h and refed a high-carbohydrate diet for a further 48 h. Starvation stops milk secretion, which resumes shortly after refeeding. Three lipogenic enzymes, fatty acid synthase, glucose 6-phosphate dehydrogenase (EC 1.1.1.49) and 'malic' enzyme (EC 1.1.1.40) all decrease in the mammary gland during starvation and are restored to the pre-starvation levels 48 h after refeeding. The same enzymes in liver also decrease during starvation, but increase to values significantly higher than those for the normal fed rats after refeeding the high-carbohydrate diet. For the fatty acid synthase these values were four times the pre-starvation values. Serum insulin and prolactin concentrations also increased upon refeeding the high-carbohydrate diet.

Animals↗
PubMed1997

Reciprocal responses to dietary diacylglycerol of hepatic enzymes of fatty acid synthesis and oxidation in the rat.

The activities of hepatic enzymes of fatty acid synthesis and oxidation were compared in rats fed on diacylglycerol and triacylglycerol. In the first trial, rats were fed on diacylglycerol or triacylglycerol (rapeseed oil) for 14 d. The diacylglycerol preparation contained 65.2 g and 32.6 g fatty acids/100 g total fatty acids as 1,3-species and 1,2-species respectively. Fatty acid compositions of these dietary lipids were similar. Dietary acylglycerols were added to experimental diets to provide the same amounts of fatty acids (93.9 g/kg diet). Dietary diacylglycerol compared with triacylglycerol significantly reduced the concentrations of serum and liver triacylglycerol. The activities of enzymes of fatty acid synthesis (fatty acid synthetase, glucose 6-phosphate dehydrogenase (EC 1.1.1.49) and malic enzyme (EC 1.1.1.40)) were significantly lower in rats fed on diacylglycerol than in those fed on triacylglycerol. In contrast, the rates of mitochondrial and peroxisomal oxidation of palmitoyl-CoA in liver homogenates were higher in rats fed on diacylglycerol than in those fed on triacylglycerol. In the second trial, varying amounts of dietary triacylglycerol were replaced by diacylglycerol while the dietary fatty acid content was maintained (93.9 g/kg diet). After 21 d of the feeding period the significant reductions in serum and liver triacylglycerol levels were confirmed in groups of rats fed on the diets in which diacylglycerol supplied more than 65.8 g fatty acids/kg diet (65.8 and 93.9 g/kg). Reductions in the activities of enzymes of fatty acid synthesis and increases in palmitoyl-CoA oxidation rates by both mitochondrial and peroxisomal pathways were also apparent when diacylglycerol replaced triacylglycerol in diets to supply more than 65.8 g fatty acid/kg. Increasing dietary levels of diacylglycerol also progressively increased the activities of enzymes involved in the beta-oxidation pathway (carnitine palmitoyltransferase (EC 2.3.1.21), acyl-CoA dehydrogenase (EC 1.3.99.3), acyl-CoA oxidase (EC 1.3.3.6), enoyl-CoA hydratase (EC 4.2.1.17), 3-hydroxyacyl-CoA dehydrogenase (EC 1.1.1.35), 2,4-dienoyl-CoA reductase (EC 1.3.1.34) and delta 3, delta 2-enoyl-CoA isomerase (EC 5.3.3.8)) in the liver. These results suggest that alteration of fatty acid metabolism in the liver is a factor responsible for the serum triacylglycerol-lowering effect of dietary diacylglycerol.

Animals↗
PubMed2001

Effects of dietary defatted squid on cholesterol metabolism and hepatic lipogenesis in rats.

Male Sprague-Dawley rats were fed a cholesterol-free (Exp. 1) or cholesterol-supplemented (Exp. 2) diet containing 20% casein (control group) or 15% defatted squid and 5% casein (defatted squid group), as protein, for 14 d. Serum and hepatic cholesterol concentrations were lower in rats fed defatted squid than in those fed casein in both cholesterol-free (-20%, P < 0.05 and -15%, P < 0.05, respectively) and cholesterol-supplemented (-25%, P < 0.05 and -15%, P < 0.05, respectively) diets. Hepatic triglyceride concentration was lower in the defatted squid than in the control groups in both cholesterol-free (-51%, P< 0.05) and cholesterol-supplemented diets (-38%, P < 0.01). The activities of cytosolic fatty acid synthase and the NADPH-generating enzymes, malic enzyme and glucose-6-phosphate dehydrogenase, in the liver were lower in the defatted squid than in the control groups in both cholesterol-free (-21%, P< 0.01, -33%, P < 0.05, and -33%, P < 0.01, respectively) and cholesterol-supplemented diets (-34%, P < 0.05, -57%, P < 0.05, and -67%, P < 0.05, respectively). The activity of mitochondrial carnitine palmitoyltransferase in the liver was comparable between the control and defatted squid groups. The activity of Mg2+-dependent phosphatidate phosphohydrolase in the liver cytosol was lower in the defatted squid (-9%, P < 0.05) than in the control groups only in the cholesterol-free diet. Fecal excretion of total steroids was stimulated by the feeding of defatted squid in both cholesterol-free (+77%, P < 0.005) and cholesterol-supplemented diets (+29%, P < 0.01). These results suggest that the nonlipid fraction of squid exerts a hypocholesterolemic effect by increasing the excretion of total steroids in feces. The fraction also induces a triglyceride-lowering activity in the liver by decreasing hepatic lipogenesis.

Animals↗
PubMed1991

Triiodothyronine control of ATP-citrate lyase and malic enzyme during differentiation of a murine preadipocyte cell line.

In the Ob 17 preadipocyte cell line, during adipose differentiation, T3 amplified the progressive expression of two enzymes of the lipogenic pathway, ATP-citrate lyase (ATP-CL) and malic enzyme (ME) as previously described for fatty acid synthase (FAS) and fatty acid synthesis, and in the same time-period of development. However, the stimulation by T3 was sustained at late stages of differentiation whereas it declined in FAS studies. The stimulation was preceded by an increase in the relative abundance of the specific mRNAs. Two ME mRNA species were detected (21S and 27S) and found to be differently distributed. Their abundance was asynchronously increased by T3 with a predominant effect on the 21S species. Culture of the cells in a thyroid-hormone depleted medium prevented any significant increase of ME activity. Early inclusion of T3 largely restored ME development whereas late elimination of T3 only moderately impaired it. It is suggested that T3 plays a crucial role at an early step of adipose differentiation, this leading to an increased expression of a set of late adipose phenotypes such as several lipogenic enzymes.

ATP Citrate (pro-S)-Lyase↗
PubMed1972

Metabolic Activities in Extracts of Mesophyll and Bundle Sheath Cells of Panicum miliaceum (L.) in Relation to the C(4) Dicarboxylic Acid Pathway of Photosynthesis.

The activities of certain enzymes related to the carbon assimilation pathway in whole leaves, mesophyll cell extracts, and bundle sheath extracts of the C(4) plant Panicum miliaceum have been measured and compared on a chlorophyll basis. Enzymes of the C(4) dicarboxylic acid pathway-phosphoenolpyruvate carboxylase and NADP-malic dehydrogenase-were localized in mesophyll cells. Carbonic anhydrase was also localized in mesophyll cell extracts. Ribose 5-phosphate isomerase, ribulose 5-phosphate kinase, and ribulose diphosphate carboxylase-enzymes of the reductive pentose phosphate pathway-were predominantly localized in bundle sheath extracts. High activities of aspartate and alanine transaminases and glyceraldehyde-3-P dehydrogenase were found about equally distributed between the photosynthetic cell types. P. miliaceum had low malic enzyme activity in both mesophyll and bundle sheath extracts.Isolated bundle sheath cells were capable of converting aspartate to oxalacetate at rates approaching the aspartate transaminase activity of bundle sheath extracts. The bundle sheath cells had a light induced CO(2) fixation of 23 mumoles of CO(2)/mg chl.hr in the absence of exogenous substrates.The photorespiratory enzymes, hydroxypyruvate reductase and glycolic oxidase, were about 3 fold higher in bundle sheath extracts than in mesophyll extracts when compared on a chlorophyll basis.

Journal Article↗
PubMed2006

A mathematical model of the mitochondrial NADH shuttles and anaplerosis in the pancreatic beta-cell.

The pancreatic beta-cells respond to an increased glycolytic flux by secreting insulin. The signal propagation goes via mitochondrial metabolism, which relays the signal to different routes. One route is an increased ATP production that, via ATP-sensitive K(+) (K(ATP)) channels, modulates the cell membrane potential to allow calcium influx, which triggers insulin secretion. There is also at least one other "amplifying" route whose nature is debated; possible candidates are cytosolic NADPH production or malonyl-CoA production. We have used mathematical modeling to analyze this relay system. The model comprises the mitochondrial NADH shuttles and the mitochondrial metabolism. We found robust signaling toward ATP, malonyl-CoA, and NADPH production. The signal toward NADPH production was particularly strong. Furthermore, the model reproduced the experimental findings that blocking the NADH shuttles attenuates the signaling to ATP production while retaining the rate of glucose oxidation (Eto K, Tsubamoto Y, Terauchi Y, Sugiyama T, Kishimoto T, Takahashi N, Yamauchi N, Kubota N, Murayama S, Aizawa T, Akanuma Y, Aizawa S, Kasai H, Yazaki Y, Kadowaki T. Science 283: 981-985, 1999) and provides an explanation for this apparent paradox. The model also predicts that the mitochondrial malate dehydrogenase reaction may proceed backward, toward malate production, if the activity of malic enzyme is sufficiently high. An increased fatty acid oxidation rate was found to attenuate the signaling strengths. This theoretical study has implications for our understanding of both the healthy and the diabetic beta-cell.

Animals↗
PubMed1979

Chronic hyperinsulinemia in the fetal rhesus monkey: effects on hepatic enzymes active in lipogenesis and carbohydrate metabolism.

Hyperinsulinemia was produced in fetal rhesus monkeys for 21 days in the last third of gestation by subcutaneous pork insulin injected at 19 U a day. Plasma insulin concentrations in treated fetuses (N = 4) were 3525 microU/ml. There was no difference in paired pre- and post-treatment fetal plasma glucose concentration. Activity of the hepatic enzymes that promote glucose utilization (glucokinase and hexokinase) and glycolysis (phosphofructokinase, pyruvate kinase, and pyruvate dehydrogenase) was unaffected. Similarly, glycogen metabolism enzymes (active and inactive synthase and phosphorylase) were unaltered. Two gluconeogenic enzymes (PEPCK and glucose-6-phosphatase) were diminished in the treated group compared with controls. Fetal hyperinsulinemia enhanced lipogenic and NADPH-producing enzyme activities, as evidenced by a twofold increase in fatty acid synthase and in citrate cleavage enzyme activity. Malic enzyme was absent. Hyperinsulinemia with euglycemia (1) increases the activity of enzymes that participate in lipogenesis, (2) decreases some of those controlling gluconeogenesis, and (3) has no effect on the enzymes of glycolysis.

Animals↗
PubMed1984

Coordinate regulation of the biosynthesis of ATP-citrate lyase and malic enzyme during adipocyte differentiation. Studies on 3T3-L1 cells.

The biosynthesis and degradation of two lipogenic enzymes were studied during the differentiation of 3T3-L1 preadipocytes into adipocytes. The activity and mass of malic enzyme, rose by an order of magnitude during adipocyte development and the enzyme accounted for 0.3% of the cytosol protein in mature fat cells. Similarly, the activity and amount of ATP-citrate lyase increased approximately 7-fold during the adipose conversion. The relative rates of synthesis of the two enzymes were less than or equal to 0.02% in preadipocytes, but increased sharply as the cells began to differentiate. Maximal steady state rates of malic enzyme and ATP-citrate lyase synthesis in 3T3-L1 adipocytes were 13- and 8-fold higher, respectively, than the basal rates in preadipocytes. In contrast, the half-lives of malic enzyme (67 h) and ATP-citrate lyase (47 h) were not altered during adipocyte development. Thus, accelerated rates of enzyme synthesis account for the differentiation-dependent accumulation of the two lipogenic enzymes. Increased rates of malic enzyme, ATP-citrate lyase, and fatty acid synthetase biosynthesis are expressed in a highly coordinated manner during adipocyte differentiation and are associated with parallel elevations in the levels of translatable mRNAs for these enzymes.

ATP Citrate (pro-S)-Lyase↗