Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.4.1.2 (acetyl-CoA carboxylase)
 2,876 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A hormonally induced change in the covalent phosphorylation state of several enzymes is generally regarded as an important mechanism for hormonal modulation of enzyme activity. We have previously demonstrated that epinephrine stimulates the phosphorylation of a peptide of Mr = 220,000 in adipocytes. Incubation of 32P-labeled cytosolic proteins from adipocytes and hepatocytes with antisera raised against homogeneous chicken and rat liver acetyl coenzyme A carboxylase results in the specific and complete precipitation of the same phosphopeptide. No other major phosphopeptide is specifically precipitated. In hepatocytes, glucagon stimulates the incorporation of 32P into this peptide associated with an inhibition of enzyme activity. These data, coupled with previous studies in adipocytes, suggest that cyclic AMP-dependent protein phosphorylation plays a major role in the regulation of acetyl-CoA carboxylase activity and of fatty acid biosynthesis in adipose tissue and liver.
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PMID:Glucagon regulation of protein phosphorylation. Identification of acetyl coenzyme A carboxylase as a substrate. 3 66

Intraperitoneal injection of inorganic 32P into rats results in the incorporation of 32P into acetyl-CoA carboxylase without inactivation of the enzyme. Administration of epinephrine stimulates 32P incorporation and results in enzyme inactivation. Incubation of epididymal fat tissues with inorganic 32P also results in incorporation of 32P into carboxylase. This 32P incorporation reaches a maximum level in 3 h and it has no effect on carboxylase activity. Administration of epinephrine at the time of maximum phosphorylation (3 h) results in further phosphorylation and inactivation of carboxylase. Propranolol, a beta-adrenergic blocking agent which inhibits epinephrine action, blocks both the epinephrine-stimulated phosphorylation and the inactivation of the carboxylase. However, propranolol has no effect on that component of the phosphorylation which is unrelated to enzyme inactivation. These results establish that phosphorylation of carboxylase occurs in vivo at two different sites, only one of which results in enzyme inactivation. The phosphorylation site associated with enzyme inactivation is hormonally controlled.
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PMID:Stimulation by epinephrine of in vivo phosphorylation and inactivation of acetyl coenzyme A carboxylase of rat epididymal adipose tissue. 3 89

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.
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PMID:Response of rat hepatic fatty acid synthesis and activities of related enzymes to changes in level of dietary fat. 3 77

In 5 French Alpine goats, omental adipose tissue acetyl-CoA carboxylase, glucose-6-phosphate deshydrogenase, malic enzyme and lipoprotein lipase activities significantly decreased during the third month of gestation, whereas plasma non-esterified fatty acid and triacyglycerol contents increased. This probably reflects an early decreasing rate of adipose tissue anabolism during gestation in the Goat. At the third week of lactation, anabolic activities relative to DNA content of adipose tissue were extremely low, and the tissue weight relative to DNA was lower than during gestation. Metabolic alterations of omental adipose tissue in early lactation do not seem to be related to milk production level. These results could contribute to a better control of the kinetic of body lipid stores during the reproductive cycle in high milk yielding ruminants.
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PMID:[Metabolic activity of adipose tissue in the goat during gestation and at the beginning of lactation]. 3 15

1. Rapid effects of hormones on the metabolism of glycogen and fatty acids were studied in the perfused liver of normal and genetically obese (ob/ob) mice. 2. In livers from normal and obese mice adrenaline and angiotensin II stimulated glycogenolysis. 3. These hormones inhibited the synthesis de novo of long-chain fatty acids in livers from normal mice, but not in livers from obese mice. 4. The proportion of acetyl-CoA carboxylase in the active form was decreased by adrenaline but not by angiotensin II in livers from obese mice. 5. The potency of hormone effects on liver suggests that they could occur in the intact animal. 6. The results add to the evidence that hepatic fatty acid synthesis in genetically obese (ob/ob) mice is irreversibly resistant to inhibition by a range of hormones. Such resistance could be of primary significance in the pathogenesis of the obesity.
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PMID:Catabolic effects of adrenaline and angiotensin II in the perfused liver of normal and genetically obese (ob/ob) mice. 3 34

Acetyl-CoA carboxylase and fatty acid synthetase are the two major enzymes involved in the synthesis of fatty acids in animals. The activities of both enzymes are affected by nutritional manipulations. Although acetyl-CoA carboxylase is considered generally to be the rate-limiting step in lipogenesis, there is evidence that suggests that fatty acid synthetase may become rate limiting under certain conditions. The principal support for the view that acetyl-CoA carboxylase is the rate-limiting enzyme for lipogenesis is that the activity of the enzyme is controlled by allosteric effectors that change the catalytic efficiency of the enzyme. Until recently, the only known control of fatty acid synthetase was through changes in rate of enzyme synthesis. Data are reviewed that show that fatty acid synthetase can exist in forms possessing different catalytic activities. Thus fatty acid synthetase appears to be subject to the type of control necessary for an enzyme to serve as a regulator of the rate of a biological process over a short term.
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PMID:Regulation of fatty acid synthesis. 4 Aug 28

The complete amino acid sequence of the biotinyl subunit from the enzyme transcarboxylase of Propionibacterium shermanii has been determined from the structures of overlapping tryptic and cyanogen bromide peptides together with sequenator analysis on the whole subunit. The subunit contains 123 amino acid residues. Eleven of nineteen residues in the region of biotin attachment, when compared to pyruvate carboxylase from avian liver (Rylatt, D. B., Keech, D. B., and Wallace, J. C. (1977) Arch. Biochem. Biophys. 183, 113-122), were found to be in identical positions relative to biocytin. There was less homology with acetyl-CoA carboxylase from Escherichia coli (Sutton, M. R., Fall, R. R., Nervi, A. M., Alberts, A. W., Vagelos, P. R., and Bradshaw, R. A. (1977) J. Biol. Chem. 252, 3934-3940), but in all of these biotin enzymes there was an alanylmethionyl-biocytinyl-methionine sequence. The secondary structure of the biotinyl subunit has been estimated using the method of Chou and Fasman (Chou, P. Y., and Fasman, G. D. (1978) Adv. Enzymol. 47, 45-148) and considered in relationship to the role of the biotinyl subunit in the structure and function in transcarboxylase.
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PMID:Amino acid sequence of the biotinyl subunit from transcarboxylase. 4 Sep 85

Rats were fed on three kinds of diets for two weeks: (I) basal diet, (II) containing 0.1% cholate and (III) containing 0.1% cholesterol and 0.1% cholate. Each dietary group was further divided into subgroups to whose diet was added 0, 5 or 10% (dry weight) of minced oyster (Callocorchina) or clam (Tapes japonica). The serum and liver cholesterol levels of the rats fed the basal diet were reduced by feeding oyster or clam. The serum and liver triglyceride levels of all dietary groups were lowered markedly by feeding oyster or clam. The activities of glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase were markedly reduced in the basal groups fed oyster or clam. These effects were observed in 5 and 10% shellfish feeding. These shellfish may be considered hypolipidemic foods.
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PMID:Influences of oyster or clam feeding on lipid metabolism in rats. 4 Oct 32

Mutant strains of Candida lipolytica defective in acyl-CoA synthetase II [acid:CoA ligase (AMP-forming), EC 6.2.1.3] have been isolated. The mutants fail to grow on fatty acid as a sole carbon source but are capable of incorporating exogenous fatty acid into cellular lipids. This observation, together with our previous finding that mutant strains defective in acyl-CoA synthetase I cannot incorporate exogenous fatty acid into cellular lipids but are able to degrade fatty acid via beta-oxidation, indicates the presence of two functionally distinct long-chain acyl-CoA pools in the cell--i.e., one for lipid synthesis and the other for beta-oxidation. Unlike the wild-type and the revertant strains as well as the mutants lacking acyl-CoA synthetase II, the mutants defective in acyl-CoA synthetase I do not exhibit the repression of acetyl-CoA carboxylase [acetyl-CoA:carbon-dioxide ligase (ADP-forming), EC 6.4.1.2] by exogenous fatty acid. Measurement of the two long-chain acyl-CoA pools with the aid of appropriate mutant strains has indicated that the long-chain acyl-CoA to be utilized for lipid synthesis, but not that to be degraded via beta-oxidation, is involved in the repression of acetyl-CoA carboxylase.
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PMID:Involvement of long-chain acyl coenzyme A for lipid synthesis in repression of acetyl-coenzyme A carboxylase in Candida lipolytica. 4 Dec 42

Chick liver cell monolayers synthesize fatty acids at in vivo rates and are responsive to insulin and glucagon. High rates of fatty acid synthesis are maintained with insulin present and lost slowly without insulin. Glucagon or 3',5'-cyclic AMP cause immediate cessation of fatty acid synthesis. The site of inhibition appears to be cytoplasmic acetyl-CoA carboxylase which catalyzes the first committed step of fatty acid synthesis. Liver carboxylase exists either as catalytically inactive protomers or active filamentous polymers. Citrate, an allosteric activator of the enzyme, is required for both catalysis and polymerization. Glucagon and cAMP cause an immediate decrease in the cytoplasmic citrate concentration of chick liver cells apparently by inhibiting the conversion of glucose to citrate at the phosphofructokinase reaction. Since fatty acid synthesis and citrate level are closely correlated, citrate appears to be a feed-forward activator of the carboxylase in vivo. Compelling evidence indicates that carboxylase filaments are present in the intact cell when citrate levels are high and depolymerize when citrate levels fall. Hence, carboxylase activity and fatty acid synthetic rate appear to be determined by cytoplasmic citrate level.
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PMID:Hormonal regulation of acetyl-CoA carboxylase activity in the liver cell. 4 83


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