Acetyl-CoA is produced by the citrate synthase homology module of ATP-citrate lyase

2021 ◽  
Author(s):  
Kenneth Verstraete ◽  
Koen H. G. Verschueren ◽  
Ann Dansercoer ◽  
Savvas N. Savvides
Keyword(s):  
Citrate Synthase ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Citrate Lyase ◽  
Homology Module

scholarly journals Identification of Catalytic Residues in ATP-Citrate Lyase

2014 ◽  
Vol 70 (a1) ◽  
pp. C1673-C1673
Author(s):  
Noreen Singh ◽  
Kelsey Holoweckyj ◽  
Marie Fraser
Keyword(s):  
Brain Development ◽  
Citrate Synthase ◽  
Sequence Similarity ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Mutant Proteins ◽  
Catalytic Residues ◽  
Amino Terminal ◽  
Citrate Lyase ◽  
Carboxy Terminal

An enzyme in the human body that regulates lipogenesis and cholesterolgenesis is ATP-citrate lyase (ACLY) [1]. ACLY synthesizes acetyl-CoA and oxaloacetate from citrate, CoA and ATP, with citryl-CoA as an intermediate [1]. The product acetyl-CoA is involved in cell growth as well as embryonic and brain development [1]. Studies in mice suggest that ACLY is important during brain development as homozygous Acly knockout mouse embryos died early in development [2]. Knowledge of the reaction mechanism is limited and will be of use in understanding the energy flow in cells. Our current insight into the mechanism by which citryl-CoA is cleaved to form acetyl-CoA and oxaloacetate is based on sequence similarity of ACLY to citrate synthase (CS). Both enzymes have histidine and aspartic acid residues at similar positions in their sequences. We hypothesize that citryl-CoA binds at this site in ACLY and is cleaved into acetyl-CoA and oxaloacetate using these residues. To test this hypothesis, we have mutated these residues to alanine in both human ACLY and ACLY from the bacterium, Chlorobium limicola. Enzymatic activities of the mutant proteins were tested using a coupled-enzyme assay with malate dehydrogenase. The inactive mutants are being used in crystallization trials with substrates, since complexes of the intermediate citryl-CoA can be trapped on the protein. To date, the crystal structure of full-length ACLY has not been published. The structure of only the amino-terminal two-thirds of the human enzyme has been determined [3]; however, the part of the protein that is similar to CS is the carboxy-terminal portion. This work identifies the catalytic residues of ACLY and complements the previous structure determination, increasing our currently limited knowledge about this enzyme.

Metabolite levels and enzyme activities in the bovine mammary gland in different stages of lactation: II. Some metabolite levels and enzyme activities of the citric acid cycle

1973 ◽  
Vol 40 (3) ◽  
pp. 361-370 ◽  
Author(s):  
Marianne Waldschmidt ◽  
S. Rilling
Keyword(s):  
Mammary Gland ◽  
Isocitrate Dehydrogenase ◽  
Enzyme Activities ◽  
Citric Acid Cycle ◽  
Citrate Synthase ◽  
Bovine Mammary Gland ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Lactating Cows ◽  
Citrate Lyase

SummarySamples of the mammary gland were obtained by the freeze-clamping technique from heifers, lactating and dry cows. Levels of acetyl CoA, citrate, isocitrate and α-oxoglutarate were determined in extracts of the samples and calculated per g fresh gland and per mg DNA. All mammary metabolite levels were significantly higher in lactating cows than in heifers or dry cows. The accumulation in the lactating gland increased in the sequence acetyl CoA–α-oxoglutarate–isocitrate–citrate. NADP/NADPH ratios in cytoplasm, as calculated from the equilibrium of isocitrate dehydrogenase, were lowest in lactating glands. The activities of some enzymes were also determined in the cytoplasm and calculated per g fresh gland, per mg protein and per mg DNA. Mammary citrate synthase activity did not vary significantly between different groups of cattle, whereas mammary isocitrate dehydrogenase activity was higher in lactating cows than in heifers or dry cows. No activity of ATP citrate lyase was detected.

scholarly journals Multiple cycles of acetyl‐CoA enolization catalyzed by citrate synthase (CS) and ATP‐citrate lyase (ACL)

2013 ◽  
Vol 27 (S1) ◽  
Author(s):  
Qingling Li ◽  
Vernon E. Anderson ◽  
Henri Brunengraber ◽  
Guo‐Fang Zhang
Keyword(s):  
Citrate Synthase ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Citrate Lyase ◽  
Multiple Cycles

scholarly journals Stereochemistry of si-Citrate Synthase and ATP-Citrate-Lyase Reactions

1971 ◽  
Vol 24 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Helmut Lenz ◽  
Wolfgang Buckel ◽  
Peter Wunderwald ◽  
Gunthard Biedermann ◽  
Verena Buschmeier ◽  
...  
Keyword(s):  
Citrate Synthase ◽  
Atp Citrate Lyase ◽  
Citrate Lyase

Abstract 15978: Acetyl-coa Catalysis by Atp-citrate Lyase is Essential for Myofibroblast Differentiation and Persistence

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Michael P Lazaropoulos ◽  
Andrew A Gibb ◽  
Anh Huynh ◽  
Kathryn Wellen ◽  
John W Elrod
Keyword(s):  
Histone Acetylation ◽  
Transcriptional Activation ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Metabolic Reprogramming ◽  
Myofibroblast Differentiation ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Matrix Deposition ◽  
Citrate Lyase

A feature of heart failure (HF) is excessive extracellular matrix deposition and cardiac remodeling by a differentiated fibroblast population known as myofibroblasts. Identifying mechanisms of myofibroblast differentiation in cardiac fibrosis could yield novel therapeutic targets to delay or reverse HF. Recent evidence suggests that myofibroblast differentiation requires metabolic reprogramming for transcriptional activation of the myofibroblast gene program by chromatin-dependent mechanisms. We previously reported that inhibition of histone demethylation blocks myofibroblast formation, however, whether histone acetylation (e.g., H3K27ac, a prominent mark associated with gene transcription) is involved in fibroblast reprogramming remains unclear. ATP-citrate lyase (ACLY) synthesizes acetyl-CoA and therein supplies acetyl-CoA to the nucleus, where it is used as a substrate by histone acetyltransferases (HATs). To define the role of acetyl-CoA metabolism in myofibroblast differentiation, we stimulated differentiation in mouse embryonic fibroblasts (MEFs) and adult mouse cardiac fibroblasts (ACFs) with the pro-fibrotic agonist transforming growth factor β (TGFβ) and treated cells with a pharmacological inhibitor of ACLY. ACLY inhibition decreased myofibroblast gene expression in ACF and MEFs in TGFβ-stimulated myofibroblast differentiation, in addition to decreasing the population of αSMA positive MEFs. Genetic deletion of ACLY in MEFs recapitulated the results observed with pharmacological inhibition. Encouragingly, the ACLY inhibitor was sufficient to revert fully differentiated myofibroblasts under continuous TGFβ stimulation to a quiescent, non-fibrotic phenotype. Altogether, our data indicate that ACLY activity is necessary for myofibroblast differentiation and persistence. We hypothesize that ACLY-dependent acetyl-CoA synthesis is necessary for histone acetylation and transcriptional activation of the myofibroblast gene program. Currently, we are examining mechanisms of ACLY-dependent chromatin remodeling in fibroblasts and the in vivo relevance of this mechanism in mutant mice. In summary, ACLY is a potential target to reverse cardiac fibrosis and lessen HF.

scholarly journals RNA-seq reveals novel mechanistic targets of withaferin A in prostate cancer cells

2020 ◽  
Vol 41 (6) ◽  
pp. 778-789 ◽  
Author(s):  
Su-Hyeong Kim ◽  
Eun-Ryeong Hahm ◽  
Krishna B Singh ◽  
Sruti Shiva ◽  
Jacob Stewart-Ornstein ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Acid Synthesis ◽  
Acetyl Coa Carboxylase ◽  
Rna Seq ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Citrate Lyase

Abstract Withaferin A (WA) is a promising phytochemical exhibiting in vitro and in vivo anticancer activities against prostate and other cancers, but the mechanism of its action is not fully understood. In this study, we performed RNA-seq analysis using 22Rv1 human prostate cancer cell line to identify mechanistic targets of WA. Kyoto Encyclopedia of Genes and Genomes pathway analysis of the differentially expressed genes showed most significant enrichment of genes associated with metabolism. These results were validated using LNCaP and 22Rv1 human prostate cancer cells and Hi-Myc transgenic mice as models. The intracellular levels of acetyl-CoA, total free fatty acids and neutral lipids were decreased significantly following WA treatment in both cells, which was accompanied by downregulation of mRNA (confirmed by quantitative reverse transcription-polymerase chain reaction) and protein levels of key fatty acid synthesis enzymes, including ATP citrate lyase, acetyl-CoA carboxylase 1, fatty acid synthase and carnitine palmitoyltransferase 1A. Ectopic expression of c-Myc, but not constitutively active Akt, conferred a marked protection against WA-mediated suppression of acetyl-CoA carboxylase 1 and fatty acid synthase protein expression, and clonogenic cell survival. WA was a superior inhibitor of cell proliferation and fatty acid synthesis in comparison with known modulators of fatty acid metabolism including cerulenin and etomoxir. Intraperitoneal WA administration to Hi-Myc transgenic mice (0.1 mg/mouse, three times/week for 5 weeks) also resulted in a significant decrease in circulating levels of total free fatty acids and phospholipids, and expression of ATP citrate lyase, acetyl-CoA carboxylase 1, fatty acid synthase and carnitine palmitoyltransferase 1A proteins in the prostate in vivo.

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