Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.2.1.13 (acetyl-CoA synthetase)
 451 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

SIRT3 is a major mitochondrial NAD(+)-dependent protein deacetylase playing important roles in regulating mitochondrial metabolism and energy production and has been linked to the beneficial effects of exercise and caloric restriction. SIRT3 is emerging as a potential therapeutic target to treat metabolic and neurological diseases. We report the first sets of crystal structures of human SIRT3, an apo-structure with no substrate, a structure with a peptide containing acetyl lysine of its natural substrate acetyl-CoA synthetase 2, a reaction intermediate structure trapped by a thioacetyl peptide, and a structure with the dethioacetylated peptide bound. These structures provide insights into the conformational changes induced by the two substrates required for the reaction, the acetylated substrate peptide and NAD(+). In addition, the binding study by isothermal titration calorimetry suggests that the acetylated peptide is the first substrate to bind to SIRT3, before NAD(+). These structures and biophysical studies provide key insight into the structural and functional relationship of the SIRT3 deacetylation activity.
J Biol Chem 2009 Sep 04
PMID:Crystal structures of human SIRT3 displaying substrate-induced conformational changes. 1953 40

We assessed the mechanisms by which specialized hypothalamic ventromedial nucleus (VMN) neurons utilize both glucose and long-chain fatty acids as signaling molecules to alter their activity as a potential means of regulating energy homeostasis. Fura-2 calcium (Ca(2+)) and membrane potential dye imaging, together with pharmacological agents, were used to assess the mechanisms by which oleic acid (OA) alters the activity of dissociated VMN neurons from 3- to 4-wk-old rats. OA excited up to 43% and inhibited up to 29% of all VMN neurons independently of glucose concentrations. In those neurons excited by both 2.5 mM glucose and OA, OA had a concentration-dependent effective excitatory concentration (EC(50)) of 13.1 nM. Neurons inhibited by both 2.5 mM glucose and OA had an effective inhibitory concentration (IC(50)) of 93 nM. At 0.5 mM glucose, OA had markedly different effects on these same neurons. Inhibition of carnitine palmitoyltransferase, reactive oxygen species formation, long-chain acetyl-CoA synthetase and ATP-sensitive K(+) channel activity or activation of uncoupling protein 2 (UCP2) accounted for only approximately 20% of OA's excitatory effects and approximately 40% of its inhibitory effects. Inhibition of CD36, a fatty acid transporter that can alter cell function independently of intracellular fatty acid metabolism, reduced the effects of OA by up to 45%. Thus OA affects VMN neuronal activity through multiple pathways. In glucosensing neurons, its effects are glucose dependent. This glucose-OA interaction provides a potential mechanism whereby such "metabolic sensing" neurons can respond to differences in the metabolic states associated with fasting and feeding.
Am J Physiol Regul Integr Comp Physiol 2009 Sep
PMID:Characteristics and mechanisms of hypothalamic neuronal fatty acid sensing. 1953 76

Recombinant Escherichia coli was constructed for co-production of hydrogen and polyhydroxybutyrate (PHB) due to its rapid growth and convenience of genetic manipulation. In particular, anaerobic metabolic pathways dedicated to co-production of hydrogen and PHB were established due to the advantages of directing fluxes away from toxic compounds such as formate and acetate to useful products. Here, recombinant E. coli expressing hydrogenase 3 and/or acetyl-CoA synthetase showed improved PHB and hydrogen production when grown with or without acetate as a carbon source. When hydrogenase 3 was over-expressed, hydrogen yield was increased from 14 to 153 mmol H(2)/mol glucose in a mineral salt (MS) medium with glucose as carbon source, accompanied by an increased PHB yield from 0.55 to 5.34 mg PHB/g glucose in MS medium with glucose and acetate as carbon source.
Metab Eng 2012 Sep
PMID:Enhanced co-production of hydrogen and poly-(R)-3-hydroxybutyrate by recombinant PHB producing E. coli over-expressing hydrogenase 3 and acetyl-CoA synthetase. 2284 73

Through metabolic engineering microorganisms can be engineered to produce new products and further produce these with higher yield and productivities. Here, we expressed the bacterial polyhydroxybutyrate (PHB) pathway in the yeast Saccharomyces cerevisiae and we further evaluated the effect of engineering the formation of acetyl coenzyme A (acetyl-CoA), an intermediate of the central carbon metabolism and precursor of the PHB pathway, on heterologous PHB production by yeast. We engineered the acetyl-CoA metabolism by co-transformation of a plasmid containing genes for native S. cerevisiae alcohol dehydrogenase (ADH2), acetaldehyde dehydrogenase (ALD6), acetyl-CoA acetyltransferase (ERG10) and a Salmonella enterica acetyl-CoA synthetase variant (acsL641P), resulting in acetoacetyl-CoA overproduction, together with a plasmid containing the PHB pathway genes coding for acetyl-CoA acetyltransferase (phaA), NADPH-linked acetoacetyl-CoA reductase (phaB) and poly(3-hydroxybutyrate) polymerase (phaC) from Ralstonia eutropha H16. Introduction of the acetyl-CoA plasmid together with the PHB plasmid, improved the productivity of PHB more than 16 times compared to the reference strain used in this study, as well as it reduced the specific product formation of side products.
AMB Express 2012 Sep 25
PMID:Engineering of acetyl-CoA metabolism for the improved production of polyhydroxybutyrate in Saccharomyces cerevisiae. 2300 57

Recently, butanols (1-butanol, 2-butanol and iso-butanol) have generated attention as alternative gasoline additives. Butanols have several properties favorable in comparison to ethanol, and strong interest therefore exists in the reconstruction of the 1-butanol pathway in commonly used industrial microorganisms. In the present study, the biosynthetic pathway for 1-butanol production was reconstructed in the yeast Saccharomyces cerevisiae. In addition to introducing heterologous enzymes for butanol production, we engineered yeast to have increased flux toward cytosolic acetyl-CoA, the precursor metabolite for 1-butanol biosynthesis. This was done through introduction of a plasmid-containing genes for alcohol dehydrogenase (ADH2), acetaldehyde dehydrogenase (ALD6), acetyl-CoA synthetase (ACS), and acetyl-CoA acetyltransferase (ERG10), as well as the use of strains containing deletions in the malate synthase (MLS1) or citrate synthase (CIT2) genes. Our results show a trend to increased butanol production in strains engineered for increased cytosolic acetyl-CoA levels, with the best-producing strains having maximal butanol titers of 16.3 mg/l. This represents a 6.5-fold improvement in butanol titers compared to previous values reported for yeast and demonstrates the importance of an improved cytosolic acetyl-CoA supply for heterologous butanol production by this organism.
J Ind Microbiol Biotechnol 2013 Sep
PMID:Improving biobutanol production in engineered Saccharomyces cerevisiae by manipulation of acetyl-CoA metabolism. 2376 Apr 99

Carbon metabolic pathways are important to the pathogenesis of Mycobacterium tuberculosis, the causative agent of tuberculosis. However, extremely little is known about metabolic regulation in mycobacteria. There is growing evidence for lysine acetylation being a mechanism of regulating bacterial metabolism. Lysine acetylation is a post-translational modification in which an acetyl group is covalently attached to the side chain of a lysine residue. This modification is mediated by acetyltransferases, which add acetyl groups, and deacetylases, which remove the acetyl groups. Here we set out to test whether lysine acetylation and deacetylation impact acetate metabolism in the model mycobacteria Mycobacterium smegmatis, which possesses 25 candidate acetyltransferases and 3 putative lysine deacetylases. Using mutants lacking predicted acetyltransferases and deacetylases we showed that acetate metabolism in M. smegmatis is regulated by reversible acetylation of acetyl-CoA synthetase (Ms-Acs) through the action of a single pair of enzymes: the acetyltransferase Ms-PatA and the sirtuin deacetylase Ms-SrtN. We also confirmed that the role of Ms-PatA in regulating Ms-Acs regulation depends on cAMP binding. We additionally demonstrated a role for Ms-Acs, Ms-PatA and Ms-SrtN in regulating the metabolism of propionate in M. smegmatis. Finally, along with Ms-Acs, we identified a candidate propionyl-CoA synthetase, Ms5404, as acetylated in whole-cell lysates. This work lays the foundation for studying the regulatory circuit of acetylation and deacetylation in the cellular context of mycobacteria.
Microbiology (Reading) 2013 Sep
PMID:Reversible acetylation regulates acetate and propionate metabolism in Mycobacterium smegmatis. 2381 78

We have developed a new screening methodology for identifying all genes that control the expression of a target gene through genetic or metabolic interactions. The screen combines mutant libraries with luciferase reporter constructs, whose expression can be monitored in vivo and over time in different environmental conditions. We apply the method to identify the genes that control the expression of the gene acs, encoding the acetyl coenzyme A synthetase, in Escherichia coli. We confirm most of the known genetic regulators, including CRP-cAMP, IHF and components of the phosphotransferase system. In addition, we identify new regulatory interactions, many of which involve metabolic intermediates or metabolic sensing, such as the genes pgi, pfkA, sucB and lpdA, encoding enzymes in glycolysis and the TCA cycle. Some of these novel interactions were validated by quantitative reverse transcriptase-polymerase chain reaction. More generally, we observe that a large number of mutants directly or indirectly influence acs expression, an effect confirmed for a second promoter, sdhC. The method is applicable to any promoter fused to a luminescent reporter gene in combination with a deletion mutant library.
Nucleic Acids Res 2013 Sep
PMID:A genome-wide screen for identifying all regulators of a target gene. 2389 89

Reversible lysine acetylation (RLA) is used by cells of all domains of life to modulate protein function. To date, bacterial acetylation/deacetylation systems have been studied in a few bacteria (e.g., Salmonella enterica, Bacillus subtilis, Escherichia coli, Erwinia amylovora, Mycobacterium tuberculosis, and Geobacillus kaustophilus), but little is known about RLA in antibiotic-producing actinomycetes. Here, we identify the Gcn5-like protein acetyltransferase AcuA of Saccharopolyspora erythraea (SacAcuA, SACE_5148) as the enzyme responsible for the acetylation of the AMP-forming acetyl coenzyme A synthetase (SacAcsA, SACE_2375). Acetylated SacAcsA was deacetylated by a sirtuin-type NAD(+)-dependent consuming deacetylase (SacSrtN, SACE_3798). In vitro acetylation/deacetylation of SacAcsA enzyme was studied by Western blotting, and acetylation of lysine residues Lys(237), Lys(380), Lys(611), and Lys(628) was confirmed by mass spectrometry. In a strain devoid of SacAcuA, none of the above-mentioned Lys residues of SacAcsA was acetylated. To our knowledge, the ability of SacAcuA to acetylate multiple Lys residues is unique among AcuA-type acetyltransferases. Results from site-specific mutagenesis experiments showed that the activity of SacAcsA was controlled by lysine acetylation. Lastly, immunoprecipitation data showed that in vivo acetylation of SacAcsA was influenced by glucose and acetate availability. These results suggested that reversible acetylation may also be a conserved regulatory posttranslational modification strategy in antibiotic-producing actinomycetes.
J Bacteriol 2014 Sep
PMID:Acetyl coenzyme A synthetase is acetylated on multiple lysine residues by a protein acetyltransferase with a single Gcn5-type N-acetyltransferase (GNAT) domain in Saccharopolyspora erythraea. 2495 27

Biogenesis of eukaryotic ribosome is a complex event involving a number of non-ribosomal factors. During assembly of the ribosome, rRNAs are post-transcriptionally modified by 2'-O-methylation, pseudouridylation, and several base-specific modifications, which are collectively involved in fine-tuning translational fidelity and/or modulating ribosome assembly. By mass-spectrometric analysis, we demonstrated that N(4)-acetylcytidine (ac(4)C) is present at position 1773 in the 18 S rRNA of Saccharomyces cerevisiae. In addition, we found an essential gene, KRE33 (human homolog, NAT10), that we renamed RRA1 (ribosomal RNA cytidine acetyltransferase 1) encoding an RNA acetyltransferase responsible for ac(4)C1773 formation. Using recombinant Rra1p, we could successfully reconstitute ac(4)C1773 in a model rRNA fragment in the presence of both acetyl-CoA and ATP as substrates. Upon depletion of Rra1p, the 23 S precursor of 18 S rRNA was accumulated significantly, which resulted in complete loss of 18 S rRNA and small ribosomal subunit (40 S), suggesting that ac(4)C1773 formation catalyzed by Rra1p plays a critical role in processing of the 23 S precursor to yield 18 S rRNA. When nuclear acetyl-CoA was depleted by inactivation of acetyl-CoA synthetase 2 (ACS2), we observed temporal accumulation of the 23 S precursor, indicating that Rra1p modulates biogenesis of 40 S subunit by sensing nuclear acetyl-CoA concentration.
J Biol Chem 2014 Sep 19
PMID:A single acetylation of 18 S rRNA is essential for biogenesis of the small ribosomal subunit in Saccharomyces cerevisiae. 2508 48

ACT domains (amino acid-binding domains) are linked to a wide range of metabolic enzymes that are regulated by amino acid concentration. Seventy proteins with ACT-GCN5-related N-acetyltransferase (GNAT) domain organization were found in actinomycetales. In this study, we investigate the ACT-containing GNAT acetyltransferase, Micau_1670 (MaKat), from Micromonospora aurantiaca ATCC 27029. Arginine and cysteine were identified as ligands by monitoring the conformational changes that occur upon amino acids binding to the ACT domain in the MaKat protein using FRET assay. It was found that MaKat is an amino acid-regulated protein acetyltransferase, whereas arginine and cysteine stimulated the activity of MaKat with regard to acetylation of acetyl-CoA synthetase (Micau_0428). Our research reveals the biochemical characterization of a protein acetyltransferase that contains a fusion of a GNAT domain with an ACT domain and provides a novel signaling pathway for regulating cellular protein acetylation. These findings indicate that acetylation of proteins and acetyltransferase activity may be tightly linked to cellular concentrations of some amino acids in actinomycetales.
J Biol Chem 2014 Sep 26
PMID:Allosteric regulation of a protein acetyltransferase in Micromonospora aurantiaca by the amino acids cysteine and arginine. 2512 41


<< Previous 1 2 3 4 Next >>