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Sample records for alcohol acyltransferase awat

  1. Suppression of PPARγ-mediated monoacylglycerol O-acyltransferase 1 expression ameliorates alcoholic hepatic steatosis

    PubMed Central

    Yu, Jung Hwan; Song, Su Jin; Kim, Ara; Choi, Yoonjeong; Seok, Jo Woon; Kim, Hyo Jung; Lee, Yoo Jeong; Lee, Kwan Sik; Kim, Jae-woo

    2016-01-01

    Alcohol consumption is one of the major causes of hepatic steatosis, fibrosis, cirrhosis, and superimposed hepatocellular carcinoma. Ethanol metabolism alters the NAD+/NADH ratio, thereby suppressing the activity of sirtuin family proteins, which may affect lipid metabolism in liver cells. However, it is not clear how long-term ingestion of ethanol eventually causes lipid accumulation in liver. Here, we demonstrate that chronic ethanol ingestion activates peroxisome proliferator-activated receptor γ (PPARγ) and its target gene, monoacylglycerol O-acyltransferase 1 (MGAT1). During ethanol metabolism, a low NAD+/NADH ratio repressed NAD-dependent deacetylase sirtuin 1 (SIRT1) activity, concomitantly resulting in increased acetylated PPARγ with high transcriptional activity. Accordingly, SIRT1 transgenic mice exhibited a low level of acetylated PPARγ and were protected from hepatic steatosis driven by alcohol or PPARγ2 overexpression, suggesting that ethanol metabolism causes lipid accumulation through activation of PPARγ through acetylation. Among the genes induced by PPARγ upon alcohol consumption, MGAT1 has been shown to be involved in triglyceride synthesis. Thus, we tested the effect of MGAT1 knockdown in mice following ethanol consumption, and found a significant reduction in alcohol-induced hepatic lipid accumulation. These results suggest that MGAT1 may afford a promising approach to the treatment of fatty liver disease. PMID:27404390

  2. Suppression of PPARγ-mediated monoacylglycerol O-acyltransferase 1 expression ameliorates alcoholic hepatic steatosis.

    PubMed

    Yu, Jung Hwan; Song, Su Jin; Kim, Ara; Choi, Yoonjeong; Seok, Jo Woon; Kim, Hyo Jung; Lee, Yoo Jeong; Lee, Kwan Sik; Kim, Jae-Woo

    2016-01-01

    Alcohol consumption is one of the major causes of hepatic steatosis, fibrosis, cirrhosis, and superimposed hepatocellular carcinoma. Ethanol metabolism alters the NAD(+)/NADH ratio, thereby suppressing the activity of sirtuin family proteins, which may affect lipid metabolism in liver cells. However, it is not clear how long-term ingestion of ethanol eventually causes lipid accumulation in liver. Here, we demonstrate that chronic ethanol ingestion activates peroxisome proliferator-activated receptor γ (PPARγ) and its target gene, monoacylglycerol O-acyltransferase 1 (MGAT1). During ethanol metabolism, a low NAD(+)/NADH ratio repressed NAD-dependent deacetylase sirtuin 1 (SIRT1) activity, concomitantly resulting in increased acetylated PPARγ with high transcriptional activity. Accordingly, SIRT1 transgenic mice exhibited a low level of acetylated PPARγ and were protected from hepatic steatosis driven by alcohol or PPARγ2 overexpression, suggesting that ethanol metabolism causes lipid accumulation through activation of PPARγ through acetylation. Among the genes induced by PPARγ upon alcohol consumption, MGAT1 has been shown to be involved in triglyceride synthesis. Thus, we tested the effect of MGAT1 knockdown in mice following ethanol consumption, and found a significant reduction in alcohol-induced hepatic lipid accumulation. These results suggest that MGAT1 may afford a promising approach to the treatment of fatty liver disease. PMID:27404390

  3. Computational study enlightens the structural role of the alcohol acyltransferase DFGWG motif.

    PubMed

    Morales-Quintana, Luis; Moya-León, María Alejandra; Herrera, Raúl

    2015-08-01

    Alcohol acyltransferases (AAT) catalyze the esterification reaction of alcohols and acyl-CoA into esters in fruits and flowers. Despite the high divergence between AAT enzymes, two important and conserved motifs are shared: the catalytic HxxxD motif, and the DFGWG motif. The latter is proposed to play a structural role; however, its function remains unclear. The DFGWG motif is located in loop 21 and stabilized by a hydrogen bond between residues Y52 and D381. Also, this motif is distant from the HxxxD motif, and most probably without a direct role in the substrate interaction. To evaluate the role of the DFGWG motif, in silico analysis was performed in the VpAAT1 protein. Three mutants (Y52F, D381A and D381E) were evaluated. Major changes (size and shape) in the solvent channels were found, although no differences were revealed in the entire 3D structure. Molecular dynamics simulations and docking studies described unfavorable energies for interaction of the mutant proteins with different substrates, as well as unfavored ligand orientations in the solvent channel. Additionally, we examined the contribution of different energetic parameters to the total free energy of protein-ligand complexes by the MM-GBSA method. The complexes differed mainly in their van der Waals contributions and have unfavorable electrostatic interactions. VpAAT1, Y52F and D381A mutants showed a dramatic reduction in the binding capacity to several substrates, which is related to differences in electrostatic potential on the protein surfaces, suggesting that D381 from the DFGWG motif and residue Y52 play a crucial role in maintenance of the adequate solvent channel structure required for catalysis. Graphical abstract Molecular docking, molecular dynamics (MD) simulations and MM-GBSA free energy calculations were employed to obtain quantitative estimates for the binding free energies of wild type Vasconcellea pubescens alcohol acyltransferase (VpAAT1-WT) and the protein mutants. Left VpAAT1

  4. Rapid ester biosynthesis screening reveals a high activity alcohol-O-acyltransferase (AATase) from tomato fruit.

    PubMed

    Lin, Jyun-Liang; Zhu, Jie; Wheeldon, Ian

    2016-05-01

    Ethyl and acetate esters are naturally produced in various yeasts, plants, and bacteria. The biosynthetic pathways that produce these esters share a common reaction step, the condensation of acetyl/acyl-CoA with an alcohol by alcohol-O-acetyl/acyltransferase (AATase). Recent metabolic engineering efforts exploit AATase activity to produce fatty acid ethyl esters as potential diesel fuel replacements as well as short- and medium-chain volatile esters as fragrance and flavor compounds. These efforts have been limited by the lack of a rapid screen to quantify ester biosynthesis. Enzyme engineering efforts have also been limited by the lack of a high throughput screen for AATase activity. Here, we developed a high throughput assay for AATase activity and used this assay to discover a high activity AATase from tomato fruit, Solanum lycopersicum (Atf-S.l). Atf1-S.l exhibited broad specificity towards acyl-CoAs with chain length from C4 to C10 and was specific towards 1-pentanol. The AATase screen also revealed new acyl-CoA substrate specificities for Atf1, Atf2, Eht1, and Eeb1 from Saccharomyces cerevisiae, and Atf-C.m from melon fruit, Cucumis melo, thus increasing the pool of characterized AATases that can be used in ester biosynthesis of ester-based fragrance and flavor compounds as well as fatty acid ethyl ester biofuels. PMID:26814045

  5. Structural and Affinity Determinants in the Interaction between Alcohol Acyltransferase from F. x ananassa and Several Alcohol Substrates: A Computational Study.

    PubMed

    Navarro-Retamal, Carlos; Gaete-Eastman, Carlos; Herrera, Raúl; Caballero, Julio; Alzate-Morales, Jans H

    2016-01-01

    Aroma and flavor are important factors of fruit quality and consumer preference. The specific pattern of aroma is generated during ripening by the accumulation of volatiles compounds, which are mainly esters. Alcohol acyltransferase (AAT) (EC 2.3.1.84) catalyzes the esterification reaction of aliphatic and aromatic alcohols and acyl-CoA into esters in fruits and flowers. In Fragaria x ananassa, there are different volatiles compounds that are obtained from different alcohol precursors, where octanol and hexanol are the most abundant during fruit ripening. At present, there is not structural evidence about the mechanism used by the AAT to synthesize esters. Experimental data attribute the kinetic role of this enzyme to 2 amino acidic residues in a highly conserved motif (HXXXD) that is located in the middle of the protein. With the aim to understand the molecular and energetic aspects of volatiles compound production from F. x ananassa, we first studied the binding modes of a series of alcohols, and also different acyl-CoA substrates, in a molecular model of alcohol acyltransferase from Fragaria x ananassa (SAAT) using molecular docking. Afterwards, the dynamical behavior of both substrates, docked within the SAAT binding site, was studied using routine molecular dynamics (MD) simulations. In addition, in order to correlate the experimental and theoretical data obtained in our laboratories, binding free energy calculations were performed; which previous results suggested that octanol, followed by hexanol, presented the best affinity for SAAT. Finally, and concerning the SAAT molecular reaction mechanism, it is suggested from molecular dynamics simulations that the reaction mechanism may proceed through the formation of a ternary complex, in where the Histidine residue at the HXXXD motif deprotonates the alcohol substrates. Then, a nucleophilic attack occurs from alcohol charged oxygen atom to the carbon atom at carbonyl group of the acyl CoA. This mechanism is in

  6. Structural and Affinity Determinants in the Interaction between Alcohol Acyltransferase from F. x ananassa and Several Alcohol Substrates: A Computational Study

    PubMed Central

    Herrera, Raúl; Caballero, Julio; Alzate-Morales, Jans H.

    2016-01-01

    Aroma and flavor are important factors of fruit quality and consumer preference. The specific pattern of aroma is generated during ripening by the accumulation of volatiles compounds, which are mainly esters. Alcohol acyltransferase (AAT) (EC 2.3.1.84) catalyzes the esterification reaction of aliphatic and aromatic alcohols and acyl-CoA into esters in fruits and flowers. In Fragaria x ananassa, there are different volatiles compounds that are obtained from different alcohol precursors, where octanol and hexanol are the most abundant during fruit ripening. At present, there is not structural evidence about the mechanism used by the AAT to synthesize esters. Experimental data attribute the kinetic role of this enzyme to 2 amino acidic residues in a highly conserved motif (HXXXD) that is located in the middle of the protein. With the aim to understand the molecular and energetic aspects of volatiles compound production from F. x ananassa, we first studied the binding modes of a series of alcohols, and also different acyl-CoA substrates, in a molecular model of alcohol acyltransferase from Fragaria x ananassa (SAAT) using molecular docking. Afterwards, the dynamical behavior of both substrates, docked within the SAAT binding site, was studied using routine molecular dynamics (MD) simulations. In addition, in order to correlate the experimental and theoretical data obtained in our laboratories, binding free energy calculations were performed; which previous results suggested that octanol, followed by hexanol, presented the best affinity for SAAT. Finally, and concerning the SAAT molecular reaction mechanism, it is suggested from molecular dynamics simulations that the reaction mechanism may proceed through the formation of a ternary complex, in where the Histidine residue at the HXXXD motif deprotonates the alcohol substrates. Then, a nucleophilic attack occurs from alcohol charged oxygen atom to the carbon atom at carbonyl group of the acyl CoA. This mechanism is in

  7. Divergence in the Enzymatic Activities of a Tomato and Solanum pennellii Alcohol Acyltransferase Impacts Fruit Volatile Ester Composition.

    PubMed

    Goulet, Charles; Kamiyoshihara, Yusuke; Lam, Nghi B; Richard, Théo; Taylor, Mark G; Tieman, Denise M; Klee, Harry J

    2014-10-29

    Tomato fruits accumulate a diverse set of volatiles including multiple esters. The content of ester volatiles is relatively low in tomato fruits (Solanum lycopersicum) and far more abundant in the closely related species S. pennellii. There are also qualitative variations in ester content between the two species. We have previously shown that high expression of a non-specific esterase is critical for the low overall ester content of S. lycopersicum fruit relative to S. pennellii fruit. Here, we show that qualitative differences in ester composition are the consequence of divergence in enzymatic activity of a ripening-related alcohol acyltransferase (AAT1). The S. pennellii AAT1 is more efficient than the tomato AAT1 for all the alcohols tested. The two enzymes have differences in their substrates preferences that explain variations observed in the volatiles. Together, the results illustrate how two related species have evolved to precisely adjust their volatile content by modulating the balance of synthesis and degradation of esters. PMID:25355057

  8. Divergence in the enzymatic activities of a tomato and Solanum pennellii alcohol acyltransferase impacts fruit volatile ester composition.

    PubMed

    Goulet, Charles; Kamiyoshihara, Yusuke; Lam, Nghi B; Richard, Théo; Taylor, Mark G; Tieman, Denise M; Klee, Harry J

    2015-01-01

    Tomato fruits accumulate a diverse set of volatiles including multiple esters. The content of ester volatiles is relatively low in tomato fruits (Solanum lycopersicum) and far more abundant in the closely related species Solanum pennellii. There are also qualitative variations in ester content between the two species. We have previously shown that high expression of a non-specific esterase is critical for the low overall ester content of S. lycopersicum fruit relative to S. pennellii fruit. Here, we show that qualitative differences in ester composition are the consequence of divergence in enzymatic activity of a ripening-related alcohol acyltransferase (AAT1). The S. pennellii AAT1 is more efficient than the tomato AAT1 for all the alcohols tested. The two enzymes have differences in their substrate preferences that explain the variations observed in the volatiles. The results illustrate how two related species have evolved to precisely adjust their volatile content by modulating the balance of the synthesis and degradation of esters. PMID:25578279

  9. Bioengineering recombinant diacylglycerol acyltransferases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferases (DGATs) catalyze the last and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. At least 115 DGAT sequences are identified from 69 organisms in the GenBank databases. Only a few papers have been published in the last 28 years on the exp...

  10. Acyltransferases in bacteria.

    PubMed

    Röttig, Annika; Steinbüchel, Alexander

    2013-06-01

    Long-chain-length hydrophobic acyl residues play a vital role in a multitude of essential biological structures and processes. They build the inner hydrophobic layers of biological membranes, are converted to intracellular storage compounds, and are used to modify protein properties or function as membrane anchors, to name only a few functions. Acyl thioesters are transferred by acyltransferases or transacylases to a variety of different substrates or are polymerized to lipophilic storage compounds. Lipases represent another important enzyme class dealing with fatty acyl chains; however, they cannot be regarded as acyltransferases in the strict sense. This review provides a detailed survey of the wide spectrum of bacterial acyltransferases and compares different enzyme families in regard to their catalytic mechanisms. On the basis of their studied or assumed mechanisms, most of the acyl-transferring enzymes can be divided into two groups. The majority of enzymes discussed in this review employ a conserved acyltransferase motif with an invariant histidine residue, followed by an acidic amino acid residue, and their catalytic mechanism is characterized by a noncovalent transition state. In contrast to that, lipases rely on completely different mechanism which employs a catalytic triad and functions via the formation of covalent intermediates. This is, for example, similar to the mechanism which has been suggested for polyester synthases. Consequently, although the presented enzyme types neither share homology nor have a common three-dimensional structure, and although they deal with greatly varying molecule structures, this variety is not reflected in their mechanisms, all of which rely on a catalytically active histidine residue. PMID:23699259

  11. Acyltransferases in Bacteria

    PubMed Central

    Röttig, Annika

    2013-01-01

    SUMMARY Long-chain-length hydrophobic acyl residues play a vital role in a multitude of essential biological structures and processes. They build the inner hydrophobic layers of biological membranes, are converted to intracellular storage compounds, and are used to modify protein properties or function as membrane anchors, to name only a few functions. Acyl thioesters are transferred by acyltransferases or transacylases to a variety of different substrates or are polymerized to lipophilic storage compounds. Lipases represent another important enzyme class dealing with fatty acyl chains; however, they cannot be regarded as acyltransferases in the strict sense. This review provides a detailed survey of the wide spectrum of bacterial acyltransferases and compares different enzyme families in regard to their catalytic mechanisms. On the basis of their studied or assumed mechanisms, most of the acyl-transferring enzymes can be divided into two groups. The majority of enzymes discussed in this review employ a conserved acyltransferase motif with an invariant histidine residue, followed by an acidic amino acid residue, and their catalytic mechanism is characterized by a noncovalent transition state. In contrast to that, lipases rely on completely different mechanism which employs a catalytic triad and functions via the formation of covalent intermediates. This is, for example, similar to the mechanism which has been suggested for polyester synthases. Consequently, although the presented enzyme types neither share homology nor have a common three-dimensional structure, and although they deal with greatly varying molecule structures, this variety is not reflected in their mechanisms, all of which rely on a catalytically active histidine residue. PMID:23699259

  12. Technical note: Improving the AWAT filter with interpolation schemes for advanced processing of high resolution data

    NASA Astrophysics Data System (ADS)

    Peters, Andre; Nehls, Thomas; Wessolek, Gerd

    2016-06-01

    Weighing lysimeters with appropriate data filtering yield the most precise and unbiased information for precipitation (P) and evapotranspiration (ET). A recently introduced filter scheme for such data is the AWAT (Adaptive Window and Adaptive Threshold) filter (Peters et al., 2014). The filter applies an adaptive threshold to separate significant from insignificant mass changes, guaranteeing that P and ET are not overestimated, and uses a step interpolation between the significant mass changes. In this contribution we show that the step interpolation scheme, which reflects the resolution of the measuring system, can lead to unrealistic prediction of P and ET, especially if they are required in high temporal resolution. We introduce linear and spline interpolation schemes to overcome these problems. To guarantee that medium to strong precipitation events abruptly following low or zero fluxes are not smoothed in an unfavourable way, a simple heuristic selection criterion is used, which attributes such precipitations to the step interpolation. The three interpolation schemes (step, linear and spline) are tested and compared using a data set from a grass-reference lysimeter with 1 min resolution, ranging from 1 January to 5 August 2014. The selected output resolutions for P and ET prediction are 1 day, 1 h and 10 min. As expected, the step scheme yielded reasonable flux rates only for a resolution of 1 day, whereas the other two schemes are well able to yield reasonable results for any resolution. The spline scheme returned slightly better results than the linear scheme concerning the differences between filtered values and raw data. Moreover, this scheme allows continuous differentiability of filtered data so that any output resolution for the fluxes is sound. Since computational burden is not problematic for any of the interpolation schemes, we suggest always using the spline scheme.

  13. Characterization of cultivar differences in alcohol acyltransferase and 1-aminocyclopropane-1carboxylate synthase gene expression and volatile compound emission during apple fruit maturation and ripening

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alcohol acyl transferase (AAT) catalyzes the last step of volatile ester biosynthesis, and ethylene purportedly regulates AAT gene expression. In this study, expession patterns of four apple AAT genes and two ethylene biosynthesis genes were investigated in two apple cultivars with relatively high ...

  14. Sequence analysis of diacylglycerol acyltransferases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferases (DGATs) catalyze the final step of triacylglycerol (TAG) biosynthesis in eukaryotes. DGATs esterify sn-1,2-diacylglycerol with a long-chain fatty acyl-CoA. Plants and animals deficient in DGATs accumulate less TAG and over-expression of DGATs increases TAG. DGAT knock...

  15. Microscopic and thermodynamic properties of the HFA134a-water interface: atomistic computer simulations and tensiometry under pressure.

    PubMed

    Peguin, Robson P S; Selvam, Parthiban; da Rocha, Sandro R P

    2006-10-10

    A combined computational and experimental approach is used to determine the interfacial thermodynamic and structural properties of the liquid 1,1,1,2-tetrafluoroethane (HFA134a)-vapor and liquid HFA134a-water (HFA134a|W) interfaces at 298 K and saturation pressure. Molecular dynamics (MD) computer simulations reveal a stable interface between HFA134a and water. The "10-90" interfacial thickness is comparable with those typically reported for organic-water systems. The interfacial tension of the HFA134a|W interface obtained from the pressure tensor analysis of the MD trajectory is in good agreement with the experimental value determined using in situ high-pressure tensiometry. These results indicate that the potential models utilized are capable of describing the intermolecular interactions between these two fluids. The tension of the HFA134a|W interface is significantly lower than those typically observed for conventional oil-water interfaces and similar to that of the compressed CO(2)-water interface, observed at moderate CO(2) pressures. The MD and tensiometric results are also compared and contrasted with the HFA134a|W and chlorofluorocarbon-water tension values estimated from a parametric relationship. This represents the first report of the interfacial and microscopic properties of the (propellant) hydrofluoroalkanes (HFA)|W interface. The results presented here are of relevance in the design of surfactants capable of forming and stabilizing water-in-HFA microemulsions. Reverse aqueous microemulsions in HFA-based pressurized metered-dose inhalers are candidate formulations for the systemic delivery of biomolecules to and through the lungs. PMID:17014124

  16. Membrane topology of hedgehog acyltransferase.

    PubMed

    Matevossian, Armine; Resh, Marilyn D

    2015-01-23

    Hedgehog acyltransferase (Hhat) is a multipass transmembrane enzyme that mediates the covalent attachment of the 16-carbon fatty acid palmitate to the N-terminal cysteine of Sonic Hedgehog (Shh). Palmitoylation of Shh by Hhat is critical for short and long range signaling. Knowledge of the topological organization of Hhat transmembrane helices would enhance our understanding of Hhat-mediated Shh palmitoylation. Bioinformatics analysis of transmembrane domains within human Hhat using 10 different algorithms resulted in highly consistent predictions in the C-terminal, but not in the N-terminal, region of Hhat. To empirically determine the topology of Hhat, we designed and exploited Hhat constructs containing either terminal or 12 different internal epitope tags. We used selective permeabilization coupled with immunofluorescence as well as a protease protection assay to demonstrate that Hhat contains 10 transmembrane domains and 2 re-entrant loops. The invariant His and highly conserved Asp residues within the membrane-bound O-acyltransferase (MBOAT) homology domain are segregated on opposite sides of the endoplasmic reticulum membrane. The localization of His-379 on the lumenal membrane surface is consistent with a role for this invariant residue in catalysis. Analysis of the activity and stability of the Hhat constructs revealed that the C-terminal MBOAT domain is especially sensitive to manipulation. Moreover, there was remarkable similarity in the overall topological organization of Hhat and ghrelin O-acyltransferase, another MBOAT family member. Knowledge of the topological organization of Hhat could serve as an important tool for further design of selective Hhat inhibitors. PMID:25488661

  17. Serine carboxypeptidase-like acyltransferases from plants.

    PubMed

    Mugford, Sam T; Milkowski, Carsten

    2012-01-01

    Serine carboxypeptidase-like (SCPL) acyltransferases facilitate transacylation reactions using energy-rich 1-O-β-glucose esters in the synthesis of an array of bioactive compounds and are associated with the diversification of plant natural products. SCPL acyltransferases have evolved from a hydrolytic ancestor by adapting functional elements of the proteases such as the catalytic triad, oxyanion hole, and substrate recognition H-bond network to their new function. As vacuolar proteins, SCPL acyltransferases define an alternative cellular route of transacylation spatially separated from the cytoplasmic enzymes of the BAHD acyltransferase family named according to the first characterized members (BEAT, AHCT, HCBT, and DAT). Recent efforts in cloning and characterization led to the identification of diagnostic peptides for SCPL acyltransferases, enabling the detection of candidate genes in several plant genomes. Detailed biochemical analysis of SCPL acyltransferases is strongly dependent on comprehensive heterologous expression systems, efficient protein purification protocols, and the supply of appropriate substrates. This chapter describes some useful techniques and strategies for identification and characterization of SCPL acyltransferases. PMID:23034234

  18. Alcohol

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Alcohol KidsHealth > For Teens > Alcohol Print A A A ... you can make an educated choice. What Is Alcohol? Alcohol is created when grains, fruits, or vegetables ...

  19. Two Predicted Transmembrane Domains Exclude Very Long Chain Fatty acyl-CoAs from the Active Site of Mouse Wax Synthase

    PubMed Central

    Kawelke, Steffen; Feussner, Ivo

    2015-01-01

    Wax esters are used as coatings or storage lipids in all kingdoms of life. They are synthesized from a fatty alcohol and an acyl-CoA by wax synthases. In order to get insights into the structure-function relationships of a wax synthase from Mus musculus, a domain swap experiment between the mouse acyl-CoA:wax alcohol acyltransferase (AWAT2) and the homologous mouse acyl-CoA:diacylglycerol O-acyltransferase 2 (DGAT2) was performed. This showed that the substrate specificity of AWAT2 is partially determined by two predicted transmembrane domains near the amino terminus of AWAT2. Upon exchange of the two domains for the respective part of DGAT2, the resulting chimeric enzyme was capable of incorporating up to 20% of very long acyl chains in the wax esters upon expression in S. cerevisiae strain H1246. The amount of very long acyl chains in wax esters synthesized by wild type AWAT2 was negligible. The effect was narrowed down to a single amino acid position within one of the predicted membrane domains, the AWAT2 N36R variant. Taken together, we provide first evidence that two predicted transmembrane domains in AWAT2 are involved in determining its acyl chain length specificity. PMID:26714272

  20. The Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase from Acinetobacter sp. Strain ADP1: Characterization of a Novel Type of Acyltransferase

    PubMed Central

    Stöveken, Tim; Kalscheuer, Rainer; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2005-01-01

    The wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT) catalyzes the final steps in triacylglycerol (TAG) and wax ester (WE) biosynthesis in the gram-negative bacterium Acinetobacter sp. strain ADP1. It constitutes a novel class of acyltransferases which is fundamentally different from acyltransferases involved in TAG and WE synthesis in eukaryotes. The enzyme was purified by a three-step purification protocol to apparent homogeneity from the soluble fraction of recombinant Escherichia coli Rosetta (DE3)pLysS (pET23a::atfA). Purified WS/DGAT revealed a remarkably low substrate specificity, accepting a broad range of various substances as alternative acceptor molecules. Besides having DGAT and WS activity, the enzyme possesses acyl-CoA:monoacylglycerol acyltransferase (MGAT) activity. The sn-1 and sn-3 positions of acylglycerols are accepted with higher specificity than the sn-2 position. Linear alcohols ranging from ethanol to triacontanol are efficiently acylated by the enzyme, which exhibits highest specificities towards medium-chain-length alcohols. The acylation of cyclic and aromatic alcohols, such as cyclohexanol or phenylethanol, further underlines the unspecific character of this enzyme. The broad range of possible substrates may lead to biotechnological production of interesting wax ester derivatives. Determination of the native molecular weight revealed organization as a homodimer. The large number of WS/DGAT-homologous genes identified in pathogenic mycobacteria and their possible importance for the pathogenesis and latency of these bacteria makes the purified WS/DGAT from Acinetobacter sp. strain ADP1 a valuable model for studying this group of proteins in pathogenic mycobacteria. PMID:15687201

  1. Alcohol

    MedlinePlus

    ... Text Size: A A A Listen En Español Alcohol Wondering if alcohol is off limits with diabetes? Most people with diabetes can have a moderate amount of alcohol. Research has shown that there can be some ...

  2. Alcohol

    MedlinePlus

    If you are like many Americans, you drink alcohol at least occasionally. For many people, moderate drinking ... risky. Heavy drinking can lead to alcoholism and alcohol abuse, as well as injuries, liver disease, heart ...

  3. Alcohol

    MedlinePlus

    ... Got Homework? Here's Help White House Lunch Recipes Alcohol KidsHealth > For Kids > Alcohol Print A A A Text Size What's in ... What Is Alcoholism? Say No en español El alcohol Getting the Right Message "Hey, who wants a ...

  4. Alcohol

    MedlinePlus

    ... as well as injuries, liver disease, heart disease, cancer, and other health problems. It can also cause problems at home, at work, and with friends. NIH: National Institute on Alcohol Abuse and Alcoholism

  5. Alcoholism.

    ERIC Educational Resources Information Center

    Caliguri, Joseph P., Ed.

    This extensive annotated bibliography provides a compilation of documents retreived from a computerized search of the ERIC, Social Science Citation Index, and Med-Line databases on the topic of alcoholism. The materials address the following areas of concern: (1) attitudes toward alcohol users and abusers; (2) characteristics of alcoholics and…

  6. Expression and purification of diacylglycerol acyltransferases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferases (DGATs) are integral membrane proteins that catalyze the last step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Plants and animals deficient in DGATs accumulate less TAG and over-expression of DGATs increases TAG. DGAT knockout mice are resistant to ...

  7. Bioengineering recombinant tung tree diacylglycerol acyltransferases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding plant oil biosynthesis will help to create new oilseed crops with value-added properties to replace petroleum-based compounds. Diacylglycerol acyltransferases (DGATs) are key enzymes catalyzing the last step of triacylglycerol (TAG) biosynthesis in eukaryotes. Plants and animals defici...

  8. Synthesis of Novel Acylglycerol Substrates for Acyltransferases.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1,2-Diacylglycerols (DG) are the native substrates for the diacylglycerol acyltransferase (DGAT). It is difficult to chemically synthesize DG containing hydroxy fatty acids in specific positions on the glycerol backbone. An alternate approach is to start from acylglycerols containing hydroxy fatty...

  9. Enhancing the Acyltransferase Activity of Candida antarctica Lipase A by Rational Design.

    PubMed

    Müller, Janett; Sowa, Miriam A; Fredrich, Birte; Brundiek, Henrike; Bornscheuer, Uwe T

    2015-08-17

    A few lipases, such as Candida antarctica lipase A (CAL-A), are known to possess acyltransferase activity. This enables the enzyme to synthesize fatty acid esters from natural oils and alcohols even in the presence of bulk water. Unfortunately, fatty acids are still formed in these reactions as undesired side-products. To reduce the amount of fatty acids, several CAL-A variants were rationally designed based on its crystal structure. These variants were expressed in Escherichia coli and Pichia pastoris, purified, and their acyltransferase/hydrolase activities were investigated by various biocatalytic approaches. Among the investigated variants, mutant Asp122Leu showed a significant decrease in the hydrolytic activity, thus reducing the side-product yield during acylation. As desired, this variant retained wild-type process-relevant features like pH profile and thermostability. PMID:26058745

  10. Membrane bound O-acyltransferases and their inhibitors.

    PubMed

    Masumoto, Naoko; Lanyon-Hogg, Thomas; Rodgers, Ursula R; Konitsiotis, Antonios D; Magee, Anthony I; Tate, Edward W

    2015-04-01

    Since the identification of the membrane-bound O-acyltransferase (MBOATs) protein family in the early 2000s, three distinct members [porcupine (PORCN), hedgehog (Hh) acyltransferase (HHAT) and ghrelin O-acyltransferase (GOAT)] have been shown to acylate specific proteins or peptides. In this review, topology determination, development of assays to measure enzymatic activities and discovery of small molecule inhibitors are compared and discussed for each of these enzymes. PMID:25849925

  11. Alcohol.

    ERIC Educational Resources Information Center

    Schibeci, Renato

    1996-01-01

    Describes the manufacturing of ethanol, the effects of ethanol on the body, the composition of alcoholic drinks, and some properties of ethanol. Presents some classroom experiments using ethanol. (JRH)

  12. Acyl-coenzyme A:cholesterol acyltransferases

    PubMed Central

    Chang, Ta-Yuan; Li, Bo-Liang; Chang, Catherine C. Y.; Urano, Yasuomi

    2009-01-01

    The enzymes acyl-coenzyme A (CoA):cholesterol acyltransferases (ACATs) are membrane-bound proteins that utilize long-chain fatty acyl-CoA and cholesterol as substrates to form cholesteryl esters. In mammals, two isoenzymes, ACAT1 and ACAT2, encoded by two different genes, exist. ACATs play important roles in cellular cholesterol homeostasis in various tissues. This chapter summarizes the current knowledge on ACAT-related research in two areas: 1) ACAT genes and proteins and 2) ACAT enzymes as drug targets for atherosclerosis and for Alzheimer's disease. PMID:19141679

  13. Structural Basis for the Acyltransferase Activity of Lecithin: Retinol Acyltransferase-like Proteins

    SciTech Connect

    Golczak, Marcin; Kiser, Philip D.; Sears, Avery E.; Lodowski, David T.; Blaner, William S.; Palczewski, Krzysztof

    2012-10-10

    Lecithin:retinol acyltransferase-like proteins, also referred to as HRAS-like tumor suppressors, comprise a vertebrate subfamily of papain-like or NlpC/P60 thiol proteases that function as phospholipid-metabolizing enzymes. HRAS-like tumor suppressor 3, a representative member of this group, plays a key role in regulating triglyceride accumulation and energy expenditure in adipocytes and therefore constitutes a novel pharmacological target for treatment of metabolic disorders causing obesity. Here, we delineate a catalytic mechanism common to lecithin:retinol acyltransferase-like proteins and provide evidence for their alternative robust lipid-dependent acyltransferase enzymatic activity. We also determined high resolution crystal structures of HRAS-like tumor suppressor 2 and 3 to gain insight into their active site architecture. Based on this structural analysis, two conformational states of the catalytic Cys-113 were identified that differ in reactivity and thus could define the catalytic properties of these two proteins. Finally, these structures provide a model for the topology of these enzymes and allow identification of the protein-lipid bilayer interface. This study contributes to the enzymatic and structural understanding of HRAS-like tumor suppressor enzymes.

  14. Evolutionary view of acyl-CoA diacylglycerol acyltransferase (DGAT), a key enzyme in neutral lipid biosynthesis

    PubMed Central

    2011-01-01

    Background Triacylglycerides (TAGs) are a class of neutral lipids that represent the most important storage form of energy for eukaryotic cells. DGAT (acyl-CoA: diacylglycerol acyltransferase; EC 2.3.1.20) is a transmembrane enzyme that acts in the final and committed step of TAG synthesis, and it has been proposed to be the rate-limiting enzyme in plant storage lipid accumulation. In fact, two different enzymes identified in several eukaryotic species, DGAT1 and DGAT2, are the main enzymes responsible for TAG synthesis. These enzymes do not share high DNA or protein sequence similarities, and it has been suggested that they play non-redundant roles in different tissues and in some species in TAG synthesis. Despite a number of previous studies on the DGAT1 and DGAT2 genes, which have emphasized their importance as potential obesity treatment targets to increase triacylglycerol accumulation, little is known about their evolutionary timeline in eukaryotes. The goal of this study was to examine the evolutionary relationship of the DGAT1 and DGAT2 genes across eukaryotic organisms in order to infer their origin. Results We have conducted a broad survey of fully sequenced genomes, including representatives of Amoebozoa, yeasts, fungi, algae, musses, plants, vertebrate and invertebrate species, for the presence of DGAT1 and DGAT2 gene homologs. We found that the DGAT1 and DGAT2 genes are nearly ubiquitous in eukaryotes and are readily identifiable in all the major eukaryotic groups and genomes examined. Phylogenetic analyses of the DGAT1 and DGAT2 amino acid sequences revealed evolutionary partitioning of the DGAT protein family into two major DGAT1 and DGAT2 clades. Protein secondary structure and hydrophobic-transmembrane analysis also showed differences between these enzymes. The analysis also revealed that the MGAT2 and AWAT genes may have arisen from DGAT2 duplication events. Conclusions In this study, we identified several DGAT1 and DGAT2 homologs in eukaryote taxa

  15. Soybean oil biosynthesis: role of diacylglycerol acyltransferases.

    PubMed

    Li, Runzhi; Hatanaka, Tomoko; Yu, Keshun; Wu, Yongmei; Fukushige, Hirotada; Hildebrand, David

    2013-03-01

    Diacylglycerol acyltransferase (DGAT) catalyzes the acyl-CoA-dependent acylation of sn-1,2-diacylglycerol to form seed oil triacylglycerol (TAG). To understand the features of genes encoding soybean (Glycine max) DGATs and possible roles in soybean seed oil synthesis and accumulation, two full-length cDNAs encoding type 1 diacylglycerol acyltransferases (GmDGAT1A and GmDGAT1B) were cloned from developing soybean seeds. These coding sequences share identities of 94 % and 95 % in protein and DNA sequences. The genomic architectures of GmDGAT1A and GmDGAT1B both contain 15 introns and 16 exons. Differences in the lengths of the first exon and most of the introns were found between GmDGAT1A and GmDGAT1B genomic sequences. Furthermore, detailed in silico analysis revealed a third predicted DGAT1, GmDGAT1C. GmDGAT1A and GmDGAT1B were found to have similar activity levels and substrate specificities. Oleoyl-CoA and sn-1,2-diacylglycerol were preferred substrates over vernoloyl-CoA and sn-1,2-divernoloylglycerol. Both transcripts are much more abundant in developing seeds than in other tissues including leaves, stem, roots, and flowers. Both soybean DGAT1A and DGAT1B are highly expressed at developing seed stages of maximal TAG accumulation with DGAT1B showing highest expression at somewhat later stages than DGAT1A. DGAT1A and DGAT1B show expression profiles consistent with important roles in soybean seed oil biosynthesis and accumulation. PMID:23322364

  16. Allostery and conformational dynamics in cAMP-binding acyltransferases.

    PubMed

    Podobnik, Marjetka; Siddiqui, Nida; Rebolj, Katja; Nambi, Subhalaxmi; Merzel, Franci; Visweswariah, Sandhya S

    2014-06-01

    Mycobacteria harbor unique proteins that regulate protein lysine acylation in a cAMP-regulated manner. These lysine acyltransferases from Mycobacterium smegmatis (KATms) and Mycobacterium tuberculosis (KATmt) show distinctive biochemical properties in terms of cAMP binding affinity to the N-terminal cyclic nucleotide binding domain and allosteric activation of the C-terminal acyltransferase domain. Here we provide evidence for structural features in KATms that account for high affinity cAMP binding and elevated acyltransferase activity in the absence of cAMP. Structure-guided mutational analysis converted KATms from a cAMP-regulated to a cAMP-dependent acyltransferase and identified a unique asparagine residue in the acyltransferase domain of KATms that assists in the enzymatic reaction in the absence of a highly conserved glutamate residue seen in Gcn5-related N-acetyltransferase-like acyltransferases. Thus, we have identified mechanisms by which properties of similar proteins have diverged in two species of mycobacteria by modifications in amino acid sequence, which can dramatically alter the abundance of conformational states adopted by a protein. PMID:24748621

  17. Thematic Review Series: Glycerolipids. Acyltransferases in bacterial glycerophospholipid synthesis*

    PubMed Central

    Zhang, Yong-Mei; Rock, Charles O.

    2008-01-01

    Phospholipid biosynthesis is a vital facet of bacterial physiology that begins with the synthesis of the fatty acids by a soluble type II fatty acid synthase. The bacterial glycerol-phosphate acyltransferases utilize the completed fatty acid chains to form the first membrane phospholipid and thus play a critical role in the regulation of membrane biogenesis. The first bacterial acyltransferase described was PlsB, a glycerol-phosphate acyltransferase. PlsB is a key regulatory point that coordinates membrane phospholipid formation with cell growth and macromolecular synthesis. Phosphatidic acid is then produced by PlsC, a 1-acylglycerol-phosphate acyltransferase. These two acyltransferases use thioesters of either CoA or acyl carrier protein (ACP) as the acyl donors and have homologs that perform the same reactions in higher organisms. However, the most prevalent glycerol-phosphate acyltransferase in the bacterial world is PlsY, which uses a recently discovered acyl-phosphate fatty acid intermediate as an acyl donor. This unique activated fatty acid is formed from the acyl-ACP end products of the fatty acid biosynthetic pathway by PlsX, an acyl-ACP:phosphate transacylase. PMID:18369234

  18. Human plasma lecithin-cholesterol acyltransferase

    SciTech Connect

    Jauhiainen, M.; Stevenson, K.J.; Dolphin, P.J.

    1988-05-15

    Lecithin-cholesterol acyltransferase (LCAT) is a plasma enzyme which catalyzes the transacylation of the fatty acid at the sn-2 position of lecithin to cholesterol forming lysolecithin and cholesteryl ester. The substrates for and products of this reaction are present within the plasma lipoproteins upon which the enzyme acts to form the majority of cholesteryl ester in human plasma. The authors proposed a covalent catalytic mechanism of action for LCAT in which serine and histidine residues mediate lecithin cleavage and two cysteine residues cholesterol esterification. With the aid of sulfhydryl reactive trivalent organoarsenical compounds which are specific for vicinal thiols they have probed the geometry of the catalytic site. They conclude that the two catalytic cysteine residues of LCAT (Cys/sup 31/ and Cys /sup 184/) are vicinal with a calculated distance between their sulfur atoms of 3.50-3.62 A. The additional residue alkylated by teh bifunctional reagent is within the catalytic site and may represent a previously identified catalytic serine or histidine residue.

  19. Lecithin retinol acyltransferase forms functional homodimers.

    PubMed

    Jahng, Wan Jin; Cheung, Eric; Rando, Robert R

    2002-05-21

    Membrane-bound lecithin retinol acyltransferase (LRAT), an essential enzyme in vitamin A processing, catalyzes the formation of retinyl esters from vitamin A and lecithin. Cloned and expressed LRAT has a molecular mass of 25.3 kDa. The enzyme is not homologous to known enzymes and is, therefore, of substantial interest mechanistically. Along these lines, the functional protomeric state of LRAT is of importance. Gel electrophoretic studies on LRAT in the presence of SDS and disulfide reducing agents show the expected 25 kDa monomer. However, gel electrophoresis in the absence of a reducing agent and/or strong denaturing conditions reveals substantial dimer formation. LRAT monomers can be efficiently and irreversibly cross-linked by thiol reactive bismaleimides in retinal pigment epithelial (RPE) membranes generating LRAT homodimers. Cross-linked LRAT homodimers are fully active catalytically. The experiments suggest that LRAT monomers interact in membranes and form functional homodimers through protein-protein interactions and disulfide bond formation. PMID:12009892

  20. Evolution of serine carboxypeptidase-like acyltransferases in the monocots

    PubMed Central

    Mugford, Sam T

    2010-01-01

    The serine carboxypeptidases are a large family of proteases. in higher plants some members of this family have diversified and adopted new functions as acyltransferases required for the synthesis of natural products. we recently reported the first serine carboxypeptidase-like (scpl) acyltransferase enzyme to be characterized from monocotyledonous plants.1 This enzyme, AsSCPL1, is required for acylation of antimicrobial terpenes (avenacins) that are produced in the roots of oat (Avena spp.) and that provide protection against soil-borne pathogens. The SCPL acyltransferase enzyme family has undergone substantial expansion following the divergence of monocots and dicots. Here we discuss the evolution of this SCPL enzyme family in monocots, their contribution to metabolic diversity, and the roles of these enzymes in biotic and abiotic stress tolerance. PMID:20173416

  1. Diacylglycerol Acyltransferase-2 (DGAT2) and Monoacylglycerol Acyltransferase-2 (MGAT2) Interact to Promote Triacylglycerol Synthesis*

    PubMed Central

    Jin, Youzhi; McFie, Pamela J.; Banman, Shanna L.; Brandt, Curtis; Stone, Scot J.

    2014-01-01

    Acyl CoA:1,2-diacylglycerol acyltransferase (DGAT)-2 is an integral membrane protein that catalyzes triacylglycerol (TG) synthesis using diacylglycerol and fatty acyl CoA as substrates. DGAT2 resides in the endoplasmic reticulum (ER), but when cells are incubated with fatty acids, DGAT2 interacts with lipid droplets presumably to catalyze localized TG synthesis for lipid droplet expansion. Previous studies have shown that DGAT2 interacts with proteins that synthesize its fatty acyl CoA substrates. In this study, we provide additional evidence that DGAT2 is present in a protein complex. Using a chemical cross-linker, disuccinimidyl suberate (DSS), we demonstrated that DGAT2 formed a dimer and was also part of a protein complex of ∼650 kDa, both in membranes and on lipid droplets. Using co-immunoprecipitation experiments and an in situ proximity ligation assay, we found that DGAT2 interacted with monoacylglycerol acyltransferase (MGAT)-2, an enzyme that catalyzes the synthesis of diacylglycerol. Deletion mutagenesis showed that the interaction with MGAT2 was dependent on the two transmembrane domains of DGAT2. No significant interaction of DGAT2 with lipin1, another enzyme that synthesizes diacylglycerol, could be detected. When co-expressed in cells, DGAT2 and MGAT2 co-localized in the ER and on lipid droplets. Co-expression also resulted in increased TG storage compared with expression of DGAT2 or MGAT2 alone. Incubating McArdle rat hepatoma RH7777 cells with 2-monoacylglycerol caused DGAT2 to translocate to lipid droplets. This also led to the formation of large cytosolic lipid droplets, characteristic of DGAT2, but not DGAT1, and indicated that DGAT2 can utilize monoacylglycerol-derived diacylglycerol. These findings suggest that the interaction of DGAT2 and MGAT2 serves to channel lipid substrates efficiently for TG biosynthesis. PMID:25164810

  2. Diacylglycerol acyltransferase-2 (DGAT2) and monoacylglycerol acyltransferase-2 (MGAT2) interact to promote triacylglycerol synthesis.

    PubMed

    Jin, Youzhi; McFie, Pamela J; Banman, Shanna L; Brandt, Curtis; Stone, Scot J

    2014-10-10

    Acyl CoA:1,2-diacylglycerol acyltransferase (DGAT)-2 is an integral membrane protein that catalyzes triacylglycerol (TG) synthesis using diacylglycerol and fatty acyl CoA as substrates. DGAT2 resides in the endoplasmic reticulum (ER), but when cells are incubated with fatty acids, DGAT2 interacts with lipid droplets presumably to catalyze localized TG synthesis for lipid droplet expansion. Previous studies have shown that DGAT2 interacts with proteins that synthesize its fatty acyl CoA substrates. In this study, we provide additional evidence that DGAT2 is present in a protein complex. Using a chemical cross-linker, disuccinimidyl suberate (DSS), we demonstrated that DGAT2 formed a dimer and was also part of a protein complex of ∼ 650 kDa, both in membranes and on lipid droplets. Using co-immunoprecipitation experiments and an in situ proximity ligation assay, we found that DGAT2 interacted with monoacylglycerol acyltransferase (MGAT)-2, an enzyme that catalyzes the synthesis of diacylglycerol. Deletion mutagenesis showed that the interaction with MGAT2 was dependent on the two transmembrane domains of DGAT2. No significant interaction of DGAT2 with lipin1, another enzyme that synthesizes diacylglycerol, could be detected. When co-expressed in cells, DGAT2 and MGAT2 co-localized in the ER and on lipid droplets. Co-expression also resulted in increased TG storage compared with expression of DGAT2 or MGAT2 alone. Incubating McArdle rat hepatoma RH7777 cells with 2-monoacylglycerol caused DGAT2 to translocate to lipid droplets. This also led to the formation of large cytosolic lipid droplets, characteristic of DGAT2, but not DGAT1, and indicated that DGAT2 can utilize monoacylglycerol-derived diacylglycerol. These findings suggest that the interaction of DGAT2 and MGAT2 serves to channel lipid substrates efficiently for TG biosynthesis. PMID:25164810

  3. Expression and purification of membrane protein diacylglycerol acyltransferase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferases (DGATs) catalyze the last and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Plants and animals deficient in DGATs accumulate less TAG. Over-expression of DGATs increases TAG in seeds and other tissues. DGAT knockout mice are resista...

  4. Expression and purification of recombinant tung tree diacylglycerol acyltransferase 2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferases (DGATs) catalyze the last step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Plants and animals deficient in DGATs accumulate less TAG. Over-expression of DGATs increases TAG. DGAT knockout mice are resistant to diet-induced obesity and lack milk secr...

  5. Purification of recombinant tung tree diacylglycerol acyltransferases from E. coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding plant oil biosynthesis will help to create new oilseed crops with value-added properties to replace petroleum-based compounds. Diacylglycerol acyltransferases (DGATs) are key enzymes catalyzing the last step of triacylglycerol (TAG) biosynthesis in eukaryotes. Over-expression of DGATs ...

  6. Expression of tung tree diacylglycerol acyltransferase 1 in E. coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferases (DGATs) catalyze the last step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGAT isoforms have nonredundant functions in TAG biosynthesis in species such as tung tree (Vernicia fordii) which contains 80% high-value eleostearic acid in its seed oils. ...

  7. Expression and purification of recombinant tung tree diacylglycerol acyltransferase 2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferases (DGATs) are responsible for the last step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Different forms of DGATs have nonredundant functions in TAG biosynthesis in species such as tung tree (Vernicia fordii), which contains approximately 80% high-valu...

  8. Lipoprotein products of lecithin: cholesterol acyltransferase and cholesteryl ester transfer.

    PubMed

    Rose, H G; Ellerbe, P

    1982-09-14

    High-density lipoprotein substrates and products of human plasma lecithin: cholesterol acyltransferase have been labelled with radioisotopic cholesteryl esters in order to facilitate identification. [3H]Cholesteryl esters were formed by endogenous HDL3/VHDL enzyme (d greater than 1.125 g/ml) following incubation with mixed vesicles of phosphatidylcholine, unesterified cholesterol and 3H-labelled unesterified cholesterol. Transfer of labelled esters to acceptor lipoproteins (VLDL+LDL, d less than 1.063 g/ml) was employed to distinguish a hypothetical transfer complex. Separation of labelled HDL3/VHDL was by gel-permeation chromatography. The results indicate that a subpopulation of labelled HDL3/VHDL cholesteryl esters (43-61% of total) were removed by VLDL/LDL during a 3 h transfer period and these derive from the smaller lipoproteins of the spectrum. HDL carrying non-transferable [3H]cholesteryl esters localize to the larger HDL3. Transfer rates were proportional to ratios of acceptor to donor lipoproteins. Net transfer of cholesteryl esters from the smaller HDL3 also occurred, but was smaller in magnitude (about 10.5% of total). Acyltransferase assays indicated that enzyme distribution is skewed to larger-sized HDL3, suggesting that the non-transferable components might be lecithin: cholesterol acyltransferase-containing parent complexes, while the smaller transfer products contain little acyltransferase. The results fit the hypothesis that a parent HDL3-lecithin: cholesterol acyltransferase complex generates a smaller-sized lipoprotein product which is active in cholesteryl ester transport. PMID:7126623

  9. Casein kinase II stimulates rat liver mitochondrial glycerophosphate acyltransferase activity.

    PubMed

    Onorato, Thomas M; Haldar, Dipak

    2002-09-01

    Rat liver mitochondrial glycerophosphate acyltransferase (mtGAT) possesses 14 consensus sites for casein kinase II (CKII) phosphorylation. To study the functional relevance of phosphorylation to the activity of mtGAT, we treated isolated rat liver mitochondria with CKII and found that CKII stimulated mtGAT activity approximately 2-fold. Protein phosphatase-lambda treatment reversed the stimulation of mtGAT by CKII. Labeling of both solubilized and non-solubilized mitochondria with CKII and [gamma-32P]ATP resulted in a 32P-labeled protein of 85kDa, the molecular weight of mtGAT. Our findings suggest that CKII stimulates mtGAT activity by phosphorylation of the acyltransferase. The significance of this observation with respect to hormonal control of the enzyme is discussed. PMID:12207885

  10. Inhibitors of Hedgehog acyltransferase block Sonic Hedgehog signaling.

    PubMed

    Petrova, Elissaveta; Rios-Esteves, Jessica; Ouerfelli, Ouathek; Glickman, J Fraser; Resh, Marilyn D

    2013-04-01

    Inhibition of Sonic hedgehog (Shh) signaling is of great clinical interest. Here we exploit Hedgehog acyltransferase (Hhat)-mediated Shh palmitoylation, a modification critical for Shh signaling, as a new target for Shh pathway inhibition. A target-oriented high-throughput screen was used to identify small-molecule inhibitors of Hhat. In cells, these Hhat inhibitors specifically block Shh palmitoylation and inhibit autocrine and paracrine Shh signaling. PMID:23416332

  11. Biosynthesis of phosphatidylcholine by human lysophosphatidylcholine acyltransferase 1.

    PubMed

    Harayama, Takeshi; Shindou, Hideo; Shimizu, Takao

    2009-09-01

    Pulmonary surfactant is a complex of phospholipids and proteins lining the alveolar walls of the lung. It reduces surface tension in the alveoli, and is critical for normal respiration. Pulmonary surfactant phospholipids consist mainly of phosphatidylcholine (PC) and phosphatidylglycerol (PG). Although the phospholipid composition of pulmonary surfactant is well known, the enzyme(s) involved in its biosynthesis have remained obscure. We previously reported the cloning of murine lysophosphatidylcholine acyltransferase 1 (mLPCAT1) as a potential biosynthetic enzyme of pulmonary surfactant phospholipids. mLPCAT1 exhibits lysophosphatidylcholine acyltransferase (LPCAT) and lysophosphatidylglycerol acyltransferase (LPGAT) activities, generating PC and PG, respectively. However, the enzymatic activity of human LPCAT1 (hLPCAT1) remains controversial. We report here that hLPCAT1 possesses LPCAT and LPGAT activities. The activity of hLPCAT1 was inhibited by N-ethylmaleimide, indicating the importance of some cysteine residue(s) for the catalysis. We found a conserved cysteine (Cys(211)) in hLPCAT1 that is crucial for its activity. Evolutionary analyses of the close homologs of LPCAT1 suggest that it appeared before the evolution of teleosts and indicate that LPCAT1 may have evolved along with the lung to facilitate respiration. hLPCAT1 mRNA is highly expressed in the human lung. We propose that hLPCAT1 is the biosynthetic enzyme of pulmonary surfactant phospholipids. PMID:19383981

  12. Mechanistic analysis of ghrelin-O-acyltransferase using substrate analogs.

    PubMed

    Taylor, Martin S; Dempsey, Daniel R; Hwang, Yousang; Chen, Zan; Chu, Nam; Boeke, Jef D; Cole, Philip A

    2015-10-01

    Ghrelin-O-Acyltransferase (GOAT) is an 11-transmembrane integral membrane protein that octanoylates the metabolism-regulating peptide hormone ghrelin at Ser3 and may represent an attractive target for the treatment of type II diabetes and the metabolic syndrome. Protein octanoylation is unique to ghrelin in humans, and little is known about the mechanism of GOAT or of related protein-O-acyltransferases HHAT or PORC. In this study, we explored an in vitro microsomal ghrelin octanoylation assay to analyze its enzymologic features. Measurement of Km for 10-mer, 27-mer, and synthetic Tat-peptide-containing ghrelin substrates provided evidence for a role of charge interactions in substrate binding. Ghrelin substrates with amino-alanine in place of Ser3 demonstrated that GOAT can catalyze the formation of an octanoyl-amide bond at a similar rate compared with the natural reaction. A pH-rate comparison of these substrates revealed minimal differences in acyltransferase activity across pH 6.0-9.0, providing evidence that these reactions may be relatively insensitive to the basicity of the substrate nucleophile. The conserved His338 residue was required both for Ser3 and amino-Ala3 ghrelin substrates, suggesting that His338 may have a key catalytic role beyond that of a general base. PMID:26246082

  13. Glycerolipid biosynthesis in Saccharomyces cerevisiae: sn-glycerol-3-phosphate and dihydroxyacetone phosphate acyltransferase activities.

    PubMed Central

    Schlossman, D M; Bell, R M

    1978-01-01

    Yeast acyl-coenzyme A:dihydroxyacetone-phosphate O-acyltransferase (DHAP acyltransferase; EC 2.3.1.42) was investigated to (i) determine whether its activity and that of acyl-coenzyme A:sn-glycerol-3-phosphate O-acyltransferase (glycerol-P acyltransferase; EC 2.3.1.15) represent dual catalytic functions of a single membranous enzyme, (ii) estimate the relative contributions of the glycerol-P and DHAP pathways for yeast glycerolipid synthesis, and (iii) evaluate the suitability of yeast for future genetic investigations of the eucaryotic glycerol-P and DHAP acyltransferase activities. The membranous DHAP acyltransferase activity showed an apparent Km of 0.79 mM for DHAP, with a Vmax of 5.3 nmol/min per mg, whereas the glycerol-P acyltransferase activity showed an apparent Km of 0.05 mM for glycerol-P, with a Vmax of 3.4 nmol/min per mg. Glycerol-P was a competitive inhibitor (Ki, 0.07 mM) of the DHAP acyltransferase activity, and DHAP was a competitive inhibitor (Ki, 0.91 mM) of the glycerol-P acyltransferase activity. The two acyltransferase activities exhibited marked similarities in their pH dependence, acyl-coenzyme A chain length preference and substrate concentration dependencies, thermolability, and patterns of inactivation by N-ethylmaleimide, trypsin, and detergents. Thus, the data strongly suggest that yeast glycerol-P and DHAP acyltransferase activities represent dual catalytic functions of a single membrane-bound enzyme. Furthermore, since no acyl-DHAP oxidoreductase activity could be detected in yeast membranes, the DHAP pathway for glycerolipid synthesis may not operate in yeast. PMID:25265

  14. Elucidation of a key position for acyltransfer activity in Candida parapsilosis lipase/acyltransferase (CpLIP2) and in Pseudozyma antarctica lipase A (CAL-A) by rational design.

    PubMed

    Jan, Anne-Hélène; Subileau, Maeva; Deyrieux, Charlotte; Perrier, Véronique; Dubreucq, Éric

    2016-02-01

    Performing transesterifications in aqueous media is becoming a priority challenge in lipid biotechnology in order to develop more eco-friendly and efficient biocatalytic processes in systems containing both polar and apolar substrates. In this context, our group has explored for several years the high potential of the lipase/acyltransferase CpLIP2 from Candida parapsilosis and of several of its homologs, that catalyze efficiently acyltransfer reactions in lipid/water media with high water activity (aw>0.9). The discovery of a new member of this group, CduLAc from Candida dubliniensis, with a higher acyltransferase activity than CpLIP2, has provided a new insight on structure-function relationships in this group. Indeed, the comparison of sequences and 3D models, especially of CpLIP2 and CduLAc, with those of the phylogenetically related lipase A from Pseudozyma antarctica (CAL-A), allowed elucidating a key structural determinant of the acyltransferase activity: serine S369 in CpLIP2 and its equivalents E370 in CAL-A and A366 in CduLAc. Mutants obtained by rational design at this key position showed significant changes in acyltransfer activity. Whereas mutation S369E resulted in an increase in the hydrolytic activity of CpLIP2, S369A increased alcoholysis. More strikingly, the single E370A mutation in CAL-A drastically increased the acyltransferase activity of this enzyme, giving it the character of a lipase/acyltransferase. Indeed, this single mutation lowered the methanol concentration for which the initial rates of alcoholysis and hydrolysis are equal from 2M in CAL-A down to 0.3M in its mutant, while the exceptional stability of the parental enzyme toward alcohol and temperature was conserved. PMID:26602447

  15. Alcoholism and Alcohol Abuse

    MedlinePlus

    ... This means that their drinking causes distress and harm. It includes alcoholism and alcohol abuse. Alcoholism, or ... brain, and other organs. Drinking during pregnancy can harm your baby. Alcohol also increases the risk of ...

  16. Topological Analysis of Hedgehog Acyltransferase, a Multipalmitoylated Transmembrane Protein*

    PubMed Central

    Konitsiotis, Antonio D.; Jovanović, Biljana; Ciepla, Paulina; Spitaler, Martin; Lanyon-Hogg, Thomas; Tate, Edward W.; Magee, Anthony I.

    2015-01-01

    Hedgehog proteins are secreted morphogens that play critical roles in development and disease. During maturation of the proteins through the secretory pathway, they are modified by the addition of N-terminal palmitic acid and C-terminal cholesterol moieties, both of which are critical for their correct function and localization. Hedgehog acyltransferase (HHAT) is the enzyme in the endoplasmic reticulum that palmitoylates Hedgehog proteins, is a member of a small subfamily of membrane-bound O-acyltransferase proteins that acylate secreted proteins, and is an important drug target in cancer. However, little is known about HHAT structure and mode of function. We show that HHAT is comprised of ten transmembrane domains and two reentrant loops with the critical His and Asp residues on opposite sides of the endoplasmic reticulum membrane. We further show that HHAT is palmitoylated on multiple cytosolic cysteines that maintain protein structure within the membrane. Finally, we provide evidence that mutation of the conserved His residue in the hypothesized catalytic domain results in a complete loss of HHAT palmitoylation, providing novel insights into how the protein may function in vivo. PMID:25505265

  17. Topological analysis of Hedgehog acyltransferase, a multipalmitoylated transmembrane protein.

    PubMed

    Konitsiotis, Antonio D; Jovanović, Biljana; Ciepla, Paulina; Spitaler, Martin; Lanyon-Hogg, Thomas; Tate, Edward W; Magee, Anthony I

    2015-02-01

    Hedgehog proteins are secreted morphogens that play critical roles in development and disease. During maturation of the proteins through the secretory pathway, they are modified by the addition of N-terminal palmitic acid and C-terminal cholesterol moieties, both of which are critical for their correct function and localization. Hedgehog acyltransferase (HHAT) is the enzyme in the endoplasmic reticulum that palmitoylates Hedgehog proteins, is a member of a small subfamily of membrane-bound O-acyltransferase proteins that acylate secreted proteins, and is an important drug target in cancer. However, little is known about HHAT structure and mode of function. We show that HHAT is comprised of ten transmembrane domains and two reentrant loops with the critical His and Asp residues on opposite sides of the endoplasmic reticulum membrane. We further show that HHAT is palmitoylated on multiple cytosolic cysteines that maintain protein structure within the membrane. Finally, we provide evidence that mutation of the conserved His residue in the hypothesized catalytic domain results in a complete loss of HHAT palmitoylation, providing novel insights into how the protein may function in vivo. PMID:25505265

  18. Structure of a bacterial toxin-activating acyltransferase

    PubMed Central

    Greene, Nicholas P.; Hughes, Colin; Koronakis, Vassilis

    2015-01-01

    Secreted pore-forming toxins of pathogenic Gram-negative bacteria such as Escherichia coli hemolysin (HlyA) insert into host–cell membranes to subvert signal transduction and induce apoptosis and cell lysis. Unusually, these toxins are synthesized in an inactive form that requires posttranslational activation in the bacterial cytosol. We have previously shown that the activation mechanism is an acylation event directed by a specialized acyl-transferase that uses acyl carrier protein (ACP) to covalently link fatty acids, via an amide bond, to specific internal lysine residues of the protoxin. We now reveal the 2.15-Å resolution X-ray structure of the 172-aa ApxC, a toxin-activating acyl-transferase (TAAT) from pathogenic Actinobacillus pleuropneumoniae. This determination shows that bacterial TAATs are a structurally homologous family that, despite indiscernible sequence similarity, form a distinct branch of the Gcn5-like N-acetyl transferase (GNAT) superfamily of enzymes that typically use acyl-CoA to modify diverse bacterial, archaeal, and eukaryotic substrates. A combination of structural analysis, small angle X-ray scattering, mutagenesis, and cross-linking defined the solution state of TAATs, with intermonomer interactions mediated by an N-terminal α-helix. Superposition of ApxC with substrate-bound GNATs, and assay of toxin activation and binding of acyl-ACP and protoxin peptide substrates by mutated ApxC variants, indicates the enzyme active site to be a deep surface groove. PMID:26016525

  19. Radioassay of the stereospecificity of 2-monoacylglycerol acyltransferase

    SciTech Connect

    Manganaro, F.; Kuksis, A.; Myher, J.J.

    1982-01-01

    The 2-monoacylglycerol acyltransferase (EC 2.3.1.22, acylglycerol palmitoyl transferase) catalyzes the synthesis of X-1,2-diacylglycerols from 2-monoacylglycerol and acyl CoA with an apparently variable stereochemical specificity. A microassay for determining the ratio of sn-1,2- and sn-2,3-diacylglycerol formed by the acylation of radioactive 2-monoacylglycerol in intact cell or in cell-free systems in the presence of free fatty acids and cofactors has been developed. The diacyglycerols isolated by thin-layer chromatography using nonradioactive racemic diacylglycerols as carriers. The enantiomer content is determined following a chemical synthesis of X-1,2-diacylphosphatidylcholines and a stereospecific stepwise release of the sn-1,2- and sn-2,3-diacylglycerols by phospholipase C. By using thin-layer chromatography for the isolation of the hydrolysis products, known samples ranging in enantiomer ratios from 0.05 to 20 and containing 5000 to 200,000 cpm can be assayed to within 1% of the major and within 10% of the minor enantiomer content. The method is applicable to the determination of the enantiomer content of X-1,2-diacylglycerols generated via other acyltransferases and via lipolysis of triacylglycerols and diacylglycerolphospholipids in other biological systems.

  20. Lysophospholipid acyltransferases and eicosanoid biosynthesis in zebrafish myeloid cells.

    PubMed

    Zarini, Simona; Hankin, Joseph A; Murphy, Robert C; Gijón, Miguel A

    2014-10-01

    Eicosanoids derived from the enzymatic oxidation of arachidonic acid play important roles in a large number of physiological and pathological processes in humans. Many animal and cellular models have been used to investigate the intricate mechanisms regulating their biosynthesis and actions. Zebrafish is a widely used model to study the embryonic development of vertebrates. It expresses homologs of the key enzymes involved in eicosanoid production, and eicosanoids have been detected in extracts from adult or embryonic fish. In this study we prepared cell suspensions from kidney marrow, the main hematopoietic organ in fish. Upon stimulation with calcium ionophore, these cells produced eicosanoids including PGE2, LTB4, 5-HETE and, most abundantly, 12-HETE. They also produced small amounts of LTB5 derived from eicosapentaenoic acid. These eicosanoids were also produced in kidney marrow cells stimulated with ATP, and this production was greatly enhanced by preincubation with thimerosal, an inhibitor of arachidonate reacylation into phospholipids. Microsomes from these cells exhibited acyltransferase activities consistent with expression of MBOAT5/LPCAT3 and MBOAT7/LPIAT1, the main arachidonoyl-CoA:lysophospholipid acyltransferases. In summary, this work introduces a new cellular model to study the regulation of eicosanoid production through a phospholipid deacylation-reacylation cycle from a well-established, versatile vertebrate model species. PMID:25175316

  1. Lysophosphatidylethanolamine acyltransferase 1/membrane-bound O-acyltransferase 1 regulates morphology and function of P19C6 cell-derived neurons.

    PubMed

    Tabe, Shirou; Hikiji, Hisako; Ariyoshi, Wataru; Hashidate-Yoshida, Tomomi; Shindou, Hideo; Okinaga, Toshinori; Shimizu, Takao; Tominaga, Kazuhiro; Nishihara, Tatsuji

    2016-07-01

    Glycerophospholipids, which are components of biomembranes, are formed de novo by the Kennedy pathway and subsequently mature through the Lands cycle. Lysophospholipid acyltransferases (LPLATs) are key enzymes in both pathways and influence the fatty acid composition of biomembranes. Neuronal differentiation is characterized by neurite outgrowth, which requires biomembrane biosynthesis. However, the role of LPLATs in neuronal differentiation remains unknown. In this study, we examined whether LPLATs are involved in neuronal differentiation using all-trans-retinoic acid (ATRA)-treated P19C6 cells. In these cells, mRNA levels of lysophosphatidylethanolamine acyltransferase (LPEAT)-1/membrane-bound O-acyltransferase (MBOAT)-1 were higher than those in undifferentiated cells. LPEAT enzymatic activity increased with 16:0- and 18:1-CoA as acyl donors. When LPEAT1/MBOAT1 was knocked down with small interfering RNA (siRNA), outgrowth of neurites and expression of neuronal markers decreased in ATRA-treated P19C6 cells. Voltage-dependent calcium channel activity was also suppressed in these cells transfected with LPEAT1/MBOAT1 siRNA. These results suggest that LPEAT1/MBOAT1 plays an important role in neurite outgrowth and function.-Tabe, S., Hikiji, H., Ariyoshi, W., Hashidate-Yoshida, T., Shindou, H., Okinaga, T., Shimizu, T., Tominaga, K., Nishihara, T. Lysophosphatidylethanolamine acyltransferase 1/membrane-bound O-acyltransferase 1 regulates morphology and function of P19C6 cell-derived neurons. PMID:27048541

  2. [Sn-glycerol-3-phosphate acyltransferases (GPATs) in plants].

    PubMed

    Liu, Cong; Xiao, Dan-Wang; Shi, Chun-Lin; Hu, Xue-Fang; Wu, Ke-Bin; Guan, Chun-Yun; Xiong, Xing-Hua

    2013-12-01

    Sn-glycerol-3-phosphate acyltransferase (GPAT) catalyzes the acylation at sn-1 position of glycerol-3-phosphate to produce lysophosphatidic acid (LPA) in an acyl-CoA or acyl-ACP-dependent manner, which is the initial and rate-determining step of TAG biosynthetic pathway. Some GPATs have sn-2 transfer activity. Part members of the GPAT gene family have been cloned from different plant species. Based on their subcellular localizations, GPATs can be classified into three types, plastid GPATs, mitochondria GPATs and endoplasmic reticulum GPATs. GPATs exhibit diverse biochemical properties and are involved in synthesis of several lipids such as TAG, suberin, and cutin which play important roles in the growth and development of plants. This review summarized the current understanding of the chromosomal locus and gene structure of GPAT genes and the subcellular localization, sn-2 regiospecificity, substrates specialty, and functions of GPATs in plants. PMID:24645344

  3. Selective inhibitors of a PAF biosynthetic enzyme lysophosphatidylcholine acyltransferase 2.

    PubMed

    Tarui, Megumi; Shindou, Hideo; Kumagai, Kazuo; Morimoto, Ryo; Harayama, Takeshi; Hashidate, Tomomi; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Nagase, Takahide; Shimizu, Takao

    2014-07-01

    Platelet-activating factor (PAF) is a potent pro-inflammatory phospholipid mediator. In response to extracellular stimuli, PAF is rapidly biosynthesized by lyso-PAF acetyltransferase (lyso-PAFAT). Previously, we identified two types of lyso-PAFATs: lysophosphatidylcholine acyltransferase (LPCAT)1, mostly expressed in the lungs where it produces PAF and dipalmitoyl-phosphatidylcholine essential for respiration, and LPCAT2, which biosynthesizes PAF and phosphatidylcholine (PC) in the inflammatory cells. Under inflammatory conditions, LPCAT2, but not LPCAT1, is activated and upregulated to produce PAF. Thus, it is important to develop inhibitors specific for LPCAT2 in order to ameliorate PAF-related inflammatory diseases. Here, we report the first identification of LPCAT2-specific inhibitors, N-phenylmaleimide derivatives, selected from a 174,000-compound library using fluorescence-based high-throughput screening followed by the evaluation of the effects on LPCAT1 and LPCAT2 activities, cell viability, and cellular PAF production. Selected compounds competed with acetyl-CoA for the inhibition of LPCAT2 lyso-PAFAT activity and suppressed PAF biosynthesis in mouse peritoneal macrophages stimulated with a calcium ionophore. These compounds had low inhibitory effects on LPCAT1 activity, indicating that adverse effects on respiratory functions may be avoided. The identified compounds and their derivatives will contribute to the development of novel drugs for PAF-related diseases and facilitate the analysis of LPCAT2 functions in phospholipid metabolism in vivo. PMID:24850807

  4. Engineering the acyltransferase substrate specificity of assembly line polyketide synthases.

    PubMed

    Dunn, Briana J; Khosla, Chaitan

    2013-08-01

    Polyketide natural products act as a broad range of therapeutics, including antibiotics, immunosuppressants and anti-cancer agents. This therapeutic diversity stems from the structural diversity of these small molecules, many of which are produced in an assembly line manner by modular polyketide synthases. The acyltransferase (AT) domains of these megasynthases are responsible for selection and incorporation of simple monomeric building blocks, and are thus responsible for a large amount of the resulting polyketide structural diversity. The substrate specificity of these domains is often targeted for engineering in the generation of novel, therapeutically active natural products. This review outlines recent developments that can be used in the successful engineering of these domains, including AT sequence and structural data, mechanistic insights and the production of a diverse pool of extender units. It also provides an overview of previous AT domain engineering attempts, and concludes with proposed engineering approaches that take advantage of current knowledge. These approaches may lead to successful production of biologically active 'unnatural' natural products. PMID:23720536

  5. Molecular evolution of the lysophosphatidic acid acyltransferase (LPAAT) gene family.

    PubMed

    Körbes, Ana Paula; Kulcheski, Franceli Rodrigues; Margis, Rogério; Margis-Pinheiro, Márcia; Turchetto-Zolet, Andreia Carina

    2016-03-01

    Lysophosphatidic acid acyltransferases (LPAATs) perform an essential cellular function by controlling the production of phosphatidic acid (PA), a key intermediate in the synthesis of membrane, signaling and storage lipids. Although LPAATs have been extensively explored by functional and biotechnological studies, little is known about their molecular evolution and diversification. We performed a genome-wide analysis using data from several plants and animals, as well as other eukaryotic and prokaryotic species, to identify LPAAT genes and analyze their evolutionary history. We used phylogenetic and molecular evolution analysis to test the hypothesis of distinct origins for these genes. The reconstructed phylogeny supported the ancient origin of some isoforms (plant LPAAT1 and LPAATB; animal AGPAAT1/2), while others emerged more recently (plant LPAAT2/3/4/5; AGPAAT3/4/5/8). Additionally, the hypothesis of endosymbiotic origin of the plastidic isoform LPAAT1 was confirmed. LPAAT genes from plants and animals mainly experienced strong purifying selection pressures with limited functional divergence after the species-specific duplications. Gene expression analyses of LPAAT isoforms in model plants demonstrated distinct LPAAT expression patterns in these organisms. The results showed that distinct origins followed by diversification of the LPAAT genes shaped the evolution of TAG biosynthesis. The expression pattern of individual genes may be responsible for adaptation into multiple ecological niches. PMID:26721558

  6. High-Density Lipoprotein, Lecithin: Cholesterol Acyltransferase, and Atherosclerosis

    PubMed Central

    Ossoli, Alice; Pavanello, Chiara

    2016-01-01

    Epidemiological data clearly show the existence of a strong inverse correlation between plasma high-density lipoprotein cholesterol (HDL-C) concentrations and the incidence of coronary heart disease. This relation is explained by a number of atheroprotective properties of HDL, first of all the ability to promote macrophage cholesterol transport. HDL are highly heterogeneous and are continuously remodeled in plasma thanks to the action of a number of proteins and enzymes. Among them, lecithin:cholesterol acyltransferase (LCAT) plays a crucial role, being the only enzyme able to esterify cholesterol within lipoproteins. LCAT is synthetized by the liver and it has been thought to play a major role in reverse cholesterol transport and in atheroprotection. However, data from animal studies, as well as human studies, have shown contradictory results. Increased LCAT concentrations are associated with increased HDL-C levels but not necessarily with atheroprotection. On the other side, decreased LCAT concentration and activity are associated with decreased HDL-C levels but not with increased atherosclerosis. These contradictory results confirm that HDL-C levels per se do not represent the functionality of the HDL system. PMID:27302716

  7. High-Density Lipoprotein, Lecithin: Cholesterol Acyltransferase, and Atherosclerosis.

    PubMed

    Ossoli, Alice; Pavanello, Chiara; Calabresi, Laura

    2016-06-01

    Epidemiological data clearly show the existence of a strong inverse correlation between plasma high-density lipoprotein cholesterol (HDL-C) concentrations and the incidence of coronary heart disease. This relation is explained by a number of atheroprotective properties of HDL, first of all the ability to promote macrophage cholesterol transport. HDL are highly heterogeneous and are continuously remodeled in plasma thanks to the action of a number of proteins and enzymes. Among them, lecithin:cholesterol acyltransferase (LCAT) plays a crucial role, being the only enzyme able to esterify cholesterol within lipoproteins. LCAT is synthetized by the liver and it has been thought to play a major role in reverse cholesterol transport and in atheroprotection. However, data from animal studies, as well as human studies, have shown contradictory results. Increased LCAT concentrations are associated with increased HDL-C levels but not necessarily with atheroprotection. On the other side, decreased LCAT concentration and activity are associated with decreased HDL-C levels but not with increased atherosclerosis. These contradictory results confirm that HDL-C levels per se do not represent the functionality of the HDL system. PMID:27302716

  8. Adiponutrin Functions as a Nutritionally Regulated Lysophosphatidic Acid Acyltransferase

    PubMed Central

    Kumari, Manju; Schoiswohl, Gabriele; Chitraju, Chandramohan; Paar, Margret; Cornaciu, Irina; Rangrez, Ashraf Y.; Wongsiriroj, Nuttaporn; Nagy, Harald M.; Ivanova, Pavlina T.; Scott, Sarah A.; Knittelfelder, Oskar; Rechberger, Gerald N.; Birner-Gruenberger, Ruth; Eder, Sandra; Brown, H. Alex; Haemmerle, Guenter; Oberer, Monika; Lass, Achim; Kershaw, Erin E.; Zimmermann, Robert; Zechner, Rudolf

    2012-01-01

    SUMMARY Numerous studies in humans link a nonsynonymous genetic polymorphism (I148M) in adiponutrin (ADPN) to various forms of fatty liver disease and liver cirrhosis. Despite its high clinical relevance, the molecular function of ADPN and the mechanism by which I148M variant affects hepatic metabolism are unclear. Here we show that ADPN promotes cellular lipid synthesis by converting lysophosphatidic acid (LPA) into phosphatidic acid. The ADPN-catalyzed LPA acyltransferase (LPAAT) reaction is specific for LPA and long-chain acyl-CoAs. Wild-type mice receiving a high-sucrose diet exhibit substantial upregulation of Adpn in the liver and a concomitant increase in LPAAT activity. In Adpn-deficient mice, this diet-induced increase in hepatic LPAAT activity is reduced. Notably, the I148M variant of human ADPN exhibits increased LPAAT activity leading to increased cellular lipid accumulation. This gain of function provides a plausible biochemical mechanism for the development of liver steatosis in subjects carrying the I148M variant. PMID:22560221

  9. Engineering the acyltransferase substrate specificity of assembly line polyketide synthases

    PubMed Central

    Dunn, Briana J.; Khosla, Chaitan

    2013-01-01

    Polyketide natural products act as a broad range of therapeutics, including antibiotics, immunosuppressants and anti-cancer agents. This therapeutic diversity stems from the structural diversity of these small molecules, many of which are produced in an assembly line manner by modular polyketide synthases. The acyltransferase (AT) domains of these megasynthases are responsible for selection and incorporation of simple monomeric building blocks, and are thus responsible for a large amount of the resulting polyketide structural diversity. The substrate specificity of these domains is often targeted for engineering in the generation of novel, therapeutically active natural products. This review outlines recent developments that can be used in the successful engineering of these domains, including AT sequence and structural data, mechanistic insights and the production of a diverse pool of extender units. It also provides an overview of previous AT domain engineering attempts, and concludes with proposed engineering approaches that take advantage of current knowledge. These approaches may lead to successful production of biologically active ‘unnatural’ natural products. PMID:23720536

  10. Alcohol Alert

    MedlinePlus

    ... main content National Institute on Alcohol Abuse and Alcoholism (NIAAA) Main Menu Search Search form Search Alcohol & ... on a single aspect of alcohol abuse and alcoholism. Please click on the desired publication for full ...

  11. A close look at a ketosynthase from a trans-acyltransferase modular polyketide synthase

    PubMed Central

    Gay, Darren C.; Gay, Glen; Axelrod, Abram J.; Jenner, Matthew; Kohlhaas, Christoph; Kampa, Annette; Oldham, Neil J.; Piel, Jörn; Keatinge-Clay, Adrian T.

    2014-01-01

    SUMMARY The recently discovered trans-acyltransferase modular polyketide synthases catalyze the biosynthesis of a wide range of bioactive natural products in bacteria. Here we report the structure of the second ketosynthase from the bacillaene trans-acyltransferase polyketide synthase. This 1.95 Å-resolution structure provides the highest resolution view available of a modular polyketide synthase ketosynthase and reveals a flanking subdomain that is homologous to an ordered linker in cis-acyltransferase modular polyketide synthases. The structure of the cysteine-to-serine mutant of the ketosynthase acylated by its natural substrate provides high-resolution details of how a native polyketide intermediate is bound and helps explain the basis of ketosynthase substrate specificity. The substrate range of the ketosynthase was further investigated by mass spectrometry. PMID:24508341

  12. Alcoholism, Alcohol, and Drugs

    ERIC Educational Resources Information Center

    Rubin, Emanuel; Lieber, Charles S.

    1971-01-01

    Describes research on synergistic effects of alcohol and other drugs, particularly barbiturates. Proposes biochemical mechanisms to explain alcoholics' tolerance of other drugs when sober, and increased sensitivity when drunk. (AL)

  13. Membrane topology of murine glycerol-3-phosphate acyltransferase 2.

    PubMed

    Nakagawa, Tadahiko; Harada, Nagakatsu; Miyamoto, Aiko; Kawanishi, Yukiko; Yoshida, Masaki; Shono, Masayuki; Mawatari, Kazuaki; Takahashi, Akira; Sakaue, Hiroshi; Nakaya, Yutaka

    2012-02-17

    Glycerol-3-phosphate acyltransferase (GPAT) is a rate-limiting enzyme in mammalian triacylglycerol biosynthesis. GPAT is a target for the treatment of metabolic disorders associated with high lipid accumulation. Although the molecular basis for GPAT1 activation has been investigated extensively, the activation of other isoforms, such as GPAT2, is less well understood. Here the membrane topology of the GPAT2 protein was examined using an epitope-tag-based method. Exogenously expressed GPAT2 protein was present in the membrane fraction of transformed HEK293 cells even in the presence of Na(2)CO(3) (100 mM), indicating that GPAT2 is a membrane-bound protein. Trypsin treatment of the membrane fraction degraded the N-terminal (FLAG) and C-terminal (myc-epitope) protein tags of the GPAT2 protein. Bioinformatic analysis of the GPAT2 protein sequence indicated four hydrophobic sequences as potential membrane-spanning regions (TM1-TM4). Immunoblotting of the myc-epitope tag, which was inserted between each TM region of the GPAT2 protein, showed that the amino acid sequence between TM3 and TM4 was protected from trypsin digestion. These results suggest that the GPAT2 protein has two transmembrane segments and that the N-terminal and C-terminal regions of this protein face the cytoplasm. These results also suggest that the enzymatically active motifs I-III of the GPAT2 protein face the cytosol, while motif IV is within the membrane. It is expected that the use of this topological model of GPAT2 will be essential in efforts to elucidate the molecular mechanisms of GPAT2 activity in mammalian cells. PMID:22285183

  14. Topology of 1-Acyl-sn-glycerol-3-phosphate Acyltransferases SLC1 and ALE1 and Related Membrane-bound O-Acyltransferases (MBOATs) of Saccharomyces cerevisiae*

    PubMed Central

    Pagac, Martin; de la Mora, Hector Vazquez; Duperrex, Cécile; Roubaty, Carole; Vionnet, Christine; Conzelmann, Andreas

    2011-01-01

    In yeast, phosphatidic acid, the biosynthetic precursor for all glycerophospholipids and triacylglycerols, is made de novo by the 1-acyl-sn-glycerol-3-phosphate acyltransferases Ale1p and Slc1p. Ale1p belongs to the membrane-bound O-acyltransferase (MBOAT) family, which contains many enzymes acylating lipids but also others that acylate secretory proteins residing in the lumen of the ER. A histidine present in a very short loop between two predicted transmembrane domains is the only residue that is conserved throughout the MBOAT gene family. The yeast MBOAT proteins of known function comprise Ale1p, the ergosterol acyltransferases Are1p and Are2p, and Gup1p, the last of which acylates lysophosphatidylinositol moieties of GPI anchors on ER lumenal GPI proteins. C-terminal topology reporters added to truncated versions of Gup1p yield a topology predicting a lumenal location of its uniquely conserved histidine 447 residue. The same approach shows that Ale1p and Are2p also have the uniquely conserved histidine residing in the ER lumen. Because these data raised the possibility that phosphatidic acid could be made in the lumen of the ER, we further investigated the topology of the second yeast 1-acyl-sn-glycerol-3-phosphate acyltransferase, Slc1p. The location of C-terminal topology reporters, microsomal assays probing the protease sensitivity of inserted tags, and the accessibility of natural or artificially inserted cysteines to membrane-impermeant alkylating agents all indicate that the most conserved motif containing the presumed active site histidine of Slc1p is oriented toward the ER lumen, whereas other conserved motifs are cytosolic. The implications of these findings are discussed. PMID:21849510

  15. Castor diacylglycerol acyltransferase type1(DGAT1)displays greater activity with diricinolein than Arabidopsis DGAT1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Castor oil contains the hydroxy fatty acid ricinoleate as a major (90%) component. The diacylglycerol acyltransferase (DGAT) carries out the final reaction step in the biosynthesis of triacylglycerol, the principal constituent of seed oil, and has been considered to be the step that controls the oil...

  16. Structure-function analysis of diacylglycerol acyltransferase sequences from tung tree and 82 other Organisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferase family (DGATs) catalyzes the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGATs esterify sn-1,2-diacylglycerol with a long-chain fatty acyl-CoA. Understanding the roles of DGATs will help to create transgenic plants with v...

  17. Developmental regulation of diacylglycerol acyltransferase family gene expression in tung tree tissues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferases (DGAT) are responsible for the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGAT genes have been identified in numerous organisms. Multiple isoforms of DGAT are present in eukaryotes, including DGAT1 and DGAT2 of tung tre...

  18. Structure-function analysis of diacylglycerol acyltransferase sequences from 70 organisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferases (DGATs) catalyze the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Understanding the roles of DGATs will help to create transgenic plants with value-added properties and provide clues for therapeutic intervention for obes...

  19. A Bifunctional Enzyme That Has Both Monoacylglycerol Acyltransferase and Acyl Hydrolase Activities1[W][OA

    PubMed Central

    Vijayaraj, Panneerselvam; Jashal, Charnitkaur B.; Vijayakumar, Anitha; Rani, Sapa Hima; Venkata Rao, D.K.; Rajasekharan, Ram

    2012-01-01

    Monoacylglycerol acyltransferase (MGAT) catalyzes the synthesis of diacylglycerol, the precursor of triacylglycerol biosynthesis and an important signaling molecule. Here, we describe the isolation and characterization of the peanut (Arachis hypogaea) MGAT gene. The soluble enzyme utilizes invariant histidine-62 and aspartate-67 residues of the acyltransferase motif for its MGAT activity. A sequence analysis revealed the presence of a hydrolase (GXSXG) motif, and enzyme assays revealed the presence of monoacylglycerol (MAG) and lysophosphatidylcholine (LPC) hydrolytic activities, indicating the bifunctional nature of the enzyme. The overexpression of the MGAT gene in yeast (Saccharomyces cerevisiae) caused an increase in triacylglycerol accumulation. Similar to the peanut MGAT, the Arabidopsis (Arabidopsis thaliana) homolog (At1g52760) also exhibited both acyltransferase and hydrolase activities. Interestingly, the yeast homolog lacks the conserved HX4D motif, and it is deficient in the acyltransferase function but exhibits MAG and LPC hydrolase activities. This study demonstrates the presence of a soluble MGAT/hydrolase in plants. The predicted three-dimensional homology modeling and substrate docking suggested the presence of two separate substrate (MAG and LPC)-binding sites in a single polypeptide. Our study describes a soluble bifunctional enzyme that has both MGAT and hydrolase functions. PMID:22915575

  20. Draft Genome Sequence of an Endophytic Actinoplanes Species, Encoding Uncommon trans-Acyltransferase Polyketide Synthases

    PubMed Central

    Centeno-Leija, Sara; Vinuesa, Pablo; Rodríguez-Peña, Karol; Trenado-Uribe, Miriam; Cárdenas-Conejo, Yair; Serrano-Posada, Hugo; Rodríguez-Sanoja, Romina

    2016-01-01

    Actinoplanes is an endophytic actinobacterium isolated from the medicinal plant Amphipterygium adstringens. The strain draft genome sequence reveals a gene cluster involved in the biosynthesis of a hybrid trans-acyltransferase (AT) polyketide, an unconventional bioactive metabolite never reported before in the genus Actinoplanes. PMID:27013046

  1. Structure-function analysis of diacylglycerol acyltransferase sequences for metabolic engineering and drug discovery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferase families (DGATs) catalyze the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGAT knockout mice are resistant to diet-induced obesity and lack milk secretion. Over-expression of DGATs increases TAG in plants. Therefore, unde...

  2. Expression of tung seed diacylglycerol acyltransferases (DGAT) in E. coli and yeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diacylglycerol acyltransferases (DGATs) catalyze the last step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Plants and animals deficient in DGATs accumulate less TAG, resist obesity, and/or lack milk secretion. Over-expression of the DGATs increases TAG content in seeds and other t...

  3. Alcohol Alert

    MedlinePlus

    ... Us You are here Home » Alcohol Alert Alcohol Alert The NIAAA Alcohol Alert is a quarterly bulletin that disseminates important research ... text. To order single copies of select Alcohol Alerts, see ordering Information . To view publications in PDF ...

  4. Alcoholism - resources

    MedlinePlus

    Resources - alcoholism ... The following organizations are good resources for information on alcoholism : Alcoholics Anonymous -- www.aa.org Al-Anon/Alateen -- www.al-anon.org/home National Institute on Alcohol ...

  5. Alcoholic ketoacidosis

    MedlinePlus

    Ketoacidosis - alcoholic ... Alcoholic ketoacidosis is caused by very heavy alcohol use. It most often occurs in a malnourished person ... Symptoms of alcoholic ketoacidosis include: Nausea and vomiting ... Changed level of alertness, which may lead to coma Confusion ...

  6. Alcohol Facts

    MedlinePlus

    ... raquo Alcohol Facts Alcohol Facts Listen Drinks like beer, malt liquor, wine, and hard liquor contain alcohol. Alcohol is the ingredient that gets you drunk. Hard liquor—such as whiskey, rum, or gin—has more ...

  7. Alcoholic neuropathy

    MedlinePlus

    Neuropathy - alcoholic; Alcoholic polyneuropathy ... The exact cause of alcoholic neuropathy is unknown. It likely includes both a direct poisoning of the nerve by the alcohol and the effect of poor nutrition ...

  8. Expression and purification of recombinant tung tree diacylglycerol acyltransferase 2.

    PubMed

    Cao, Heping; Chapital, Dorselyn C; Howard, O D; Deterding, Leesa J; Mason, Catherine B; Shockey, Jay M; Klasson, K Thomas

    2012-11-01

    Diacylglycerol acyltransferases (DGATs) esterify sn-1,2-diacylglycerol with a long-chain fatty acyl-CoA, the last and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. At least 74 DGAT2 sequences from 61 organisms have been identified, but the expression of any DGAT2 as a partial or full-length protein in Escherichia coli had not been reported. The main objective of this study was to express and purify recombinant DGAT2 (rDGAT2) from E. coli for antigen production with a minor objective to compare rDGAT2 expression in yeast. A plasmid was engineered to express tung tree DGAT2 fused to maltose binding protein and poly-histidine (His) affinity tags. Immunoblotting showed that rDGAT2 was detected in the soluble, insoluble, and membrane fractions. The rDGAT2 in the soluble fraction was partially purified by amylose resin, nickel-nitrilotriacetic agarose (Ni-NTA) beads, and tandem affinity chromatography. Multiple proteins co-purified with rDGAT2. Size exclusion chromatography estimated the size of the rDGAT2-enriched fraction to be approximately eight times the monomer size. Affinity-purified rDGAT2 fractions had a yellow tint and contained fatty acids. The rDGAT2 in the insoluble fraction was partially solubilized by seven detergents with SDS being the most effective. Recombinant DGAT2 was purified to near homogeneity by SDS solubilization and Ni-NTA affinity chromatography. Mass spectrometry identified rDGAT2 as a component in the bands corresponding to the monomer and dimer forms as observed by SDS-PAGE. Protein bands with monomer and dimer sizes were also observed in the microsomal membranes of Saccharomyces cerevisiae expressing hemagglutinin-tagged DGAT2. Nonradioactive assay showed TAG synthesis activity of DGAT2 from yeast but not E. coli. The results suggest that rDGAT2 is present as monomer and dimer forms on SDS-PAGE, associated with other proteins, lipids, and membranes, and that post-translational modification of rDGAT2 may

  9. Overexpression of Peanut Diacylglycerol Acyltransferase 2 in Escherichia coli

    PubMed Central

    Yang, Lianqun; Zhang, Bin; Chen, Gao; Bi, Yuping

    2013-01-01

    Diacylglycerol acyltransferase (DGAT) is the rate-limiting enzyme in triacylglycerol biosynthesis in eukaryotic organisms. Triacylglycerols are important energy-storage oils in plants such as peanuts, soybeans and rape. In this study, Arachis hypogaea type 2 DGAT (AhDGAT2) genes were cloned from the peanut cultivar ‘Luhua 14’ using a homologous gene sequence method and rapid amplification of cDNA ends. To understand the role of AhDGAT2 in triacylglycerol biosynthesis, two AhDGAT2 nucleotide sequences that differed by three amino acids were expressed as glutathione S-transferase (GST) fusion proteins in Escherichia coli Rosetta (DE3). Following IPTG induction, the isozymes (AhDGAT2a and AhDGAT2b) were expressed as 64.5 kDa GST fusion proteins. Both AhDGAT2a and AhDGAT2b occurred in the host cell cytoplasm and inclusion bodies, with larger amounts in the inclusion bodies. Overexpression of AhDGATs depressed the host cell growth rates relative to non-transformed cells, but cells harboring empty-vector, AhDGAT2a–GST, or AhDGAT2b–GST exhibited no obvious growth rate differences. Interestingly, induction of AhDGAT2a–GST and AhDGAT2b–GST proteins increased the sizes of the host cells by 2.4–2.5 times that of the controls (post-IPTG induction). The total fatty acid (FA) levels of the AhDGAT2a–GST and AhDGAT2a–GST transformants, as well as levels of C12:0, C14:0, C16:0, C16:1, C18:1n9c and C18:3n3 FAs, increased markedly, whereas C15:0 and C21:0 levels were lower than in non-transformed cells or those containing empty-vectors. In addition, the levels of some FAs differed between the two transformant strains, indicating that the two isozymes might have different functions in peanuts. This is the first time that a full-length recombinant peanut DGAT2 has been produced in a bacterial expression system and the first analysis of its effects on the content and composition of fatty acids in E. coli. Our results indicate that AhDGAT2 is a strong candidate gene for

  10. Functional Roles of Three Cutin Biosynthetic Acyltransferases in Cytokinin Responses and Skotomorphogenesis

    PubMed Central

    Chai, Juan; Zhou, Qin; Wang, Li; Hirnerová, Eva; Mrvková, Michaela; Novák, Ondřej; Guo, Guang-Qin

    2015-01-01

    Cytokinins (CKs) regulate plant development and growth via a two-component signaling pathway. By forward genetic screening, we isolated an Arabidopsis mutant named grow fast on cytokinins 1 (gfc1), whose seedlings grew larger aerial parts on MS medium with CK. gfc1 is allelic to a previously reported cutin mutant defective in cuticular ridges (dcr). GFC1/DCR encodes a soluble BAHD acyltransferase (a name based on the first four enzymes characterized in this family: Benzylalcohol O-acetyltransferase, Anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoyltransferase and Deacetylvindoline 4-O-acetyltransferase) with diacylglycerol acyltransferase (DGAT) activity in vitro and is necessary for normal cuticle formation on epidermis in vivo. Here we show that gfc1 was a CK-insensitive mutant, as revealed by its low regeneration frequency in vitro and resistance to CK in adventitious root formation and dark-grown hypocotyl inhibition assays. In addition, gfc1 had de-etiolated phenotypes in darkness and was therefore defective in skotomorphogenesis. The background expression levels of most type-A Arabidopsis Response Regulator (ARR) genes were higher in the gfc1 mutant. The gfc1-associated phenotypes were also observed in the cutin-deficient glycerol-3-phosphate acyltransferase 4/8 (gpat4/8) double mutant [defective in glycerol-3-phosphate (G3P) acyltransferase enzymes GPAT4 and GPAT8, which redundantly catalyze the acylation of G3P by hydroxyl fatty acid (OH-FA)], but not in the cutin-deficient mutant cytochrome p450, family 86, subfamily A, polypeptide 2/aberrant induction of type three 1 (cyp86A2/att1), which affects the biosynthesis of some OH-FAs. Our results indicate that some acyltransferases associated with cutin formation are involved in CK responses and skotomorphogenesis in Arabidopsis. PMID:25803274

  11. Alcohol Alert: Genetics of Alcoholism

    MedlinePlus

    ... and Reports » Alcohol Alert » Alcohol Alert Number 84 Alcohol Alert Number 84 Print Version The Genetics of ... immune defense system. Genes Encoding Enzymes Involved in Alcohol Breakdown Some of the first genes linked to ...

  12. Evolutionarily Distinct BAHD N-Acyltransferases Are Responsible for Natural Variation of Aromatic Amine Conjugates in Rice.

    PubMed

    Peng, Meng; Gao, Yanqiang; Chen, Wei; Wang, Wensheng; Shen, Shuangqian; Shi, Jian; Wang, Cheng; Zhang, Yu; Zou, Li; Wang, Shouchuang; Wan, Jian; Liu, Xianqing; Gong, Liang; Luo, Jie

    2016-07-01

    Phenolamides (PAs) are specialized (secondary) metabolites mainly synthesized by BAHD N-acyltransferases. Here, we report metabolic profiling coupled with association and linkage mapping of 11 PAs in rice (Oryza sativa). We identified 22 loci affecting PAs in leaves and 16 loci affecting PAs in seeds. We identified eight BAHD N-acyltransferases located on five chromosomes with diverse specificities, including four aromatic amine N-acyltransferases. We show that genetic variation in PAs is determined, at least in part, by allelic variation in the tissue specificity of expression of the BAHD genes responsible for their biosynthesis. Tryptamine hydroxycinnamoyl transferase 1/2 (Os-THT1/2) and tryptamine benzoyl transferase 1/2 (Os-TBT1/2) were found to be bifunctional tryptamine/tyramine N-acyltransferases. The specificity of Os-THT1 and Os-TBT1 for agmatine involved four tandem arginine residues, which have not been identified as specificity determinants for other plant BAHD transferases, illustrating the versatility of plant BAHD transferases in acquiring new acyl acceptor specificities. With phylogenetic analysis, we identified both divergent and convergent evolution of N-acyltransferases in plants, and we suggest that the BAHD family of tryptamine/tyramine N-acyltransferases evolved conservatively in monocots, especially in Gramineae. Our work demonstrates that omics-assisted gene-to-metabolite analysis provides a useful tool for bulk gene identification and crop genetic improvement. PMID:27354554

  13. Evolutionarily Distinct BAHD N-Acyltransferases Are Responsible for Natural Variation of Aromatic Amine Conjugates in Rice[OPEN

    PubMed Central

    Peng, Meng; Chen, Wei; Wang, Wensheng; Shen, Shuangqian; Shi, Jian; Wang, Cheng; Zhang, Yu; Zou, Li; Wang, Shouchuang; Wan, Jian; Liu, Xianqing; Gong, Liang; Luo, Jie

    2016-01-01

    Phenolamides (PAs) are specialized (secondary) metabolites mainly synthesized by BAHD N-acyltransferases. Here, we report metabolic profiling coupled with association and linkage mapping of 11 PAs in rice (Oryza sativa). We identified 22 loci affecting PAs in leaves and 16 loci affecting PAs in seeds. We identified eight BAHD N-acyltransferases located on five chromosomes with diverse specificities, including four aromatic amine N-acyltransferases. We show that genetic variation in PAs is determined, at least in part, by allelic variation in the tissue specificity of expression of the BAHD genes responsible for their biosynthesis. Tryptamine hydroxycinnamoyl transferase 1/2 (Os-THT1/2) and tryptamine benzoyl transferase 1/2 (Os-TBT1/2) were found to be bifunctional tryptamine/tyramine N-acyltransferases. The specificity of Os-THT1 and Os-TBT1 for agmatine involved four tandem arginine residues, which have not been identified as specificity determinants for other plant BAHD transferases, illustrating the versatility of plant BAHD transferases in acquiring new acyl acceptor specificities. With phylogenetic analysis, we identified both divergent and convergent evolution of N-acyltransferases in plants, and we suggest that the BAHD family of tryptamine/tyramine N-acyltransferases evolved conservatively in monocots, especially in Gramineae. Our work demonstrates that omics-assisted gene-to-metabolite analysis provides a useful tool for bulk gene identification and crop genetic improvement. PMID:27354554

  14. Modification of seed oil content and acyl composition in the brassicaceae by expression of a yeast sn-2 acyltransferase gene.

    PubMed Central

    Zou, J; Katavic, V; Giblin, E M; Barton, D L; MacKenzie, S L; Keller, W A; Hu, X; Taylor, D C

    1997-01-01

    A putative yeast sn-2 acyltransferase gene (SLC1-1), reportedly a variant acyltransferase that suppresses a genetic defect in sphingolipid long-chain base biosynthesis, has been expressed in a yeast SLC deletion strain. The SLC1-1 gene product was shown in vitro to encode an sn-2 acyltransferase capable of acylating sn-1 oleoyl-lysophosphatidic acid, using a range of acyl-CoA thioesters, including 18:1-, 22:1-, and 24:0-CoAs. The SLC1-1 gene was introduced into Arabidopsis and a high erucic acid-containing Brassica napus cv Hero under the control of a constitutive (tandem cauliflower mosaic virus 35S) promoter. The resulting transgenic plants showed substantial increases of 8 to 48% in seed oil content (expressed on the basis of seed dry weight) and increases in both overall proportions and amounts of very-long-chain fatty acids in seed triacylglycerols (TAGs). Furthermore, the proportion of very-long-chain fatty acids found at the sn-2 position of TAGs was increased, and homogenates prepared from developing seeds of transformed plants exhibited elevated lysophosphatidic acid acyltransferase (EC 2.3.1.51) activity. Thus, the yeast sn-2 acyltransferase has been shown to encode a protein that can exhibit lysophosphatidic acid acyltransferase activity and that can be used to change total fatty acid content and composition as well as to alter the stereospecific acyl distribution of fatty acids in seed TAGs. PMID:9212466

  15. Characterization of mouse lysophosphatidic acid acyltransferase 3: an enzyme with dual functions in the testis1s⃞

    PubMed Central

    Yuki, Koichi; Shindou, Hideo; Hishikawa, Daisuke; Shimizu, Takao

    2009-01-01

    Glycerophospholipids are structural and functional components of cellular membranes as well as precursors of various lipid mediators. Using acyl-CoAs as donors, glycerophospholipids are formed by the de novo pathway (Kennedy pathway) and modified in the remodeling pathway (Lands' cycle). Various acyltransferases, including two lysophosphatidic acid acyltransferases (LPAATs), have been discovered from a 1-acylglycerol-3-phosphate O-acyltransferase (AGPAT) family. Proteins of this family contain putative acyltransferase motifs, but their biochemical properties and physiological roles are not completely understood. Here, we demonstrated that mouse LPAAT3, previously known as mouse AGPAT3, possesses strong LPAAT activity and modest lysophosphatidylinositol acyltransferase activity with a clear preference for arachidonoyl-CoA as a donor. This enzyme is highly expressed in the testis, where CDP-diacylglycerol synthase 1 preferring 1-stearoyl-2-arachidonoyl-phosphatidic acid as a substrate is also highly expressed. Since 1-stearoyl-2-arachidonoyl species are the main components of phosphatidylinositol, mouse LPAAT3 may function in both the de novo and remodeling pathways and contribute to effective biogenesis of 1-stearoyl-2-arachidonoyl-phosphatidylinositol in the testis. Additionally, the expression of this enzyme in the testis increases significantly in an age-dependent manner, and β-estradiol may be an important regulator of this enzyme's induction. Our findings identify this acyltransferase as an alternative important enzyme to produce phosphatidylinositol in the testis. PMID:19114731

  16. Characterization of an Acyltransferase Capable of Synthesizing Benzylbenzoate and Other Volatile Esters in Flowers and Damaged Leaves of Clarkia breweri1

    PubMed Central

    D'Auria, John C.; Chen, Feng; Pichersky, Eran

    2002-01-01

    A cDNA encoding a protein with 456 amino acids whose sequence shows considerable similarity to plant acyltransferases was identified among 750 Clarkia breweri flower expressed sequence tags. The cDNA was expressed in Escherichia coli, and the protein produced was shown to encode the enzyme benzoyl-coenzyme A (CoA):benzyl alcohol benzoyl transferase (BEBT). BEBT catalyzes the formation of benzylbenzoate, a minor constituent of the C. breweri floral aroma, but it also has activity with a number of other alcohols and acyl CoAs. The BEBT gene is expressed in different parts of the flowers with maximal RNA transcript levels in the stigma, and no expression was observed in the leaves under normal conditions. However, BEBT expression was induced in damaged leaves, reaching a maximum 6 h after damage occurred. We also show here that a closely related tobacco (Nicotiana tabacum) gene previously shown to be induced in leaves after being challenged by phytopathogenic bacteria also has BEBT activity, whereas the most similar protein to BEBT in the Arabidopsis proteome does not use benzoyl CoA as a substrate and instead can use acetyl CoA to catalyze the formation of cis-3-hexen-1-yl acetate, a green-leaf volatile. PMID:12226525

  17. Alcoholic ketoacidosis

    MedlinePlus

    ... attention improves the overall outlook. How severe the alcoholism is, and the presence of liver disease or ... A.M. Editorial team. Related MedlinePlus Health Topics Alcoholism and Alcohol Abuse Browse the Encyclopedia A.D. ...

  18. Alcohol withdrawal

    MedlinePlus

    ... counseling to discuss the long-term issue of alcoholism Testing and treatment for other medical problems linked ... following organizations are good resources for information on alcoholism: Alcoholics Anonymous -- www.aa.org Al-Anon/Alateen -- ...

  19. Alcoholic neuropathy

    MedlinePlus

    ... objects in the shoes Guarding the extremities to prevent injury from pressure Alcohol must be stopped to prevent the damage from ... The only way to prevent alcoholic neuropathy is not to drink excessive amounts of alcohol.

  20. The rv1184c Locus Encodes Chp2, an Acyltransferase in Mycobacterium tuberculosis Polyacyltrehalose Lipid Biosynthesis

    PubMed Central

    Touchette, Megan H.; Holsclaw, Cynthia M.; Previti, Mary L.; Solomon, Viven C.; Leary, Julie A.; Bertozzi, Carolyn R.

    2014-01-01

    Trehalose glycolipids are found in many bacteria in the suborder Corynebacterineae, but methyl-branched acyltrehaloses are exclusive to virulent species such as the human pathogen Mycobacterium tuberculosis. In M. tuberculosis, the acyltransferase PapA3 catalyzes the formation of diacyltrehalose (DAT), but the enzymes responsible for downstream reactions leading to the final product, polyacyltrehalose (PAT), have not been identified. The PAT biosynthetic gene locus is similar to that of another trehalose glycolipid, sulfolipid 1. Recently, Chp1 was characterized as the terminal acyltransferase in sulfolipid 1 biosynthesis. Here we provide evidence that the homologue Chp2 (Rv1184c) is essential for the final steps of PAT biosynthesis. Disruption of chp2 led to the loss of PAT and a novel tetraacyltrehalose species, TetraAT, as well as the accumulation of DAT, implicating Chp2 as an acyltransferase downstream of PapA3. Disruption of the putative lipid transporter MmpL10 resulted in a similar phenotype. Chp2 activity thus appears to be regulated by MmpL10 in a relationship similar to that between Chp1 and MmpL8 in sulfolipid 1 biosynthesis. Chp2 is localized to the cell envelope fraction, consistent with its role in DAT modification and possible regulatory interactions with MmpL10. Labeling of purified Chp2 by an activity-based probe was dependent on the presence of the predicted catalytic residue Ser141 and was inhibited by the lipase inhibitor tetrahydrolipstatin (THL). THL treatment of M. tuberculosis resulted in selective inhibition of Chp2 over PapA3, confirming Chp2 as a member of the serine hydrolase superfamily. Efforts to produce in vitro reconstitution of acyltransferase activity using straight-chain analogues were unsuccessful, suggesting that Chp2 has specificity for native methyl-branched substrates. PMID:25331437

  1. Isolation of Acyl-CoA:cholesterol acyltransferase inhibitor from Persicaria vulgaris.

    PubMed

    Song, Hye Young; Rho, Mun-Chual; Lee, Seung Woong; Kwon, Oh Eok; Chang, Young-Duck; Lee, Hyun Sun; Kim, Young-Kook

    2002-09-01

    In the course of our search for Acyl-CoA:cholesterol acyltransferase (ACAT) inhibitors from natural sources, a new type of ACAT inhibitor was isolated from the methanol extract of Persicaria vulgaris. On the basis of spectral evidence, the structure of the active compound was identified as pheophorbide A. Pheophorbide A inhibited ACAT activity with an IC 50 value of 1.1 microg/ml in an enzyme assay using rat liver microsomes with a dose dependent fashion. PMID:12357403

  2. The LINKS motif zippers trans-acyltransferase polyketide synthase assembly lines into a biosynthetic megacomplex.

    PubMed

    Gay, Darren C; Wagner, Drew T; Meinke, Jessica L; Zogzas, Charles E; Gay, Glen R; Keatinge-Clay, Adrian T

    2016-03-01

    Polyketides such as the clinically-valuable antibacterial agent mupirocin are constructed by architecturally-sophisticated assembly lines known as trans-acyltransferase polyketide synthases. Organelle-sized megacomplexes composed of several copies of trans-acyltransferase polyketide synthase assembly lines have been observed by others through transmission electron microscopy to be located at the Bacillus subtilis plasma membrane, where the synthesis and export of the antibacterial polyketide bacillaene takes place. In this work we analyze ten crystal structures of trans-acyltransferase polyketide synthases ketosynthase domains, seven of which are reported here for the first time, to characterize a motif capable of zippering assembly lines into a megacomplex. While each of the three-helix LINKS (Laterally-INteracting Ketosynthase Sequence) motifs is observed to similarly dock with a spatially-reversed copy of itself through hydrophobic and ionic interactions, the amino acid sequences of this motif are not conserved. Such a code is appropriate for mediating homotypic contacts between assembly lines to ensure the ordered self-assembly of a noncovalent, yet tightly-knit, enzymatic network. LINKS-mediated lateral interactions would also have the effect of bolstering the vertical association of the polypeptides that comprise a polyketide synthase assembly line. PMID:26724270

  3. Glucose Polyester Biosynthesis. Purification and Characterization of a Glucose Acyltransferase1

    PubMed Central

    Li, Alice X.; Eannetta, Nancy; Ghangas, Gurdev S.; Steffens, John C.

    1999-01-01

    Glandular trichomes of the wild tomato species Lycopersicon pennellii secrete 2,3,4-O-tri-acyl-glucose (-Glc), which contributes to insect resistance. A Glc acyltransferase catalyzes the formation of diacyl-Glc by disproportionating two equivalents of 1-O-acyl-β-Glc, a high-energy molecule formed by a UDP-Glc dependent reaction. The acyltransferase was purified 4,900-fold from L. pennellii leaves by polyethylene glycol fractionation, diethylaminoethyl chromatography, concanavalin A affinity chromatography, and chromatofocusing. The acyltransferase possesses an isoelectric point of 4.8, a relative molecular mass around 110 kD, and is composed of 34- and 24-kD polypeptides as a heterotetramer. The 34- and 24-kD proteins were partially sequenced. The purified enzyme catalyzes both the disproportionation of 1-O-acyl-β-Glcs to generate 1,2-di-O-acyl-β-Glc and anomeric acyl exchange between 1-O-acyl-β-Glc and Glc. PMID:10517836

  4. Identification of a broad family of lipid A late acyltransferases with non-canonical substrate specificity

    PubMed Central

    Rubin, Erica J.; O’Brien, John P.; Ivanov, Petko L.; Brodbelt, Jennifer S.; Trent, M. Stephen

    2014-01-01

    Summary Most gram-negative organisms produce lipopolysaccharide (LPS), a complex macromolecule anchored to the bacterial membrane by the lipid A moiety. Lipid A is synthesized via the Raetz pathway, a conserved nine-step enzymatic process first characterized in Escherichia coli. The Epsilonproteobacterium Helicobacter pylori uses the Raetz pathway to synthesize lipid A; however, only eight of nine enzymes in the pathway have been identified in this organism. Here, we identify the missing acyltransferase, Jhp0255, which transfers a secondary acyl chain to the 3′-linked primary acyl chain of lipid A, an activity similar to that of E. coli LpxM. This enzyme, reannotated as LpxJ due to limited sequence similarity with LpxM, catalyzes addition of a C12:0 or C14:0 acyl chain to the 3′-linked primary acyl chain of lipid A, complementing an E. coli LpxM mutant. Enzymatic assays demonstrate that LpxJ and homologs in Campylobacter jejuni and Wolinella succinogenes can act before the 2′ secondary acyltransferase, LpxL, as well as the 3-deoxy-D-manno-octulosonic acid (Kdo) transferase, KdtA. Ultimately, LpxJ is one member of a large class of acyltransferases found in a diverse range of organisms that lack an E. coli LpxM homolog, suggesting that LpxJ participates in lipid A biosynthesis in place of an LpxM homolog. PMID:24372821

  5. Characterization of monoacylglycerol acyltransferase 2 inhibitors by a novel probe in binding assays.

    PubMed

    Ma, Zhengping; Chao, Hannguang J; Turdi, Huji; Hangeland, Jon J; Friends, Todd; Kopcho, Lisa M; Lawrence, R Michael; Cheng, Dong

    2016-05-15

    Monoacylglycerol acyltransferase 2 (MGAT2) is a membrane-bound lipid acyltransferase that catalyzes the formation of diacylglycerol using monoacylglycerol and fatty acyl CoA as substrates. MGAT2 is important for intestinal lipid absorption and is an emerging target for the treatment of metabolic diseases. In the current study, we identified and characterized four classes of novel MGAT2 inhibitors. We established both steady state and kinetic binding assay protocols using a novel radioligand, [(3)H]compound A. Diverse chemotypes of MGAT2 inhibitors were found to compete binding of [(3)H]compound A to MGAT2, indicating the broad utility of [(3)H]compound A for testing various classes of MGAT2 inhibitors. In the dynamic binding assays, the kinetic values of MGAT2 inhibitors such as Kon, Koff, and T1/2 were systematically defined. Of particular value, the residence times of inhibitors on MGAT2 enzyme were derived. We believe that the identification of novel classes of MGAT2 inhibitors and the detailed kinetic characterization provide valuable information for the identification of superior candidates for in vivo animal and clinical studies. The current work using a chemical probe to define inhibitory kinetics can be broadly applied to other membrane-bound acyltransferases. PMID:26925857

  6. Overexpression of diacylglycerol acyltransferase in Yarrowia lipolytica affects lipid body size, number and distribution.

    PubMed

    Gajdoš, Peter; Ledesma-Amaro, Rodrigo; Nicaud, Jean-Marc; Čertík, Milan; Rossignol, Tristan

    2016-09-01

    In the oleaginous yeast Yarrowia lipolytica, the diacylglycerol acyltransferases (DGATs) are major factors for triacylglycerol (TAG) synthesis. The Q4 strain, in which the four acyltransferases have been deleted, is unable to accumulate lipids and to form lipid bodies (LBs). However, the expression of a single acyltransferase in this strain restores TAG accumulation and LB formation. Using this system, it becomes possible to characterize the activity and specificity of an individual DGAT. Here, we examined the effects of DGAT overexpression on lipid accumulation and LB formation in Y. lipolytica Specifically, we evaluated the consequences of introducing one or two copies of the Y. lipolytica DGAT genes YlDGA1 and YlDGA2 Overall, multi-copy DGAT overexpression increased the lipid content of yeast cells. However, the size and distribution of LBs depended on the specific DGAT overexpressed. YlDGA2 overexpression caused the formation of large LBs, while YlDGA1 overexpression generated smaller but more numerous LBs. This phenotype was accentuated through the addition of a second copy of the overexpressed gene and might be linked to the distinct subcellular localization of each DGAT, i.e. YlDga1 being localized in LBs, while YlDga2 being localized in a structure strongly resembling the endoplasmic reticulum. PMID:27506614

  7. Alcoholism and Alcohol Abuse

    MedlinePlus

    ... increase the risk of certain cancers. It can cause damage to the liver, brain, and other organs. Drinking during pregnancy can harm your baby. Alcohol also increases the risk of death from car crashes, injuries, homicide, and suicide. If you want to stop drinking, there is ...

  8. Metabolic engineering of Escherichia coli for production of biodiesel from fatty alcohols and acetyl-CoA.

    PubMed

    Guo, Daoyi; Pan, Hong; Li, Xun

    2015-09-01

    Microbial production of biodiesel from renewable feedstock has attracted intensive attention. Biodiesel is known to be produced from short-chain alcohols and fatty acyl-CoAs through the expression of wax ester synthase/fatty acyl-CoA: diacylglycerol acyltransferase that catalyzes the esterification of short-chain alcohols and fatty acyl-CoAs. Here, we engineered Escherichia coli to produce various fatty alcohol acetate esters, which depend on the expression of Saccharomyces cerevisiae alcohol acetyltransferase ATF1 that catalyzes the esterification of fatty alcohols and acetyl-CoA. The fatty acid biosynthetic pathways generate fatty acyl-ACPs, fatty acyl-CoAs, or fatty acids, which can be converted to fatty alcohols by fatty acyl-CoA reductase, fatty acyl-ACP reductase, or carboxylic acid reductase, respectively. This study showed the biosynthesis of biodiesel from three fatty acid biosynthetic pathway intermediates. PMID:26205521

  9. Alcohol Calorie Calculator

    MedlinePlus

    ... Alcohol Calorie Calculator Weekly Total 0 Calories Alcohol Calorie Calculator Find out the number of beer and ... Calories College Alcohol Policies Interactive Body Calculators Alcohol Calorie Calculator Alcohol Cost Calculator Alcohol BAC Calculator Alcohol ...

  10. Identification of acyltransferases required for cutin biosynthesis and production of cutin with suberin-like monomers.

    PubMed

    Li, Yonghua; Beisson, Fred; Koo, Abraham J K; Molina, Isabel; Pollard, Mike; Ohlrogge, John

    2007-11-13

    Cutin and suberin are the two major lipid-based polymers of plants. Cutin is the structural polymer of the epidermal cuticle, the waterproof layer covering primary aerial organs and which is often the structure first encountered by phytopathogens. Suberin contributes to the control of diffusion of water and solutes across internal root tissues and in periderms. The enzymes responsible for assembly of the cutin polymer are largely unknown. We have identified two Arabidopsis acyltransferases essential for cutin biosynthesis, glycerol-3-phosphate acyltransferase (GPAT) 4 and GPAT8. Double knockouts gpat4/gpat8 were strongly reduced in cutin and were less resistant to desiccation and to infection by the fungus Alternaria brassicicola. They also showed striking defects in stomata structure including a lack of cuticular ledges between guard cells, highlighting the importance of cutin in stomatal biology. Overexpression of GPAT4 or GPAT8 in Arabidopsis increased the content of C16 and C18 cutin monomers in leaves and stems by 80%. In order to modify cutin composition, the acyltransferase GPAT5 and the cytochrome P450-dependent fatty acyl oxidase CYP86A1, two enzymes associated with suberin biosynthesis, were overexpressed. When both enzymes were overexpressed together the epidermal polyesters accumulated new C20 and C22 omega-hydroxyacids and alpha,omega-diacids typical of suberin, and the fine structure and water-barrier function of the cuticle were altered. These results identify GPATs as partners of fatty acyl oxidases in lipid polyester synthesis and indicate that their cooverexpression provides a strategy to probe the role of cutin composition and quantity in the function of plant cuticles. PMID:17991776

  11. CGI-58/ABHD5 is a coenzyme A-dependent lysophosphatidic acid acyltransferase.

    PubMed

    Montero-Moran, Gabriela; Caviglia, Jorge M; McMahon, Derek; Rothenberg, Alexis; Subramanian, Vidya; Xu, Zhi; Lara-Gonzalez, Samuel; Storch, Judith; Carman, George M; Brasaemle, Dawn L

    2010-04-01

    Mutations in human CGI-58/ABHD5 cause Chanarin-Dorfman syndrome (CDS), characterized by excessive storage of triacylglycerol in tissues. CGI-58 is an alpha/beta-hydrolase fold enzyme expressed in all vertebrates. The carboxyl terminus includes a highly conserved consensus sequence (HXXXXD) for acyltransferase activity. Mouse CGI-58 was expressed in Escherichia coli as a fusion protein with two amino terminal 6-histidine tags. Recombinant CGI-58 displayed acyl-CoA-dependent acyltransferase activity to lysophosphatidic acid, but not to other lysophospholipid or neutral glycerolipid acceptors. Production of phosphatidic acid increased with time and increasing concentrations of recombinant CGI-58 and was optimal between pH 7.0 and 8.5. The enzyme showed saturation kinetics with respect to 1-oleoyl-lysophosphatidic acid and oleoyl-CoA and preference for arachidonoyl-CoA and oleoyl-CoA. The enzyme showed slight preference for 1-oleoyl lysophosphatidic acid over 1-palmitoyl, 1-stearoyl, or 1-arachidonoyl lysophosphatidic acid. Recombinant CGI-58 showed intrinsic fluorescence for tryptophan that was quenched by the addition of 1-oleoyl-lysophosphatidic acid, oleoyl-CoA, arachidonoyl-CoA, and palmitoyl-CoA, but not by lysophosphatidyl choline. Expression of CGI-58 in fibroblasts from humans with CDS increased the incorporation of radiolabeled fatty acids released from the lipolysis of stored triacylglycerols into phospholipids. CGI-58 is a CoA-dependent lysophosphatidic acid acyltransferase that channels fatty acids released from the hydrolysis of stored triacylglycerols into phospholipids. PMID:19801371

  12. Inhibition by acetyl-CoA of hepatic carnitine acyltransferase and fatty acid oxidation.

    PubMed Central

    McCormick, K; Notar-Francesco, V J; Sriwatanakul, K

    1983-01-01

    At micromolar concentrations, acetyl-CoA inhibited hepatic carnitine acyltransferase activity and mitochondrial fatty acid oxidation. The inhibitory effects were not nearly as potent on a molar basis as those of malonyl-CoA; nevertheless, the cytosolic concentrations of acetyl-CoA, as yet unknown, may be sufficient (greater than 30 microM) to curtail appreciably the mitochondrial transfer of long-chain acyl-CoA units and fatty acid oxidation. Hence acetyl-CoA may also partially regulate hepatic ketogenesis. PMID:6661211

  13. Functional study of diacylglycerol acyltransferase type 2 family in Chlamydomonas reinhardtii.

    PubMed

    Hung, Chun-Hsien; Ho, Ming-Yang; Kanehara, Kazue; Nakamura, Yuki

    2013-08-01

    Algal triacylglycerol biosynthesis is of increasing interest for potential biodiesel production. A model microalga, Chlamydomonas, has multiple isoforms of diacylglycerol acyltransferase type 2 (DGTT) catalyzing the final step of triacylglycerol biosynthesis; however, the functions of the isoforms are poorly understood. Here, we performed heterologous complementation assay of Chlamydomonas DGTT1 to 4 in a yeast mutant defective in triacylglycerol biosynthesis. DGTT1, 2 and 3 but not 4 complemented the phenotype, including triacylglycerol levels. Interestingly, complementation by DGTT2 increased triacylglycerol content by 9-fold. PMID:23770092

  14. Some kinetic properties of plasma lecithin-cholesterol acyltransferase in hyper-alphalipoproteinemia in man

    SciTech Connect

    Nikiforova, A.A.; Alksnis, E.G.; Ivanova, E.M.

    1985-07-01

    The aim of this investigation was to study some kinetic properties of lecithin-cholesterol acyltransferase (LCAT) in the blood plasma of patients with hyper-alpha-lipoproteinemia, enabling the presence of LCAT isozymes in the blood to be detected. The velocity of the LCAT reaction was judged by determining labeled CHE formed from /sup 14/C-nonesterified CH and lecithin of HDL on incubation of the latter with the enzyme. Dependence of the velocity of the LCAT reaction on concentration of substrate (nonesterified HDL cholesterol) in four subjects with hyper-alpha-lipoproteinemia is shown.

  15. Selectivity of pyripyropene derivatives in inhibition toward acyl-CoA:cholesterol acyltransferase 2 isozyme.

    PubMed

    Ohshiro, Taichi; Ohte, Satoshi; Matsuda, Daisuke; Ohtawa, Masaki; Nagamitsu, Tohru; Sunazuka, Toshiaki; Harigaya, Yoshihiro; Rudel, Lawrence L; Omura, Satoshi; Tomoda, Hiroshi

    2008-08-01

    Selectivity of 96 semisynthetic derivatives prepared from fungal pyripyropene A, originally isolated as a potent inhibitor of acyl-CoA:cholesterol acyltransferase (ACAT), toward ACAT1 and ACAT2 isozymes was investigated in the cell-based assay using ACAT1- and ACAT2-expressing CHO cells. Eighteen derivatives including PR-71 (7-O-isocaproyl derivative) showed much more potent ACAT2 inhibition (IC50: 6.0 to 62 nM) than pyripyropene A (IC50: 70 nM). Among them, however, natural pyripyropene A showed the highest selectivity toward ACAT2 with a selectivity index (SI) of >1000, followed by PR-71 (SI, 667). PMID:18997389

  16. Propyl alcohol

    MedlinePlus

    Rubbing alcohol Alcohol swabs Skin and hair products Nail polish remover Note: This list may not be all ... number will let you talk to experts in poisoning. They will give you further instructions. This is ...

  17. Alcoholic hallucinosis.

    PubMed

    Bhat, Pookala S; Ryali, Vssr; Srivastava, Kalpana; Kumar, Shashi R; Prakash, Jyoti; Singal, Ankit

    2012-07-01

    Alcoholic hallucinosis is a rare complication of chronic alcohol abuse characterized by predominantly auditory hallucinations that occur either during or after a period of heavy alcohol consumption. Bleuler (1916) termed the condition as alcohol hallucinosis and differentiated it from Delirium Tremens. Usually it presents with acoustic verbal hallucinations, delusions and mood disturbances arising in clear consciousness and sometimes may progress to a chronic form mimicking schizophrenia. One such case with multimodal hallucinations in a Defence Service Corps soldier is presented here. PMID:24250051

  18. Alcohol Abuse

    ERIC Educational Resources Information Center

    O'Farrell, Timothy J.; Fals-Stewart, William

    2003-01-01

    We received 38 controlled studies of marital and family therapy (MFT) in alcoholism treatment. We conclude that, when the alcoholic is unwilling to seek help, MFT is effective in helping the family cope better and motivating alcoholics to enter treatment. Specifically, (a) Al-Anon facilitation and referral help family members cope better; (b)…

  19. Involvement of an octose ketoreductase and two acyltransferases in the biosynthesis of paulomycins

    NASA Astrophysics Data System (ADS)

    Li, Jine; Wang, Min; Ding, Yong; Tang, Yue; Zhang, Zhiguo; Chen, Yihua

    2016-02-01

    C-4 hydroxyethyl branched octoses have been observed in polysaccharides of several genera of gram negative bacteria and in various antibiotics produced by gram positive bacteria. The C-4 hydroxyethyl branch was proposed to be converted from C-4 acetyl branch by an uncharacterized ketoreduction step. Paulomycins (PAUs) are glycosylated antibiotics with potent inhibitory activity against gram positive bacteria and are structurally defined by its unique C-4‧ hydroxyethyl branched paulomycose moiety. A novel aldo-keto-reductase, Pau7 was characterized as the enzyme catalyzing the stereospecific ketoreduction of 7‧-keto of PAU E (1) to give the C-4‧ hydroxyethyl branched paulomycose moiety of PAU F (2). An acyltransferase Pau6 further decorates the C-4‧ hydroxyethyl branch of paulomycose moiety of 2 by attaching various fatty acyl chains to 7‧-OH to generate diverse PAUs. In addition, another acyltransferase Pau24 was proposed to be responsible for the 13-O-acetylation of PAUs.

  20. Regulation of acyltransferase activity in immature maize embryos by abscisic acid and the osmotic environment.

    PubMed Central

    Pacheco-Moisés, F; Valencia-Turcotte, L; Altuzar-Martínez, M; Rodríguez-Sotres, R

    1997-01-01

    Maize (Zes mays L.) embryos, isolated from the developing seed and incubated in dilute buffer, show reduced triacylglycerol (TAG) synthesis, and accumulation stops after 24 h. Synthesis and accumulation can be maintained at high levels if the incubation medium contains abscisic acid (ABA) and/or a high osmotic concentration. Radiolabeled free fatty acids accumulate at higher levels in embryos that contain less TAG, and acetyl coenzyme A carboxylase activity remains essentially unchanged under all of the conditions tested. In contrast, the activities of the acyltransferases required for TAG synthesis remain high only in embryos incubated with ABA and/or a high osmotic concentration. Dose-response curves showed that 4 microM of ABA or mannitol at -1.0 MPa elicits a full response; both values are within the range considered to be physiological. The TAG synthesis capacity and discylglycerol acyltransferase activity lost by pretreatment of the embryos can be restored by re-exposure to ABA or high osmoticum. Germination is not involved because isolated scutellum halves showed the same changes in enzyme activity found in the whole embryo but did not germinate. Our results provide direct evidence for the regulation of TAG-synthesizing activities in maize embryos by ABA and the osmotic potential of the environment. PMID:9232885

  1. Diacylglycerol O-Acyltransferase Type-1 Synthesizes Retinyl Esters in the Retina and Retinal Pigment Epithelium

    PubMed Central

    Kaylor, Joanna J.; Radu, Roxana A.; Bischoff, Nicholas; Makshanoff, Jacob; Hu, Jane; Lloyd, Marcia; Eddington, Shannan; Bianconi, Tran; Bok, Dean; Travis, Gabriel H.

    2015-01-01

    Retinyl esters represent an insoluble storage form of vitamin A and are substrates for the retinoid isomerase (Rpe65) in cells of the retinal pigment epithelium (RPE). The major retinyl-ester synthase in RPE cells is lecithin:retinol acyl-transferase (LRAT). A second palmitoyl coenzyme A-dependent retinyl-ester synthase activity has been observed in RPE homogenates but the protein responsible has not been identified. Here we show that diacylglycerol O-acyltransferase-1 (DGAT1) is expressed in multiple cells of the retina including RPE and Müller glial cells. DGAT1 catalyzes the synthesis of retinyl esters from multiple retinol isomers with similar catalytic efficiencies. Loss of DGAT1 in dgat1 -/- mice has no effect on retinal anatomy or the ultrastructure of photoreceptor outer-segments (OS) and RPE cells. Levels of visual chromophore in dgat1 -/- mice were also normal. However, the normal build-up of all-trans-retinyl esters (all-trans-RE’s) in the RPE during the first hour after a deep photobleach of visual pigments in the retina was not seen in dgat1 -/- mice. Further, total retinyl-ester synthase activity was reduced in both dgat1 -/- retina and RPE. PMID:25974161

  2. Role of HXXXD-motif/BAHD acyltransferases in the biosynthesis of extracellular lipids.

    PubMed

    Molina, Isabel; Kosma, Dylan

    2015-04-01

    Terrestrial plants have evolved specific adaptations to preserve water and protect themselves from their environment. Such adaptations range from secondary metabolites and specialized structures that conduct water and nutrients, to cell wall modifications (i.e., cuticle and suberin) that prevent dehydration and provide a physical barrier to pathogens. Both the plant cuticle and suberized cell walls contain a lipid polymer framework embedded with waxes, and constitute a promising target for controlled genetic modification to improve desirable agronomic traits. Recent advances in genomic and molecular techniques coupled with the development of robust analytical methods have accelerated progress in comprehending these intractable lipid polymers. Gene products characterized in the wax, cutin and suberin pathways include a subset of HXXXD/BAHD family enzymes that catalyze acyl transfer reactions between CoA-activated hydroxycinnamic acid derivatives and hydroxylated aliphatics. This review highlights our current understanding of HXXXD/BAHD acyltransferases in extracellular lipid biosynthesis and discusses the chemical, ultrastructural and physiological ramifications of impairing the expression of BAHD acyltransferase-encoding genes related to cutin and suberin synthesis. PMID:25510356

  3. Architectural Organization of the Metabolic Regulatory Enzyme Ghrelin O-Acyltransferase*

    PubMed Central

    Taylor, Martin S.; Ruch, Travis R.; Hsiao, Po-Yuan; Hwang, Yousang; Zhang, Pingfeng; Dai, Lixin; Huang, Cheng Ran Lisa; Berndsen, Christopher E.; Kim, Min-Sik; Pandey, Akhilesh; Wolberger, Cynthia; Marmorstein, Ronen; Machamer, Carolyn; Boeke, Jef D.; Cole, Philip A.

    2013-01-01

    Ghrelin O-acyltransferase (GOAT) is a polytopic integral membrane protein required for activation of ghrelin, a secreted metabolism-regulating peptide hormone. Although GOAT is a potential therapeutic target for the treatment of obesity and diabetes and plays a key role in other physiologic processes, little is known about its structure or mechanism. GOAT is a member of the membrane-bound O-acyltransferase (MBOAT) family, a group of polytopic integral membrane proteins involved in lipid-biosynthetic and lipid-signaling reactions from prokaryotes to humans. Here we use phylogeny and a variety of bioinformatic tools to predict the topology of GOAT. Using selective permeabilization indirect immunofluorescence microscopy in combination with glycosylation shift immunoblotting, we demonstrate that GOAT contains 11 transmembrane helices and one reentrant loop. Development of the V5Glyc tag, a novel, small, and sensitive dual topology reporter, facilitated these experiments. The MBOAT family invariant residue His-338 is in the ER lumen, consistent with other family members, but conserved Asn-307 is cytosolic, making it unlikely that both are involved in catalysis. Photocross-linking of synthetic ghrelin analogs and inhibitors demonstrates binding to the C-terminal region of GOAT, consistent with a role of His-338 in the active site. This knowledge of GOAT architecture is important for a deeper understanding of the mechanism of GOAT and other MBOATs and could ultimately advance the discovery of selective inhibitors for these enzymes. PMID:24045953

  4. A soluble diacylglycerol acyltransferase is involved in triacylglycerol biosynthesis in the oleaginous yeast Rhodotorula glutinis.

    PubMed

    Rani, Sapa Hima; Saha, Saikat; Rajasekharan, Ram

    2013-01-01

    The biosynthesis of triacylglycerol (TAG) occurs in the microsomal membranes of eukaryotes. Here, we report the identification and functional characterization of diacylglycerol acyltransferase (DGAT), a member of the 10 S cytosolic TAG biosynthetic complex (TBC) in Rhodotorula glutinis. Both a full-length and an N-terminally truncated cDNA clone of a single gene were isolated from R. glutinis. The DGAT activity of the protein encoded by RgDGAT was confirmed in vivo by the heterologous expression of cDNA in a Saccharomyces cerevisiae quadruple mutant (H1246) that is defective in TAG synthesis. RgDGAT overexpression in yeast was found to be capable of acylating diacylglycerol (DAG) in an acyl-CoA-dependent manner. Quadruple mutant yeast cells exhibit growth defects in the presence of oleic acid, but wild-type yeast cells do not. In an in vivo fatty acid supplementation experiment, RgDGAT expression rescued quadruple mutant growth in an oleate-containing medium. We describe a soluble acyl-CoA-dependent DAG acyltransferase from R. glutinis that belongs to the DGAT3 class of enzymes. The study highlights the importance of an alternative TAG biosynthetic pathway in oleaginous yeasts. PMID:23103975

  5. Involvement of an octose ketoreductase and two acyltransferases in the biosynthesis of paulomycins

    PubMed Central

    Li, Jine; Wang, Min; Ding, Yong; Tang, Yue; Zhang, Zhiguo; Chen, Yihua

    2016-01-01

    C-4 hydroxyethyl branched octoses have been observed in polysaccharides of several genera of gram negative bacteria and in various antibiotics produced by gram positive bacteria. The C-4 hydroxyethyl branch was proposed to be converted from C-4 acetyl branch by an uncharacterized ketoreduction step. Paulomycins (PAUs) are glycosylated antibiotics with potent inhibitory activity against gram positive bacteria and are structurally defined by its unique C-4′ hydroxyethyl branched paulomycose moiety. A novel aldo-keto-reductase, Pau7 was characterized as the enzyme catalyzing the stereospecific ketoreduction of 7′-keto of PAU E (1) to give the C-4′ hydroxyethyl branched paulomycose moiety of PAU F (2). An acyltransferase Pau6 further decorates the C-4′ hydroxyethyl branch of paulomycose moiety of 2 by attaching various fatty acyl chains to 7′-OH to generate diverse PAUs. In addition, another acyltransferase Pau24 was proposed to be responsible for the 13-O-acetylation of PAUs. PMID:26877148

  6. The Mycobacterium tuberculosis LipB enzyme functions as a cysteine/lysine dyad acyltransferase

    PubMed Central

    Ma, Qingjun; Zhao, Xin; Eddine, Ali Nasser; Geerlof, Arie; Li, Xinping; Cronan, John E.; Kaufmann, Stefan H. E.; Wilmanns, Matthias

    2006-01-01

    Lipoic acid is essential for the activation of a number of protein complexes involved in key metabolic processes. Growth of Mycobacterium tuberculosis relies on a pathway in which the lipoate attachment group is synthesized from an endogenously produced octanoic acid moiety. In patients with multiple-drug-resistant M. tuberculosis, expression of one gene from this pathway, lipB, encoding for octanoyl-[acyl carrier protein]-protein acyltransferase is considerably up-regulated, thus making it a potential target in the search for novel antiinfectives against tuberculosis. Here we present the crystal structure of the M. tuberculosis LipB protein at atomic resolution, showing an unexpected thioether-linked active-site complex with decanoic acid. We provide evidence that the transferase functions as a cysteine/lysine dyad acyltransferase, in which two invariant residues (Lys-142 and Cys-176) are likely to function as acid/base catalysts. Analysis by MS reveals that the LipB catalytic reaction proceeds by means of an internal thioesteracyl intermediate. Structural comparison of LipB with lipoate protein ligase A indicates that, despite conserved structural and sequence active-site features in the two enzymes, 4′-phosphopantetheine-bound octanoic acid recognition is a specific property of LipB. PMID:16735476

  7. Human 1-Acylglycerol-3-phosphate O-Acyltransferase Isoforms 1 and 2

    PubMed Central

    Agarwal, Anil K.; Sukumaran, Suja; Cortés, Víctor A.; Tunison, Katie; Mizrachi, Dario; Sankella, Shireesha; Gerard, Robert D.; Horton, Jay D.; Garg, Abhimanyu

    2011-01-01

    Loss-of-function mutations in 1-acylglycerol-3-phosphate O-acyltransferase (AGPAT) 2 in humans and mice result in loss of both the white and brown adipose tissues from birth. AGPAT2 generates precursors for the synthesis of glycerophospholipids and triacylglycerols. Loss of adipose tissue, or lipodystrophy, results in hyperinsulinemia, diabetes mellitus, and severe hepatic steatosis. Here, we analyzed biochemical properties of human AGPAT2 and its close homolog, AGPAT1, and we studied their role in liver by transducing their expression via recombinant adenoviruses in Agpat2−/− mice. The in vitro substrate specificities of AGPAT1 and AGPAT2 are quite similar for lysophosphatidic acid and acyl-CoA. Protein homology modeling of both the AGPATs with glycerol-3-phosphate acyltransferase 1 (GPAT1) revealed that they have similar tertiary protein structure, which is consistent with their similar substrate specificities. When co-expressed, both isoforms co-localize to the endoplasmic reticulum. Despite such similarities, restoring AGPAT activity in liver by overexpression of either AGPAT1 or AGPAT2 in Agpat2−/− mice failed to ameliorate the hepatic steatosis. From these studies, we suggest that the role of AGPAT1 or AGPAT2 in liver lipogenesis is minimal and that accumulation of liver fat is primarily a consequence of insulin resistance and loss of adipose tissue in Agpat2−/− mice. PMID:21873652

  8. Facts about Alcohol and Alcoholism.

    ERIC Educational Resources Information Center

    Hall, Leonard C.

    Recognition of alcoholism as a treatable illness is a result of public education based on scientific facts. This publication, a digest of a more detailed survey of research about drinking and alcoholism, presents information about alcohol and its effects on individuals and society. It provides facts about the short-term and long-term effects of…

  9. Alcoholic cardiomyopathy

    PubMed Central

    Guzzo-Merello, Gonzalo; Cobo-Marcos, Marta; Gallego-Delgado, Maria; Garcia-Pavia, Pablo

    2014-01-01

    Alcohol is the most frequently consumed toxic substance in the world. Low to moderate daily intake of alcohol has been shown to have beneficial effects on the cardiovascular system. In contrast, exposure to high levels of alcohol for a long period could lead to progressive cardiac dysfunction and heart failure. Cardiac dysfunction associated with chronic and excessive alcohol intake is a specific cardiac disease known as alcoholic cardiomyopathy (ACM). In spite of its clinical importance, data on ACM and how alcohol damages the heart are limited. In this review, we evaluate available evidence linking excessive alcohol consumption with heart failure and dilated cardiomyopathy. Additionally, we discuss the clinical presentation, prognosis and treatment of ACM. PMID:25228956

  10. Plant acyl-CoA:lysophosphatidylcholine acyltransferases (LPCATs) have different specificities in their forward and reverse reactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT) enzymes have central roles inacyl editing of phosphatidylcholine (PC). Plant LPCAT genes were expressed in yeast and characterized biochemically in microsomal preparations of the cells. Specificities for different acyl-CoAs were similar for se...

  11. The Glycerol-3-Phosphate Acyltransferase TbGAT is Dispensable for Viability and the Synthesis of Glycerolipids in Trypanosoma brucei.

    PubMed

    Patel, Nipul; Pirani, Karim A; Zhu, Tongtong; Cheung-See-Kit, Melanie; Lee, Sungsu; Chen, Daniel G; Zufferey, Rachel

    2016-09-01

    Glycerolipids are the main constituents of biological membranes in Trypanosoma brucei, which causes sleeping sickness in humans. Importantly, they occur as a structural component of the glycosylphosphatidylinositol lipid anchor of the abundant cell surface glycoproteins procyclin in procyclic forms and variant surface glycoprotein in bloodstream form, that play crucial roles for the development of the parasite in the insect vector and the mammalian host, respectively. The present work reports the characterization of the glycerol-3-phosphate acyltransferase TbGAT that initiates the biosynthesis of ester glycerolipids. TbGAT restored glycerol-3-phosphate acyltransferase activity when expressed in a Leishmania major deletion strain lacking this activity and exhibited preference for medium length, unsaturated fatty acyl-CoAs. TbGAT localized to the endoplasmic reticulum membrane with its N-terminal domain facing the cytosol. Despite that a TbGAT null mutant in T. brucei procyclic forms lacked glycerol-3-phosphate acyltransferase activity, it remained viable and exhibited similar growth rate as the wild type. TbGAT was dispensable for the biosynthesis of phosphatidylcholine, phosphatidylinositol, phosphatidylserine, and GPI-anchored protein procyclin. However, the null mutant exhibited a slight decrease in phosphatidylethanolamine biosynthesis that was compensated with a modest increase in production of ether phosphatidylcholine. Our data suggest that an alternative initial acyltransferase takes over TbGAT's function in its absence. PMID:26909872

  12. Molecular Characterization of Two Lysophospholipid:acyl-CoA Acyltransferases Belonging to the MBOAT Family in Nicotiana benthamiana.

    PubMed

    Zhang, Donghui; Jasieniecka-Gazarkiewicz, Katarzyna; Wan, Xia; Luo, Ling; Zhang, Yinbo; Banas, Antoni; Jiang, Mulan; Gong, Yangmin

    2015-01-01

    In the remodeling pathway for the synthesis of phosphatidylcholine (PC), acyl-CoA-dependent lysophosphatidylcholine (lysoPC) acyltransferase (LPCAT) catalyzes the reacylation of lysoPC. A number of genes encoding LPCATs have been cloned and characterized from several plants in recent years. Using Arabidopsis and other plant LPCAT sequences to screen the genome database of Nicotiana benthamiana, we identified two cDNAs encoding the putative tobacco LPCATs (NbLPCAT1 and NbLPCAT2). Both of them were predicted to encode a protein of 463 amino acids with high similarity to LPCATs from other plants. Protein sequence features such as the presence of at least eight putative transmembrane regions, four highly conserved signature motifs and several invariant residues indicate that NbLPCATs belong to the membrane bound O-acyltransferase family. Lysophospholipid acyltransferase activity of NbLPCATs was confirmed by testing lyso-platelet-activating factor (lysoPAF) sensitivity through heterologous expression of each full-length cDNA in a yeast mutant Y02431 (lca1△) disrupted in endogenous LPCAT enzyme activity. Analysis of fatty acid profiles of phospholipids from the NbLPCAT-expressing yeast mutant Y02431 cultures supplemented with polyunsaturated fatty acids suggested more incorporation of linoleic acid (18:2n6, LA) and α-linolenic acid (18:3n3, ALA) into PC compared to yeast mutant harbouring empty vector. In vitro enzymatic assay demonstrated that NbLPCAT1had high lysoPC acyltransferase activity with a clear preference for α-linolenoyl-CoA (18:3), while NbLPCAT2 showed a high lysophosphatidic acid (lysoPA) acyltransferase activity towards α-linolenoyl-CoA and a weak lysoPC acyltransferase activity. Tissue-specific expression analysis showed a ubiquitous expression of NbLPCAT1 and NbLPCAT2 in roots, stems, leaves, flowers and seeds, and a strong expression in developing flowers. This is the first report on the cloning and characterization of lysophospholipid

  13. Molecular Characterization of Two Lysophospholipid:acyl-CoA Acyltransferases Belonging to the MBOAT Family in Nicotiana benthamiana

    PubMed Central

    Wan, Xia; Luo, Ling; Zhang, Yinbo; Banas, Antoni; Jiang, Mulan; Gong, Yangmin

    2015-01-01

    In the remodeling pathway for the synthesis of phosphatidylcholine (PC), acyl-CoA-dependent lysophosphatidylcholine (lysoPC) acyltransferase (LPCAT) catalyzes the reacylation of lysoPC. A number of genes encoding LPCATs have been cloned and characterized from several plants in recent years. Using Arabidopsis and other plant LPCAT sequences to screen the genome database of Nicotiana benthamiana, we identified two cDNAs encoding the putative tobacco LPCATs (NbLPCAT1 and NbLPCAT2). Both of them were predicted to encode a protein of 463 amino acids with high similarity to LPCATs from other plants. Protein sequence features such as the presence of at least eight putative transmembrane regions, four highly conserved signature motifs and several invariant residues indicate that NbLPCATs belong to the membrane bound O-acyltransferase family. Lysophospholipid acyltransferase activity of NbLPCATs was confirmed by testing lyso-platelet-activating factor (lysoPAF) sensitivity through heterologous expression of each full-length cDNA in a yeast mutant Y02431 (lca1△) disrupted in endogenous LPCAT enzyme activity. Analysis of fatty acid profiles of phospholipids from the NbLPCAT-expressing yeast mutant Y02431 cultures supplemented with polyunsaturated fatty acids suggested more incorporation of linoleic acid (18:2n6, LA) and α-linolenic acid (18:3n3, ALA) into PC compared to yeast mutant harbouring empty vector. In vitro enzymatic assay demonstrated that NbLPCAT1had high lysoPC acyltransferase activity with a clear preference for α-linolenoyl-CoA (18:3), while NbLPCAT2 showed a high lysophosphatidic acid (lysoPA) acyltransferase activity towards α-linolenoyl-CoA and a weak lysoPC acyltransferase activity. Tissue-specific expression analysis showed a ubiquitous expression of NbLPCAT1 and NbLPCAT2 in roots, stems, leaves, flowers and seeds, and a strong expression in developing flowers. This is the first report on the cloning and characterization of lysophospholipid

  14. Overview of Alcohol Consumption

    MedlinePlus

    ... Search Alcohol & Your Health Overview of Alcohol Consumption Alcohol's Effects on the Body Alcohol Use Disorder Fetal Alcohol ... other questions about alcohol. Here’s what we know: Alcohol’s effects vary from person to person, depending on a ...

  15. A Cytosolic Acyltransferase Contributes to Triacylglycerol Synthesis in Sucrose-Rescued Arabidopsis Seed Oil Catabolism Mutants1[W][OA

    PubMed Central

    Hernández, M. Luisa; Whitehead, Lynne; He, Zhesi; Gazda, Valeria; Gilday, Alison; Kozhevnikova, Ekaterina; Vaistij, Fabián E.; Larson, Tony R.; Graham, Ian A.

    2012-01-01

    Triacylglycerol (TAG) levels and oil bodies persist in sucrose (Suc)-rescued Arabidopsis (Arabidopsis thaliana) seedlings disrupted in seed oil catabolism. This study set out to establish if TAG levels persist as a metabolically inert pool when downstream catabolism is disrupted, or if other mechanisms, such as fatty acid (FA) recycling into TAG are operating. We show that TAG composition changes significantly in Suc-rescued seedlings compared with that found in dry seeds, with 18:2 and 18:3 accumulating. However, 20:1 FA is not efficiently recycled back into TAG in young seedlings, instead partitioning into the membrane lipid fraction and diacylglycerol. In the lipolysis mutant sugar dependent1and the β-oxidation double mutant acx1acx2 (for acyl-Coenzyme A oxidase), levels of TAG actually increased in seedlings growing on Suc. We performed a transcriptomic study and identified up-regulation of an acyltransferase gene, DIACYLGLYCEROL ACYLTRANSFERASE3 (DGAT3), with homology to a peanut (Arachis hypogaea) cytosolic acyltransferase. The acyl-Coenzyme A substrate for this acyltransferase accumulates in mutants that are blocked in oil breakdown postlipolysis. Transient expression in Nicotiana benthamiana confirmed involvement in TAG synthesis and specificity toward 18:3 and 18:2 FAs. Double-mutant analysis with the peroxisomal ATP-binding cassette transporter mutant peroxisomal ABC transporter1 indicated involvement of DGAT3 in the partitioning of 18:3 into TAG in mutant seedlings growing on Suc. Fusion of the DGAT3 protein with green fluorescent protein confirmed localization to the cytosol of N. benthamiana. This work has demonstrated active recycling of 18:2 and 18:3 FAs into TAG when seed oil breakdown is blocked in a process involving a soluble cytosolic acyltransferase. PMID:22760209

  16. A land-plant-specific glycerol-3-phosphate acyltransferase family in Arabidopsis: substrate specificity, sn-2 preference, and evolution.

    PubMed

    Yang, Weili; Simpson, Jeffrey P; Li-Beisson, Yonghua; Beisson, Fred; Pollard, Mike; Ohlrogge, John B

    2012-10-01

    Arabidopsis (Arabidopsis thaliana) has eight glycerol-3-phosphate acyltransferase (GPAT) genes that are members of a plant-specific family with three distinct clades. Several of these GPATs are required for the synthesis of cutin or suberin. Unlike GPATs with sn-1 regiospecificity involved in membrane or storage lipid synthesis, GPAT4 and -6 are unique bifunctional enzymes with both sn-2 acyltransferase and phosphatase activity resulting in 2-monoacylglycerol products. We present enzymology, pathway organization, and evolutionary analysis of this GPAT family. Within the cutin-associated clade, GPAT8 is demonstrated as a bifunctional sn-2 acyltransferase/phosphatase. GPAT4, -6, and -8 strongly prefer C16:0 and C18:1 ω-oxidized acyl-coenzyme As (CoAs) over unmodified or longer acyl chain substrates. In contrast, suberin-associated GPAT5 can accommodate a broad chain length range of ω-oxidized and unsubstituted acyl-CoAs. These substrate specificities (1) strongly support polyester biosynthetic pathways in which acyl transfer to glycerol occurs after oxidation of the acyl group, (2) implicate GPAT specificities as one major determinant of cutin and suberin composition, and (3) argue against a role of sn-2-GPATs (Enzyme Commission 2.3.1.198) in membrane/storage lipid synthesis. Evidence is presented that GPAT7 is induced by wounding, produces suberin-like monomers when overexpressed, and likely functions in suberin biosynthesis. Within the third clade, we demonstrate that GPAT1 possesses sn-2 acyltransferase but not phosphatase activity and can utilize dicarboxylic acyl-CoA substrates. Thus, sn-2 acyltransferase activity extends to all subbranches of the Arabidopsis GPAT family. Phylogenetic analyses of this family indicate that GPAT4/6/8 arose early in land-plant evolution (bryophytes), whereas the phosphatase-minus GPAT1 to -3 and GPAT5/7 clades diverged later with the appearance of tracheophytes. PMID:22864585

  17. Mutations in the midway gene disrupt a Drosophila acyl coenzyme A: diacylglycerol acyltransferase.

    PubMed Central

    Buszczak, Michael; Lu, Xiaohui; Segraves, William A; Chang, Ta Yuan; Cooley, Lynn

    2002-01-01

    During Drosophila oogenesis, defective or unwanted egg chambers are eliminated during mid-oogenesis by programmed cell death. In addition, final cytoplasm transport from nurse cells to the oocyte depends upon apoptosis of the nurse cells. To study the regulation of germline apoptosis, we analyzed the midway mutant, in which egg chambers undergo premature nurse cell death and degeneration. The midway gene encodes a protein similar to mammalian acyl coenzyme A: diacylglycerol acyltransferase (DGAT), which converts diacylglycerol (DAG) into triacylglycerol (TAG). midway mutant egg chambers contain severely reduced levels of neutral lipids in the germline. Expression of midway in insect cells results in high levels of DGAT activity in vitro. These results show that midway encodes a functional DGAT and that changes in acylglycerol lipid metabolism disrupt normal egg chamber development in Drosophila. PMID:11973306

  18. Structure and function of lysosomal phospholipase A2 and lecithin:cholesterol acyltransferase.

    PubMed

    Glukhova, Alisa; Hinkovska-Galcheva, Vania; Kelly, Robert; Abe, Akira; Shayman, James A; Tesmer, John J G

    2015-01-01

    Lysosomal phospholipase A2 (LPLA2) and lecithin:cholesterol acyltransferase (LCAT) belong to a structurally uncharacterized family of key lipid-metabolizing enzymes responsible for lung surfactant catabolism and for reverse cholesterol transport, respectively. Whereas LPLA2 is predicted to underlie the development of drug-induced phospholipidosis, somatic mutations in LCAT cause fish eye disease and familial LCAT deficiency. Here we describe several high-resolution crystal structures of human LPLA2 and a low-resolution structure of LCAT that confirms its close structural relationship to LPLA2. Insertions in the α/β hydrolase core of LPLA2 form domains that are responsible for membrane interaction and binding the acyl chains and head groups of phospholipid substrates. The LCAT structure suggests the molecular basis underlying human disease for most of the known LCAT missense mutations, and paves the way for rational development of new therapeutics to treat LCAT deficiency, atherosclerosis and acute coronary syndrome. PMID:25727495

  19. Identification of the active-site serine in human lecithin: cholesterol acyltransferase

    SciTech Connect

    Farooqui, J.; Wohl, R.C.; Kezdy, F.J.; Scanu, A.M.

    1987-05-01

    Lecithin:cholesterol acyltransferase (LCAT) from human plasma reacts stoichiometrically with diisopropylphosphorofluoridate (DFP) resulting in the complete loss of transacylase activity. Purified LCAT was covalently labeled with (TH) DFP and the labeled protein was reduced and carboxymethylated. Cyanogen bromide cleavage followed by gel permeation chromatography yielded a peptide of 4-5 KDa (LCAT CNBr-III) containing most of the radioactive label. Preliminary studies comparing the amino acid composition of the LCAT-CNBr-III with the sequence of LCAT indicate that this peptide corresponds to fragment 168-220. Automated Edman degradation of the radioactive peptide recovered a radioactive PTC-amino acid at cycle 14. Of all predicted CNBr fragments only peptide 168-220 contained a serine at residue 14 from the amino terminus of the peptide. The authors conclude that serine 181 is the active site serine of LCAT.

  20. Catalytic center of lecithin:cholesterol acyltransferase: isolation and sequence of diisopropyl fluorophosphate-labeled peptides

    SciTech Connect

    Park, Y.B.; Yueksel, U.G.; Gracy, R.W.; Lacko, A.G.

    1987-02-27

    Lecithin:cholesterol acyltransferase (LCAT) was purified from hog plasma and subsequently reacted with (/sup 3/H)-Diisopropyl fluorophosphate (DFP). The labeled enzyme was digested with pepsin and the peptides separated by high performance liquid chromatography (HPLC). Two radioactive peptides were isolated, subjected to automated amino acid sequencing and yielded the following data: A) Ile-Ser-Leu-Gly-Ala-Pro-Trp-Gly-Gly-Ser, and B) Tyr-Ile-Phe-Asp-x-Gly-Phe-Pro-Tyr-x-Asp-Pro-Val. Both of these sequences represent very highly conserved regions of the enzyme when compared to the sequence of human LCAT. Peptide (A) is considered to represent the catalytic center of LCAT based on comparisons with data reported in the literature.

  1. Structure and function of lysosomal phospholipase A2 and lecithin:cholesterol acyltransferase

    NASA Astrophysics Data System (ADS)

    Glukhova, Alisa; Hinkovska-Galcheva, Vania; Kelly, Robert; Abe, Akira; Shayman, James A.; Tesmer, John J. G.

    2015-03-01

    Lysosomal phospholipase A2 (LPLA2) and lecithin:cholesterol acyltransferase (LCAT) belong to a structurally uncharacterized family of key lipid-metabolizing enzymes responsible for lung surfactant catabolism and for reverse cholesterol transport, respectively. Whereas LPLA2 is predicted to underlie the development of drug-induced phospholipidosis, somatic mutations in LCAT cause fish eye disease and familial LCAT deficiency. Here we describe several high-resolution crystal structures of human LPLA2 and a low-resolution structure of LCAT that confirms its close structural relationship to LPLA2. Insertions in the α/β hydrolase core of LPLA2 form domains that are responsible for membrane interaction and binding the acyl chains and head groups of phospholipid substrates. The LCAT structure suggests the molecular basis underlying human disease for most of the known LCAT missense mutations, and paves the way for rational development of new therapeutics to treat LCAT deficiency, atherosclerosis and acute coronary syndrome.

  2. BacMam production of active recombinant lecithin-cholesterol acyltransferase: Expression, purification and characterization.

    PubMed

    Romanow, William G; Piper, Derek E; Fordstrom, Preston; Thibault, Stephen; Zhou, Mingyue; Walker, Nigel P C

    2016-09-01

    Lecithin-cholesterol acyltransferase (LCAT) is a key enzyme in the esterification of cholesterol and its subsequent incorporation into the core of high density lipoprotein (HDL) particles. It is also involved in reverse cholesterol transport (RCT), the mechanism by which cholesterol is removed from peripheral cells and transported to the liver for excretion. These processes are involved in the development of atherosclerosis and coronary heart disease (CHD) and may have therapeutic implications. This work describes the use of baculovirus as a transducing vector to express LCAT in mammalian cells, expression of the recombinant protein as a high-mannose glycoform suitable for deglycosylation by Endo H and its purification to homogeneity and characterization. The importance of producing underglycosylated forms of secreted glycoproteins to obtain high-resolution crystal structures is discussed. PMID:26363122

  3. Structure and function of lysosomal phospholipase A2 and lecithin:cholesterol acyltransferase

    PubMed Central

    Glukhova, Alisa; Hinkovska-Galcheva, Vania; Kelly, Robert; Abe, Akira; Shayman, James A; Tesmer, John JG

    2015-01-01

    Lysosomal phospholipase A2 (LPLA2) and lecithin:cholesterol acyltransferase (LCAT) belong to a structurally uncharacterized family of key lipid metabolizing enzymes responsible for lung surfactant catabolism and for reverse cholesterol transport, respectively. Whereas LPLA2 is predicted to underlie the development of drug-induced phospholipidosis, somatic mutations in LCAT cause fish eye disease and familial LCAT deficiency. Here we describe several high resolution crystal structures of human LPLA2 and a low resolution structure of LCAT that confirms its close structural relationship to LPLA2. Insertions in the α/β hydrolase core of LPLA2 form domains that are responsible for membrane interaction and binding the acyl chains and head groups of phospholipid substrates. The LCAT structure suggests the molecular basis underlying human disease for most of the known LCAT missense mutations, and paves the way for rational development of new therapeutics to treat LCAT deficiency, atherosclerosis and acute coronary syndrome. PMID:25727495

  4. Molecular characterization of three loss-of-function mutations in the isopenicillin N-acyltransferase gene (penDE) of Penicillium chrysogenum.

    PubMed Central

    Fernández, F J; Gutierrez, S; Velasco, J; Montenegro, E; Marcos, A T; Martín, J F

    1994-01-01

    Five mutants of Penicillium chrysogenum blocked in penicillin biosynthesis (npe) which are deficient in isopenicillin N-acyltransferase were isolated previously. Three of these mutants, npe6, npe7, and npe8, have been characterized at the molecular level and compared with npe10, a deletion mutant. Transcripts of normal size (1.15 kb) of the penDE genes, which encode isopenicillin N-acyltransferase, and also of the pcbAB (11.5 kb) and pcbC (1.1 kb) genes were observed in all mutants except for the npe10 mutant. Immunoblotting studies using antibodies against isopenicillin N-acyltransferase showed that all mutants (except npe10) formed the 40-kDa (unprocessed) protein and the 29-kDa subunit of the isopenicillin N-acyltransferase. The 11-kDa subunit could not be observed in the immunoblots. The mutant penDE genes of strains npe6, npe7, and npe8 were cloned and sequenced. These three strains showed a mutation in the penDE genes which results in a single amino acid change in each modified isopenicillin N-acyltransferase. The mutation in npe6 resulted in a change of Gly-150 to Val, whereas the mutation in both npe7 and npe8 introduced a change of Glu-258 to Lys. Replacement of the Val-150 and Lys-258 mutations by constructing hybrid isopenicillin N-acyltransferase molecules led to the recovery of the isopenicillin N-acyltransferase activity. The mutations in npe6, npe7, and npe8 do not affect the ability of the 40-kDa isopenicillin N-acyltransferase to be processed into the component subunits. Images PMID:7519594

  5. Characterization of a Novel Intestinal Glycerol-3-phosphate Acyltransferase Pathway and Its Role in Lipid Homeostasis.

    PubMed

    Khatun, Irani; Clark, Ronald W; Vera, Nicholas B; Kou, Kou; Erion, Derek M; Coskran, Timothy; Bobrowski, Walter F; Okerberg, Carlin; Goodwin, Bryan

    2016-02-01

    Dietary triglycerides (TG) are absorbed by the enterocytes of the small intestine after luminal hydrolysis into monacylglycerol and fatty acids. Before secretion on chylomicrons, these lipids are reesterified into TG, primarily through the monoacylglycerol pathway. However, targeted deletion of the primary murine monoacylglycerol acyltransferase does not quantitatively affect lipid absorption, suggesting the existence of alternative pathways. Therefore, we investigated the role of the glycerol 3-phosphate pathway in dietary lipid absorption. The expression of glycerol-3-phosphate acyltransferase (GPAT3) was examined throughout the small intestine. To evaluate the role for GPAT3 in lipid absorption, mice harboring a disrupted GPAT3 gene (Gpat3(-/-)) were subjected to an oral lipid challenge and fed a Western-type diet to characterize the role in lipid and cholesterol homeostasis. Additional mechanistic studies were performed in primary enterocytes. GPAT3 was abundantly expressed in the apical surface of enterocytes in the small intestine. After an oral lipid bolus, Gpat3(-/-) mice exhibited attenuated plasma TG excursion and accumulated lipid in the enterocytes. Electron microscopy studies revealed a lack of lipids in the lamina propria and intercellular space in Gpat3(-/-) mice. Gpat3(-/-) enterocytes displayed a compensatory increase in the synthesis of phospholipid and cholesteryl ester. When fed a Western-type diet, hepatic TG and cholesteryl ester accumulation was significantly higher in Gpat3(-/-) mice compared with the wild-type mice accompanied by elevated levels of alanine aminotransferase, a marker of liver injury. Dysregulation of bile acid metabolism was also evident in Gpat3-null mice. These studies identify GPAT3 as a novel enzyme involved in intestinal lipid metabolism. PMID:26644473

  6. Comparative gene identification-58 (CGI-58) promotes autophagy as a putative lysophosphatidylglycerol acyltransferase.

    PubMed

    Zhang, Jun; Xu, Dan; Nie, Jia; Han, Ruili; Zhai, Yonggong; Shi, Yuguang

    2014-11-21

    CGI-58 is a lipid droplet-associated protein that, when mutated, causes Chanarin-Dorfman syndrome in humans, which is characterized by excessive storage of triglyceride in various tissues. However, the molecular mechanisms underlying the defect remain elusive. CGI-58 was previously reported to catalyze the resynthesis of phosphatidic acid as a lysophosphatidic acid acyltransferase. In addition to triglyceride, phosphatidic acid is also used a substrate for the synthesis of various mitochondrial phospholipids. In this report, we investigated the propensity of CGI-58 in the remodeling of various phospholipids. We found that the recombinant CGI-58 overexpressed in mammalian cells or purified from Sf9 insect cells catalyzed efficiently the reacylation of lysophosphatidylglycerol to phosphatidylglycerol (PG), which requires acyl-CoA as the acyl donor. In contrast, the recombinant CGI-58 was devoid of acyltransferase activity toward other lysophospholipids. Accordingly, overexpression and knockdown of CGI-58 adversely affected the endogenous PG level in C2C12 cells. PG is a substrate for the synthesis of cardiolipin, which is required for mitochondrial oxidative phosphorylation and mitophagy. Consequently, overexpression and knockdown of CGI-58 adversely affected autophagy and mitophagy in C2C12 cells. In support for a key role of CGI-58 in mitophagy, overexpression of CGI-58 significantly stimulated mitochondrial fission and translocation of PINK1 to mitochondria, key steps involved in mitophagy. Furthermore, overexpression of CGI-58 promoted mitophagic initiation through activation of 5'-AMP-activated protein kinase and inhibition of mTORC1 mammalian target of rapamycin complex 1 signaling, the positive and negative regulators of autophagy, respectively. Together, these findings identified novel molecular mechanisms by which CGI-58 regulates lipid homeostasis, because defective autophagy is implicated in dyslipidemia and fatty liver diseases. PMID:25315780

  7. Molecular characterization of a lysophosphatidylcholine acyltransferase gene belonging to the MBOAT family in Ricinus communis L.

    PubMed

    Arroyo-Caro, José María; Chileh, Tarik; Alonso, Diego López; García-Maroto, Federico

    2013-07-01

    Acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT, EC 2.3.1.23) catalyzes acylation of lysophosphatidylcholine (lysoPtdCho) to produce phosphatidylcholine (PtdCho), the main phospholipid in cellular membranes. This reaction is a key component of the acyl-editing process, involving recycling of the fatty acids (FA) mainly at the sn-2 position of PtdCho. Growing evidences indicate that the LPCAT reaction controls the direct entry of newly synthesized FA into PtdCho and, at least in some plant species, it has an important impact on the synthesis and composition of triacylglycerols. Here we describe the molecular characterization of the single LPCAT gene found in the genome of Ricinus communis (RcLPCAT) that is homologous to LPCAT genes of the MBOAT family previously described in Arabidopsis and Brassica. RcLPCAT is ubiquitously expressed in all organs of the castor plant. Biochemical properties have been studied by heterologous expression of RcLPCAT in the ale1 yeast mutant, defective in lysophospholipid acyltransferase activity. RcLPCAT preferentially acylates lysoPtdCho against other lysophospholipids (lysoPL) and does not discriminates the acyl chain in the acceptor, displaying a strong activity with alkyl lysoPL. Regarding the acyl-CoA donor, RcLPCAT uses monounsaturated fatty acid thioesters, such as oleoyl-CoA (18:1-CoA), as preferred donors, while it has a low activity with saturated fatty acids and shows a poor utilization of ricinoleoyl-CoA (18:1-OH-CoA). These characteristics are discussed in terms of a possible role of RcLPCAT in regulating the entry of FA into PtdCho and the exclusion from the membranes of the hydroxylated FA. PMID:23700249

  8. Homologous yeast lipases/acyltransferases exhibit remarkable cold-active properties.

    PubMed

    Neang, Pisey M; Subileau, Maeva; Perrier, Véronique; Dubreucq, Eric

    2014-11-01

    Lipases/acyltransferases catalyse acyltransfer to various nucleophiles preferentially to hydrolysis even in aqueous media with high thermodynamic activity of water (a w >0.9). Characterization of hydrolysis and acyltransfer activities in a large range of temperature (5 to 80 °C) of secreted recombinant homologous lipases of the Pseudozyma antarctica lipase A superfamily (CaLA) expressed in Pichia pastoris, enlighten the exceptional cold-activity of two remarkable lipases/acyltransferases: CpLIP2 from Candida parapsilosis and CtroL4 from Candida tropicalis. The activation energy of the reactions catalysed by CpLIP2 and CtroL4 was 18-23 kJ mol(-1) for hydrolysis and less than 15 kJ mol(-1) for transesterification between 5 and 35 °C, while it was respectively 43 and 47 kJ mol(-1) with the thermostable CaLA. A remarkable consequence is the high rate of the reactions catalysed by CpLIP2 and CtroL4 at very low temperatures, with CpLIP2 displaying at 5 °C 65 % of its alcoholysis activity and 45 % of its hydrolysis activity at 30 °C. These results suggest that, within the CaLA superfamily and its homologous subgroups, common structural determinants might allow both acyltransfer and cold-active properties. Such biocatalysts are of great interest for the efficient synthesis or functionalization of temperature-sensitive lipid derivatives, or more generally to lessen the environmental impact of biocatalytic processes. PMID:24770385

  9. Lysophosphatidate Acyltransferase in the Microsomes from Maturing Seeds of Meadowfoam (Limnanthes alba) 1

    PubMed Central

    Cao, Yi-zhi; Oo, Khaik-Cheang; Huang, Anthony H. C.

    1990-01-01

    Lysophosphatidate (LPA) acyltransferase (EC 2.3. 1.51) in the microsomes from the maturing seeds of meadowfoam (Limnanthes alba), nasturtium (Tropaeolum majus), palm (Syagrus cocoides), castor bean (Ricinus communis), soybean (Glycine max), maize (Zea mays), and rapeseed (Brassica napus) were tested for their specificities toward 1-oleoyl-LPA or 1-erucoyl-LPA, and oleoyl coenzyme A (CoA) or erucoyl CoA. All the enzymes could use either of the two acyl acceptors and oleoyl CoA, but only the meadowfoam enzyme could use erucoyl CoA as the acyl donor to produce dierucoyl phosphatidic acid (PA). The meadowfoam enzyme was studied further. It had an optimal activity at pH 7 to 8, and its activity was inhibited by 1 millimolar MnCl2, ZnCl2, or p-chloromercuribenzoate. In a test of substrate specificity using increasing concentrations of either 1-oleoyl-LPA or 1-erucoyl-LPA, and either oleoyl CoA or erucoyl CoA, the enzyme activity in producing PA was highest for dioleoyl-PA, followed successively by 1-oleoyl-2-erucoyl-PA, dierucoyl-PA, and 1-erucoyl-2-oleoyl-PA. In a test of substrate selectivity using a fixed combined concentration, but varying proportions, of 1-oleoyl-LPA and 1-erucoyl-LPA, and of oleoyl CoA and erucoyl CoA, the enzyme showed a pattern of acyl preference similar to that observed in the test of substrate specificity, but the preference toward oleoyl moiety in the substrates was slightly stronger. The meadowfoam microsomes could convert [14C]glycerol-3-phosphate to diacylglycerols and triacylglycerols in the presence of erucoyl CoA. The meadowfoam LPA acyltransferase is unique in its ability to produce dierucoyl-PA, and should be a prime candidate for use in the production of trierucin oils in rapeseed via genetic engineering. PMID:16667817

  10. Activity and Crystal Structure of Arabidopsis thalianaUDP-N-Acetylglucosamine Acyltransferase

    SciTech Connect

    Joo, Sang Hoon; Chung, Hak Suk; Raetz, Christian R.H.; Garrett, Teresa A.

    2012-08-31

    The UDP-N-acetylglucosamine (UDP-GlcNAc) acyltransferase, encoded by lpxA, catalyzes the first step of lipid A biosynthesis in Gram-negative bacteria, the (R)-3-hydroxyacyl-ACP-dependent acylation of the 3-OH group of UDP-GlcNAc. Recently, we demonstrated that the Arabidopsis thaliana orthologs of six enzymes of the bacterial lipid A pathway produce lipid A precursors with structures similar to those of Escherichia coli lipid A precursors [Li, C., et al. (2011) Proc. Natl. Acad. Sci. U.S.A. 108, 11387-11392]. To build upon this finding, we have cloned, purified, and determined the crystal structure of the A. thaliana LpxA ortholog (AtLpxA) to 2.1 {angstrom} resolution. The overall structure of AtLpxA is very similar to that of E. coli LpxA (EcLpxA) with an {alpha}-helical-rich C-terminus and characteristic N-terminal left-handed parallel {beta}-helix (L{beta}H). All key catalytic and chain length-determining residues of EcLpxA are conserved in AtLpxA; however, AtLpxA has an additional coil and loop added to the L{beta}H not seen in EcLpxA. Consistent with the similarities between the two structures, purified AtLpxA catalyzes the same reaction as EcLpxA. In addition, A. thaliana lpxA complements an E. coli mutant lacking the chromosomal lpxA and promotes the synthesis of lipid A in vivo similar to the lipid A produced in the presence of E. coli lpxA. This work shows that AtLpxA is a functional UDP-GlcNAc acyltransferase that is able to catalyze the same reaction as EcLpxA and supports the hypothesis that lipid A molecules are biosynthesized in Arabidopsis and other plants.

  11. Alcohol Energy Drinks

    MedlinePlus

    ... Home / About Addiction / Alcohol / Alcohol Energy Drinks Alcohol Energy Drinks Read 14635 times font size decrease font size increase font size Print Email Alcohol energy drinks (AEDs) or Caffeinated alcoholic beverages (CABs) are ...

  12. Alcohol Energy Drinks

    MedlinePlus

    ... Home / About Addiction / Alcohol / Alcohol Energy Drinks Alcohol Energy Drinks Read 17728 times font size decrease font size increase font size Print Email Alcohol energy drinks (AEDs) or Caffeinated alcoholic beverages (CABs) are ...

  13. Alcohol during Pregnancy

    MedlinePlus

    ... Home > Pregnancy > Is it safe? > Alcohol during pregnancy Alcohol during pregnancy E-mail to a friend Please ... and fetal alcohol spectrum disorders. How does drinking alcohol during pregnancy affect your baby's health? Drinking alcohol ...

  14. Cloning and identification of the human LPAAT-zeta gene, a novel member of the lysophosphatidic acid acyltransferase family.

    PubMed

    Li, Dan; Yu, Long; Wu, Hai; Shan, Yuxi; Guo, Jinhu; Dang, Yongjun; Wei, Youheng; Zhao, Shouyuan

    2003-01-01

    Lysophosphatidic acid (LPA) is a naturally occurring component of phospholipid and plays a critical role in the regulation of many physiological and pathophysiological processes including cell growth, survival, and pro-angiogenesis. LPA is converted to phosphatidic acid by the action of lysophosphatidic acid acyltransferase (LPAAT). Five members of the LPAAT gene family have been detected in humans to date. Here, we report the identification of a novel LPAAT member, which is designated as LPAAT-zeta. LPAAT-zeta was predicted to encode a protein consisting of 456 amino acid residues with a signal peptide sequence and the acyltransferase domain. Northern blot analysis showed that LPAAT-zeta was ubiquitously expressed in all 16 human tissues examined, with levels in the skeletal muscle, heart, and testis being relatively high and in the lung being relatively low. The human LPAAT-zeta gene consisted of 13 exons and is positioned at chromosome 8p11.21. PMID:12938015

  15. Alcohol conversion

    DOEpatents

    Wachs, Israel E.; Cai, Yeping

    2002-01-01

    Preparing an aldehyde from an alcohol by contacting the alcohol in the presence of oxygen with a catalyst prepared by contacting an intimate mixture containing metal oxide support particles and particles of a catalytically active metal oxide from Groups VA, VIA, or VIIA, with a gaseous stream containing an alcohol to cause metal oxide from the discrete catalytically active metal oxide particles to migrate to the metal oxide support particles and to form a monolayer of catalytically active metal oxide on said metal oxide support particles.

  16. A distinct type of glycerol-3-phosphate acyltransferase with sn-2 preference and phosphatase activity producing 2-monoacylglycerol.

    PubMed

    Yang, Weili; Pollard, Mike; Li-Beisson, Yonghua; Beisson, Fred; Feig, Michael; Ohlrogge, John

    2010-06-29

    The first step in assembly of membrane and storage glycerolipids is acylation of glycerol-3-phosphate (G3P). All previously characterized membrane-bound, eukaryotic G3P acyltransferases (GPATs) acylate the sn-1 position to produce lysophosphatidic acid (1-acyl-LPA). Cutin is a glycerolipid with omega-oxidized fatty acids and glycerol as integral components. It occurs as an extracellular polyester on the aerial surface of all plants, provides a barrier to pathogens and resistance to stress, and maintains organ identity. We have determined that Arabidopsis acyltransferases GPAT4 and GPAT6 required for cutin biosynthesis esterify acyl groups predominantly to the sn-2 position of G3P. In addition, these acyltransferases possess a phosphatase domain that results in sn-2 monoacylglycerol (2-MAG) rather than LPA as the major product. Such bifunctional activity has not been previously described in any organism. The possible roles of 2-MAGs as intermediates in cutin synthesis are discussed. GPAT5, which is essential for the accumulation of suberin aliphatics, also exhibits a strong preference for sn-2 acylation. However, phosphatase activity is absent and 2-acyl-LPA is the major product. Clearly, plant GPATs can catalyze more reactions than the sn-1 acylation by which they are currently categorized. Close homologs of GPAT4-6 are present in all land plants, but not in animals, fungi or microorganisms (including algae). Thus, these distinctive acyltransferases may have been important for evolution of extracellular glycerolipid polymers and adaptation of plants to a terrestrial environment. These results provide insight into the biosynthetic assembly of cutin and suberin, the two most abundant glycerolipid polymers in nature. PMID:20551224

  17. Possible Role of Different Yeast and Plant Lysophospholipid:Acyl-CoA Acyltransferases (LPLATs) in Acyl Remodelling of Phospholipids.

    PubMed

    Jasieniecka-Gazarkiewicz, Katarzyna; Demski, Kamil; Lager, Ida; Stymne, Sten; Banaś, Antoni

    2016-01-01

    Recent results have suggested that plant lysophosphatidylcholine:acyl-coenzyme A acyltransferases (LPCATs) can operate in reverse in vivo and thereby catalyse an acyl exchange between the acyl-coenzyme A (CoA) pool and the phosphatidylcholine. We have investigated the abilities of Arabidopsis AtLPCAT2, Arabidopsis lysophosphatidylethanolamine acyltransferase (LPEAT2), S. cerevisiae lysophospholipid acyltransferase (Ale1) and S. cerevisiae lysophosphatidic acid acyltransferase (SLC1) to acylate lysoPtdCho, lysoPtdEtn and lysoPtdOH and act reversibly on the products of the acylation; the PtdCho, PtdEtn and PtdOH. The tested LPLATs were expressed in an S. cervisiae ale1 strain and enzyme activities were assessed in assays using microsomal preparations of the different transformants. The results show that, despite high activity towards lysoPtdCho, lysoPtdEtn and lysoPtdOH by the ALE1, its capacities to operate reversibly on the products of the acylation were very low. Slc1 readily acylated lysoPtdOH, lysoPtdCho and lysoPtdEtn but showed no reversibility towards PtdCho, very little reversibility towards PtdEtn and very high reversibility towards PtdOH. LPEAT2 showed the highest levels of reversibility towards PtdCho and PtdEtn of all LPLATs tested but low ability to operate reversibly on PtdOH. AtLPCAT2 showed good reversible activity towards PtdCho and PtdEtn and very low reversibility towards PtdOH. Thus, it appears that some of the LPLATs have developed properties that, to a much higher degree than other LPLATs, promote the reverse reaction during the same assay conditions and with the same phospholipid. The results also show that the capacity of reversibility can be specific for a particular phospholipid, albeit the lysophospholipid derivatives of other phospholipids serve as good acyl acceptors for the forward reaction of the enzyme. PMID:26643989

  18. A serine carboxypeptidase-like acyltransferase is required for synthesis of antimicrobial compounds and disease resistance in oats.

    PubMed

    Mugford, Sam T; Qi, Xiaoquan; Bakht, Saleha; Hill, Lionel; Wegel, Eva; Hughes, Richard K; Papadopoulou, Kalliopi; Melton, Rachel; Philo, Mark; Sainsbury, Frank; Lomonossoff, George P; Roy, Abhijeet Deb; Goss, Rebecca J M; Osbourn, Anne

    2009-08-01

    Serine carboxypeptidase-like (SCPL) proteins have recently emerged as a new group of plant acyltransferases. These enzymes share homology with peptidases but lack protease activity and instead are able to acylate natural products. Several SCPL acyltransferases have been characterized to date from dicots, including an enzyme required for the synthesis of glucose polyesters that may contribute to insect resistance in wild tomato (Solanum pennellii) and enzymes required for the synthesis of sinapate esters associated with UV protection in Arabidopsis thaliana. In our earlier genetic analysis, we identified the Saponin-deficient 7 (Sad7) locus as being required for the synthesis of antimicrobial triterpene glycosides (avenacins) and for broad-spectrum disease resistance in diploid oat (Avena strigosa). Here, we report on the cloning of Sad7 and show that this gene encodes a functional SCPL acyltransferase, SCPL1, that is able to catalyze the synthesis of both N-methyl anthraniloyl- and benzoyl-derivatized forms of avenacin. Sad7 forms part of an operon-like gene cluster for avenacin synthesis. Oat SCPL1 (SAD7) is the founder member of a subfamily of monocot-specific SCPL proteins that includes predicted proteins from rice (Oryza sativa) and other grasses with potential roles in secondary metabolism and plant defense. PMID:19684243

  19. Alcohol withdrawal

    MedlinePlus

    ... Seeing or feeling things that aren't there (hallucinations) Seizures Severe confusion ... alcohol withdrawal. You will be watched closely for hallucinations and other signs of delirium tremens. Treatment may ...

  20. Alcoholism (image)

    MedlinePlus

    ... that interferes with physical or mental health, and social, family or job responsibilities. This addiction can lead to liver, circulatory and neurological problems. Pregnant women who drink alcohol in any amount ...

  1. Alcohol Abuse: Alcohol Withdrawal Syndrome

    MedlinePlus

    ... they quit drinking. What are the symptoms of alcohol withdrawal syndrome? Symptoms can be mild or severe, and may include: Shakiness Sweats Anxiety Irritability Fatigue Depression Headaches Insomnia Nightmares Decreased appetite More severe withdrawal symptoms ...

  2. Alcohol withdrawal.

    PubMed

    Manasco, Anton; Chang, Shannon; Larriviere, Joseph; Hamm, L Lee; Glass, Marcia

    2012-11-01

    Alcohol withdrawal is a common clinical condition that has a variety of complications and morbidities. The manifestations can range from mild agitation to withdrawal seizures and delirium tremens. The treatments for alcohol withdrawal include benzodiazepines, anticonvulsants, beta-blockers and antihypertensives. Although benzodiazepines are presently a first-line therapy, there is controversy regarding the efficacies of these medications compared with others. Treatment protocols often involve one of two contrasting approaches: symptom-triggered versus fixed-schedule dosing of benzodiazepines. We describe these protocols in our review and examine the data supporting symptom-triggered dosing as the preferred method for most patients in withdrawal.The Clinical Institute Withdrawal Assessment for Alcohol scoring system for alcohol withdrawal streamlines care, optimizes patient management, and is the best scale available for withdrawal assessment. Quality improvement implications for inpatient management of alcohol withdrawal include increasing training for signs of withdrawal and symptom recognition, adding new hospital protocols to employee curricula, and ensuring manageable patient-to-physician and patient-to-nurse ratios. PMID:23128805

  3. Structural and Functional Studies of a trans-Acyltransferase Polyketide Assembly Line Enzyme that Catalyzes Stereoselective α- and β-Ketoreduction

    PubMed Central

    Piasecki, Shawn K.; Zheng, Jianting; Axelrod, Abram J.; Detelich, Madeline; Keatinge-Clay, Adrian T.

    2014-01-01

    While the cis-acyltransferase modular polyketide synthase assembly lines have largely been structurally dissected, enzymes from within the recently discovered trans-acyltransferase polyketide synthase assembly lines are just starting to be observed crystallographically. Here we examine the ketoreductase from the first polyketide synthase module of the bacillaene nonribosomal peptide synthetase/polyketide synthase at 2.35-Å resolution. This ketoreductase naturally reduces both α- and β-keto groups and is the only ketoreductase known to do so during the biosynthesis of a polyketide. The isolated ketoreductase not only reduced an N-acetylcysteamine-bound β-keto substrate to a D-β-hydroxy product, but also an N-acetylcysteamine- bound α-keto substrate to an L-α-hydroxy product. That the substrates must enter the active site from opposite directions to generate these stereochemistries suggests that the acyl-phosphopantetheine moiety is capable of accessing very different conformations despite being anchored to a serine residue of a docked acyl carrier protein. The features enabling stereocontrolled α-ketoreduction may not be extensive since a β-ketoreductase from a cis-acyltransferase polyketide synthase was identified that performs a completely stereoselective reduction of the same α-keto substrate to generate the D-α-hydroxy product. A sequence analysis of trans-acyltransferase ketoreductases reveals that a single residue, rather than a three-residue motif found in cis-acyltransferase ketoreductases, is predictive of the orientation of the resulting β-hydroxyl group. PMID:24634061

  4. Expression of Fungal diacylglycerol acyltransferase2 Genes to Increase Kernel Oil in Maize[OA

    PubMed Central

    Oakes, Janette; Brackenridge, Doug; Colletti, Ron; Daley, Maureen; Hawkins, Deborah J.; Xiong, Hui; Mai, Jennifer; Screen, Steve E.; Val, Dale; Lardizabal, Kathryn; Gruys, Ken; Deikman, Jill

    2011-01-01

    Maize (Zea mays) oil has high value but is only about 4% of the grain by weight. To increase kernel oil content, fungal diacylglycerol acyltransferase2 (DGAT2) genes from Umbelopsis (formerly Mortierella) ramanniana and Neurospora crassa were introduced into maize using an embryo-enhanced promoter. The protein encoded by the N. crassa gene was longer than that of U. ramanniana. It included 353 amino acids that aligned to the U. ramanniana DGAT2A protein and a 243-amino acid sequence at the amino terminus that was unique to the N. crassa DGAT2 protein. Two forms of N. crassa DGAT2 were tested: the predicted full-length protein (L-NcDGAT2) and a shorter form (S-NcDGAT2) that encoded just the sequences that share homology with the U. ramanniana protein. Expression of all three transgenes in maize resulted in small but statistically significant increases in kernel oil. S-NcDGAT2 had the biggest impact on kernel oil, with a 26% (relative) increase in oil in kernels of the best events (inbred). Increases in kernel oil were also obtained in both conventional and high-oil hybrids, and grain yield was not affected by expression of these fungal DGAT2 transgenes. PMID:21245192

  5. Metabolism of low-density lipoprotein free cholesterol by human plasma lecithin-cholesterol acyltransferase

    SciTech Connect

    Fielding, P.E.; Miida, Takashi; Fielding, C.J. )

    1991-09-03

    The metabolism of cholesterol derived from ({sup 3}H) cholesterol-labeled low-density lipoprotein (LDL) was determined in human blood plasma. LDL-derived free cholesterol first appeared in large {alpha}-migrating HDL (HDL{sub 2}) and was then transferred to small {alpha}-HDL (HDL{sub 3}) for esterification. The major part of such esters was retained within HDL of increasing size in the course of lecithin-cholesterol acyltransferase (LCAT) activity; the balance was recovered in LDL. Transfer of preformed cholesteryl esters within HDL contributed little to the labeled cholesteryl ester accumulating HDL{sub 2}. When cholesterol for esterification was derived instead from cell membranes, a significantly smaller proportion of this cholesteryl ester was subsequently recovered in LDL. These data suggest compartmentation of cholesteryl esters within plasma that have been formed from cell membrane or LDL free cholesterol, and the role for HDL{sub 2} as a relatively unreactive sink for LCAT-derived cholesteryl esters.

  6. Identification and characterization of a type-2 diacylglycerol acyltransferase (DGAT2) from Rhodosporidium diobovatum.

    PubMed

    Chen, Zhihuan; Liu, Pengyan; Liu, Yanhua; Tang, Hui; Chen, Yunping; Zhang, Liping

    2014-12-01

    Triacylglycerols (TAGs), synthesized in the microsomal membranes of eukaryotes, serve as a primary storage form of carbon and energy in microorganisms. For this reason, TAGs produced by organisms have great potential to become biofuels and facilitate researchers to look for alternative renewable sources of energy. The present study describes the identification and functional characterization of a type-2 diacylglycerol acyltransferase from Rhodosporidium diobovatum, designated as RdDGAT, which catalyzed the final step of TAG synthesis. A full-length cDNA clone for RdDGAT was obtained, and its biological activity was proven by being expressed in a Saccharomyces cerevisiae quadruple mutant that was defective in TAG synthesis. Enzymatic assays were performed and finally the existence of TAGs in the transformed Saccharomyces cerevisiae quadruple mutant was determined using the method of thin-layer chromatography. Substrate preference experiments revealed that RdDGAT preferred unsaturated fatty acids over saturated ones. Through further analysis, we assume that the evolution and expression characteristics of the RdDGAT gene perhaps is the result of adaption to its oligotrophic and cold living environment. PMID:25294723

  7. Abrogating monoacylglycerol acyltransferase activity in liver improves glucose tolerance and hepatic insulin signaling in obese mice.

    PubMed

    Hall, Angela M; Soufi, Nisreen; Chambers, Kari T; Chen, Zhouji; Schweitzer, George G; McCommis, Kyle S; Erion, Derek M; Graham, Mark J; Su, Xiong; Finck, Brian N

    2014-07-01

    Monoacylglycerol acyltransferase (MGAT) enzymes convert monoacylglycerol to diacylglycerol (DAG), a lipid that has been linked to the development of hepatic insulin resistance through activation of protein kinase C (PKC). The expression of genes that encode MGAT enzymes is induced in the livers of insulin-resistant human subjects with nonalcoholic fatty liver disease, but whether MGAT activation is causal of hepatic steatosis or insulin resistance is unknown. We show that the expression of Mogat1, which encodes MGAT1, and MGAT activity are also increased in diet-induced obese (DIO) and ob/obmice. To probe the metabolic effects of MGAT1 in the livers of obese mice, we administered antisense oligonucleotides (ASOs) against Mogat1 to DIO and ob/ob mice for 3 weeks. Knockdown of Mogat1 in liver, which reduced hepatic MGAT activity, did not affect hepatic triacylglycerol content and unexpectedly increased total DAG content. Mogat1 inhibition also increased both membrane and cytosolic compartment DAG levels. However, Mogat1 ASO treatment significantly improved glucose tolerance and hepatic insulin signaling in obese mice. In summary, inactivation of hepatic MGAT activity, which is markedly increased in obese mice, improved glucose tolerance and hepatic insulin signaling independent of changes in body weight, intrahepatic DAG and TAG content, and PKC signaling. PMID:24595352

  8. Cloning and Functional Analysis of Three Diacylglycerol Acyltransferase Genes from Peanut (Arachis hypogaea L.)

    PubMed Central

    Zhang, Xiaowen; Chen, Mingna; Chen, Na; Pan, Lijuan; Wang, Tong; Wang, Mian; Yang, Zhen; Wang, Quanfu; Yu, Shanlin

    2014-01-01

    Diacylglycerol acyltransferase (DGAT) catalyzes the final and only committed acylation step in the synthesis of triacylglycerols. In this study, three novel AhDGATs genes were identified and isolated from peanut. Quantitative real-time RT-PCR analysis indicated that the AhDGAT1-2 transcript was more abundant in roots, seeds, and cotyledons, whereas the transcript abundances of AhDGAT1-1 and AhDGAT3-3 were higher in flowers than in the other tissues examined. During seed development, transcript levels of AhDGAT1-1 remained relatively low during the initial developmental stage but increased gradually during later stages, peaking at 50 days after pegging (DAP). Levels of AhDGAT1-2 transcripts were higher at 10 and 60 DAPs and much lower during other stages, whereas AhDGAT3-3 showed higher expression levels at 20 and 50 DAPs. In addition, AhDGAT transcripts were differentially expressed following exposure to abiotic stresses or abscisic acid. The activity of the three AhDGAT genes was confirmed by heterologous expression in a Saccharomyces cerevisiae TAG-deficient quadruple mutant. The recombinant yeasts restored lipid body formation and TAG biosynthesis, and preferentially incorporated unsaturated C18 fatty acids into lipids. The present study provides significant information useful in modifying the oil deposition of peanut through molecular breeding. PMID:25181516

  9. Poly specific trans-acyltransferase machinery revealed via engineered acyl-CoA synthetases.

    PubMed

    Koryakina, Irina; McArthur, John; Randall, Shan; Draelos, Matthew M; Musiol, Ewa M; Muddiman, David C; Weber, Tilmann; Williams, Gavin J

    2013-01-18

    Polyketide synthases construct polyketides with diverse structures and biological activities via the condensation of extender units and acyl thioesters. Although a growing body of evidence suggests that polyketide synthases might be tolerant to non-natural extender units, in vitro and in vivo studies aimed at probing and utilizing polyketide synthase specificity are severely limited to only a small number of extender units, owing to the lack of synthetic routes to a broad variety of acyl-CoA extender units. Here, we report the construction of promiscuous malonyl-CoA synthetase variants that can be used to synthesize a broad range of malonyl-CoA extender units substituted at the C2-position, several of which contain handles for chemoselective ligation and are not found in natural biosynthetic systems. We highlighted utility of these enzymes by probing the acyl-CoA specificity of several trans-acyltransferases, leading to the unprecedented discovery of poly specificity toward non-natural extender units, several of which are not found in naturally occurring biosynthetic pathways. These results reveal that polyketide biosynthetic machinery might be more tolerant to non-natural substrates than previously established, and that mutant synthetases are valuable tools for probing the specificity of biosynthetic machinery. Our data suggest new synthetic biology strategies for harnessing this promiscuity and enabling the regioselective modification of polyketides. PMID:23083014

  10. Click chemistry armed enzyme-linked immunosorbent assay to measure palmitoylation by hedgehog acyltransferase

    PubMed Central

    Lanyon-Hogg, Thomas; Masumoto, Naoko; Bodakh, George; Konitsiotis, Antonio D.; Thinon, Emmanuelle; Rodgers, Ursula R.; Owens, Raymond J.; Magee, Anthony I.; Tate, Edward W.

    2015-01-01

    Hedgehog signaling is critical for correct embryogenesis and tissue development. However, on maturation, signaling is also found to be aberrantly activated in many cancers. Palmitoylation of the secreted signaling protein sonic hedgehog (Shh) by the enzyme hedgehog acyltransferase (Hhat) is required for functional signaling. To quantify this important posttranslational modification, many in vitro Shh palmitoylation assays employ radiolabeled fatty acids, which have limitations in terms of cost and safety. Here we present a click chemistry armed enzyme-linked immunosorbent assay (click–ELISA) for assessment of Hhat activity through acylation of biotinylated Shh peptide with an alkyne-tagged palmitoyl-CoA (coenzyme A) analogue. Click chemistry functionalization of the alkyne tag with azido-FLAG peptide allows analysis through an ELISA protocol and colorimetric readout. This assay format identified the detergent n-dodecyl β-d-maltopyranoside as an improved solubilizing agent for Hhat activity. Quantification of the potency of RU-SKI small molecule Hhat inhibitors by click–ELISA indicated IC50 values in the low- or sub-micromolar range. A stopped assay format was also employed that allows measurement of Hhat kinetic parameters where saturating substrate concentrations exceed the binding capacity of the streptavidin-coated plate. Therefore, click–ELISA represents a nonradioactive method for assessing protein palmitoylation in vitro that is readily expandable to other classes of protein lipidation. PMID:26334609

  11. Beta2-adrenergic activity modulates vascular tone regulation in lecithin:cholesterol acyltransferase knockout mice

    PubMed Central

    Manzini, S.; Pinna, C.; Busnelli, M.; Cinquanta, P.; Rigamonti, E.; Ganzetti, G.S.; Dellera, F.; Sala, A.; Calabresi, L.; Franceschini, G.; Parolini, C.; Chiesa, G.

    2015-01-01

    Lecithin:cholesterol acyltransferase (LCAT) deficiency is associated with hypoalphalipoproteinemia, generally a predisposing factor for premature coronary heart disease. The evidence of accelerated atherosclerosis in LCAT-deficient subjects is however controversial. In this study, the effect of LCAT deficiency on vascular tone and endothelial function was investigated in LCAT knockout mice, which reproduce the human lipoprotein phenotype. Aortas from wild-type (Lcatwt) and LCAT knockout (LcatKO) mice exposed to noradrenaline showed reduced contractility in LcatKO mice (P < 0.005), whereas acetylcholine exposure showed a lower NO-dependent relaxation in LcatKO mice (P < 0.05). Quantitative PCR and Western blotting analyses suggested an adequate eNOS expression in LcatKO mouse aortas. Real-time PCR analysis indicated increased expression of β2-adrenergic receptors vs wild-type mice. Aorta stimulation with noradrenaline in the presence of propranolol, to abolish the β-mediated relaxation, showed the same contractile response in the two mouse lines. Furthermore, propranolol pretreatment of mouse aortas exposed to L-NAME prevented the difference in responses between Lcatwt and LcatKO mice. The results indicate that LCAT deficiency leads to increased β2-adrenergic relaxation and to a consequently decreased NO-mediated vasodilation that can be reversed to guarantee a correct vascular tone. The present study suggests that LCAT deficiency is not associated with an impaired vascular reactivity. PMID:26254103

  12. Beta2-adrenergic activity modulates vascular tone regulation in lecithin:cholesterol acyltransferase knockout mice.

    PubMed

    Manzini, S; Pinna, C; Busnelli, M; Cinquanta, P; Rigamonti, E; Ganzetti, G S; Dellera, F; Sala, A; Calabresi, L; Franceschini, G; Parolini, C; Chiesa, G

    2015-11-01

    Lecithin:cholesterol acyltransferase (LCAT) deficiency is associated with hypoalphalipoproteinemia, generally a predisposing factor for premature coronary heart disease. The evidence of accelerated atherosclerosis in LCAT-deficient subjects is however controversial. In this study, the effect of LCAT deficiency on vascular tone and endothelial function was investigated in LCAT knockout mice, which reproduce the human lipoprotein phenotype. Aortas from wild-type (Lcat(wt)) and LCAT knockout (Lcat(KO)) mice exposed to noradrenaline showed reduced contractility in Lcat(KO) mice (P<0.005), whereas acetylcholine exposure showed a lower NO-dependent relaxation in Lcat(KO) mice (P<0.05). Quantitative PCR and Western blotting analyses suggested an adequate eNOS expression in Lcat(KO) mouse aortas. Real-time PCR analysis indicated increased expression of β2-adrenergic receptors vs wild-type mice. Aorta stimulation with noradrenaline in the presence of propranolol, to abolish the β-mediated relaxation, showed the same contractile response in the two mouse lines. Furthermore, propranolol pretreatment of mouse aortas exposed to L-NAME prevented the difference in responses between Lcat(wt) and Lcat(KO) mice. The results indicate that LCAT deficiency leads to increased β2-adrenergic relaxation and to a consequently decreased NO-mediated vasodilation that can be reversed to guarantee a correct vascular tone. The present study suggests that LCAT deficiency is not associated with an impaired vascular reactivity. PMID:26254103

  13. Hyperspectral Imaging and Spectroscopy of Fluorescently Coupled Acyl-CoA: Cholesterol Acyltransferase in Insect Cells

    NASA Technical Reports Server (NTRS)

    Malak, H.; Mahtani, H.; Herman, P.; Vecer, J.; Lu, X.; Chang, T. Y.; Richmond, Robert C.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    A high-performance hyperspectral imaging module with high throughput of light suitable for low-intensity fluorescence microscopic imaging and subsequent analysis, including single-pixel-defined emission spectroscopy, was tested on Sf21 insect cells expressing green fluorescence associated with recombinant green fluorescent protein linked or not with the membrane protein acyl-CoA:cholesterol acyltransferase. The imager utilized the phenomenon of optical activity as a new technique providing information over a spectral range of 220-1400 nm, and was inserted between the microscope and an 8-bit CCD video-rate camera. The resulting fluorescence image did not introduce observable image aberrations. The images provided parallel acquisition of well resolved concurrent spatial and spectral information such that fluorescence associated with green fluorescent protein alone was demonstrated to be diffuse within the Sf21 insect cell, and that green fluorescence associated with the membrane protein was shown to be specifically concentrated within regions of the cell cytoplasm. Emission spectra analyzed from different regions of the fluorescence image showed blue shift specific for the regions of concentration associated with the membrane protein.

  14. Putative DHHC-Cysteine-Rich Domain S-Acyltransferase in Plants

    PubMed Central

    Sun, Meihong; Liu, Shiyang; Qi, Baoxiu; Li, Xinzheng

    2013-01-01

    Protein S-acyltransferases (PATs) containing Asp-His-His-Cys within a Cys-rich domain (DHHC-CRD) are polytopic transmembrane proteins that are found in eukaryotic cells and mediate the S-acylation of target proteins. S-acylation is an important secondary and reversible modification that regulates the membrane association, trafficking and function of target proteins. However, little is known about the characteristics of PATs in plants. Here, we identified 804 PATs from 31 species with complete genomes. The analysis of the phylogenetic relationships suggested that all of the PATs fell into 8 groups. In addition, we analysed the phylogeny, genomic organization, chromosome localisation and expression pattern of PATs in Arabidopsis, Oryza sative, Zea mays and Glycine max. The microarray data revealed that PATs genes were expressed in different tissues and during different life stages. The preferential expression of the ZmPATs in specific tissues and the response of Zea mays to treatments with phytohormones and abiotic stress demonstrated that the PATs play roles in plant growth and development as well as in stress responses. Our data provide a useful reference for the identification and functional analysis of the members of this protein family. PMID:24155879

  15. A type 2 diacylglycerol acyltransferase accelerates the triacylglycerol biosynthesis in heterokont oleaginous microalga Nannochloropsis oceanica.

    PubMed

    Li, Da-Wei; Cen, Shi-Ying; Liu, Yu-Hong; Balamurugan, Srinivasan; Zheng, Xin-Yan; Alimujiang, Adili; Yang, Wei-Dong; Liu, Jie-Sheng; Li, Hong-Ye

    2016-07-10

    Oleaginous microalgae have received a considerable attention as potential biofuel feedstock. However, lack of industry-suitable strain with lipid rich biomass limits its commercial applications. Targeted engineering of lipogenic pathways represents a promising strategy to enhance the efficacy of microalgal oil production. In this study, a type 2 diacylglycerol acyltransferase (DGAT), a rate-limiting enzyme in triacylglycerol (TAG) biosynthesis, was identified and overexpressed in heterokont oleaginous microalga Nannochloropsis oceanica for the first time. Overexpression of DGAT2 in Nannochloropsis increased the relative transcript abundance by 3.48-fold in engineered microalgae cells. TAG biosynthesis was subsequently accelerated by DGAT2 overexpression and neutral lipid content was significantly elevated by 69% in engineered microalgae. The fatty acid profile determined by GC-MS revealed that fatty acid composition was altered in engineered microalgae. Saturated fatty acids and polyunsaturated fatty acids were found to be increased whereas monounsaturated fatty acids content decreased. Furthermore, DGAT2 overexpression did not show negative impact on algal growth parameters. The present investigation showed that the identified DGAT2 would be a potential candidate for enhancing TAG biosynthesis and might facilitate the development of promising oleaginous strains with industrial potential. PMID:27164260

  16. Selectivity of microbial acyl-CoA: cholesterol acyltransferase inhibitors toward isozymes.

    PubMed

    Ohshiro, Taichi; Rudel, Lawrence L; Omura, Satoshi; Tomoda, Hiroshi

    2007-01-01

    The selectivity of microbial inhibitors of acyl-CoA: cholesterol acyltransferase (ACAT) toward the two isozymes, ACAT1 and ACAT2, was assessed in cell-based assays. Purpactin A (IC50 values of ACAT1 vs. IC50 values of ACAT2; 2.5 microM vs. 1.5 microM), terpendole C (10 microM vs. 10 microM), glisoprenin A (4.3 microM vs. 10 microM), spylidone (25 microM vs. 5.0 microM) and synthetic CL-283,546 (0.1 microM vs. 0.09 microM) inhibited ACAT1 and ACAT2 to similar extents. Beauveriolides I (0.6 microM vs. 20 microM) and III (0.9 microM vs. >20 microM) inhibited ACAT1 rather selectively, while pyripyropenes A (>80 microM vs. 0.07 microM), B (48 microM vs. 2.0 microM), C (32 microM vs. 0.36 microM) and D (38 microM vs. 1.5 microM) showed selective inhibition against ACAT2. In particular, pyripyropene A was found to be the most selective ACAT2 inhibitor with a selective index of more than 1,000. PMID:17390588

  17. Acute Sterol O-Acyltransferase 2 (SOAT2) Knockdown Rapidly Mobilizes Hepatic Cholesterol for Fecal Excretion

    PubMed Central

    Marshall, Stephanie M.; Gromovsky, Anthony D.; Kelley, Kathryn L.; Davis, Matthew A.; Wilson, Martha D.; Lee, Richard G.; Crooke, Rosanne M.; Graham, Mark J.; Rudel, Lawrence L.

    2014-01-01

    The primary risk factor for atherosclerotic cardiovascular disease is LDL cholesterol, which can be reduced by increasing cholesterol excretion from the body. Fecal cholesterol excretion can be driven by a hepatobiliary as well as a non-biliary pathway known as transintestinal cholesterol efflux (TICE). We previously showed that chronic knockdown of the hepatic cholesterol esterifying enzyme sterol O-acyltransferase 2 (SOAT2) increased fecal cholesterol loss via TICE. To elucidate the initial events that stimulate TICE, C57Bl/6 mice were fed a high cholesterol diet to induce hepatic cholesterol accumulation and were then treated for 1 or 2 weeks with an antisense oligonucleotide targeting SOAT2. Within 2 weeks of hepatic SOAT2 knockdown (SOAT2HKD), the concentration of cholesteryl ester in the liver was reduced by 70% without a reciprocal increase in hepatic free cholesterol. The rapid mobilization of hepatic cholesterol stores resulted in a ∼2-fold increase in fecal neutral sterol loss but no change in biliary cholesterol concentration. Acute SOAT2HKD increased plasma cholesterol carried primarily in lipoproteins enriched in apoB and apoE. Collectively, our data suggest that acutely reducing SOAT2 causes hepatic cholesterol to be swiftly mobilized and packaged onto nascent lipoproteins that feed cholesterol into the TICE pathway for fecal excretion. PMID:24901470

  18. Molecular and phylogenetic analysis of pyridoxal phosphate-dependent acyltransferase of Exiguobacterium acetylicum.

    PubMed

    Rajendran, Narayanan; Smith, Colby; Mazhawidza, Williard

    2009-01-01

    The pyridoxal-5'-phosphate (PLP)-dependent family of enzymes is a very diverse group of proteins that metabolize small molecules like amino acids and sugars, and synthesize cofactors for other metabolic pathways through transamination, decarboxylation, racemization, and substitution reactions. In this study we employed degenerated primer-based PCR amplification, using genomic DNA isolated from the soil bacterium Exiguobacterium acetylicum strain SN as template. We revealed the presence of a PLP-dependent family of enzymes, such as PLP-dependent acyltransferase, and similarity to 8-amino-7-oxononoate synthase. Sequencing analysis and multiple alignment of the thymidine-adenine-cloned PCR amplicon revealed PLP-dependent family enzymes with specific confering codes and consensus amino acid residues specific to this group of functional proteins. Amino acid residues common to the majority of PLP-dependent enzymes were also revealed by the Lasergene MegAlign software. A phylogenetic tree was constructed. Its analysis revealed a close relationship of E. acetylicum to other bacteria isolated from extreme environments suggesting similarities in anabolic adaptability and evolutionary development. PMID:20158163

  19. Phosphatidic acid phosphatase and diacylglycerol acyltransferase: potential targets for metabolic engineering of microorganism oil.

    PubMed

    Jin, Hong-Hao; Jiang, Jian-Guo

    2015-04-01

    Oleaginous microorganism is becoming one of the most promising oil feedstocks for biodiesel production due to its great advantages in triglyceride (TAG) accumulation. Previous studies have shown that de novo TAG biosynthesis can be divided into two parts: the fatty acid biosynthesis pathway (the upstream part which generates acyl-CoAs) and the glycerol-3-phosphate acylation pathway (the downstream part in which three acyl groups are sequentially added onto a glycerol backbone). This review mainly focuses on two enzymes in the G3P pathway, phosphatidic acid phosphatase (PAP) and diacylglycerol acyltransferase (DGAT). The former catalyzes a dephosphorylation reaction, and the latter catalyzes a subsequent acylation reaction. Genes, functional motifs, transmembrane domains, action mechanism, and new studies of the two enzymes are discussed in detail. Furthermore, this review also covers diacylglycerol kinase, an enzyme that catalyzes the reverse reaction of diacylglycerol formation. In addition, PAP and DGAT are the conjunction points of the G3P pathway, the Kennedy pathway, and the CDP-diacylglycerol pathway (CDP-DAG pathway), and the mutual transformation between TAGs and phospholipids is discussed as well. Given that both the Kennedy and CDP-diacylglycerol pathways are in metabolic interlock (MI) with the G3P pathway, it is suggested that, via metabolic engineering, TAG accumulation can be improved by the two pathways based on the pivotal function of PAP and DGAT. PMID:25672855

  20. Engineering increased triacylglycerol accumulation in Saccharomyces cerevisiae using a modified type 1 plant diacylglycerol acyltransferase.

    PubMed

    Greer, Michael S; Truksa, Martin; Deng, Wei; Lung, Shiu-Cheung; Chen, Guanqun; Weselake, Randall J

    2015-03-01

    Diacylglycerol acyltransferase (DGAT) catalyzes the acyl-CoA-dependent acylation of sn-1,2-diacylglycerol to produce triacylglycerol (TAG). This enzyme, which is critical to numerous facets of oilseed development, has been highlighted as a genetic engineering target to increase storage lipid production in microorganisms designed for biofuel applications. Here, four transcriptionally active DGAT1 genes were identified and characterized from the oil crop Brassica napus. Overexpression of each BnaDGAT1 in Saccharomyces cerevisiae increased TAG biosynthesis. Further studies showed that adding an N-terminal tag could mask the deleterious influence of the DGATs' native N-terminal sequences, resulting in increased in vivo accumulation of the polypeptides and an increase of up to about 150-fold in in vitro enzyme activity. The levels of TAG and total lipid fatty acids in S. cerevisiae producing the N-terminally tagged BnaDGAT1.b at 72 h were 53 and 28 % higher than those in cultures producing untagged BnaA.DGAT1.b, respectively. These modified DGATs catalyzed the synthesis of up to 453 mg fatty acid/L by this time point. The results will be of benefit in the biochemical analysis of recombinant DGAT1 produced through heterologous expression in yeast and offer a new approach to increase storage lipid content in yeast for industrial applications. PMID:25520169

  1. Selective inhibitors of a PAF biosynthetic enzyme lysophosphatidylcholine acyltransferase 2[S

    PubMed Central

    Tarui, Megumi; Shindou, Hideo; Kumagai, Kazuo; Morimoto, Ryo; Harayama, Takeshi; Hashidate, Tomomi; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Nagase, Takahide; Shimizu, Takao

    2014-01-01

    Platelet-activating factor (PAF) is a potent pro-inflammatory phospholipid mediator. In response to extracellular stimuli, PAF is rapidly biosynthesized by lyso-PAF acetyltransferase (lyso-PAFAT). Previously, we identified two types of lyso-PAFATs: lysophosphatidylcholine acyltransferase (LPCAT)1, mostly expressed in the lungs where it produces PAF and dipalmitoyl-phosphatidylcholine essential for respiration, and LPCAT2, which biosynthesizes PAF and phosphatidylcholine (PC) in the inflammatory cells. Under inflammatory conditions, LPCAT2, but not LPCAT1, is activated and upregulated to produce PAF. Thus, it is important to develop inhibitors specific for LPCAT2 in order to ameliorate PAF-related inflammatory diseases. Here, we report the first identification of LPCAT2-specific inhibitors, N-phenylmaleimide derivatives, selected from a 174,000-compound library using fluorescence-based high-throughput screening followed by the evaluation of the effects on LPCAT1 and LPCAT2 activities, cell viability, and cellular PAF production. Selected compounds competed with acetyl-CoA for the inhibition of LPCAT2 lyso-PAFAT activity and suppressed PAF biosynthesis in mouse peritoneal macrophages stimulated with a calcium ionophore. These compounds had low inhibitory effects on LPCAT1 activity, indicating that adverse effects on respiratory functions may be avoided. The identified compounds and their derivatives will contribute to the development of novel drugs for PAF-related diseases and facilitate the analysis of LPCAT2 functions in phospholipid metabolism in vivo. PMID:24850807

  2. Rimonabant is a dual inhibitor of acyl CoA:cholesterol acyltransferases 1 and 2.

    PubMed

    Netherland, Courtney; Thewke, Douglas P

    2010-08-01

    Acyl coenzyme A:cholesterol acyltransferase (ACAT) catalyzes the intracellular synthesis of cholesteryl esters (CE). Both ACAT isoforms, ACAT1 and ACAT2, play key roles in the pathophysiology of atherosclerosis and ACAT inhibition retards atherosclerosis in animal models. Rimonabant, a type 1 cannabinoid receptor (CB1) antagonist, produces anti-atherosclerotic effects in humans and animals by mechanisms which are not completely understood. Rimonabant is structurally similar to two other cannabinoid receptor antagonists, AM251 and SR144528, recently identified as potent inhibitors of ACAT. Therefore, we examined the effects of Rimonabant on ACAT using both in vivo cell-based assays and in vitro cell-free assays. Rimonabant dose-dependently reduced ACAT activity in Raw 264.7 macrophages (IC(50)=2.9+/-0.38 microM) and isolated peritoneal macrophages. Rimonabant inhibited ACAT activity in intact CHO-ACAT1 and CHO-ACAT2 cells and in cell-free assays with approximately equal efficiency (IC(50)=1.5+/-1.2 microM and 2.2+/-1.1 microM for CHO-ACAT1 and CHO-ACAT2, respectively). Consistent with ACAT inhibition, Rimonabant treatment blocked ACAT-dependent processes in macrophages, oxysterol-induced apoptosis and acetylated-LDL induced foam cell formation. From these results we conclude that Rimonabant is an ACAT1/2 dual inhibitor and suggest that some of the atherosclerotic beneficial effects of Rimonabant are, at least partly, due to inhibition of ACAT. PMID:20609360

  3. Reprogramming acyl carrier protein interactions of an acyl-CoA promiscuous trans-acyltransferase

    PubMed Central

    Ye, Zhixia; Musiol, Ewa M; Weber, Tilmann; Williams, Gavin J

    2014-01-01

    SUMMARY Protein interactions between acyl carrier proteins (ACP’s) and trans-acting acyltransferase domains (trans-AT’s) are critical for regioselective extender unit installation by many polyketide synthases. Yet, little is known regarding the specificity of these interactions, particularly for trans-AT’s with unusual extender unit specificities. Currently, the best-studied trans-AT with non-malonyl specificity is KirCII from kirromycin biosynthesis. Here, we developed a new assay to probe ACP interactions based on leveraging the extender unit promiscuity of KirCII. The assay allows us to identify residues on the ACP surface that contribute to specific recognition by KirCII. This information proved sufficient to modify a non-cognate ACP from a different biosynthetic system to be a substrate for KirCII. The findings form a foundation for further understanding the specificity of trans-AT:ACP protein interactions, and for engineering modular polyketide synthases to produce analogues. PMID:24726832

  4. Lecithin-cholesterol acyltransferase in brain: Does oxidative stress influence the 24-hydroxycholesterol esterification?

    PubMed

    La Marca, Valeria; Maresca, Bernardetta; Spagnuolo, Maria Stefania; Cigliano, Luisa; Dal Piaz, Fabrizio; Di Iorio, Giuseppe; Abrescia, Paolo

    2016-04-01

    24-Hydroxycholesterol (24OH-C) is esterified by the enzyme lecithin-cholesterol acyltransferase (LCAT) in the cerebrospinal fluid (CSF). We report here that the level of 24OH-C esters was lower in CSF of patients with amyotrophic lateral sclerosis than in healthy subjects (54% vs 68% of total 24OH-C, p=0.0005; n=8). Similarly, the level of 24OH-C esters in plasma was lower in patients than in controls (62% vs 77% of total 24OH-C; p=0.0076). The enzyme amount in CSF, as measured by densitometry of the protein band revealed by immunoblotting, was about 4-fold higher in patients than in controls (p=0.0085). As differences in the concentration of the LCAT stimulator Apolipoprotein E were not found, we hypothesized that the reduced 24OH-C esterification in CSF of patients might depend on oxidative stress. We actually found that oxidative stress reduced LCAT activity in vitro, and 24OH-C effectively stimulated the enzyme secretion from astrocytoma cells in culture. Enhanced LCAT secretion from astrocytes might represent an adaptive response to the increase of non-esterified 24OH-C percentage, aimed to avoid the accumulation of this neurotoxic compound. The low degree of 24OH-C esterification in CSF or plasma might reflect reduced activity of LCAT during neurodegeneration. PMID:26454063

  5. Comparative gene identification 58/α/β hydrolase domain 5 lacks lysophosphatidic acid acyltransferase activity

    PubMed Central

    McMahon, Derek; Dinh, Anna; Kurz, Daniel; Shah, Dharika; Han, Gil-Soo; Carman, George M.; Brasaemle, Dawn L.

    2014-01-01

    Mutations in the gene encoding comparative gene identification 58 (CGI-58)/α/β hydrolase domain 5 (ABHD5) cause Chanarin-Dorfman syndrome, characterized by excessive triacylglycerol storage in cells and tissues. CGI-58 has been identified as a coactivator of adipose TG lipase (ATGL) and a lysophosphatidic acid acyltransferase (LPAAT). We developed a molecular model of CGI-58 structure and then mutated predicted active site residues and performed LPAAT activity assays of recombinant WT and mutated CGI-58. When mutations of predicted catalytic residues failed to reduce LPAAT activity, we determined that LPAAT activity was due to a bacterial contaminant of affinity purification procedures, plsC, the sole LPAAT in Escherichia coli. Purification protocols were optimized to reduce plsC contamination, in turn reducing LPAAT activity. When CGI-58 was expressed in SM2-1(DE3) cells that lack plsC, lysates lacked LPAAT activity. Additionally, mouse CGI-58 expressed in bacteria as a glutathione-S-transferase fusion protein and human CGI-58 expressed in yeast lacked LPAAT activity. Previously reported lipid binding activity of CGI-58 was revisited using protein-lipid overlays. Recombinant CGI-58 failed to bind lysophosphatidic acid, but interestingly, bound phosphatidylinositol 3-phosphate [PI(3)P] and phosphatidylinositol 5-phosphate [PI(5)P]. Prebinding CGI-58 with PI(3)P or PI(5)P did not alter its coactivation of ATGL in vitro. In summary, purified recombinant CGI-58 that is functional as an ATGL coactivator lacks LPAAT activity. PMID:24879803

  6. The last step in cocaine biosynthesis is catalyzed by a BAHD acyltransferase.

    PubMed

    Schmidt, Gregor Wolfgang; Jirschitzka, Jan; Porta, Tiffany; Reichelt, Michael; Luck, Katrin; Torre, José Carlos Pardo; Dolke, Franziska; Varesio, Emmanuel; Hopfgartner, Gérard; Gershenzon, Jonathan; D'Auria, John Charles

    2015-01-01

    The esterification of methylecgonine (2-carbomethoxy-3β-tropine) with benzoic acid is the final step in the biosynthetic pathway leading to the production of cocaine in Erythoxylum coca. Here we report the identification of a member of the BAHD family of plant acyltransferases as cocaine synthase. The enzyme is capable of producing both cocaine and cinnamoylcocaine via the activated benzoyl- or cinnamoyl-Coenzyme A thioesters, respectively. Cocaine synthase activity is highest in young developing leaves, especially in the palisade parenchyma and spongy mesophyll. These data correlate well with the tissue distribution pattern of cocaine as visualized with antibodies. Matrix-assisted laser-desorption ionization mass spectral imaging revealed that cocaine and cinnamoylcocaine are differently distributed on the upper versus lower leaf surfaces. Our findings provide further evidence that tropane alkaloid biosynthesis in the Erythroxylaceae occurs in the above-ground portions of the plant in contrast with the Solanaceae, in which tropane alkaloid biosynthesis occurs in the roots. PMID:25406120

  7. The Last Step in Cocaine Biosynthesis Is Catalyzed by a BAHD Acyltransferase[OPEN

    PubMed Central

    Schmidt, Gregor Wolfgang; Porta, Tiffany; Reichelt, Michael; Luck, Katrin; Torre, José Carlos Pardo; Dolke, Franziska; Varesio, Emmanuel; Hopfgartner, Gérard; Gershenzon, Jonathan

    2015-01-01

    The esterification of methylecgonine (2-carbomethoxy-3β-tropine) with benzoic acid is the final step in the biosynthetic pathway leading to the production of cocaine in Erythoxylum coca. Here we report the identification of a member of the BAHD family of plant acyltransferases as cocaine synthase. The enzyme is capable of producing both cocaine and cinnamoylcocaine via the activated benzoyl- or cinnamoyl-Coenzyme A thioesters, respectively. Cocaine synthase activity is highest in young developing leaves, especially in the palisade parenchyma and spongy mesophyll. These data correlate well with the tissue distribution pattern of cocaine as visualized with antibodies. Matrix-assisted laser-desorption ionization mass spectral imaging revealed that cocaine and cinnamoylcocaine are differently distributed on the upper versus lower leaf surfaces. Our findings provide further evidence that tropane alkaloid biosynthesis in the Erythroxylaceae occurs in the above-ground portions of the plant in contrast with the Solanaceae, in which tropane alkaloid biosynthesis occurs in the roots. PMID:25406120

  8. Acyl-coenzyme A:cholesterol O-acyltransferase is not identical to liver microsomal carboxylesterase.

    PubMed

    Diczfalusy, M A; Björkhem, I; Einarsson, K; Alexson, S E

    1996-04-01

    Acyl-coenzyme A (CoA):cholesterol O-acyltransferase (ACAT) is responsible for esterification of cholesterol in the cell. The enzyme has never been purified, but two cDNA sequences coding for this enzyme were recently reported. One of the sequences was identical to human liver carboxylesterase. We have used inhibitors to elucidate the relation between microsomal carboxylesterase, acyl-CoA hydrolase (ACH), and ACAT activities in rat liver. Low concentrations of serine esterase inhibitors strongly inhibited carboxylesterase and acyl-CoA hydrolase activities but stimulated ACAT activity. At higher concentrations, ACAT activity was also inhibited. A sulfhydryl-modifying agent was found to be a potent inhibitor of ACAT without affecting carboxylesterase activity. Similarly, two specific ACAT inhibitors, DL-melinamide and PD 138142-15, inhibited ACAT activity but did not affect carboxylesterase or ACH activities. Our data thus exclude ACAT as a liver microsomal carboxylesterase. The complex inhibition patterns observed with serine esterase inhibitors indicate that carboxylesterases and ACHs may interfere with ACAT activity by competing for the substrate. It is obvious that final identification of ACAT requires demonstration of an active homogenous protein. PMID:8624784

  9. Naltrexone for Alcoholism

    MedlinePlus

    MENU Return to Web version Naltrexone for Alcoholism Naltrexone for Alcoholism Is alcoholism a disease? Yes. Most experts agree that alcoholism is a disease, just as high blood pressure, diabetes and ...

  10. Fetal Alcohol Spectrum Disorders

    MedlinePlus

    ... alcohol can cause a group of conditions called fetal alcohol spectrum disorders (FASDs). Effects can include physical and behavioral problems such ... alcohol syndrome is the most serious type of FASD. People with fetal alcohol syndrome have facial abnormalities, ...

  11. Understanding the role of histidine in the GHSxG acyltransferase active site motif: Evidence for histidine stabilization of the malonyl-enzyme intermediate

    DOE PAGESBeta

    Poust, Sean; Yoon, Isu; Adams, Paul D.; Katz, Leonard; Petzold, Christopher J.; Keasling, Jay D.

    2014-10-06

    Acyltransferases determine which extender units are incorporated into polyketide and fatty acid products. Thus, the ping-pong acyltransferase mechanism utilizes a serine in a conserved GHSxG motif. However, the role of the conserved histidine in this motif is poorly understood. We observed that a histidine to alanine mutation (H640A) in the GHSxG motif of the malonyl-CoA specific yersiniabactin acyltransferase results in an approximately seven-fold higher hydrolysis rate over the wildtype enzyme, while retaining transacylation activity. We propose two possibilities for the reduction in hydrolysis rate: either H640 structurally stabilizes the protein by hydrogen bonding with a conserved asparagine in the ferredoxin-likemore » subdomain of the protein, or a water-mediated hydrogen bond between H640 and the malonyl moiety stabilizes the malonyl-O-AT ester intermediate.« less

  12. A Double-Hotdog with a New Trick: Structure and Mechanism of the trans-Acyltransferase Polyketide Synthase Enoyl-isomerase

    PubMed Central

    2015-01-01

    Many polyketide natural products exhibit invaluable medicinal properties, yet much remains to be understood regarding the machinery responsible for their biosynthesis. The recently discovered trans-acyltransferase polyketide synthases employ processing enzymes that catalyze modifications unique from those of the classical cis-acyltransferase polyketide synthases. The enoyl-isomerase domains of these megasynthases shift double bonds and are well-represented by an enzyme that helps forge the triene system within the antibiotic produced by the prototypical bacillaene synthase. This first crystal structure of an enoyl-isomerase, at 1.73 Å resolution, not only revealed relationships between this class of enzymes and dehydratases but also guided an investigation into the mechanism of double bond migration. The catalytic histidine, positioned differently from that of dehydratases, was demonstrated to independently shuttle a proton between the γ- and α-positions of the intermediate. This unprecedented mechanism highlights the catalytic diversity of divergent enzymes within trans-acyltransferase polyketide synthases. PMID:25089587

  13. Understanding the role of histidine in the GHSxG acyltransferase active site motif: Evidence for histidine stabilization of the malonyl-enzyme intermediate

    SciTech Connect

    Poust, Sean; Yoon, Isu; Adams, Paul D.; Katz, Leonard; Petzold, Christopher J.; Keasling, Jay D.

    2014-10-06

    Acyltransferases determine which extender units are incorporated into polyketide and fatty acid products. Thus, the ping-pong acyltransferase mechanism utilizes a serine in a conserved GHSxG motif. However, the role of the conserved histidine in this motif is poorly understood. We observed that a histidine to alanine mutation (H640A) in the GHSxG motif of the malonyl-CoA specific yersiniabactin acyltransferase results in an approximately seven-fold higher hydrolysis rate over the wildtype enzyme, while retaining transacylation activity. We propose two possibilities for the reduction in hydrolysis rate: either H640 structurally stabilizes the protein by hydrogen bonding with a conserved asparagine in the ferredoxin-like subdomain of the protein, or a water-mediated hydrogen bond between H640 and the malonyl moiety stabilizes the malonyl-O-AT ester intermediate.

  14. Allyl alcohol

    Integrated Risk Information System (IRIS)

    Allyl alcohol ; CASRN 107 - 18 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  15. Isobutyl alcohol

    Integrated Risk Information System (IRIS)

    Isobutyl alcohol ; CASRN 78 - 83 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  16. Propargyl alcohol

    Integrated Risk Information System (IRIS)

    Propargyl alcohol ; CASRN 107 - 19 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  17. Alcohol fuels

    SciTech Connect

    Not Available

    1981-07-01

    The API publication 4312 reports a detailed study carried out by Battelle on the energy balances for five alcohol-fuel-producing technologies. The results indicate that processes for producing ethanol from corn are net consumers of energy while ethanol from sugar cane and methanol from wood are net energy producers.

  18. Alcoholism and Minority Populations.

    ERIC Educational Resources Information Center

    Watts, Thomas D.; Wright, Roosevelt, Jr.

    1991-01-01

    Briefly discusses some aspects of the role of the state and the position of minorities in respect to alcoholism policies and services. Includes case study of a Black alcoholic. Refers readers to studies on Black alcoholism, Native American alcoholism, Hispanic alcoholism, and Asian-American alcoholism. (Author/NB)

  19. Novel serum biomarkers for detection of excessive alcohol use

    PubMed Central

    Liangpunsakul, Suthat; Lai, Xianyin; Ross, Ruth A.; Yu, Zhangsheng; Modlik, Elizabeth; Westerhold, Chi; Heathers, Laura; Paul, Robin; O’Connor, Sean; Crabb, David W.; Witzmann, Frank

    2015-01-01

    Objectives Construct interview that correctly identifies those with alcohol use disorder have limitation, especially when the subjects are motivated to minimize the magnitude of drinking behavior. Current laboratory tests to detect excessive alcohol consumption are limited by marginal sensitivity/specificity. Excessive drinking has been shown to affect several organ systems; which may be reflected in changes in quantity of plasma proteins. Our aim was to employ novel proteomic analyses to identify potential markers for excessive alcohol use. METHODS A prospective case-control study that included 39 controls and 54 excessive drinkers (discovery cohort). The serum proteomic analyses in these subjects were performed and the results were tested in the verification cohort (40 controls and 40 excessive drinkers). RESULTS Using the appropriate cutoff and confirmation with ELISA, we identified 4 proteins which were significantly elevated in the serum of excessive drinkers; AT-rich interactive domain-containing protein 4B (ARID4B), Phosphatidylcholine-sterol acyltransferase (LCAT), Hepatocyte growth factor-like protein (MST1), and ADP-ribosylation factor 6 (ARL6). The performance of the conventional markers (AST, ALT, GGT, %CDT, and MCV) discriminating between excessive alcohol use and controls had an area under the curve (AUC) ranging from 0.21 (ALT) to 0.67 (MCV). The AUC of these novel proteins showed the improvement in the detection of excessive drinkers compared to conventional lab tests, ranging from 0.73 (for ARID4B) to 0.86 (for ARL6). CONCLUSIONS We have identified four novel proteins that can discern subjects with excessive alcohol use. Further studies are needed to determine the clinical implications of these markers to detect excessive alcohol use and confirm abstinence. PMID:25704570

  20. Alcohol exposure in utero perturbs retinoid homeostasis in adult rats

    PubMed Central

    Kim, Youn-Kyung; Zuccaro, Michael V.; Zhang, Changqing; Sarkar, Dipak

    2015-01-01

    Background Maternal alcohol exposure and adult alcohol intake have been shown to perturb the metabolism of various micro- and macro-nutrients, including vitamin A and its derivatives (retinoids). Therefore, it has been hypothesized that the well-known detrimental consequences of alcohol consumption may be due to deregulations of the metabolism of such nutrients rather than to a direct effect of alcohol. Alcohol exposure in utero also has long-term harmful consequences on the health of the offspring with mechanisms that have not been fully clarified. Disruption of tissue retinoid homeostasis has been linked not only to abnormal embryonic development, but also to various adult pathological conditions, including cancer, metabolic disorders and abnormal lung function. We hypothesized that prenatal alcohol exposure may permanently perturb tissue retinoid metabolism, predisposing the offspring to adult chronic diseases. Methods Serum and tissues (liver, lung and prostate from males; liver and lung from females) were collected from 60-75 day-old sprague dawley rats born from dams that were: (I) fed a liquid diet containing 6.7% alcohol between gestational day 7 and 21; or (II) pair-fed with isocaloric liquid diet during the same gestational window; or (III) fed ad libitum with regular rat chow diet throughout pregnancy. Serum and tissue retinoid levels were analyzed by reverse-phase high-performance liquid chromatography (HPLC). Serum retinol-binding protein (RBP) levels were measured by western blot analysis, and liver, lung and prostate mRNA levels of lecithin-retinol acyltransferase (LRAT) were measured by qPCR. Results Retinyl ester levels were significantly reduced in the lung of both males and females, as well as in the liver and ventral prostate of males born from alcohol-fed dams. Tissue LRAT mRNA levels remained unchanged upon maternal alcohol treatment. Conclusions Prenatal alcohol exposure in rats affects retinoid metabolism in adult life, in a tissue- and sex

  1. Mitsugumin 56 (hedgehog acyltransferase-like) is a sarcoplasmic reticulum-resident protein essential for postnatal muscle maturation.

    PubMed

    Van, Bo; Nishi, Miyuki; Komazaki, Shinji; Ichimura, Atsuhiko; Kakizawa, Sho; Nakanaga, Keita; Aoki, Junken; Park, Ki-Ho; Ma, Jianjie; Ueyama, Tomomi; Ogata, Takehiro; Maruyama, Naoki; Takeshima, Hiroshi

    2015-04-28

    Mitsugumin 56 (MG56), also known as the membrane-bound O-acyl-transferase family member hedgehog acyltransferase-like, was identified as a new sarcoplasmic reticulum component in striated muscle. Mg56-knockout mice grew normally for a week after birth, but shortly thereafter exhibited a suckling defect and died under starvation conditions. In the knockout skeletal muscle, regular contractile features were largely preserved, but sarcoplasmic reticulum elements swelled and further developed enormous vacuoles. In parallel, the unfolded protein response was severely activated in the knockout muscle, and presumably disrupted muscle development leading to the suckling failure. Therefore, MG56 seems essential for postnatal skeletal muscle maturation. PMID:25841338

  2. Severe high-density lipoprotein deficiency associated with autoantibodies against lecithin:cholesterol acyltransferase in non-Hodgkin lymphoma.

    PubMed

    Simonelli, Sara; Gianazza, Elisabetta; Mombelli, Giuliana; Bondioli, Alighiero; Ferraro, Giovanni; Penco, Silvana; Sirtori, Cesare R; Franceschini, Guido; Calabresi, Laura

    2012-01-23

    An antibody against the lecithin:cholesterol acyltransferase (LCAT) enzyme, which negates cholesterol esterification in plasma, causing severe high-density lipoprotein deficiency (HD), was identified in a woman with a large-cell non-Hodgkin lymphoma. Successful treatment of the lymphoma resulted in clearance of the antibody and complete correction of the defective cholesterol esterification and HD. To our knowledge, an acquired LCAT deficiency leading to severe HD has not been reported previously in association with a malignant disease, and this patient represents the first such documented case. PMID:22271127

  3. Pyripyropenes, novel inhibitors of acyl-CoA:cholesterol acyltransferase produced by Aspergillus fumigatus. I. Production, isolation, and biological properties.

    PubMed

    Tomoda, H; Kim, Y K; Nishida, H; Masuma, R; Omura, S

    1994-02-01

    Aspergillus fumigatus FO-1289, a soil isolate, was found to produce a series of novel inhibitors of acyl-CoA:cholesterol acyltransferase (ACAT). Four active compounds, named pyripyropenes A, B, C and D, were isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography, ODS column chromatography and preparative HPLC. Pyripyropenes A, B, C and D show very potent ACAT inhibitory activity in an enzyme assay system using rat liver microsomes with IC50 values of 58, 117, 53 and 268 nM, respectively. PMID:8150709

  4. Inhibiting monoacylglycerol acyltransferase 1 ameliorates hepatic metabolic abnormalities but not inflammation and injury in mice.

    PubMed

    Soufi, Nisreen; Hall, Angela M; Chen, Zhouji; Yoshino, Jun; Collier, Sara L; Mathews, James C; Brunt, Elizabeth M; Albert, Carolyn J; Graham, Mark J; Ford, David A; Finck, Brian N

    2014-10-24

    Abnormalities in hepatic lipid metabolism and insulin action are believed to play a critical role in the etiology of nonalcoholic steatohepatitis. Monoacylglycerol acyltransferase (MGAT) enzymes convert monoacylglycerol to diacylglycerol, which is the penultimate step in one pathway for triacylglycerol synthesis. Hepatic expression of Mogat1, which encodes an MGAT enzyme, is increased in the livers of mice with hepatic steatosis, and knocking down Mogat1 improves glucose metabolism and hepatic insulin signaling, but whether increased MGAT activity plays a role in the etiology of nonalcoholic steatohepatitis is unclear. To examine this issue, mice were placed on a diet containing high levels of trans fatty acids, fructose, and cholesterol (HTF-C diet) or a low fat control diet for 4 weeks. Mice were injected with antisense oligonucleotides (ASOs) to knockdown Mogat1 or a scrambled ASO control for 12 weeks while remaining on diet. The HTF-C diet caused glucose intolerance, hepatic steatosis, and induced hepatic gene expression markers of inflammation, macrophage infiltration, and stellate cell activation. Mogat1 ASO treatment, which suppressed Mogat1 expression in liver and adipose tissue, attenuated weight gain, improved glucose tolerance, improved hepatic insulin signaling, and decreased hepatic triacylglycerol content compared with control ASO-treated mice on HTF-C chow. However, Mogat1 ASO treatment did not reduce hepatic diacylglycerol, cholesterol, or free fatty acid content; improve histologic measures of liver injury; or reduce expression of markers of stellate cell activation, liver inflammation, and injury. In conclusion, inhibition of hepatic Mogat1 in HTF-C diet-fed mice improves hepatic metabolic abnormalities without attenuating liver inflammation and injury. PMID:25213859

  5. Overexpression of lecithin:cholesterol acyltransferase in transgenic rabbits prevents diet-induced atherosclerosis.

    PubMed Central

    Hoeg, J M; Santamarina-Fojo, S; Bérard, A M; Cornhill, J F; Herderick, E E; Feldman, S H; Haudenschild, C C; Vaisman, B L; Hoyt, R F; Demosky, S J; Kauffman, R D; Hazel, C M; Marcovina, S M; Brewer, H B

    1996-01-01

    Lecithin:cholesterol acyltransferase (LCAT) is a key plasma enzyme in cholesterol and high density lipoprotein (HDL) metabolism. Transgenic rabbits overexpressing human LCAT had 15-fold greater plasma LCAT activity that nontransgenic control rabbits. This degree of overexpression was associated with a 6.7-fold increase in the plasma HDL cholesterol concentration in LCAT transgenic rabbits. On a 0.3% cholesterol diet, the HDL cholesterol concentrations increased from 24 +/- 1 to 39 +/- 3 mg/dl in nontransgenic control rabbits (n = 10; P < 0.05) and increased from 161 +/- 5 to 200 +/- 21 mg/dl (P < 0.001) in the LCAT transgenic rabbits (n = 9). Although the baseline non-HDL concentrations of control (4 +/- 3 mg/dl) and transgenic rabbits (18 +/- 4 mg/dl) were similar, the cholesterol-rich diet raised the non-HDL cholesterol concentrations, reflecting the atherogenic very low density, intermediate density, and low density lipoprotein particles observed by gel filtration chromatography. The non-HDL cholesterol rose to 509 +/- 57 mg/dl in controls compared with only 196 +/- 14 mg/dl in the LCAT transgenic rabbits (P < 0.005). The differences in the plasma lipoprotein response to a cholesterol-rich diet observed in the transgenic rabbits paralleled the susceptibility to developing aortic atherosclerosis. Compared with nontransgenic controls, LCAT transgenic rabbits were protected from diet-induced atherosclerosis with significant reductions determined by both quantitative planimetry (-86%; P < 0.003) and quantitative immunohistochemistry (-93%; P < 0.009). Our results establish the importance of LCAT in the metabolism of both HDL and apolipoprotein B-containing lipoprotein particles with cholesterol feeding and the response to diet-induced atherosclerosis. In addition, these findings identify LCAT as a new target for therapy to prevent atherosclerosis. Images Fig. 2 Fig. 3 Fig. 4 PMID:8876155

  6. Regulation of plasma lecithin:cholesterol acyltransferase. II. Activation during alimentary lipemia.

    PubMed

    Rose, H G; Juliano, J

    1977-03-01

    The effect of dietary fat on plasma lecithin:cholesterol acyltransferase (LCAT) activity has been investigated in 14 normal male subjects. After determination of postabsorptive lipid and LCAT levels, a high-fat liquid test meal (1 to 2 gm./kg. body weight) was fed, followed by lipid and LCAT determinations at 2.5 hour intervals. Plasma triglycerides were elevated by 2.5 hours, peaked at 5.0 hours, fell at 7.5 hours, and were normalized by 10 hours. LCAT was unchanged at 2.5 hours but was elevated by 5.0 hours, exhibiting a broad plateau through 10 hours. Most subjects manifested peak responses at 7.5 hours. The mean maximal increase in individual subjects was 37.2 +/- 13.3 (S.D.) percent. LCAT changes similarly followed the elevation and recession of chylomicrons (Sf greater than 400) and very-low-density lipoprotein triglycerides, both of which closely paralleled plasma triglycerides. Enzyme responses were proportional to percentage elevations of plasma triglycerides (r = 0.93, p less than 0.01) and related to quantity of fat in the test diet. Three subjects who ingested the test diet devoid of the fat component showed no significant change in enzyme activity. Enzyme progress curves revealed linearity for 3 hours for both postabsorptive and lipemic (7.5 hour) plasma from the same subjects, supporting the validity of the assay as a measure of enzyme rate. These studies demonstrate an increase in cholesterol esterifying activity temporally related to the clearance of alimentary particles, suggesting a physiologic role in the clearance process. PMID:839110

  7. Type 1 diacylglycerol acyltransferases of Brassica napus preferentially incorporate oleic acid into triacylglycerol

    PubMed Central

    Aznar-Moreno, Jose; Denolf, Peter; Van Audenhove, Katrien; De Bodt, Stefanie; Engelen, Steven; Fahy, Deirdre; Wallis, James G.; Browse, John

    2015-01-01

    DGAT1 enzymes (acyl-CoA:diacylglycerol acyltransferase 1, EC 2.3.1.20) catalyse the formation of triacylglycerols (TAGs), the most abundant lipids in vegetable oils. Thorough understanding of the enzymology of oil accumulation is critical to the goal of modifying oilseeds for improved vegetable oil production. Four isoforms of BnDGAT1, the final and rate-limiting step in triacylglycerol synthesis, were characterized from Brassica napus, one of the world’s most important oilseed crops. Transcriptional profiling of developing B. napus seeds indicated two genes, BnDGAT1-1 and BnDGAT1-2, with high expression and two, BnDGAT1-3 and BnDGAT1-4, with low expression. The activities of each BnDGAT1 isozyme were characterized following expression in a strain of yeast deficient in TAG synthesis. TAG from B. napus seeds contain only 10% palmitic acid (16:0) at the sn-3 position, so it was surprising that all four BnDGAT1 isozymes exhibited strong (4- to 7-fold) specificity for 16:0 over oleic acid (18:1) as the acyl-CoA substrate. However, the ratio of 18:1-CoA to 16:0-CoA in B. napus seeds during the peak period of TAG synthesis is 3:1. When substrate selectivity assays were conducted with 18:1-CoA and 16:0-CoA in a 3:1 ratio, the four isozymes incorporated 18:1 in amounts 2- to 5-fold higher than 16:0. This strong sensitivity of the BnDGAT1 isozymes to the relative concentrations of acyl-CoA substrates substantially explains the observed fatty acid composition of B. napus seed oil. Understanding these enzymes that are critical for triacylglycerol synthesis will facilitate genetic and biotechnological manipulations to improve this oilseed crop. PMID:26195728

  8. Agonistic Human Antibodies Binding to Lecithin-Cholesterol Acyltransferase Modulate High Density Lipoprotein Metabolism*

    PubMed Central

    Gunawardane, Ruwanthi N.; Fordstrom, Preston; Piper, Derek E.; Masterman, Stephanie; Siu, Sophia; Liu, Dongming; Brown, Mike; Lu, Mei; Tang, Jie; Zhang, Richard; Cheng, Janet; Gates, Andrew; Meininger, David; Chan, Joyce; Carlson, Tim; Walker, Nigel; Schwarz, Margrit; Delaney, John; Zhou, Mingyue

    2016-01-01

    Drug discovery opportunities where loss-of-function alleles of a target gene link to a disease-relevant phenotype often require an agonism approach to up-regulate or re-establish the activity of the target gene. Antibody therapy is increasingly recognized as a favored drug modality due to multiple desirable pharmacological properties. However, agonistic antibodies that enhance the activities of the target enzymes are rarely developed because the discovery of agonistic antibodies remains elusive. Here we report an innovative scheme of discovery and characterization of human antibodies capable of binding to and agonizing a circulating enzyme lecithin cholesterol acyltransferase (LCAT). Utilizing a modified human LCAT protein with enhanced enzymatic activity as an immunogen, we generated fully human monoclonal antibodies using the XenoMouseTM platform. One of the resultant agonistic antibodies, 27C3, binds to and substantially enhances the activity of LCAT from humans and cynomolgus macaques. X-ray crystallographic analysis of the 2.45 Å LCAT-27C3 complex shows that 27C3 binding does not induce notable structural changes in LCAT. A single administration of 27C3 to cynomolgus monkeys led to a rapid increase of plasma LCAT enzymatic activity and a 35% increase of the high density lipoprotein cholesterol that was observed up to 32 days after 27C3 administration. Thus, this novel scheme of immunization in conjunction with high throughput screening may represent an effective strategy for discovering agonistic antibodies against other enzyme targets. 27C3 and other agonistic human anti-human LCAT monoclonal antibodies described herein hold potential for therapeutic development for the treatment of dyslipidemia and cardiovascular disease. PMID:26644477

  9. Inhibiting Monoacylglycerol Acyltransferase 1 Ameliorates Hepatic Metabolic Abnormalities but Not Inflammation and Injury in Mice*

    PubMed Central

    Soufi, Nisreen; Hall, Angela M.; Chen, Zhouji; Yoshino, Jun; Collier, Sara L.; Mathews, James C.; Brunt, Elizabeth M.; Albert, Carolyn J.; Graham, Mark J.; Ford, David A.; Finck, Brian N.

    2014-01-01

    Abnormalities in hepatic lipid metabolism and insulin action are believed to play a critical role in the etiology of nonalcoholic steatohepatitis. Monoacylglycerol acyltransferase (MGAT) enzymes convert monoacylglycerol to diacylglycerol, which is the penultimate step in one pathway for triacylglycerol synthesis. Hepatic expression of Mogat1, which encodes an MGAT enzyme, is increased in the livers of mice with hepatic steatosis, and knocking down Mogat1 improves glucose metabolism and hepatic insulin signaling, but whether increased MGAT activity plays a role in the etiology of nonalcoholic steatohepatitis is unclear. To examine this issue, mice were placed on a diet containing high levels of trans fatty acids, fructose, and cholesterol (HTF-C diet) or a low fat control diet for 4 weeks. Mice were injected with antisense oligonucleotides (ASOs) to knockdown Mogat1 or a scrambled ASO control for 12 weeks while remaining on diet. The HTF-C diet caused glucose intolerance, hepatic steatosis, and induced hepatic gene expression markers of inflammation, macrophage infiltration, and stellate cell activation. Mogat1 ASO treatment, which suppressed Mogat1 expression in liver and adipose tissue, attenuated weight gain, improved glucose tolerance, improved hepatic insulin signaling, and decreased hepatic triacylglycerol content compared with control ASO-treated mice on HTF-C chow. However, Mogat1 ASO treatment did not reduce hepatic diacylglycerol, cholesterol, or free fatty acid content; improve histologic measures of liver injury; or reduce expression of markers of stellate cell activation, liver inflammation, and injury. In conclusion, inhibition of hepatic Mogat1 in HTF-C diet-fed mice improves hepatic metabolic abnormalities without attenuating liver inflammation and injury. PMID:25213859

  10. Developmental Regulation of Diacylglycerol Acyltransferase Family Gene Expression in Tung Tree Tissues

    PubMed Central

    Cao, Heping; Shockey, Jay M.; Klasson, K. Thomas; Chapital, Dorselyn C.; Mason, Catherine B.; Scheffler, Brian E.

    2013-01-01

    Diacylglycerol acyltransferases (DGAT) catalyze the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGAT genes have been identified in numerous organisms. Multiple isoforms of DGAT are present in eukaryotes. We previously cloned DGAT1 and DGAT2 genes of tung tree (Vernicia fordii), whose novel seed TAGs are useful in a wide range of industrial applications. The objective of this study was to understand the developmental regulation of DGAT family gene expression in tung tree. To this end, we first cloned a tung tree gene encoding DGAT3, a putatively soluble form of DGAT that possesses 11 completely conserved amino acid residues shared among 27 DGAT3s from 19 plant species. Unlike DGAT1 and DGAT2 subfamilies, DGAT3 is absent from animals. We then used TaqMan and SYBR Green quantitative real-time PCR, along with northern and western blotting, to study the expression patterns of the three DGAT genes in tung tree tissues. Expression results demonstrate that 1) all three isoforms of DGAT genes are expressed in developing seeds, leaves and flowers; 2) DGAT2 is the major DGAT mRNA in tung seeds, whose expression profile is well-coordinated with the oil profile in developing tung seeds; and 3) DGAT3 is the major form of DGAT mRNA in tung leaves, flowers and immature seeds prior to active tung oil biosynthesis. These results suggest that DGAT2 is probably the major TAG biosynthetic isoform in tung seeds and that DGAT3 gene likely plays a significant role in TAG metabolism in other tissues. Therefore, DGAT2 should be a primary target for tung oil engineering in transgenic organisms. PMID:24146944

  11. A Lipolytic Lecithin:Cholesterol Acyltransferase Secreted by Toxoplasma Facilitates Parasite Replication and Egress.

    PubMed

    Pszenny, Viviana; Ehrenman, Karen; Romano, Julia D; Kennard, Andrea; Schultz, Aric; Roos, David S; Grigg, Michael E; Carruthers, Vern B; Coppens, Isabelle

    2016-02-19

    The protozoan parasite Toxoplasma gondii develops within a parasitophorous vacuole (PV) in mammalian cells, where it scavenges cholesterol. When cholesterol is present in excess in its environment, the parasite expulses this lipid into the PV or esterifies it for storage in lipid bodies. Here, we characterized a unique T. gondii homologue of mammalian lecithin:cholesterol acyltransferase (LCAT), a key enzyme that produces cholesteryl esters via transfer of acyl groups from phospholipids to the 3-OH of free cholesterol, leading to the removal of excess cholesterol from tissues. TgLCAT contains a motif characteristic of serine lipases "AHSLG" and the catalytic triad consisting of serine, aspartate, and histidine (SDH) from LCAT enzymes. TgLCAT is secreted by the parasite, but unlike other LCAT enzymes it is cleaved into two proteolytic fragments that share the residues of the catalytic triad and need to be reassembled to reconstitute enzymatic activity. TgLCAT uses phosphatidylcholine as substrate to form lysophosphatidylcholine that has the potential to disrupt membranes. The released fatty acid is transferred to cholesterol, but with a lower transesterification activity than mammalian LCAT. TgLCAT is stored in a subpopulation of dense granule secretory organelles, and following secretion, it localizes to the PV and parasite plasma membrane. LCAT-null parasites have impaired growth in vitro, reduced virulence in animals, and exhibit delays in egress from host cells. Parasites overexpressing LCAT show increased virulence and faster egress. These observations demonstrate that TgLCAT influences the outcome of an infection, presumably by facilitating replication and egress depending on the developmental stage of the parasite. PMID:26694607

  12. Identification of genetic variants of lecithin cholesterol acyltransferase in individuals with high HDL‑C levels.

    PubMed

    Naseri, Mohsen; Hedayati, Mehdi; Daneshpour, Maryam Sadat; Bandarian, Fatemeh; Azizi, Fereidoun

    2014-07-01

    Among the most common lipid abnormalities, a low level of high-density lipoprotein-cholesterol (HDL‑C) is one of the first risk factors identified for coronary heart disease. Lecithin cholesterol acyltransferase (LCAT) has a pivotal role in the formation and maturation of HDL-C and in reverse cholesterol transport. To identify genetic loci associated with low HDL-C in a population-based cohort in Tehran, the promoter, coding regions and exon/intron boundaries of LCAT were amplified and sequenced in consecutive individuals (n=150) who had extremely low or high HDL-C levels but no other major lipid abnormalities. A total of 14 single-nucleotide polymorphisms (SNPs) were identified, of which 10 were found to be novel; the L393L, S232T and 16:67977696 C>A polymorphisms have been previously reported in the SNP Database (as rs5923, rs4986970 and rs11860115, respectively) and the non-synonymous R47M mutation has been reported in the Catalogue of Somatic Mutations in Cancer (COSM972635). Three of the SNPs identified in the present study (position 6,531 in exon 5, position 6,696 in exon 5 and position 5,151 in exon 1) led to an amino acid substitution. The most common variants were L393L (4886C/T) in exon 6 and Q177E, a novel mutation, in exon 5, and the prevalence of the heterozygous genotype of these two SNPs was significantly higher in the low HDL-C groups. Univariate conditional logistic regression odds ratios (ORs) were nominally significant for Q177E (OR, 5.64; P=0.02; 95% confidence interval, 1.2‑26.2). However, this finding was attenuated following adjustment for confounders. Further studies using a larger sample size may enhance the determination of the role of these SNPs. PMID:24789697

  13. Agonistic Human Antibodies Binding to Lecithin-Cholesterol Acyltransferase Modulate High Density Lipoprotein Metabolism.

    PubMed

    Gunawardane, Ruwanthi N; Fordstrom, Preston; Piper, Derek E; Masterman, Stephanie; Siu, Sophia; Liu, Dongming; Brown, Mike; Lu, Mei; Tang, Jie; Zhang, Richard; Cheng, Janet; Gates, Andrew; Meininger, David; Chan, Joyce; Carlson, Tim; Walker, Nigel; Schwarz, Margrit; Delaney, John; Zhou, Mingyue

    2016-02-01

    Drug discovery opportunities where loss-of-function alleles of a target gene link to a disease-relevant phenotype often require an agonism approach to up-regulate or re-establish the activity of the target gene. Antibody therapy is increasingly recognized as a favored drug modality due to multiple desirable pharmacological properties. However, agonistic antibodies that enhance the activities of the target enzymes are rarely developed because the discovery of agonistic antibodies remains elusive. Here we report an innovative scheme of discovery and characterization of human antibodies capable of binding to and agonizing a circulating enzyme lecithin cholesterol acyltransferase (LCAT). Utilizing a modified human LCAT protein with enhanced enzymatic activity as an immunogen, we generated fully human monoclonal antibodies using the XenoMouse(TM) platform. One of the resultant agonistic antibodies, 27C3, binds to and substantially enhances the activity of LCAT from humans and cynomolgus macaques. X-ray crystallographic analysis of the 2.45 Å LCAT-27C3 complex shows that 27C3 binding does not induce notable structural changes in LCAT. A single administration of 27C3 to cynomolgus monkeys led to a rapid increase of plasma LCAT enzymatic activity and a 35% increase of the high density lipoprotein cholesterol that was observed up to 32 days after 27C3 administration. Thus, this novel scheme of immunization in conjunction with high throughput screening may represent an effective strategy for discovering agonistic antibodies against other enzyme targets. 27C3 and other agonistic human anti-human LCAT monoclonal antibodies described herein hold potential for therapeutic development for the treatment of dyslipidemia and cardiovascular disease. PMID:26644477

  14. Type 1 diacylglycerol acyltransferases of Brassica napus preferentially incorporate oleic acid into triacylglycerol.

    PubMed

    Aznar-Moreno, Jose; Denolf, Peter; Van Audenhove, Katrien; De Bodt, Stefanie; Engelen, Steven; Fahy, Deirdre; Wallis, James G; Browse, John

    2015-10-01

    DGAT1 enzymes (acyl-CoA:diacylglycerol acyltransferase 1, EC 2.3.1.20) catalyse the formation of triacylglycerols (TAGs), the most abundant lipids in vegetable oils. Thorough understanding of the enzymology of oil accumulation is critical to the goal of modifying oilseeds for improved vegetable oil production. Four isoforms of BnDGAT1, the final and rate-limiting step in triacylglycerol synthesis, were characterized from Brassica napus, one of the world's most important oilseed crops. Transcriptional profiling of developing B. napus seeds indicated two genes, BnDGAT1-1 and BnDGAT1-2, with high expression and two, BnDGAT1-3 and BnDGAT1-4, with low expression. The activities of each BnDGAT1 isozyme were characterized following expression in a strain of yeast deficient in TAG synthesis. TAG from B. napus seeds contain only 10% palmitic acid (16:0) at the sn-3 position, so it was surprising that all four BnDGAT1 isozymes exhibited strong (4- to 7-fold) specificity for 16:0 over oleic acid (18:1) as the acyl-CoA substrate. However, the ratio of 18:1-CoA to 16:0-CoA in B. napus seeds during the peak period of TAG synthesis is 3:1. When substrate selectivity assays were conducted with 18:1-CoA and 16:0-CoA in a 3:1 ratio, the four isozymes incorporated 18:1 in amounts 2- to 5-fold higher than 16:0. This strong sensitivity of the BnDGAT1 isozymes to the relative concentrations of acyl-CoA substrates substantially explains the observed fatty acid composition of B. napus seed oil. Understanding these enzymes that are critical for triacylglycerol synthesis will facilitate genetic and biotechnological manipulations to improve this oilseed crop. PMID:26195728

  15. Ghrelin O-acyltransferase knockout mice show resistance to obesity when fed high-sucrose diet.

    PubMed

    Kouno, Tetsuya; Akiyama, Nobuteru; Ito, Takahito; Okuda, Tomohiko; Nanchi, Isamu; Notoya, Mitsuru; Oka, Shogo; Yukioka, Hideo

    2016-02-01

    Ghrelin is an appetite-stimulating hormone secreted from stomach. Since the discovery that acylation of the serine-3 residue by ghrelin O-acyltransferase (GOAT) is essential for exerting its functions, GOAT has been regarded as an therapeutic target for attenuating appetite, and thus for the treatment of obesity and diabetes. However, contrary to the expectations, GOAT-knockout (KO) mice have not shown meaningful body weight reduction, under high-fat diet. Here, in this study, we sought to determine whether GOAT has a role in body weight regulation and glucose metabolism with a focus on dietary sucrose, because macronutrient composition of diet is important for appetite regulation. We found that peripherally administered acylated-ghrelin, but not unacylated one, stimulated sucrose consumption in a two-bottle-drinking test. The role of acylated-ghrelin in sucrose preference was further supported by the finding that GOAT KO mice consumed less sucrose solution compared with WT littermates. Then, we investigated the effect of dietary composition of sucrose on food intake and body weight in GOAT KO and WT mice. As a result, when fed on high-fat diet, food intake and body weight were similar between GOAT KO and WT mice. However, when fed on high-fat, high-sucrose diet, GOAT KO mice showed significantly reduced food intake and marked resistance to obesity, leading to amelioration of glucose metabolism. These results suggest that blockade of acylated-ghrelin production offers therapeutic potential for obesity and metabolic disorders caused by overeating of palatable food. PMID:26645250

  16. Lecithin:Cholesterol Acyltransferase Deficiency Protects against Cholesterol-induced Hepatic Endoplasmic Reticulum Stress in Mice*

    PubMed Central

    Hager, Lauren; Li, Lixin; Pun, Henry; Liu, Lu; Hossain, Mohammad A.; Maguire, Graham F.; Naples, Mark; Baker, Chris; Magomedova, Lilia; Tam, Jonathan; Adeli, Khosrow; Cummins, Carolyn L.; Connelly, Philip W.; Ng, Dominic S.

    2012-01-01

    We recently reported that lecithin:cholesterol acyltransferase (LCAT) knock-out mice, particularly in the LDL receptor knock-out background, are hypersensitive to insulin and resistant to high fat diet-induced insulin resistance (IR) and obesity. We demonstrated that chow-fed Ldlr−/−xLcat+/+ mice have elevated hepatic endoplasmic reticulum (ER) stress, which promotes IR, compared with wild-type controls, and this effect is normalized in Ldlr−/−xLcat−/− mice. In the present study, we tested the hypothesis that hepatic ER cholesterol metabolism differentially regulates ER stress using these models. We observed that the Ldlr−/−xLcat+/+ mice accumulate excess hepatic total and ER cholesterol primarily attributed to increased reuptake of biliary cholesterol as we observed reduced biliary cholesterol in conjunction with decreased hepatic Abcg5/g8 mRNA, increased Npc1l1 mRNA, and decreased Hmgr mRNA and nuclear SREBP2 protein. Intestinal NPC1L1 protein was induced. Expression of these genes was reversed in the Ldlr−/−xLcat−/− mice, accounting for the normalization of total and ER cholesterol and ER stress. Upon feeding a 2% high cholesterol diet (HCD), Ldlr−/−xLcat−/− mice accumulated a similar amount of total hepatic cholesterol compared with the Ldlr−/−xLcat+/+ mice, but the hepatic ER cholesterol levels remained low in conjunction with being protected from HCD-induced ER stress and IR. Hepatic ER stress correlates strongly with hepatic ER free cholesterol but poorly with hepatic tissue free cholesterol. The unexpectedly low ER cholesterol seen in HCD-fed Ldlr−/−xLcat−/− mice was attributable to a coordinated marked up-regulation of ACAT2 and suppressed SREBP2 processing. Thus, factors influencing the accumulation of ER cholesterol may be important for the development of hepatic insulin resistance. PMID:22500017

  17. Oral Carcinogenesis Induced by 4-Nitroquinoline 1-Oxide in Lecithin:retinol Acyltransferase Gene Knockout Mice

    PubMed Central

    Liu, Limin; Tang, Xiao-Han; Scognamiglio, Theresa; Gudas, Lorraine J.

    2010-01-01

    Lecithin:retinol acyltransferase (LRAT) regulates retinol (vitamin A) metabolism by esterifying retinol. LRAT expression is decreased in cultured human head and neck squamous cell carcinoma (SCCHN) relative to normal epithelial cells. We investigated whether the carcinogen 4-nitroquinoline 1-oxide (4-NQO) induced a higher incidence of oral cancer in LRAT knockout than wild type (Wt) mice. We also investigated retinol deprivation during 4-NQO treatment in LRAT−/− mice as a model for rapid retinol deficiency. We observed higher levels of secreted frizzled-related protein 2 (Sfrp2), an inhibitor of WNT signaling, in tongue tumors in LRAT−/− versus Wt. LRAT−/− embryonic stem cells also expressed higher Sfrp2 transcripts, indicating an interaction between retinol and WNT signaling. Cox-2, Cyclin D1, p21, Trop2, and RARβ2 were not differentially expressed in Wt versus LRAT−/− tongue tumors. Wt and LRAT−/− mice fed a retinol sufficient diet showed the same oral tumor incidence after 4-NQO. In contrast, tongue tumors developed in 60% of Wt and in 100% of LRAT−/− mice fed a retinol deficient diet during 4-NQO treatment (p=0.22); moreover, the BrdU labeling index was 21.0±2.4% in LRAT−/− normal tongue epithelium as compared to 9.9±0.8% in Wt (p<0.001). Thus, partial retinol deficiency during carcinogen treatment (achieved in LRAT−/−) resulted in more proliferating cells in tongue epithelia from LRAT−/− mice and ultimately a greater probability of carcinogenesis. PMID:19954945

  18. Coexpressing Escherichia coli cyclopropane synthase with Sterculia foetida Lysophosphatidic acid acyltransferase enhances cyclopropane fatty acid accumulation.

    PubMed

    Yu, Xiao-Hong; Prakash, Richa Rawat; Sweet, Marie; Shanklin, John

    2014-01-01

    Cyclopropane fatty acids (CPAs) are desirable as renewable chemical feedstocks for the production of paints, plastics, and lubricants. Toward our goal of creating a CPA-accumulating crop, we expressed nine higher plant cyclopropane synthase (CPS) enzymes in the seeds of fad2fae1 Arabidopsis (Arabidopsis thaliana) and observed accumulation of less than 1% CPA. Surprisingly, expression of the Escherichia coli CPS gene resulted in the accumulation of up to 9.1% CPA in the seed. Coexpression of a Sterculia foetida lysophosphatidic acid acyltransferase (SfLPAT) increases CPA accumulation up to 35% in individual T1 seeds. However, seeds with more than 9% CPA exhibit wrinkled seed morphology and reduced size and oil accumulation. Seeds with more than 11% CPA exhibit strongly decreased seed germination and establishment, and no seeds with CPA more than 15% germinated. That previous reports suggest that plant CPS prefers the stereospecific numbering (sn)-1 position whereas E. coli CPS acts on sn-2 of phospholipids prompted us to investigate the preferred positions of CPS on phosphatidylcholine (PC) and triacylglycerol. Unexpectedly, in planta, E. coli CPS acts primarily on the sn-1 position of PC; coexpression of SfLPAT results in the incorporation of CPA at the sn-2 position of lysophosphatidic acid. This enables a cycle that enriches CPA at both sn-1 and sn-2 positions of PC and results in increased accumulation of CPA. These data provide proof of principle that CPA can accumulate to high levels in transgenic seeds and sets the stage for the identification of factors that will facilitate the movement of CPA from PC into triacylglycerol to produce viable seeds with additional CPA accumulation. PMID:24204024

  19. Apolipoprotein A-I Helsinki promotes intracellular acyl-CoA cholesterol acyltransferase (ACAT) protein accumulation.

    PubMed

    Toledo, Juan D; Garda, Horacio A; Cabaleiro, Laura V; Cuellar, Angela; Pellon-Maison, Magali; Gonzalez-Baro, Maria R; Gonzalez, Marina C

    2013-05-01

    Reverse cholesterol transport is a process of high antiatherogenic relevance in which apolipoprotein AI (apoA-I) plays an important role. The interaction of apoA-I with peripheral cells produces through mechanisms that are still poorly understood the mobilization of intracellular cholesterol depots toward plasma membrane. In macrophages, these mechanisms seem to be related to the modulation of the activity of acyl-CoA cholesterol acyltransferase (ACAT), the enzyme responsible for the intracellular cholesterol ester biosynthesis that is stored in lipid droplets. The activation of ACAT and the accumulation of lipid droplets play a key role in the transformation of macrophages into foam cells, leading to the formation of atheroma or atherosclerotic plaque. ApoA-I Helsinki (or ∆K107) is a natural apoA-I variant with a lysine deletion in the central protein region, carriers of which have increased atherosclerosis risk. We herein show that treatment of cultured RAW macrophages or CHOK1 cells with ∆K107, but not with wild-type apoA-I or a variant containing a similar deletion at the C-terminal region (∆K226), lead to a marked increase (more than 10 times) in the intracellular ACAT1 protein level as detected by western blot analysis. However, we could only detect a slight increase in cholesteryl ester produced by ∆K107 mainly when Chol loading was supplied by low-density lipoprotein (LDL). Although a similar choline-phospholipid efflux is evoked by these apoA-I variants, the change in phosphatidylcholine/sphyngomyelin distribution produced by wild-type apoA-I is not observed with either ∆K107 or ∆K226. PMID:23456478

  20. Crystal structure of the acyltransferase domain of the iterative polyketide synthase in enediyne biosynthesis.

    PubMed

    Liew, Chong Wai; Nilsson, Martina; Chen, Ming Wei; Sun, Huihua; Cornvik, Tobias; Liang, Zhao-Xun; Lescar, Julien

    2012-06-29

    Biosynthesis of the enediyne natural product dynemicin in Micromonospora chersina is initiated by DynE8, a highly reducing iterative type I polyketide synthase that assembles polyketide intermediates from the acetate units derived solely from malonyl-CoA. To understand the substrate specificity and the evolutionary relationship between the acyltransferase (AT) domains of DynE8, fatty acid synthase, and modular polyketide synthases, we overexpressed a 44-kDa fragment of DynE8 (hereafter named AT(DYN10)) encompassing its entire AT domain and the adjacent linker domain. The crystal structure at 1.4 Å resolution unveils a α/β hydrolase and a ferredoxin-like subdomain with the Ser-His catalytic dyad located in the cleft between the two subdomains. The linker domain also adopts a α/β fold abutting the AT catalytic domain. Co-crystallization with malonyl-CoA yielded a malonyl-enzyme covalent complex that most likely represents the acyl-enzyme intermediate. The structure explains the preference for malonyl-CoA with a conserved arginine orienting the carboxylate group of malonate and several nonpolar residues that preclude α-alkyl malonyl-CoA binding. Co-crystallization with acetyl-CoA revealed two noncovalently bound acetates generated by the enzymatic hydrolysis of acetyl-CoA that acts as an inhibitor for DynE8. This suggests that the AT domain can upload the acyl groups from either malonyl-CoA or acetyl-CoA onto the catalytic Ser(651) residue. However, although the malonyl group can be transferred to the acyl carrier protein domain, transfer of the acetyl group to the acyl carrier protein domain is suppressed. Local structural differences may account for the different stability of the acyl-enzyme intermediates. PMID:22589546

  1. Lecithin:Retinol Acyltransferase: A Key Enzyme Involved in the Retinoid (visual) Cycle.

    PubMed

    Sears, Avery E; Palczewski, Krzysztof

    2016-06-01

    Lecithin:retinol acyltransferase (LRAT) catalyzes the acyl transfer from the sn-1 position of phosphatidylcholine (PC) to all-trans-retinol, creating fatty acid retinyl esters (palmitoyl, stearoyl, and some unsaturated derivatives). In the eye, these retinyl esters are substrates for the 65 kDa retinoid isomerase (RPE65). LRAT is well characterized biochemically, and recent structural data from closely related family members of the NlpC/P60 superfamily and a chimeric protein have established its catalytic mechanism. Mutations in the LRAT gene are responsible for approximately 1% of reported cases of Leber congenital amaurosis (LCA). Lack of functional LRAT, expressed in the retinal pigmented epithelium (RPE), results in loss of the visual chromophore and photoreceptor degeneration. LCA is a rare hereditary retinal dystrophy with an early onset associated with mutations in one of 21 known genes. Protocols have been devised to identify therapeutics that compensate for mutations in RPE65, also associated with LCA. The same protocols can be adapted to combat dystrophies associated with LRAT. Improvement in the visual function of clinical recipients of therapy with recombinant adeno-associated virus (rAAV) vectors incorporating the RPE65 gene provides a proof of concept for LRAT, which functions in the same cell type and metabolic pathway as RPE65. In parallel, a clinical trial that employs oral 9-cis-retinyl acetate to replace the missing chromophore in RPE65 and LRAT causative disease has proven to be effective and free of adverse effects. This article summarizes the biochemistry of LRAT and examines chromophore replacement as a treatment for LCA caused by LRAT mutations. PMID:27183166

  2. Ldl modified by hypochlorous acid is a potent inhibitor of lecithin-cholesterol acyltransferase activity.

    PubMed

    McCall, M R; Carr, A C; Forte, T M; Frei, B

    2001-06-01

    Modification of low density lipoprotein (LDL) by myeloperoxidase-generated HOCl has been implicated in human atherosclerosis. Incubation of LDL with HOCl generates several reactive intermediates, primarily N-chloramines, which may react with other biomolecules. In this study, we investigated the effects of HOCl-modified LDL on the activity of lecithin-cholesterol acyltransferase (LCAT), an enzyme essential for high density lipoprotein maturation and the antiatherogenic reverse cholesterol transport pathway. We exposed human LDL (0.5 mg protein/mL) to physiological concentrations of HOCl (25 to 200 micromol/L) and characterized the resulting LDL modifications to apolipoprotein B and lipids; the modified LDL was subsequently incubated with apolipoprotein B-depleted plasma (density >1.063 g/mL fraction), which contains functional LCAT. Increasing concentrations of HOCl caused various modifications to LDL, primarily, loss of lysine residues and increases in N-chloramines and electrophoretic mobility, whereas lipid hydroperoxides were only minor products. LCAT activity was extremely sensitive to HOCl-modified LDL and was reduced by 23% and 93% by LDL preincubated with 25 and 100 micromol/L HOCl, respectively. Addition of 200 micromol/L ascorbate or N-acetyl derivatives of cysteine or methionine completely prevented LCAT inactivation by LDL preincubated with

  3. Lysophosphatidic Acid Acyltransferase β (LPAATβ) Promotes the Tumor Growth of Human Osteosarcoma

    PubMed Central

    Rastegar, Farbod; Gao, Jian-Li; Shenaq, Deana; Luo, Qing; Shi, Qiong; Kim, Stephanie H.; Jiang, Wei; Wagner, Eric R.; Huang, Enyi; Gao, Yanhong; Shen, Jikun; Yang, Ke; He, Bai-Cheng; Chen, Liang; Zuo, Guo-Wei; Luo, Jinyong; Luo, Xiaoji; Bi, Yang; Liu, Xing; Li, Mi; Hu, Ning; Wang, Linyuan; Luther, Gaurav; Luu, Hue H.; Haydon, Rex C.; He, Tong-Chuan

    2010-01-01

    Background Osteosarcoma is the most common primary malignancy of bone with poorly characterized molecular pathways important in its pathogenesis. Increasing evidence indicates that elevated lipid biosynthesis is a characteristic feature of cancer. We sought to investigate the role of lysophosphatidic acid acyltransferase β (LPAATβ, aka, AGPAT2) in regulating the proliferation and growth of human osteosarcoma cells. LPAATβ can generate phosphatidic acid, which plays a key role in lipid biosynthesis as well as in cell proliferation and survival. Although elevated expression of LPAATβ has been reported in several types of human tumors, the role of LPAATβ in osteosarcoma progression has yet to be elucidated. Methodology/Principal Findings Endogenous expression of LPAATβ in osteosarcoma cell lines is analyzed by using semi-quantitative PCR and immunohistochemical staining. Adenovirus-mediated overexpression of LPAATβ and silencing LPAATβ expression is employed to determine the effect of LPAATβ on osteosarcoma cell proliferation and migration in vitro and osteosarcoma tumor growth in vivo. We have found that expression of LPAATβ is readily detected in 8 of the 10 analyzed human osteosarcoma lines. Exogenous expression of LPAATβ promotes osteosarcoma cell proliferation and migration, while silencing LPAATβ expression inhibits these cellular characteristics. We further demonstrate that exogenous expression of LPAATβ effectively promotes tumor growth, while knockdown of LPAATβ expression inhibits tumor growth in an orthotopic xenograft model of human osteosarcoma. Conclusions/Significance Our results strongly suggest that LPAATβ expression may be associated with the aggressive phenotypes of human osteosarcoma and that LPAATβ may play an important role in regulating osteosarcoma cell proliferation and tumor growth. Thus, targeting LPAATβ may be exploited as a novel therapeutic strategy for the clinical management of osteosarcoma. This is especially

  4. Expression, Purification, and Characterization of Mouse Glycine N-acyltransferase in Escherichia coli

    PubMed Central

    Dempsey, Daniel R.; Bond, Jason D.; Carpenter, Anne-Marie; Ospina, Santiago Rodriguez; Merkler, David J.

    2014-01-01

    Glycine N-acyltransferase (GLYAT) is a phase II metabolic detoxification enzyme for exogenous (xenobiotic) and endogenous carboxylic acids; consisting of fatty acids, benzoic acid, and salicylic acid. GLYAT catalyzes the formation of hippurate (N-benzoylglycine) from the corresponding glycine and benzoyl-CoA. Herein, we report the successful expression, purification, and characterization of recombinant mouse GLYAT (mGLYAT). A 34 kDa mGLYAT protein was expressed in Escherichia coli and purified to homogeneity by nickel affinity chromatography to a final yield of 2.5 mg/L culture. Characterization for both amino donors and amino acceptors were completed, with glycine serving as the best amino donor substrate, (kcat/Km)app = (5.2 ± 0.20) × 102M−1s−1, and benzoyl-CoA serving as the best the amino acceptor substrate, (kcat/Km)app = (4.5 ± 0.27) × 105M−1s−1. Our data demonstrate that mGLYAT will catalyzed the chain length specific (C2-C6) formation of N-acylglycines. The steady-state kinetic constants determined for recombinant mGLYAT for the substrates benzoyl-CoA and glycine, were shown to be consistent with other reported species (rat, human, bovine, ovine, and rhesus monkey). The successful recombinant expression and purification of mGLYAT can lead to solve unanswered questions associated with this enzyme, consisting of what is the chemical mechanism and what catalytic residues are essential for the how this phase II metabolic detoxification enzyme conjugates glycine to xenobiotic and endogenous carboxylic acids. PMID:24576660

  5. Altering small and medium alcohol selectivity in the wax ester synthase.

    PubMed

    Barney, Brett M; Ohlert, Janet M; Timler, Jacobe G; Lijewski, Amelia M

    2015-11-01

    The bifunctional wax ester synthase/acyl-coenzyme A:diacylglycerol acyltransferase (WS/DGAT or wax ester synthase) catalyzes the terminal reaction in the bacterial wax ester biosynthetic pathway, utilizing a range of alcohols and fatty acyl-CoAs to synthesize the corresponding wax ester. The wild-type wax ester synthase Maqu_0168 from Marinobacter aquaeolei VT8 exhibits a preference for longer fatty alcohols, while applications with smaller alcohols would yield products with desired biotechnological properties. Small and medium chain length alcohol substrates are much poorer substrates for the native enzyme, which may hinder broad application of the wax ester synthase in many proposed biosynthetic schemes. Developing approaches to improve enzyme activity toward specific smaller alcohol substrates first requires a clear understanding of which amino acids of the primary sequences of these enzymes contribute to substrate specificity in the native enzyme. In this report, we surveyed a range of potential residues and identified the leucine at position 356 and methionine at position 405 in Maqu_0168 as residues that affected selectivity toward small, branched, and aromatic alcohols when substituted with different amino acids. This analysis provides evidence of residues that line the binding site for wax ester synthase, which will aid rational approaches to improve this enzyme with specific substrates. PMID:26205519

  6. Interstellar Alcohols

    NASA Technical Reports Server (NTRS)

    Charnley, S. B.; Kress, M. E.; Tielens, A. G. G. M.; Millar, T. J.

    1995-01-01

    We have investigated the gas-phase chemistry in dense cores where ice mantles containing ethanol and other alcohols have been evaporated. Model calculations show that methanol, ethanol, propanol, and butanol drive a chemistry leading to the formation of several large ethers and esters. Of these molecules, methyl ethyl ether (CH3OC2H5) and diethyl ether (C2H5)2O attain the highest abundances and should be present in detectable quantities within cores rich in ethanol and methanol. Gas-phase reactions act to destroy evaporated ethanol and a low observed abundance of gas-phase C,H,OH does not rule out a high solid-phase abundance. Grain surface formation mechanisms and other possible gas-phase reactions driven by alcohols are discussed, as are observing strategies for the detection of these large interstellar molecules.

  7. Formation of fatty acid ethyl esters in rat liver microsomes. Evidence for a key role for acyl-CoA: ethanol O-acyltransferase.

    PubMed

    Diczfalusy, M A; Björkhem, I; Einarsson, C; Alexson, S E

    1999-01-01

    Fatty acid ethyl esters have been detected in high concentrations in organs commonly damaged by alcohol abuse and are regarded as being important non-oxidative metabolites of ethanol. The formation of fatty acid ethyl esters (FAEEs) has been ascribed to two enzymic activities, acyl-CoA : ethanol O-acyltransferase (AEAT) and FAEE synthase. In the present study we determined AEAT and FAEE synthase activities in isolated rat liver microsomes and further characterized the microsomal AEAT activity in more detail. The determined AEAT and FAEE synthase activities were found to be similar (about 1.7 nmol.min-1.mg-1). However, the AEAT activity was increased about sixfold by the addition of 250 microm bis-(4-nitrophenyl) phosphate (a serine esterase inhibitor) to the incubation whereas FAEE synthase activity was completely inhibited. p-Hydroxymercuribenzoic acid (a cysteine-reacting compound) also stimulated AEAT activity (about fourfold) but had no effect on FAEE synthase activity. The effects of the inhibitors suggest that the formation of FAEEs by AEAT was severely counteracted by enzymic hydrolysis of the substrate (acyl-CoA) and to a lesser extent the product by serine esterases. dl-Melinamide, a hypocholesterolaemic drug, was found to be a very potent inhibitor of AEAT activity with an IC50 value of about 2.5 microm. Furthermore, we compared the activities of two purified microsomal carboxylesterases, ES-4 and ES-10, and identified ES-4 as the enzyme responsible for hydrolysis of FAEEs. The two carboxyesterases were also tested for FAEE synthase activity, but neither had any detectable activity. Esterase ES-4 was found to have some AEAT activity, but it was low. When measured under optimal conditions without competing hydrolysis the capacity of AEAT is thus considerably higher than FAEE synthase and the results are consistent with an important role for AEAT in the formation of ethyl esters. As the ratio acyl-CoA/non-esterified fatty acids is high under normal

  8. Thio Wax Ester Biosynthesis Utilizing the Unspecific Bifunctional Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase of Acinetobacter sp. Strain ADP1

    PubMed Central

    Uthoff, Stefan; Stöveken, Tim; Weber, Nikolaus; Vosmann, Klaus; Klein, Erika; Kalscheuer, Rainer; Steinbüchel, Alexander

    2005-01-01

    The bifunctional wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT) from Acinetobacter sp. strain ADP1 (formerly Acinetobacter calcoaceticus ADP1) mediating the biosyntheses of wax esters and triacylglycerols was used for the in vivo and in vitro biosynthesis of thio wax esters and dithio wax esters. For in vitro biosynthesis, 5′His6WS/DGAT comprising an N-terminal His6 tag was purified from the soluble protein fraction of Escherichia coli Rosetta(DE3)pLysS (pET23a::5′His6atf). By employing SP-Sepharose high-pressure and Ni-nitrilotriacetic acid fast-protein liquid chromatographies, a 19-fold enrichment with a final specific activity of 165.2 nmol mg of protein−1 min−1 was achieved by using 1-hexadecanol and palmitoyl-CoA as substrates. Incubation of purified 5′His6WS/DGAT with 1-hexadecanethiol and palmitoyl-CoA as substrates resulted in the formation of palmitic acid hexadecyl thio ester (10.4% relative specific activity of a 1-hexadecanol control). Utilization of 1,8-octanedithiol and palmitoyl-CoA as substrates led to the formation of 1-S-monopalmitoyloctanedithiol and minor amounts of 1,8-S-dipalmitoyloctanedithiol (59.3% relative specific activity of a 1-hexadecanol control). The latter dithio wax ester was efficiently produced when 1-S-monopalmitoyloctanedithiol and palmitoyl-CoA were used as substrates (13.4% specific activity relative to that of a 1-hexadecanol control). For the in vivo biosynthesis of thio wax esters, the knockout mutant Acinetobacter sp. strain ADP1acr1ΩKm, which is unable to produce fatty alcohols, was used. Cultivation of Acinetobacter sp. strain ADP1acr1ΩKm in the presence of gluconate, 1-hexadecanethiol, and oleic acid in nitrogen-limited mineral salts medium resulted in the accumulation of unusual thio wax esters that accounted for around 1.19% (wt/wt) of the cellular dry weight and consisted mainly of oleic acid hexadecyl thioester as revealed by gas chromatography-mass spectrometry

  9. Polymorphism of rs1044925 in the acyl-CoA:cholesterol acyltransferase-1 gene and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

    PubMed Central

    2010-01-01

    Background The association of rs1044925 polymorphism in the acyl-CoA:cholesterol acyltransferase-1 (ACAT-1) gene and serum lipid profiles is not well known in different ethnic groups. Bai Ku Yao is a special subgroup of the Yao minority in China. The present study was carried out to clarify the association of rs1044925 polymorphism in the ACAT-1 gene and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations. Methods A total of 626 subjects of Bai Ku Yao and 624 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of rs1044925 polymorphism in the ACAT-1 gene was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. Results The levels of serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (Apo) AI and ApoB were lower in Bai Ku Yao than in Han (P < 0.01 for all). The frequency of A and C alleles was 79.0% and 21.0% in Bai Ku Yao, and 87.3% and 12.7% in Han (P < 0.001); respectively. The frequency of AA, AC and CC genotypes was 63.2%, 31.4% and 5.2% in Bai Ku Yao, and 75.6%, 23.2% and 1.1% in Han (P < 0.001); respectively. The levels of TC, LDL-C and ApoB in Bai Ku Yao but not in Han were different between the AA and AC/CC genotypes in females but not in males (P < 0.05 for all). The C allele carriers had lower serum TC, LDL-C and ApoB levels as compared with the C allele noncarriers. The levels of TC, LDL-C and ApoB in Bai Ku Yao but not in Han were correlated with genotypes in females but not in males (P < 0.05 for all). Serum lipid parameters were also correlated with sex, age, body mass index, alcohol consumption, and blood pressure in both ethnic groups (P < 0.05-0.001). Conclusions These results suggest that the polymorphism of rs1044925 in the ACAT-1 gene is mainly associated with female serum TC, LDL-C and

  10. Kinetic characterization of the inhibition of acyl coenzyme A: steroid acyltransferases by tributyltin in the eastern mud snail (Ilyanassa obsoleta).

    PubMed

    Sternberg, Robin M; LeBlanc, Gerald A

    2006-06-30

    Exposure to tributyltin (TBT) has been causally associated with the global occurrence of a pseudohermaphroditic condition called imposex in neogastropod species. TBT elevates free testosterone levels in these organisms, and this upsurge in testosterone may be involved in the development of imposex. We investigated the ability of TBT to inhibit acyl coenzyme A:testosterone acyltransferase (ATAT) activity as well as microsomal acyl-coenzyme A:17beta-estradiol acyltransferase (AEAT) in a neogastropod, the eastern mud snail Ilyanassa obsoleta as a mechanism by which TBT elevates free testosterone. TBT significantly inhibited both ATAT and AEAT activities in vitro at toxicologically relevant in vivo concentrations. Kinetic analyses revealed that TBT is a competitive inhibitor of ATAT (K(i)= approximately 9microM) and is a weaker, noncompetitive inhibitor of AEAT (K(i)= approximately 31microM). ATAT and AEAT activities associated with different microsome preparations were significantly correlated, and 17beta-estradiol competitively inhibited the fatty acid esterification of testosterone suggesting that one enzyme is responsible for biotransforming both testosterone and 17beta-estradiol to their corresponding fatty acid esters. Overall, the results of this study supply the much-needed mechanistic support for the hypothesis that TBT elevates free testosterone in neogastropods by inhibiting their major regulatory process for maintaining free testosterone homeostasis-the fatty acid esterification of testosterone. PMID:16638618

  11. Glycerol-3-phosphate acyltransferase 4 is essential for the normal development of reproductive organs and the embryo in Brassica napus

    PubMed Central

    Chen, Xue; Chen, Guanqun; Truksa, Martin; Snyder, Crystal L.; Shah, Saleh; Weselake, Randall J.

    2014-01-01

    The enzyme sn-glycerol-3-phosphate acyltransferase 4 (GPAT4) is involved in the biosynthesis of plant lipid poly-esters. The present study further characterizes the enzymatic activities of three endoplasmic reticulum-bound GPAT4 isoforms of Brassica napus and examines their roles in the development of reproductive organs and the embryo. All three BnGPAT4 isoforms exhibited sn-2 acyltransferase and phosphatase activities with dicarboxylic acid-CoA as acyl donor. When non-substituted acyl-CoA was used as acyl donor, the rate of acylation was considerably lower and phosphatase activity was not manifested. RNA interference (RNAi)-mediated down-regulation of all GPAT4 homologues in B. napus under the control of the napin promoter caused abnormal development of several reproductive organs and reduced seed set. Microscopic examination and reciprocal crosses revealed that both pollen grains and developing embryo sacs of the B. napus gpat4 lines were affected. The gpat4 mature embryos showed decreased cutin content and altered monomer composition. The defective embryo development further affected the oil body morphology, oil content, and fatty acid composition in gpat4 seeds. These results suggest that GPAT4 has a critical role in the development of reproductive organs and the seed of B. napus. PMID:24821955

  12. Structural basis for selective recognition of acyl chains by the membrane-associated acyltransferase PatA

    PubMed Central

    Albesa-Jové, David; Svetlíková, Zuzana; Tersa, Montse; Sancho-Vaello, Enea; Carreras-González, Ana; Bonnet, Pascal; Arrasate, Pedro; Eguskiza, Ander; Angala, Shiva K.; Cifuente, Javier O.; Korduláková, Jana; Jackson, Mary; Mikušová, Katarína; Guerin, Marcelo E.

    2016-01-01

    The biosynthesis of phospholipids and glycolipids are critical pathways for virtually all cell membranes. PatA is an essential membrane associated acyltransferase involved in the biosynthesis of mycobacterial phosphatidyl-myo-inositol mannosides (PIMs). The enzyme transfers a palmitoyl moiety from palmitoyl–CoA to the 6-position of the mannose ring linked to 2-position of inositol in PIM1/PIM2. We report here the crystal structures of PatA from Mycobacterium smegmatis in the presence of its naturally occurring acyl donor palmitate and a nonhydrolyzable palmitoyl–CoA analog. The structures reveal an α/β architecture, with the acyl chain deeply buried into a hydrophobic pocket that runs perpendicular to a long groove where the active site is located. Enzyme catalysis is mediated by an unprecedented charge relay system, which markedly diverges from the canonical HX4D motif. Our studies establish the mechanistic basis of substrate/membrane recognition and catalysis for an important family of acyltransferases, providing exciting possibilities for inhibitor design. PMID:26965057

  13. Structural basis for selective recognition of acyl chains by the membrane-associated acyltransferase PatA.

    PubMed

    Albesa-Jové, David; Svetlíková, Zuzana; Tersa, Montse; Sancho-Vaello, Enea; Carreras-González, Ana; Bonnet, Pascal; Arrasate, Pedro; Eguskiza, Ander; Angala, Shiva K; Cifuente, Javier O; Korduláková, Jana; Jackson, Mary; Mikušová, Katarína; Guerin, Marcelo E

    2016-01-01

    The biosynthesis of phospholipids and glycolipids are critical pathways for virtually all cell membranes. PatA is an essential membrane associated acyltransferase involved in the biosynthesis of mycobacterial phosphatidyl-myo-inositol mannosides (PIMs). The enzyme transfers a palmitoyl moiety from palmitoyl-CoA to the 6-position of the mannose ring linked to 2-position of inositol in PIM1/PIM2. We report here the crystal structures of PatA from Mycobacterium smegmatis in the presence of its naturally occurring acyl donor palmitate and a nonhydrolyzable palmitoyl-CoA analog. The structures reveal an α/β architecture, with the acyl chain deeply buried into a hydrophobic pocket that runs perpendicular to a long groove where the active site is located. Enzyme catalysis is mediated by an unprecedented charge relay system, which markedly diverges from the canonical HX4D motif. Our studies establish the mechanistic basis of substrate/membrane recognition and catalysis for an important family of acyltransferases, providing exciting possibilities for inhibitor design. PMID:26965057

  14. Fatty acyl donor selectivity in membrane bound O-acyltransferases and communal cell fate decision-making

    PubMed Central

    Tuladhar, Rubina; Lum, Lawrence

    2015-01-01

    The post-translational modification of proteins with lipid moieties confers spatial and temporal control of protein function by restricting their subcellular distribution or movement in the extracellular milieu. Yet, little is known about the significance of lipid selectivity to the activity of proteins targeted for such modifications. Membrane bound O-acyl transferases (MBOATs) are a superfamily of multipass enzymes that transfer fatty acids on to lipid or protein substrates. Three MBOATs constitute a subfamily with secreted signalling molecules for substrates, the Wnt, Hedgehog (Hh) and Ghrelin proteins. Given their important roles in adult tissue homoeostasis, all three molecules and their respective associated acyltransferases provide a framework for interrogating the role of extracellular acylation events in cell-to-cell communication. Here, we discuss how the preference for a fatty acyl donor in the Wnt acyltransferase porcupine (Porcn) and possibly in other protein lipidation enzymes may provide a means for coupling metabolic health at the single cell level to communal cell fate decision-making in complex multicellular organisms. PMID:25849923

  15. Fatty acyl donor selectivity in membrane bound O-acyltransferases and communal cell fate decision-making.

    PubMed

    Tuladhar, Rubina; Lum, Lawrence

    2015-04-01

    The post-translational modification of proteins with lipid moieties confers spatial and temporal control of protein function by restricting their subcellular distribution or movement in the extracellular milieu. Yet, little is known about the significance of lipid selectivity to the activity of proteins targeted for such modifications. Membrane bound O-acyl transferases (MBOATs) are a superfamily of multipass enzymes that transfer fatty acids on to lipid or protein substrates. Three MBOATs constitute a subfamily with secreted signalling molecules for substrates, the Wnt, Hedgehog (Hh) and Ghrelin proteins. Given their important roles in adult tissue homoeostasis, all three molecules and their respective associated acyltransferases provide a framework for interrogating the role of extracellular acylation events in cell-to-cell communication. Here, we discuss how the preference for a fatty acyl donor in the Wnt acyltransferase porcupine (Porcn) and possibly in other protein lipidation enzymes may provide a means for coupling metabolic health at the single cell level to communal cell fate decision-making in complex multicellular organisms. PMID:25849923

  16. Purification and characterisation of acyl-CoA: glycerol 3-phosphate acyltransferase from oil palm (Elaeis guineensis) tissues.

    PubMed

    Manaf, A M; Harwood, J L

    2000-01-01

    Glycerol 3-phosphate acyltransferase (GPAT, EC 2.3.15) catalyses the first step of the Kennedy pathway for acyl lipid formation. This enzyme was studied using high-speed particulate fractions from oil palm (Elaeis guineensis Jacq.) tissue cultures and mesocarp acetone powders. The fractions were incubated with [(14)C]glycerol 3-phosphate and incorporation of radioactivity into Kennedy pathway intermediates studied. Optimal conditions were broadly similar between the two preparations but those from fruit mesocarp clearly contained more active enzymes for the subsequent stages of the Kennedy pathway - as exemplified by the appreciable accumulation of radioactivity in triacylglycerol. Experiments with different acyl-CoA substrates showed that the GPAT in both high-speed particulate preparations had a significant preference for palmitate. Glycerol 3-phosphate acyltransferase was solubilised from both preparations with optimal solubilisation being achieved at 0.5% (w/v) CHAPS concentrations. Solubilised GPATs were purified further using DE52 ion-exchange chromatography and Sephadex G-100 molecular exclusion chromatography. Purifications of up to about 70-fold were achieved. The purified GPATs showed a strong preference for palmitoyl-CoA compared to other acyl-CoA donors, in keeping with the importance of palmitate in palm oil. PMID:10664139

  17. Functionally Divergent Alleles and Duplicated Loci Encoding an Acyltransferase Contribute to Acylsugar Metabolite Diversity in Solanum Trichomes[OPEN

    PubMed Central

    Schilmiller, Anthony L.; Moghe, Gaurav D.; Fan, Pengxiang; Ghosh, Banibrata; Ning, Jing; Jones, A. Daniel; Last, Robert L.

    2015-01-01

    Glandular trichomes from tomato (Solanum lycopersicum) and other species in the Solanaceae produce and secrete a mixture of O-acylsugars (aliphatic esters of sucrose and glucose) that contribute to insect defense. Despite their phylogenetic distribution and diversity, relatively little is known about how these specialized metabolites are synthesized. Mass spectrometric profiling of acylsugars in the S. lycopersicum x Solanum pennellii introgression lines identified a chromosome 11 locus containing a cluster of BAHD acyltransferases with one gene (named Sl-ASAT3) expressed in tip cells of type I trichomes where acylsugars are made. Sl-ASAT3 was shown to encode an acyl-CoA-dependent acyltransferase that catalyzes the transfer of short (four to five carbons) branched acyl chains to the furanose ring of di-acylsucrose acceptors to produce tri-acylsucroses, which can be further acetylated by Sl-ASAT4 (previously Sl-AT2). Among the wild tomatoes, diversity in furanose ring acyl chains on acylsucroses was most striking in Solanum habrochaites. S. habrochaites accessions from Ecuador and northern Peru produced acylsucroses with short (≤C5) or no acyl chains on the furanose ring. Accessions from central and southern Peru had the ability to add short or long (up to C12) acyl chains to the furanose ring. Multiple ASAT3-like sequences were found in most accessions, and their in vitro activities correlated with observed geographical diversity in acylsugar profiles. PMID:25862303

  18. Castor Phospholipid:Diacylglycerol Acyltransferase Facilitates Efficient Metabolism of Hydroxy Fatty Acids in Transgenic Arabidopsis1[W][OA

    PubMed Central

    van Erp, Harrie; Bates, Philip D.; Burgal, Julie; Shockey, Jay; Browse, John

    2011-01-01

    Producing unusual fatty acids (FAs) in crop plants has been a long-standing goal of green chemistry. However, expression of the enzymes that catalyze the primary synthesis of these unusual FAs in transgenic plants typically results in low levels of the desired FA. For example, seed-specific expression of castor (Ricinus communis) fatty acid hydroxylase (RcFAH) in Arabidopsis (Arabidopsis thaliana) resulted in only 17% hydroxy fatty acids (HFAs) in the seed oil. In order to increase HFA levels, we investigated castor phospholipid:diacylglycerol acyltransferase (PDAT). We cloned cDNAs encoding three putative PDAT enzymes from a castor seed cDNA library and coexpressed them with RcFAH12. One isoform, RcPDAT1A, increased HFA levels to 27%. Analysis of HFA-triacylglycerol molecular species and regiochemistry, along with analysis of the HFA content of phosphatidylcholine, indicates that RcPDAT1A functions as a PDAT in vivo. Expression of RcFAH12 alone leads to a significant decrease in FA content of seeds. Coexpression of RcPDAT1A and RcDGAT2 (for diacylglycerol acyltransferase 2) with RcFAH12 restored FA levels to nearly wild-type levels, and this was accompanied by a major increase in the mass of HFAs accumulating in the seeds. We show the usefulness of RcPDAT1A for engineering plants with high levels of HFAs and alleviating bottlenecks due to the production of unusual FAs in transgenic oilseeds. PMID:21173026

  19. The yeast acyltransferase Sct1p regulates fatty acid desaturation by competing with the desaturase Ole1p

    PubMed Central

    De Smet, Cedric H.; Vittone, Elisa; Scherer, Max; Houweling, Martin; Liebisch, Gerhard; Brouwers, Jos F.; de Kroon, Anton I.P.M.

    2012-01-01

    The degree of fatty acid unsaturation, that is, the ratio of unsaturated versus saturated fatty acyl chains, determines membrane fluidity. Regulation of expression of the fatty acid desaturase Ole1p was hitherto the only known mechanism governing the degree of fatty acid unsaturation in Saccharomyces cerevisiae. We report a novel mechanism for the regulation of fatty acid desaturation that is based on competition between Ole1p and the glycerol-3-phosphate acyltransferase Sct1p/Gat2p for the common substrate C16:0-CoA. Deletion of SCT1 decreases the content of saturated fatty acids, whereas overexpression of SCT1 dramatically decreases the desaturation of fatty acids and affects phospholipid composition. Whereas overexpression of Ole1p increases desaturation, co-overexpression of Ole1p and Sct1p results in a fatty acid composition intermediate between those obtained upon overexpression of the enzymes separately. On the basis of these results, we propose that Sct1p sequesters C16:0-CoA into lipids, thereby shielding it from desaturation by Ole1p. Ta­king advantage of the growth defect conferred by overexpressing SCT1, we identified the acyltransferase Cst26p/Psi1p as a regulator of Sct1p activity by affecting the phosphorylation state and overexpression level of Sct1p. The level of Sct1p phosphorylation is increased when cells are supplemented with saturated fatty acids, demonstrating the physiological relevance of our findings. PMID:22323296

  20. Synthesis and characterisation of 5-acyl-6,7-dihydrothieno[3,2-c]pyridine inhibitors of Hedgehog acyltransferase.

    PubMed

    Lanyon-Hogg, Thomas; Masumoto, Naoko; Bodakh, George; Konitsiotis, Antonio D; Thinon, Emmanuelle; Rodgers, Ursula R; Owens, Raymond J; Magee, Anthony I; Tate, Edward W

    2016-06-01

    In this data article we describe synthetic and characterisation data for four members of the 5-acyl-6,7-dihydrothieno[3,2-c]pyridine (termed "RU-SKI") class of inhibitors of Hedgehog acyltransferase, including associated NMR spectra for final compounds. RU-SKI compounds were selected for synthesis based on their published high potencies against the enzyme target. RU-SKI 41 (9a), RU-SKI 43 (9b), RU-SKI 101 (9c), and RU-SKI 201 (9d) were profiled for activity in the related article "Click chemistry armed enzyme linked immunosorbent assay to measure palmitoylation by Hedgehog acyltransferase" (Lanyon-Hogg et al., 2015) [1]. (1)H NMR spectral data indicate different amide conformational ratios between the RU-SKI inhibitors, as has been observed in other 5-acyl-6,7-dihydrothieno[3,2-c]pyridines. The synthetic and characterisation data supplied in the current article provide validated access to the class of RU-SKI inhibitors. PMID:27077078

  1. Glycerol-3-phosphate acyltransferase 4 is essential for the normal development of reproductive organs and the embryo in Brassica napus.

    PubMed

    Chen, Xue; Chen, Guanqun; Truksa, Martin; Snyder, Crystal L; Shah, Saleh; Weselake, Randall J

    2014-08-01

    The enzyme sn-glycerol-3-phosphate acyltransferase 4 (GPAT4) is involved in the biosynthesis of plant lipid poly-esters. The present study further characterizes the enzymatic activities of three endoplasmic reticulum-bound GPAT4 isoforms of Brassica napus and examines their roles in the development of reproductive organs and the embryo. All three BnGPAT4 isoforms exhibited sn-2 acyltransferase and phosphatase activities with dicarboxylic acid-CoA as acyl donor. When non-substituted acyl-CoA was used as acyl donor, the rate of acylation was considerably lower and phosphatase activity was not manifested. RNA interference (RNAi)-mediated down-regulation of all GPAT4 homologues in B. napus under the control of the napin promoter caused abnormal development of several reproductive organs and reduced seed set. Microscopic examination and reciprocal crosses revealed that both pollen grains and developing embryo sacs of the B. napus gpat4 lines were affected. The gpat4 mature embryos showed decreased cutin content and altered monomer composition. The defective embryo development further affected the oil body morphology, oil content, and fatty acid composition in gpat4 seeds. These results suggest that GPAT4 has a critical role in the development of reproductive organs and the seed of B. napus. PMID:24821955

  2. Leishmania Dihydroxyacetonephosphate Acyltransferase LmDAT is Important for Ether Lipid Biosynthesis but not for the Integrity of Detergent Resistant Membranes

    PubMed Central

    Zufferey, Rachel; Al-Ani, Gada K.; Dunlap, Kara

    2009-01-01

    Glycerolipid biosynthesis in Leishmania initiates with the acylation of glycerol-3-phosphate by a single glycerol-3-phosphate acyltransferase, LmGAT, or of dihydroxyacetonephosphate by a dihydroxyacetonephosphate acyltransferase, LmDAT. We previously reported that acylation of the precursor dihydroxyacetonephosphate rather than glycerol-3-phosphate is the physiologically relevant pathway for Leishmania parasites. We demonstrated that LmDAT is important for normal growth, survival during the stationary phase, and for virulence. Here, we assessed the role of LmDAT in glycerolipid metabolism and metacyclogenesis. LmDAT was found to be implicated in the biosynthesis of ether glycerolipids, including the ether-lipid derived virulence factor lipophosphoglycan and glycosylphosphatidylinositol-anchored proteins. The null mutant produced longer lipophosphoglycan molecules that were not released in the medium, and augmented levels of glycosylphosphatidylinositol-anchored proteins. In addition, the integrity of detergent resistant membranes was not affected by the absence of the LmDAT gene. Further, our genetic analyses strongly suggest that LmDAT was colethal with the glycerol-3-phosphate acyltransferase encoding gene LmGAT, implying that Leishmania expresses only two acyltransferases that initiate the biosynthesis of its cellular glycerolipids. Last, despite the fact that LmDAT is important for virulence the null mutant still exhibited the typical characteristics of metacyclics. PMID:19720088

  3. Morphological and metabolic changes in transgenic wheat with altered glycerol-3-phosphate acyltransferase or acyl-acyl carrier protein (ACP) thioesterase activities.

    PubMed

    Edlin, D A; Kille, P; Wilkinson, M D; Jones, H D; Harwood, J L

    2000-12-01

    We have transformed varieties of wheat with a Pisum sativum glycerol-3-phosphate acyltransferase gene, and also with an Arabidopsis thaliana acyl-ACP thioesterase gene. Morphological (growth, organelle development) and metabolic changes (fatty acid labelling of chloroplast and non-chloroplast lipids) have been observed in transgenics with altered gene expression for either enzyme. PMID:11171169

  4. Identification of D-amino acid dehydrogenase as an upstream regulator of the autoinduction of a putative acyltransferase in Corynebacterium glutamicum.

    PubMed

    Lee, Jung-Hoon; Kim, Yong-Jae; Shin, Hee-Sung; Lee, Heung-Shick; Jin, Shouguang; Ha, Un-Hwan

    2016-06-01

    Expression of a putative acyltransferase encoded by NCgl- 0350 of Corynebacterium glutamicum is induced by cell-free culture fluids obtained from stationary-phase growth of both C. glutamicum and Pseudomonas aeruginosa, providing evidence for interspecies communication. Here, we further confirmed that such communication occurs by showing that acyltransferase expression is induced by culture fluid obtained from diverse Gram-negative and -positive bacterial strains, including Escherichia coli, Salmonella Typhimurium, Bacillus subtilis, Staphylococcus aureus, Mycobacterium sp. strain JC1, and Mycobacterium smegmatis. A homologous acyltransferase encoded by PA5238 of P. aeruginosa was also induced by fluids obtained from P. aeruginosa as well as other bacterial strains, as observed for NCgl0350 of C. glutamicum. Because C. glutamicum is difficult to study using molecular approaches, the homologous gene PA5238 of P. aeruginosa was used to identify PA5309 as an upstream regulator of expression. A homologous D-amino acid dehydrogenase encoded by NCgl- 2909 of C. glutamicum was cloned based on amino acid similarity to PA5309, and its role in the regulation of NCgl0350 expression was confirmed. Moreover, NCgl2909 played positive roles in growth of C. glutamicum. Thus, we identified a D-amino acid dehydrogenase as an upstream regulator of the autoinduction of a putative acyltransferase in C. glutamicum. PMID:27225460

  5. [Alcoholism and aging. 2. Alcoholic dementia or alcoholic cognitive impairment?].

    PubMed

    Pierucci-Lagha, Amira; Derouesné, Christian

    2003-12-01

    Chronic alcohol consumption results in considerable damage to many of the body's organs, and particularly to the brain. Beyond the confusional state occurring with acute intoxication or withdrawal, alcohol abuse is responsible of a constellation of neuropsychiatric syndromes including cognitive dysfunction, Wernicke-Korsakoff Syndrome, alcoholic cerebellar degeneration, Marchiafava-Bignami disease and alcohol-related dementia, ARD. ARD would account for nearly 20% of all admissions to state mental hospitals in the United-States. According to the DSM-IV, ARD is defined by a dementia associated with alcohol abuse. However, the concept of a dementia directly related to the neurotoxicity of alcohol for brain neurons is still a matter of debate. Several hypotheses have been proposed to explain the mechanisms of cognitive deficits related to chronic alcohol intoxication. This paper presents the epidemiological, neuropathological, neurochemical and clinical data on ARD. Alcoholism is responsible for cognitive deficits of various severity, which could be reversible or not with alcohol abstinence, but can also participate to the cognitive impairment related to other pathologies, such as Alzheimer disease. On account of this review, it is suggested that the term alcohol-related cognitive impairment should be more convenient than that of ARD, more restrictive and more confusing. Presently, there are no established treatment for alcohol-related cognitive impairment. Alcohol abstinence is a most important step. Psychosocial interventions are essential to support the patients in the daily life. PMID:15683959

  6. Overexpression of the active diacylglycerol acyltransferase variant transforms Saccharomyces cerevisiae into an oleaginous yeast.

    PubMed

    Kamisaka, Yasushi; Kimura, Kazuyoshi; Uemura, Hiroshi; Yamaoka, Masakazu

    2013-08-01

    Lipid production by Saccharomyces cerevisiae was improved by overexpression of the yeast diacylglycerol acyltransferase Dga1p lacking the N-terminal 29 amino acids (Dga1∆Np), which was previously found to be an active form in the ∆snf2 mutant. Overexpression of Dga1∆Np in the ∆snf2 mutant, however, did not increase lipid content as expected, which prompted us to search for a more suitable strain in which to study the role of Dga1∆Np in lipid accumulation. We found that the overexpression of Dga1∆Np in the ∆dga1 mutant effectively increased the lipid content up to about 45 % in the medium containing 10 % glucose. The high lipid content of the transformant was dependent on glucose concentration, nitrogen limitation, and active leucine biosynthesis. To better understand the effect of dga1 disruption on the ability of Dga1∆Np to stimulate lipid accumulation, the ∆dga1-1 mutant, in which the 3'-terminal 36 bp of the dga1 open reading frame (ORF) remained, and the ∆dga1-2 mutant, in which the 3'-terminal 36 bp were also deleted, were prepared with URA3 disruption cassettes. Surprisingly, the overexpression of Dga1∆Np in the ∆dga1-1 mutant had a lower lipid content than the original ∆dga1 mutant, whereas overexpression in the ∆dga1-2 mutant led to a high lipid content of about 45 %. These results indicated that deletion of the 3' terminal region of the dga1 ORF, rather than abrogation of genomic Dga1p expression, was crucial for the effect of Dga1∆Np on lipid accumulation. To investigate whether dga1 disruption affected gene expression adjacent to DGA1, we found that the overexpression of Esa1p together with Dga1∆Np in the ∆dga1 mutant reverted the lipid content to the level of the wild-type strain overexpressing Dga1∆Np. In addition, RT-qPCR analysis revealed that ESA1 mRNA expression in the ∆dga1 mutant was decreased compared to the wild-type strain at the early stages of culture, suggesting that lowered Esa1p expression is

  7. Insomnia, alcoholism and relapse.

    PubMed

    Brower, Kirk J

    2003-12-01

    Insomnia and alcoholism are significantly associated in community surveys and patient samples. Insomnia occurs in 36-72% of alcoholic patients and may last for weeks to months after initiating abstinence from alcohol. Some correlates of insomnia in alcoholic patients are identical to those observed in non-alcoholic insomniacs, including anxiety and depression, tobacco smoking, and the use of alcohol to aid sleep. Other studies suggest that as the severity of alcoholism increases, so does the likelihood of insomnia in alcoholic patients. In the sleep laboratory, alcoholic patients who complain of insomnia have disrupted sleep continuity when compared to alcoholic patients without insomnia complaints. Recently sober alcoholics are also more likely than non-alcoholics to have sleep-disordered breathing and increased periodic leg movements, which might contribute to insomnia in some alcoholic patients. The co-occurrence of insomnia and alcoholism is clinically significant because alcoholism can exacerbate the adverse consequences of insomnia (e.g. mood changes and performance decrements) and because insomnia among patients entering treatment for alcoholism has been significantly associated with subsequent alcoholic relapse. Baseline polysomnographic correlates of subsequent relapse include prolonged sleep latency, decreased sleep efficiency and total sleep time, increased rapid eye movement sleep pressure, and decreased slow wave sleep. Whether treatment of insomnia in alcoholic patients reduces relapse rates is unknown, but preliminary treatment guidelines that accommodate the special characteristics of alcoholic patients are provided, with a goal to reduce daytime impairment and psychological distress. PMID:15018094

  8. A Land-Plant-Specific Glycerol-3-Phosphate Acyltransferase Family in Arabidopsis: Substrate Specificity, sn-2 Preference, and Evolution1[W][OA

    PubMed Central

    Yang, Weili; Simpson, Jeffrey P.; Li-Beisson, Yonghua; Beisson, Fred; Pollard, Mike; Ohlrogge, John B.

    2012-01-01

    Arabidopsis (Arabidopsis thaliana) has eight glycerol-3-phosphate acyltransferase (GPAT) genes that are members of a plant-specific family with three distinct clades. Several of these GPATs are required for the synthesis of cutin or suberin. Unlike GPATs with sn-1 regiospecificity involved in membrane or storage lipid synthesis, GPAT4 and -6 are unique bifunctional enzymes with both sn-2 acyltransferase and phosphatase activity resulting in 2-monoacylglycerol products. We present enzymology, pathway organization, and evolutionary analysis of this GPAT family. Within the cutin-associated clade, GPAT8 is demonstrated as a bifunctional sn-2 acyltransferase/phosphatase. GPAT4, -6, and -8 strongly prefer C16:0 and C18:1 ω-oxidized acyl-coenzyme As (CoAs) over unmodified or longer acyl chain substrates. In contrast, suberin-associated GPAT5 can accommodate a broad chain length range of ω-oxidized and unsubstituted acyl-CoAs. These substrate specificities (1) strongly support polyester biosynthetic pathways in which acyl transfer to glycerol occurs after oxidation of the acyl group, (2) implicate GPAT specificities as one major determinant of cutin and suberin composition, and (3) argue against a role of sn-2-GPATs (Enzyme Commission 2.3.1.198) in membrane/storage lipid synthesis. Evidence is presented that GPAT7 is induced by wounding, produces suberin-like monomers when overexpressed, and likely functions in suberin biosynthesis. Within the third clade, we demonstrate that GPAT1 possesses sn-2 acyltransferase but not phosphatase activity and can utilize dicarboxylic acyl-CoA substrates. Thus, sn-2 acyltransferase activity extends to all subbranches of the Arabidopsis GPAT family. Phylogenetic analyses of this family indicate that GPAT4/6/8 arose early in land-plant evolution (bryophytes), whereas the phosphatase-minus GPAT1 to -3 and GPAT5/7 clades diverged later with the appearance of tracheophytes. PMID:22864585

  9. Fetal alcohol syndrome

    MedlinePlus

    Alcohol in pregnancy; Alcohol-related birth defects; Fetal alcohol effects; FAS ... the baby is in the womb and after birth Decreased muscle tone and ... Heart defects such as ventricular septal defect (VSD) or atrial ...

  10. Breath alcohol test

    MedlinePlus

    Alcohol test - breath ... There are various brands of breath alcohol tests. Each one uses a different method to test the level of alcohol in the breath. The machine may be electronic or manual. One ...

  11. Alcohol use disorder

    MedlinePlus

    ... who are dealing with alcohol use. ALCOHOLICS ANONYMOUS (AA) Alcoholics Anonymous is a self-help group of ... approach. There are local chapters throughout the U.S. AA offers help 24 hours a day. AL-ANON ...

  12. Fetal Alcohol Syndrome

    MedlinePlus

    ... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Fetal Alcohol Syndrome Read in Chinese What is Fetal Alcohol Syndrome (FAS)? Fetal Alcohol Syndrome (FAS) describes changes in ...

  13. Alcoholic liver disease

    MedlinePlus

    Liver disease due to alcohol; Cirrhosis or hepatitis - alcoholic; Laennec's cirrhosis ... Alcoholic liver disease occurs after years of heavy drinking. Over time, scarring and cirrhosis can occur. Cirrhosis is the ...

  14. Golgi membrane fission requires the CtBP1-S/BARS-induced activation of lysophosphatidic acid acyltransferase δ.

    PubMed

    Pagliuso, Alessandro; Valente, Carmen; Giordano, Lucia Laura; Filograna, Angela; Li, Guiling; Circolo, Diego; Turacchio, Gabriele; Marzullo, Vincenzo Manuel; Mandrich, Luigi; Zhukovsky, Mikhail A; Formiggini, Fabio; Polishchuk, Roman S; Corda, Daniela; Luini, Alberto

    2016-01-01

    Membrane fission is an essential cellular process by which continuous membranes split into separate parts. We have previously identified CtBP1-S/BARS (BARS) as a key component of a protein complex that is required for fission of several endomembranes, including basolateral post-Golgi transport carriers. Assembly of this complex occurs at the Golgi apparatus, where BARS binds to the phosphoinositide kinase PI4KIIIβ through a 14-3-3γ dimer, as well as to ARF and the PKD and PAK kinases. We now report that, when incorporated into this complex, BARS binds to and activates a trans-Golgi lysophosphatidic acid (LPA) acyltransferase type δ (LPAATδ) that converts LPA into phosphatidic acid (PA); and that this reaction is essential for fission of the carriers. LPA and PA have unique biophysical properties, and their interconversion might facilitate the fission process either directly or indirectly (via recruitment of proteins that bind to PA, including BARS itself). PMID:27401954

  15. Golgi membrane fission requires the CtBP1-S/BARS-induced activation of lysophosphatidic acid acyltransferase δ

    PubMed Central

    Pagliuso, Alessandro; Valente, Carmen; Giordano, Lucia Laura; Filograna, Angela; Li, Guiling; Circolo, Diego; Turacchio, Gabriele; Marzullo, Vincenzo Manuel; Mandrich, Luigi; Zhukovsky, Mikhail A.; Formiggini, Fabio; Polishchuk, Roman S.; Corda, Daniela; Luini, Alberto

    2016-01-01

    Membrane fission is an essential cellular process by which continuous membranes split into separate parts. We have previously identified CtBP1-S/BARS (BARS) as a key component of a protein complex that is required for fission of several endomembranes, including basolateral post-Golgi transport carriers. Assembly of this complex occurs at the Golgi apparatus, where BARS binds to the phosphoinositide kinase PI4KIIIβ through a 14-3-3γ dimer, as well as to ARF and the PKD and PAK kinases. We now report that, when incorporated into this complex, BARS binds to and activates a trans-Golgi lysophosphatidic acid (LPA) acyltransferase type δ (LPAATδ) that converts LPA into phosphatidic acid (PA); and that this reaction is essential for fission of the carriers. LPA and PA have unique biophysical properties, and their interconversion might facilitate the fission process either directly or indirectly (via recruitment of proteins that bind to PA, including BARS itself). PMID:27401954

  16. Crystallization and preliminary X-ray analysis of the glycerol-3-phosphate 1-acyltransferase from squash (Cucurbita moschata).

    PubMed

    Turnbull, A P; Rafferty, J B; Sedelnikova, S E; Slabas, A R; Schierer, T P; Kroon, J T; Nishida, I; Murata, N; Simon, J W; Rice, D W

    2001-03-01

    Glycerol-3-phosphate 1-acyltransferase (E.C. 2.3.1.15; G3PAT) catalyses the incorporation of an acyl group from either acyl-acyl carrier proteins (acylACPs) or acylCoAs into the sn-1 position of glycerol 3-phosphate to yield 1-acylglycerol 3-phosphate. Crystals of squash G3PAT have been obtained by the hanging-drop method of vapour diffusion using PEG 4000 as the precipitant. These crystals are most likely to belong to space group P2(1)2(1)2(1), with approximate unit-cell parameters a = 61.1, b = 65.1, c = 103.3 A, alpha = beta = gamma = 90 degrees and a monomer in the asymmetric unit. X-ray diffraction data to 1.9 A resolution have been collected in-house using a MAR 345 imaging-plate system. PMID:11223529

  17. Two Clades of Type-1 Brassica napus Diacylglycerol Acyltransferase Exhibit Differences in Acyl-CoA Preference.

    PubMed

    Greer, Michael S; Pan, Xue; Weselake, Randall J

    2016-06-01

    Diacylglycerol acyltransferase (DGAT) catalyzes the acyl-CoA-dependent acylation of sn-1, 2-diacylglycerol to produce triacylglycerol, which is the main component of the seed oil of Brassica oilseed species. Phylogenetic analysis of the amino acid sequences encoded by four transcriptionally active DGAT1 genes from Brassica napus suggests that the gene forms diverged over time into two clades (I and II), with representative members in each genome (A and C). The majority of the amino acid sequence differences in these forms of DGAT1, however, reside outside of motifs suggested to be involved in catalysis. Despite this, the clade II enzymes displayed a significantly enhanced preference for linoleoyl-CoA when assessed using in-vitro enzyme assays with yeast microsomes containing recombinant enzyme forms. These findings contribute to our understanding of triacylglycerol biosynthesis in B. napus, and may advance our ability to engineer DGAT1s with desired substrate selectivity properties. PMID:27138895

  18. TG-interacting factor 1 acts as a transcriptional repressor of sterol O-acyltransferase 2[S

    PubMed Central

    Pramfalk, Camilla; Melhuish, Tiffany A.; Wotton, David; Jiang, Zhao-Yan; Eriksson, Mats; Parini, Paolo

    2014-01-01

    Acat2 [gene name: sterol O-acyltransferase 2 (SOAT2)] esterifies cholesterol in enterocytes and hepatocytes. This study aims to identify repressor elements in the human SOAT2 promoter and evaluate their in vivo relevance. We identified TG-interacting factor 1 (Tgif1) to function as an important repressor of SOAT2. Tgif1 could also block the induction of the SOAT2 promoter activity by hepatocyte nuclear factor 1α and 4α. Women have ∼30% higher hepatic TGIF1 mRNA compared with men. Depletion of Tgif1 in mice increased the hepatic Soat2 expression and resulted in higher hepatic lipid accumulation and plasma cholesterol levels. Tgif1 is a new player in human cholesterol metabolism. PMID:24478032

  19. Limnanthes douglasii lysophosphatidic acid acyltransferases: immunological quantification, acyl selectivity and functional replacement of the Escherichia coli plsC gene.

    PubMed Central

    Brown, Adrian P; Carnaby, Simon; Brough, Clare; Brazier, Melissa; Slabas, Antoni R

    2002-01-01

    Antibodies were raised against the two membrane-bound lysophosphatidic acid acyltransferase (LPAAT) enzymes from Limnanthes douglasii (meadowfoam), LAT1 and LAT2, using the predicted soluble portion of each protein as recombinant protein antigens. The antibodies can distinguish between the two acyltransferase proteins and demonstrate that both migrate in an anomalous fashion on SDS/PAGE gels. The antibodies were used to determine that LAT1 is present in both leaf and developing seeds, whereas LAT2 is only detectable in developing seeds later than 22 daf (days after flowering). Both proteins were found exclusively in microsomal fractions and their amount was determined using the recombinant antigens as quantification standards. LAT1 is present at a level of 27 pg/microg of membrane protein in leaf tissue and

  20. Silencing an N-acyltransferase-like involved in lignin biosynthesis in Nicotiana attenuata dramatically alters herbivory-induced phenolamide metabolism.

    PubMed

    Gaquerel, Emmanuel; Kotkar, Hemlata; Onkokesung, Nawaporn; Galis, Ivan; Baldwin, Ian T

    2013-01-01

    In a transcriptomic screen of Manduca sexta-induced N-acyltransferases in leaves of Nicotiana attenuata, we identified an N-acyltransferase gene sharing a high similarity with the tobacco lignin-biosynthetic hydroxycinnamoyl-CoA:shikimate/quinate hydroxycinnamoyl transferase (HCT) gene whose expression is controlled by MYB8, a transcription factor that regulates the production of phenylpropanoid polyamine conjugates (phenolamides, PAs). To evaluate the involvement of this HCT-like gene in lignin production as well as the resulting crosstalk with PA metabolism during insect herbivory, we transiently silenced (by VIGs) the expression of this gene and performed non-targeted (UHPLC-ESI/TOF-MS) metabolomics analyses. In agreement with a conserved function of N. attenuata HCT-like in lignin biogenesis, HCT-silenced plants developed weak, soft stems with greatly reduced lignin contents. Metabolic profiling demonstrated large shifts (up to 12% deregulation in total extracted ions in insect-attacked leaves) due to a large diversion of activated coumaric acid units into the production of developmentally and herbivory-induced coumaroyl-containing PAs (N',N''-dicoumaroylspermidine, N',N''-coumaroylputrescine, etc) and to minor increases in the most abundant free phenolics (chlorogenic and cryptochlorogenic acids), all without altering the production of well characterized herbivory-responsive caffeoyl- and feruloyl-based putrescine and spermidine PAs. These data are consistent with a strong metabolic tension, exacerbated during herbivory, over the allocation of coumaroyl-CoA units among lignin and unusual coumaroyl-containing PAs, and rule out a role for HCT-LIKE in tuning the herbivory-induced accumulation of other PAs. Additionally, these results are consistent with a role for lignification as an induced anti-herbivore defense. PMID:23704878

  1. Sex and depot differences in ex vivo adipose tissue fatty acid storage and glycerol-3-phosphate acyltransferase activity

    PubMed Central

    Morgan-Bathke, Maria; Chen, Liang; Oberschneider, Elisabeth; Harteneck, Debra

    2015-01-01

    Adipose tissue fatty acid storage varies according to sex, adipose tissue depot, and degree of fat gain. However, the mechanism(s) for these variations is not completely understood. We examined whether differences in adipose tissue glycerol-3-phosphate acyltransferase (GPAT) might play a role in these variations. We optimized an enzyme activity assay for total GPAT and GPAT1 activity in human adipose tissue and measured GPAT activity. Omental and subcutaneous adipose tissue was collected from obese and nonobese adults for measures of GPAT and GPAT1 activities, ex vivo palmitate storage, acyl-CoA synthetase (ACS) and diacylglycerol-acyltransferase (DGAT) activities, and CD36 protein. Total GPAT and GPAT1 activities decreased as a function of adipocyte size in both omental (r = −0.71, P = 0.003) and subcutaneous (r = −0.58, P = 0.04) fat. The relative contribution of GPAT1 to total GPAT activity increased as a function of adipocyte size, accounting for up to 60% of GPAT activity in those with the largest adipocytes. We found strong, positive correlations between ACS, GPAT, and DGAT activities for both sexes and depots (r values 0.58–0.91) and between these storage factors and palmitate storage rates into TAG (r values 0.55–0.90). We conclude that: 1) total GPAT activity decreases as a function of adipocyte size; 2) GPAT1 can account for over half of adipose GPAT activity in hypertrophic obesity; and 3) ACS, GPAT, and DGAT are coordinately regulated. PMID:25738782

  2. Essential Role of Lysophosphatidylcholine Acyltransferase 3 in the Induction of Macrophage Polarization in PMA-Treated U937 Cells.

    PubMed

    Taniguchi, Kosuke; Hikiji, Hisako; Okinaga, Toshinori; Hashidate-Yoshida, Tomomi; Shindou, Hideo; Ariyoshi, Wataru; Shimizu, Takao; Tominaga, Kazuhiro; Nishihara, Tatsuji

    2015-12-01

    Lysophospholipid acyltransferases (LPLATs) regulate the diversification of fatty acid composition in biological membranes. Lysophosphatidylcholine acyltransferases (LPCATs) are members of the LPLATs that play a role in inflammatory responses. M1 macrophages differentiate in response to lipopolysaccharide (LPS) and are pro-inflammatory, whereas M2 macrophages, which differentiate in response to interleukin-4 (IL-4), are anti-inflammatory and involved in homeostasis and wound healing. In the present study, we showed that LPCATs play an important role in M1/M2-macrophage polarization. LPS changed the shape of PMA-treated U937 cells from rounded to spindle shaped and upregulated the mRNA and protein expression of the M1 macrophage markers CXCL10, TNF-α, and IL-1β. IL-4 had no effect on the shape of PMA-treated U937 cells and upregulated the M2 macrophage markers CD206, IL-1ra, and TGF-β in PMA-treated U937 cells. These results suggest that LPS and IL-4 promote the differentiation of PMA-treated U937 cells into M1- and M2-polarized macrophages, respectively. LPS significantly downregulated the mRNA expression of LPCAT3, one of four LPCAT isoforms, and suppressed its enzymatic activity toward linoleoyl-CoA and arachidonoyl-CoA in PMA-treated U937 cells. LPCAT3 knockdown induced a spindle-shaped morphology typical of M1-polarized macrophages, and increased the secretion of CXCL10 and decreased the levels of CD206 in IL-4-activated U937 cells. This indicates that knockdown of LPCAT3 shifts the differentiation of PMA-treated U937 cells to M1-polarized macrophages. Our findings suggest that LPCAT3 plays an important role in M1/M2-macrophage polarization, providing novel potential therapeutic targets for the regulation of immune and inflammatory disorders. PMID:25994902

  3. Silencing an N-Acyltransferase-Like Involved in Lignin Biosynthesis in Nicotiana attenuata Dramatically Alters Herbivory-Induced Phenolamide Metabolism

    PubMed Central

    Onkokesung, Nawaporn; Galis, Ivan; Baldwin, Ian T.

    2013-01-01

    In a transcriptomic screen of Manduca sexta-induced N-acyltransferases in leaves of Nicotiana attenuata, we identified an N-acyltransferase gene sharing a high similarity with the tobacco lignin-biosynthetic hydroxycinnamoyl-CoA:shikimate/quinate hydroxycinnamoyl transferase (HCT) gene whose expression is controlled by MYB8, a transcription factor that regulates the production of phenylpropanoid polyamine conjugates (phenolamides, PAs). To evaluate the involvement of this HCT-like gene in lignin production as well as the resulting crosstalk with PA metabolism during insect herbivory, we transiently silenced (by VIGs) the expression of this gene and performed non-targeted (UHPLC-ESI/TOF-MS) metabolomics analyses. In agreement with a conserved function of N. attenuata HCT-like in lignin biogenesis, HCT-silenced plants developed weak, soft stems with greatly reduced lignin contents. Metabolic profiling demonstrated large shifts (up to 12% deregulation in total extracted ions in insect-attacked leaves) due to a large diversion of activated coumaric acid units into the production of developmentally and herbivory-induced coumaroyl-containing PAs (N′,N′′-dicoumaroylspermidine, N′,N′′-coumaroylputrescine, etc) and to minor increases in the most abundant free phenolics (chlorogenic and cryptochlorogenic acids), all without altering the production of well characterized herbivory-responsive caffeoyl- and feruloyl-based putrescine and spermidine PAs. These data are consistent with a strong metabolic tension, exacerbated during herbivory, over the allocation of coumaroyl-CoA units among lignin and unusual coumaroyl-containing PAs, and rule out a role for HCT-LIKE in tuning the herbivory-induced accumulation of other PAs. Additionally, these results are consistent with a role for lignification as an induced anti-herbivore defense. PMID:23704878

  4. Alcohol in America.

    ERIC Educational Resources Information Center

    Rorabaugh, W. J.

    1991-01-01

    Traces the history of alcohol use in the United States from the colonial period to the present. Discusses changes in public attitudes toward drinking. Explores attempts at prohibition, alcohol preferences, the relationship between alcohol consumption and economic prosperity, and the dichotomy of alcohol as a part of a European heritage that is…

  5. Nurses' Attitudes towards Alcoholics.

    ERIC Educational Resources Information Center

    Speer, Rita D.

    Nurses' attitudes toward the alcoholic can have a profound impact on the person suffering from alcoholism. These attitudes can affect the alcoholic's care and even whether the alcoholic chooses to recover. This study investigated attitudes of approximately 68 nurses employed in hospitals, 49 nurses in treatment facilities, 58 nursing students, and…

  6. Alcoholic metabolic emergencies.

    PubMed

    Allison, Michael G; McCurdy, Michael T

    2014-05-01

    Ethanol intoxication and ethanol use are associated with a variety of metabolic derangements encountered in the Emergency Department. In this article, the authors discuss alcohol intoxication and its treatment, dispel the myth that alcohol intoxication is associated with hypoglycemia, comment on electrolyte derangements and their management, review alcoholic ketoacidosis, and end with a section on alcoholic encephalopathy. PMID:24766933

  7. Internet Alcohol Marketing and Underage Alcohol Use

    PubMed Central

    McClure, Auden C.; Tanski, Susanne E.; Li, Zhigang; Jackson, Kristina; Morgenstern, Matthis; Li, Zhongze; Sargent, James D.

    2016-01-01

    BACKGROUND AND OBJECTIVE Internet alcohol marketing is not well studied despite its prevalence and potential accessibility and attractiveness to youth. The objective was to examine longitudinal associations between self-reported engagement with Internet alcohol marketing and alcohol use transitions in youth. METHODS A US sample of 2012 youths aged 15 to 20 was surveyed in 2011. An Internet alcohol marketing receptivity score was developed, based on number of positive responses to seeing alcohol advertising on the Internet, visiting alcohol brand Web sites, being an online alcohol brand fan, and cued recall of alcohol brand home page images. We assessed the association between baseline marketing receptivity and both ever drinking and binge drinking (≥6 drinks per occasion) at 1-year follow-up with multiple logistic regression, controlling for baseline drinking status, Internet use, sociodemographics, personality characteristics, and peer or parent drinking. RESULTS At baseline, ever-drinking and binge-drinking prevalence was 55% and 27%, respectively. Many (59%) reported seeing Internet alcohol advertising, but few reported going to an alcohol Web site (6%) or being an online fan (3%). Higher Internet use, sensation seeking, having family or peers who drank, and past alcohol use were associated with Internet alcohol marketing receptivity, and a score of 1 or 2 was independently associated with greater adjusted odds of initiating binge drinking (odds ratio 1.77; 95% confidence interval, 1.13–2.78 and odds ratio 2.15; 95% confidence interval, 1.06–4.37 respectively) but not with initiation of ever drinking. CONCLUSIONS Although high levels of engagement with Internet alcohol marketing were uncommon, most underage youths reported seeing it, and we found a prospective association between receptivity to this type of alcohol marketing and future problem drinking, making additional research and ongoing surveillance important. PMID:26738886

  8. [Alcohol and psychiatric disorders].

    PubMed

    Bouzyk-Szutkiewicz, Joanna; Waszkiewicz, Napoleon; Szulc, Agata

    2012-09-01

    Alcohol dependence and abuse is one of the most costly health problems in the world from both a social and an economic point of view. It is a widespread problem, focusing attention not only psychiatrists but also doctors of other specialties. Patterns of drinking appear to be changing throughout the world, with more women and young people drinking heavily. Even risky drinking is a potential health risk, while chronic alcohol abuse contribute to the serious physical and mental complications. Alcohol used disorders associated with alcohol-induced brain damage include: withdrawal state, delirium tremens, alcoholic hallucinosis, alcoholic paranoia, Korsakoffs psychosis, alcoholic dementia, alcoholic depression. On the other hand, mental disorders as panic disorder, social anxiety disorder, agoraphobia, depression, bipolar disorder, schizophrenia, personality disorder most frequently comorbid with alcohol abuse or they trigger alcohol. PMID:23157139

  9. [Alcohol and arrhythmias].

    PubMed

    Pfeiffer, D; Jurisch, D; Neef, M; Hagendorff, A

    2016-09-01

    The effects of alcohol on induction of arrhythmias is dose-dependent, independent of preexisting cardiovascular diseases or heart failure and can affect otherwise healthy subjects. While the probability of atrial fibrillation increases with the alcohol dosage, events of sudden cardiac death are less frequent with low and moderate consumption but occur more often in heavy drinkers with alcoholic cardiomyopathy. Men are first affected at higher dosages of alcohol but women can suffer from arrhythmias at lower dosages. Thromboembolisms and ischemic stroke can occur less often at lower dosages of alcohol; however, hemorrhagic stroke and subarachnoid hemorrhage are increased with higher alcohol dosages. Recognizable protective mechanisms of alcohol with respect to cardiovascular diseases only occur with lower amounts of alcohol of less than 10 g per day. Underlying mechanisms explain these controversial effects. Specific therapeutic options for alcohol-related arrhythmias apart from abstinence from alcohol consumption are not known. PMID:27582366

  10. Alcohol fuels

    SciTech Connect

    Not Available

    1990-07-01

    Ethanol is an alcohol made from grain that can be blended with gasoline to extend petroleum supplies and to increase gasoline octane levels. Congressional proposals to encourage greater use of alternative fuels could increase the demand for ethanol. This report evaluates the growth potential of the ethanol industry to meet future demand increases and the impacts increased production would have on American agriculture and the federal budget. It is found that ethanol production could double or triple in the next eight years, and that American farmers could provide the corn for this production increase. While corn growers would benefit, other agricultural segments would not; soybean producers, for example could suffer for increased corn oil production (an ethanol byproduct) and cattle ranchers would be faced with higher feed costs because of higher corn prices. Poultry farmers might benefit from lower priced feed. Overall, net farm cash income should increase, and consumers would see slightly higher food prices. Federal budget impacts would include a reduction in federal farm program outlays by an annual average of between $930 million (for double current production of ethanol) to $1.421 billion (for triple production) during the eight-year growth period. However, due to an partial tax exemption for ethanol blended fuels, federal fuel tax revenues could decrease by between $442 million and $813 million.

  11. Osthole improves alcohol-induced fatty liver in mice by reduction of hepatic oxidative stress.

    PubMed

    Zhang, Jianjun; Xue, Jie; Wang, Hengbin; Zhang, Yan; Xie, Meilin

    2011-05-01

    The aim of our study was to examine the therapeutic effect of osthole, an active constituent isolated from the fruit of Cnidium monnieri (L.) Cusson, on alcohol-induced fatty liver in mice and investigate its potential mechanisms of treatment. A mouse alcoholic fatty liver model was established by feeding 52% alcohol for 4 weeks. These experimental mice were then treated with osthole 10, 20 and 40 mg/kg for 6 weeks. The levels of serum total cholesterol (TC), triglyceride (TG), low density lipoprotein-cholesterol (LDL-C) and hepatic tissue contents of TC, TG and malondialdehyde (MDA) in osthole-treated groups were significantly decreased, while the level of superoxide dismutase (SOD) was significantly increased compared with the model group. Moreover, the cytochrome P450 (CYP) 2E1 and diacylglycerol acyltransferase (DGAT) mRNA expressions in mouse liver were significantly decreased, and the carnitine palmitoyltransferase (CPT) 1A mRNA expression was increased by osthole treatment. Importantly, the histological evaluation of liver demonstrated that osthole dramatically decreased lipid accumulation. It was concluded that osthole was effective in treating mouse alcoholic fatty liver, and its main mechanisms might be related to reduction of hepatic oxidative stress, including the inhibition of reactive oxygen species (ROS) production, enhancement of antioxidative enzyme activity, and reduction of lipid accumulation and peroxidation. PMID:20981870

  12. Alcoholic hepatitis.

    PubMed

    Damgaard Sandahl, Thomas

    2014-10-01

    Alcoholic hepatitis (AH) is an acute inflammatory syndrome causing significant morbidity and mortality. The prognosis is strongly dependent on disease severity, as assessed by clinical scoring systems. Reliable epidemiological data as well as knowledge of the clinical course of AH are essential for planning and resource allocation within the health care system. Likewise, individual evaluation of risk is desirable in the clinical handling of patients with AH as it can guide treatment, improve patient information, and serve as strata in clinical trials. The present PhD thesis is based on three studies using a cohort of nearly 2000 patients diagnosed with AH in Denmark from 1999 to 2008 as a cohort, in a population-based study design. The aims of this thesis were as follows. (1) To describe the incidence and short- and long-term mortality, of AH in Denmark (Study I). (2) To validate and compare the ability of the currently available prognostic scores to predict mortality in AH (Study II). (3) To investigate the short- and long-term causes of death of patients with AH (Study III). During the study decade, the annual incidence rate in the Danish population rose from 37 to 46 per 106 for men and from 24 to 34 per 106 for women. Both short- and long-term mortality rose for men and women, and the increase in short-term mortality was attributable to increasing patient age and prevalence of cirrhosis. Our evaluation of the most commonly used prognostic scores for predicting the mortality of patients with AH showed that all scores performed similarly, with Area under the Receiver Operator Characteristics curves giving values between 0.74 and 0.78 for 28-day mortality assessed on admission. Our study on causes of death showed that in the short-term (< 84 days after diagnosis), patients with AH were likely to die from liver-related events and infections. In the long-term (≥ 84 days after diagnosis), those who developed cirrhosis mainly died from liver-related causes, and

  13. Perillyl Alcohol (Monoterpene Alcohol), Limonene.

    PubMed

    Shojaei, Shahla; Kiumarsi, Amir; Moghadam, Adel Rezaei; Alizadeh, Javad; Marzban, Hassan; Ghavami, Saeid

    2014-01-01

    Natural products have a long history of use in traditional medicines and their activities against different diseases have been the focus of many basic and clinical researches in past few decades. The essential oils, volatile liquid containing aroma compound from plants, are known as active ingredients in the herbal medicine. Perillyl alcohol (POH) is usually available through dietary sources and is being explored for its cancer chemoprevention, tumor growth suppression, and regression. Citrus peels are the waste product of juice manufacturing industries and have been considered as a critical problem for environmental green ecology policies for years. One of the most well-known approaches to overcome this problem is transformation of these monoterpene by the use of specific strains of bacteria or yeasts. Limonene (1-methyl-4-isopropyl-cyclohexene) is a monoterpene, as other monoterpenes consists of two isoprene units, that comprises more than 90% of citrus essential oil and it exists in many fruits and vegetables. Although, the anticancer activity of d-limonene has identified nearly two decades ago, it has recently attracted much more attention in translational medicine. In this chapter, we will overview the anticancer effects of POH and d-limonene. Later, we will address the pharmacokinetics of these compounds, highlight the signaling pathways which are targeted by these proteins, review the clinical trials which have been done for these compounds in different cancer models, and finally discuss the future directions of the research in this field that might be more applicable in future cancer therapy strategies. PMID:27102697

  14. Identification and characterization of a novel anthocyanin malonyltransferase from scarlet sage (Salvia splendens) flowers: an enzyme that is phylogenetically separated from other anthocyanin acyltransferases.

    PubMed

    Suzuki, Hirokazu; Sawada, Shin'ya; Watanabe, Kazufumi; Nagae, Shiro; Yamaguchi, Masa-Atsu; Nakayama, Toru; Nishino, Tokuzo

    2004-06-01

    Anthocyanin acyltransferases (AATs) catalyze a regiospecific acyl transfer from acyl-CoA to the glycosyl moiety of anthocyanins, thus playing an important role in flower coloration. The known AATs are subfamily members of an acyltransferase family, the BAHD family, which play important roles in secondary metabolism in plants. Here, we describe the purification, characterization, and cDNA cloning of a novel anthocyanin malonyltransferase from scarlet sage (Salvia splendens) flowers. The purified enzyme (hereafter referred to as Ss5MaT2) is a monomeric 46-kDa protein that catalyzes the transfer of the malonyl group from malonyl-CoA to the 4"'-hydroxyl group of the 5-glucosyl moiety of anthocyanins. Thus, it is a malonyl-CoA:anthocyanin 5-glucoside 4"'-O-malonyltransferase. On the basis of the partial amino acid sequences of the purified enzyme, we isolated a cDNA that encodes an acyltransferase protein. The steady-state transcript level of the gene was the highest in recently opened, fully pigmented flowers and was also correlated with the trend observed for an AAT gene responsible for the first malonylation step during salvianin biosynthesis. Immunoprecipitation studies using antibodies against the recombinant acyltransferase protein corroborated the identity of this cDNA as that encoding Ss5MaT2. The deduced amino acid sequence of Ss5MaT2 showed a low similarity (22-24% identity) to those of AATs and lacked the AAT-specific signature sequence. A phylogenetic analysis suggested that Ss5MaT2 is more related to acetyl-CoA:benzylalcohol acetyltransferase (BEAT) rather than to AAT. This is another example in which enzymes with similar, although not identical, substrate evolved from different branches of the BAHD family. PMID:15165190

  15. Pyripyropenes, novel inhibitors of acyl-CoA:cholesterol acyltransferase produced by Aspergillus fumigatus. II. Structure elucidation of pyripyropenes A, B, C and D.

    PubMed

    Kim, Y K; Tomoda, H; Nishida, H; Sunazuka, T; Obata, R; Omura, S

    1994-02-01

    The structures of pyripyropenes A, B, C and D, novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitors, were determined mainly by spectroscopic studies including various NMR measurements. Pyripyropenes have a common structure which consists of pyridine, alpha-pyrone and sesquiterpene moieties. One of the three O-acetyl residues in the sesquiterpene moiety of pyripyropene A is replaced with an O-propionyl residue in pyripyropenes B, C and D. PMID:8150710

  16. Identification of an arylalkylamine N-acyltransferase from Drosophila melanogaster that catalyzes the formation of long-chain N-acylserotonins

    PubMed Central

    Dempsey, Daniel R.; Jeffries, Kristen A.; Anderson, Ryan L.; Carpenter, Anne-Marie; Ospina, Santiago Rodriguez; Merkler, David J.

    2014-01-01

    Arylalkylamine N-acyltransferase-like 22 (AANATL2) from Drosophila melanogaster was expressed and shown to catalyze the formation of long-chain N-acylserotonins and N-acydopamines. Subsequent identification of endogenous amounts of N-acylserotonins and colocalization of these fatty acid amides and AANATL2 transcripts gives supporting evidence that AANATL2 has a role in the biosynthetic formation of these important cell signalling lipids. PMID:24444601

  17. Health risks of alcohol use

    MedlinePlus

    Alcoholism - risks; Alcohol abuse - risks; Alcohol dependence - risks; Risky drinking - risks ... sleep problems or make them worse Increase the risk of suicide Families are often affected when someone ...

  18. A Serine Carboxypeptidase-Like Acyltransferase Is Required for Synthesis of Antimicrobial Compounds and Disease Resistance in Oats[W][OA

    PubMed Central

    Mugford, Sam T.; Qi, Xiaoquan; Bakht, Saleha; Hill, Lionel; Wegel, Eva; Hughes, Richard K.; Papadopoulou, Kalliopi; Melton, Rachel; Philo, Mark; Sainsbury, Frank; Lomonossoff, George P.; Roy, Abhijeet Deb; Goss, Rebecca J.M.; Osbourn, Anne

    2009-01-01

    Serine carboxypeptidase-like (SCPL) proteins have recently emerged as a new group of plant acyltransferases. These enzymes share homology with peptidases but lack protease activity and instead are able to acylate natural products. Several SCPL acyltransferases have been characterized to date from dicots, including an enzyme required for the synthesis of glucose polyesters that may contribute to insect resistance in wild tomato (Solanum pennellii) and enzymes required for the synthesis of sinapate esters associated with UV protection in Arabidopsis thaliana. In our earlier genetic analysis, we identified the Saponin-deficient 7 (Sad7) locus as being required for the synthesis of antimicrobial triterpene glycosides (avenacins) and for broad-spectrum disease resistance in diploid oat (Avena strigosa). Here, we report on the cloning of Sad7 and show that this gene encodes a functional SCPL acyltransferase, SCPL1, that is able to catalyze the synthesis of both N-methyl anthraniloyl- and benzoyl-derivatized forms of avenacin. Sad7 forms part of an operon-like gene cluster for avenacin synthesis. Oat SCPL1 (SAD7) is the founder member of a subfamily of monocot-specific SCPL proteins that includes predicted proteins from rice (Oryza sativa) and other grasses with potential roles in secondary metabolism and plant defense. PMID:19684243

  19. Neurologic effects of alcoholism.

    PubMed Central

    Diamond, I; Messing, R O

    1994-01-01

    Alcoholism, a worldwide disorder, is the cause of a variety of neurologic disorders. In this article we discuss the cellular pathophysiology of ethanol addition and abuse as well as evidence supporting and refuting the role of inheritance in alcoholism. A genetic marker for alcoholism has not been identified, but neurophysiologic studies may be promising. Some neurologic disorders related to longterm alcoholism are due predominantly to inadequate nutrition (the thiamine deficiency that causes Wernicke's encephalopathy), but others appear to involve the neurotoxicity of ethanol on brain (alcohol withdrawal syndrome and dementia) and peripheral nerves (alcoholic neuropathy and myopathy). Images PMID:7975567

  20. Fetal Alcohol Spectrum Disorders.

    PubMed

    Williams, Janet F; Smith, Vincent C

    2015-11-01

    Prenatal exposure to alcohol can damage the developing fetus and is the leading preventable cause of birth defects and intellectual and neurodevelopmental disabilities. In 1973, fetal alcohol syndrome was first described as a specific cluster of birth defects resulting from alcohol exposure in utero. Subsequently, research unequivocally revealed that prenatal alcohol exposure causes a broad range of adverse developmental effects. Fetal alcohol spectrum disorder (FASD) is the general term that encompasses the range of adverse effects associated with prenatal alcohol exposure. The diagnostic criteria for fetal alcohol syndrome are specific, and comprehensive efforts are ongoing to establish definitive criteria for diagnosing the other FASDs. A large and growing body of research has led to evidence-based FASD education of professionals and the public, broader prevention initiatives, and recommended treatment approaches based on the following premises:▪ Alcohol-related birth defects and developmental disabilities are completely preventable when pregnant women abstain from alcohol use.▪ Neurocognitive and behavioral problems resulting from prenatal alcohol exposure are lifelong.▪ Early recognition, diagnosis, and therapy for any condition along the FASD continuum can result in improved outcomes.▪ During pregnancy:◦no amount of alcohol intake should be considered safe;◦there is no safe trimester to drink alcohol;◦all forms of alcohol, such as beer, wine, and liquor, pose similar risk; and◦binge drinking poses dose-related risk to the developing fetus. PMID:26482673

  1. THE ALCOHOL AND ALCOHOL PROBLEMS SCIENCE DATABASE (ETOH)

    EPA Science Inventory

    The Alcohol and Alcohol Problems Science Database, commonly referred to as ETOH, is the most comprehensive online resource covering all aspects of alcohol abuse and alcoholism. Produced by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), ETOH contains over 110,000 ...

  2. Deciding to quit drinking alcohol

    MedlinePlus

    Alcohol use disorder - quitting drinking; Alcohol abuse - quitting drinking; Quitting drinking; Quitting alcohol ... a drinking problem when your body depends on alcohol to function and your drinking is causing problems ...

  3. Alcohol Use and Older Adults

    MedlinePlus

    ... version of this page please turn Javascript on. Alcohol Use and Older Adults Alcohol and Aging Adults of any age can have ... Escape (Esc) button on your keyboard.) What Is Alcohol? Alcohol, also known as ethanol, is a chemical ...

  4. Differential distribution of ghrelin-O-acyltransferase (GOAT) immunoreactive cells in the mouse and rat gastric oxyntic mucosa

    PubMed Central

    Stengel, Andreas; Goebel, Miriam; Wang, Lixin; Taché, Yvette; Sachs, George; Lambrecht, Nils W.G.

    2013-01-01

    The enzyme that acylates ghrelin was recently identified in mice as the fourth member of the membrane-bound O-acyltransferases superfamily (MBOAT4) and named ghrelin-O-acyltransferase (GOAT). Only one report showed GOAT mRNA expression in ghrelin-expressing cells of the mouse stomach. We investigated the distribution of GOAT protein in peripheral tissues and co-expression with endocrine markers in the gastric mucosa using a custom-made anti-GOAT antibody. Tissues were collected from male Sprague-Dawley rats and C57BL/6 mice. Western blot revealed two immunoreactive bands in rat and mouse gastric corpus mucosal proteins, a 50 kDa band corresponding to the GOAT protein and a 100 kDa band likely corresponding to a dimer. Western blot also detected GOAT in the plasma and levels were strongly increased after 24-h fasting in mice and slightly in rats. GOAT-immunoreactive cells were located in the gastric corpus mucosa and the anterior pituitary gland, whereas other peripheral tissues of rats and mice examined were negative. In mice, GOAT-immunoreactive cells were mainly distributed throughout the middle portion of the oxyntic glands, whereas in rats they were localized mainly in the lower portion of the glands. Double labeling showed that 95±1% of GOAT-immunoreactive cells in mice co-labeled with ghrelin, whereas in rats only 56±4% of GOAT-positive cells showed co-expression of ghrelin. The remainder of the GOAT-immunopositive cells in rats co-expressed histidine decarboxylase (44±3%). No co-localization was observed with somatostatin in rats or mice. These data suggest species differences between rats and mice in gastric GOAT expression perhaps resulting in a different role of the MBOAT4 enzyme in the rat stomach. Detection of GOAT in the plasma raises the possibility that ghrelin octanoylation may occur in the circulation and the fasting-induced increase in GOAT may contribute to the increase of acylated ghrelin after fasting. PMID:20059966

  5. Alcohol and pregnancy

    MedlinePlus

    ... Heavy drinkers (those who drink more than 2 alcoholic beverages a day) are at greater risk of giving ... the healthier your baby will be. Choose non-alcoholic versions of beverages you like. If you cannot control your drinking, ...

  6. Benzyl Alcohol Topical

    MedlinePlus

    Benzyl alcohol lotion is used to treat head lice (small insects that attach themselves to the skin) in adults and children ... It works by killing the lice. Benzyl alcohol lotion will not kill lice eggs, so the medication ...

  7. Women and Alcohol

    MedlinePlus

    ... turn JavaScript on. Feature: Rethinking Drinking Women and Alcohol Past Issues / Spring 2014 Table of Contents Women react differently than men to alcohol and face higher risks from it. Pound for ...

  8. Alcohol and Cancer Risk

    MedlinePlus

    ... Overview Cancer Prevention Overview–for health professionals Research Alcohol and Cancer Risk On This Page What is ... in the risk of colorectal cancer. Research on alcohol consumption and other cancers: Numerous studies have examined ...

  9. Myths about drinking alcohol

    MedlinePlus

    ... gov/ency/patientinstructions/000856.htm Myths about drinking alcohol To use the sharing features on this page, ... We know much more about the effects of alcohol today than in the past. Yet, myths remain ...

  10. Alcohol and Migraine

    MedlinePlus

    ... on Pinterest Follow us on Instagram DONATE TODAY Alcohol and Migraine Abuse, Maltreatment, and PTSD and Their ... to Migraine Altitude, Acute Mountain Sickness and Headache Alcohol and Migraine Anxiety and Depression Caffeine and Migraine ...

  11. Alcohol and Cancer

    MedlinePlus

    ... developing some kinds of cancer. The way alcohol causes cancer isn’t completely understood. In fact, there might ... For example, it could be that alcohol itself causes cancer by increasing hormone levels, or it may be ...

  12. Alcohol and pregnancy

    MedlinePlus

    ... group of defects in the baby known as fetal alcohol syndrome. Symptoms can include: Behavior and attention problems Heart ... risk of giving birth to a child with fetal alcohol syndrome . The more you drink, the more you raise ...

  13. Fetal Alcohol Spectrum Disorders

    MedlinePlus

    ... Daily life skills, such as feeding and bathing Fetal alcohol syndrome is the most serious type of FASD. People with fetal alcohol syndrome have facial abnormalities, including wide-set and narrow ...

  14. Alcohol Calorie Calculator

    MedlinePlus

    ... Alcohol Calorie Calculator Find out the number of beer and hard alcohol calories you are consuming. Simply ... calories) Average Drinks Per Week Monthly Subtotal Calories Beer Regular 12 149 Regular Beer Light 12 110 ...

  15. Alcohol advertising and alcohol consumption by adolescents.

    PubMed

    Saffer, Henry; Dave, Dhaval

    2006-06-01

    This study investigates the effects of alcohol advertising on adolescent alcohol consumption. The theory of an industry response function and evidence from prior studies indicate the importance of maximizing the variance in advertising measures. Monitoring the Future (MTF) and National Longitudinal Survey of Youth 1997 (NLSY97) data are augmented with alcohol advertising, originating on the market level, for five media. The large sample of the MTF allows estimation of race and gender-specific models. The longitudinal nature of the NLSY97 allows controls for unobserved heterogeneity with state-level and individual fixed effects. Price and advertising effects are generally larger for females relative to males. Controls for individual heterogeneity yield larger advertising effects, implying that the MTF results may understate the effects of alcohol advertising. Results from the NLSY97 suggest that a 28% reduction in alcohol advertising would reduce adolescent monthly alcohol participation from 25% to between 24 and 21%. For binge participation, the reduction would be from 12% to between 11 and 8%. The past month price-participation elasticity is estimated at -0.26, consistent with prior studies. The results show that reduction of alcohol advertising can produce a modest decline in adolescent alcohol consumption, though effects may vary by race and gender. PMID:16475245

  16. In Focus: Alcohol and Alcoholism Audiovisual Guide.

    ERIC Educational Resources Information Center

    National Clearinghouse for Alcohol Information (DHHS), Rockville, MD.

    This guide reviews audiovisual materials currently available on alcohol abuse and alcoholism. An alphabetical index of audiovisual materials is followed by synopses of the indexed materials. Information about the intended audience, price, rental fee, and distributor is included. This guide also provides a list of publications related to media…

  17. Alcohol and motorcycle fatalities.

    PubMed Central

    Baker, S P; Fisher, R S

    1977-01-01

    A series of 99 fatal motorcycle crashes in Maryland was studied retrospectively, using police and medical examiner records. Blood alcohol concentrations were determined for 62 motorcycle drivers; measurable amounts of alcohol were found in two-thirds (41), and one-half (31) had illegally high concentrations of 100 mg/100 ml or more. The police report mentioned alcohol in only 9 instances. High blood alcohol concentrations were found most commonly among drivers age 20-34. PMID:842762

  18. Alcohol Use among Youth.

    ERIC Educational Resources Information Center

    Roth, Paula; Friedman, Lora

    1987-01-01

    States that adolescents begin to drink alcohol at ever younger ages, partly because they receive mixed messages from the media. Argues that drug prevention groups must project accurate, consistent, and effective messages about alcohol for youth and that schools must provide education about the specific health risks of alcohol beginning in grade…

  19. Alcohol and Family Violence.

    ERIC Educational Resources Information Center

    Cantrell, Leslie A., Comp.

    This document reports on the relationship between alcohol abuse and battering. Several theories, e.g., the disinhibition, disavowal, and learned behavior theories concerning the relationship between alcohol abuse and family violence are discussed. Literature on the relationship between alcohol and family violence is reviewed. Five intervention and…

  20. Biological Vulnerability to Alcoholism.

    ERIC Educational Resources Information Center

    Schuckit, Marc A.

    1987-01-01

    Reviews the role of biological factors in the risk for alcoholism. Notes the importance of the definition of primary alcoholism and highlights data indicating that this disorder is genetically influenced. In studies of men at high risk for the future development of alcoholism, vulnerability shows up in reactions to ethanol brain wave amplitude and…

  1. Television: Alcohol's Vast Adland.

    ERIC Educational Resources Information Center

    2002

    Concern about how much television alcohol advertising reaches underage youth and how the advertising influences their attitudes and decisions about alcohol use has been widespread for many years. Lacking in the policy debate has been solid, reliable information about the extent of youth exposure to television alcohol advertising. To address this…

  2. Alcoholism and Lesbians

    ERIC Educational Resources Information Center

    Gedro, Julie

    2014-01-01

    This chapter explores the issues involved in the relationship between lesbianism and alcoholism. It examines the constellation of health and related problems created by alcoholism, and it critically interrogates the societal factors that contribute to the disproportionately high rates of alcoholism among lesbians by exploring the antecedents and…

  3. Adult Children of Alcoholics.

    ERIC Educational Resources Information Center

    Goodman, Ronald W.

    1987-01-01

    Presents analysis of adult children of alcoholics, their experience and adjustment in relation to the severity and type of alcoholism, age considerations and perceptions as a child, and existence and nature of significant others. Discusses alcoholics' and others' family issues, focusing on roles taken, and personality characteristics. Emphasizes…

  4. Alcohol on Campus.

    ERIC Educational Resources Information Center

    ACU-I Bulletin, 1984

    1984-01-01

    Alcohol use on campus and strategies colleges are using to educate students about alcohol are considered in two articles. In "When Alternatives Aren't," Ruth Bradford Burnham and Stephen J. Nelson explore the role alcoholic beverages play in young people's social lives and some of the implications for planning social events. They offer a balanced…

  5. Alcoholism's Hidden Curriculum.

    ERIC Educational Resources Information Center

    Gress, James R.

    1988-01-01

    Discusses children of alcoholics as victims of fetal alcohol syndrome, family violence, retarded social development, and severe emotional scars. These children bring family roles to school that allow survival in the alcoholic home but are dysfunctional outside it. Educators can take certain steps to address these students' problems. Includes six…

  6. Alcohol and the law.

    PubMed

    Karasov, Ariela O; Ostacher, Michael J

    2014-01-01

    Society has had an interest in controlling the production, distribution, and use of alcohol for millennia. The use of alcohol has always had consequences, be they positive or negative, and the role of government in the regulation of alcohol is now universal. This is accomplished at several levels, first through controls on production, importation, distribution, and use of alcoholic beverages, and second, through criminal laws, the aim of which is to address the behavior of users themselves. A number of interventions and policies reduce alcohol-related consequences to society by regulating alcohol pricing, targeting alcohol-impaired driving, and limiting alcohol availability. The legal system defines criminal responsibility in the context of alcohol use, as an enormous percentage of violent crime and motor death is associated with alcohol intoxication. In recent years, recovery-oriented policies have aimed to expand social supports for recovery and to improve access to treatment for substance use disorders within the criminal justice system. The Affordable Care Act, also know as "ObamaCare," made substantial changes to access to substance abuse treatment by mandating that health insurance include services for substance use disorders comparable to coverage for medical and surgical treatments. Rather than a simplified "war on drugs" approach, there appears to be an increasing emphasis on evidence-based policy development that approaches alcohol use disorders with hope for treatment and prevention. This chapter focuses on alcohol and the law in the United States. PMID:25307602

  7. Women and Alcohol

    MedlinePlus

    ... alcohol, which is found in: »» 12 ounces of beer with 5 percent alcohol content »» 5 ounces of wine with 12 percent alcohol content »» 1.5 ounces ... reflect customary serving sizes. A large cup of beer, an overpoured glass of wine, or a single ...

  8. Alcohol and Minority Youth.

    ERIC Educational Resources Information Center

    Wright, Roosevelt, Jr.; Watts, Thomas D.

    1991-01-01

    Maintains that minority youth who use (or abuse) alcohol in American society deal with using alcohol, being minority, and being young, three dimensions viewed by society with mixed, sometimes hostile and/or fearful reactions. Suggests that examining alcoholism among minority youth involves coming to grips with poverty, education, income, and life…

  9. Carboxy-terminal mutations of bile acid CoA:N-acyltransferase alter activity and substrate specificity.

    PubMed

    Styles, Nathan A; Shonsey, Erin M; Falany, Josie L; Guidry, Amber L; Barnes, Stephen; Falany, Charles N

    2016-07-01

    Bile acid CoA:amino acid N-acyltransferase (BAAT) is the terminal enzyme in the synthesis of bile salts from cholesterol and catalyzes the conjugation of taurine or glycine to bile acid CoA thioesters to form bile acid N-acylamidates. BAAT has a dual localization to the cytosol and peroxisomes, possibly due to an inefficient carboxy-terminal peroxisomal targeting signal (PTS), -serine-glutamine-leucine (-SQL). Mutational analysis was used to define the role of the carboxy terminus in peroxisomal localization and kinetic activity. Amidation activity of BAAT and BAAT lacking the final two amino acids (AAs) (BAAT-S) were similar, whereas the activity of BAAT with a canonical PTS sequence (BAAT-SKL) was increased >2.5-fold. Kinetic analysis of BAAT and BAAT-SKL showed that BAAT-SKL had a lower Km for taurine and glycine as well as a greater Vmax There was no difference in the affinity for cholyl-CoA. In contrast to BAAT, BAAT-SKL forms bile acid N-acylamidates with β-alanine. BAAT-S immunoprecipitated when incubated with peroxisomal biogenesis factor 5 (Pex5) and rabbit anti-Pex5 antibodies; however, deleting the final 12 AAs prevented coimmunoprecipitation with Pex5, indicating the Pex5 interaction involves more than the -SQL sequence. These results indicate that even small changes in the carboxy terminus of BAAT can have significant effects on activity and substrate specificity. PMID:27230263

  10. Biosynthesis of Rhizobium meliloti lipooligosaccharide Nod factors: NodA is required for an N-acyltransferase activity

    SciTech Connect

    Atkinson, E.M.; Long, S.R. ); Palcic, M.M.; Hindsgaul, O. )

    1994-08-30

    Rhizobium bacteria synthesize N-acylated [beta]-1,4-N-acetylglucosamine lipooligosaccharides, called Nod factors, which act as morphogenic signal molecules to legume roots during development of nitrogen-fixing nodules. The biosynthesis of Nod factors is genetically dependent upon the nodulation (nod) genes, including the common nod genes nodABC. We used the Rhizobium meliloti NodH sulfotransferase to prepare [sup 35]S-labeled oligosaccharides which served as metabolic tracers for Nod enzyme activities. This approach provides a general method for following chitooligosaccharide modifications. We found nodAB-dependent conversion of N-acetylchitotetraose (chitotetraose) monosulfate into hydrophobic compounds which by chromatographic and chemical tests were equivalent to acylated Nod factors. Sequential incubation of labeled intermediates with Escherichia coli containing either NodA or NodB showed that NodB was required before NodA during Nod factor biosynthesis. The acylation activity was sensitive to oligosaccharide chain length, with chitotetraose serving as a better substrate than chitobiose or chitotriose. We constructed a putative Nod factor intermediate, GlcN-[beta]1,4-(GlcNac)[sub 3], by enzymatic synthesis and labeled it by NodH-mediated sulfation to create a specific metabolic probe. Acylation of this oligosaccharide required only NodA. These results confirm previous reports that NodB is an N-deacetylase and suggest that NodA is an N-acyltransferase. 31 refs., 6 figs.

  11. The palmitoyl acyltransferase DHHC2 regulates recycling endosome exocytosis and synaptic potentiation through palmitoylation of AKAP79/150.

    PubMed

    Woolfrey, Kevin M; Sanderson, Jennifer L; Dell'Acqua, Mark L

    2015-01-14

    Phosphorylation and dephosphorylation of AMPA-type ionotropic glutamate receptors (AMPARs) by kinases and phosphatases and interactions with scaffold proteins play essential roles in regulating channel biophysical properties and trafficking events that control synaptic strength during NMDA receptor-dependent synaptic plasticity, such as LTP and LTD. We previously demonstrated that palmitoylation of the AMPAR-linked scaffold protein A-kinase anchoring protein (AKAP) 79/150 is required for its targeting to recycling endosomes in dendrites, where it regulates exocytosis from these compartments that is required for LTP-stimulated enlargement of postsynaptic dendritic spines, delivery of AMPARs to the plasma membrane, and maintenance of synaptic potentiation. Here, we report that the recycling endosome-resident palmitoyl acyltransferase DHHC2 interacts with and palmitoylates AKAP79/150 to regulate these plasticity signaling mechanisms. In particular, RNAi-mediated knockdown of DHHC2 expression in rat hippocampal neurons disrupted stimulation of exocytosis from recycling endosomes, enlargement of dendritic spines, AKAP recruitment to spines, and potentiation of AMPAR-mediated synaptic currents that occur during LTP. Importantly, expression of a palmitoylation-independent lipidated AKAP mutant in DHHC2-deficient neurons largely restored normal plasticity regulation. Thus, we conclude that DHHC2-AKAP79/150 signaling is an essential regulator of dendritic recycling endosome exocytosis that controls both structural and functional plasticity at excitatory synapses. PMID:25589740

  12. BAHD superfamily of acyl-CoA dependent acyltransferases in Populus and Arabidopsis: bioinformatics and gene expression

    SciTech Connect

    Yu, X.; Liu, C.

    2009-04-03

    Plant acyl-CoA dependent acyltransferases constitute a large specific protein superfamily, named BAHD. Using the conserved sequence motifs of BAHD members, we searched the genome sequences of Populus and Arabidopsis, and identified, respectively, 94- and 61-putative genes. Subsequently, we analyzed the phylogeny, gene structure, and chromosomal distribution of BAHD members of both species; then, we profiled expression patterns of BAHD genes by 'in silico' northern- and microarray-analyses based on public databases, and by RT-PCR. While our genomic- and bioinformatic- analyses provided full sets of BAHD superfamily genes, and cleaned up a few existing annotation errors, importantly it led to our recognizing several unique Arabidopsis BAHD genes that inversely overlapped with their neighboring genes on the genome, and disclosing a potential natural anti-sense regulation for gene expressions. Systemic gene-expression profiling of BAHD members revealed distinct tissue-specific/preferential expression patterns, indicating their diverse biological functions. Our study affords a strong knowledge base for understanding BAHD members evolutionary relationships and gene functions implicated in plant growth, development and metabolism.

  13. Acyl-CoA N-acyltransferase influences fertility by regulating lipid metabolism and jasmonic acid biogenesis in cotton

    PubMed Central

    Fu, Wenfeng; Shen, Ying; Hao, Juan; Wu, Jianyong; Ke, Liping; Wu, Caiyun; Huang, Kai; Luo, Binglun; Xu, Mingfeng; Cheng, Xiaofei; Zhou, Xueping; Sun, Jie; Xing, Chaozhu; Sun, Yuqiang

    2015-01-01

    Cotton (Gossypium spp.) is an important economic crop and there is obvious heterosis in cotton, fertility has played an important role in this heterosis. However, the genes that exhibit critical roles in anther development and fertility are not well understood. Here, we report an acyl-CoA N-acyltransferase (EC2.3; GhACNAT) that plays a key role in anther development and fertility. Suppression of GhACNAT by virus-induced gene silencing in transgenic cotton (G. hirsutum L. cv. C312) resulted in indehiscent anthers that were full of pollen, diminished filaments and stamens, and plant sterility. We found GhACNAT was involved in lipid metabolism and jasmonic acid (JA) biosynthesis. The genes differentially expressed in GhACNAT-silenced plants and C312 were mainly involved in catalytic activity and transcription regulator activity in lipid metabolism. In GhACNAT-silenced plants, the expression levels of genes involved in lipid metabolism and jasmonic acid biosynthesis were significantly changed, the amount of JA in leaves and reproductive organs was significantly decreased compared with the amounts in C312. Treatments with exogenous methyl jasmonate rescued anther dehiscence and pollen release in GhACNAT-silenced plants and caused self-fertility. The GhACNAT gene may play an important role in controlling cotton fertility by regulating the pathways of lipid synthesis and JA biogenesis. PMID:26134787

  14. Small Intestine but Not Liver Lysophosphatidylcholine Acyltransferase 3 (Lpcat3) Deficiency Has a Dominant Effect on Plasma Lipid Metabolism.

    PubMed

    Kabir, Inamul; Li, Zhiqiang; Bui, Hai H; Kuo, Ming-Shang; Gao, Guangping; Jiang, Xian-Cheng

    2016-04-01

    Lysophosphatidylcholine acyltransferase 3 (Lpcat3) is involved in phosphatidylcholine remodeling in the small intestine and liver. We investigated lipid metabolism in inducible intestine-specific and liver-specificLpcat3gene knock-out mice. We producedLpcat3-Flox/villin-Cre-ER(T2)mice, which were treated with tamoxifen (at days 1, 3, 5, and 7), to deleteLpcat3specifically in the small intestine. At day 9 after the treatment, we found that Lpcat3 deficiency in enterocytes significantly reduced polyunsaturated phosphatidylcholines in the enterocyte plasma membrane and reduced Niemann-Pick C1-like 1 (NPC1L1), CD36, ATP-binding cassette transporter 1 (ABCA1), and ABCG8 levels on the membrane, thus significantly reducing lipid absorption, cholesterol secretion through apoB-dependent and apoB-independent pathways, and plasma triglyceride, cholesterol, and phospholipid levels, as well as body weight. Moreover, Lpcat3 deficiency does not cause significant lipid accumulation in the small intestine. We also utilized adenovirus-associated virus-Cre to depleteLpcat3in the liver. We found that liver deficiency only reduces plasma triglyceride levels but not other lipid levels. Furthermore, there is no significant lipid accumulation in the liver. Importantly, small intestine Lpcat3 deficiency has a much bigger effect on plasma lipid levels than that of liver deficiency. Thus, inhibition of small intestine Lpcat3 might constitute a novel approach for treating hyperlipidemia. PMID:26828064

  15. Plasma lecithin:cholesterol acyltransferase and carotid intima-media thickness in European individuals at high cardiovascular risk

    PubMed Central

    Calabresi, Laura; Baldassarre, Damiano; Simonelli, Sara; Gomaraschi, Monica; Amato, Mauro; Castelnuovo, Samuela; Frigerio, Beatrice; Ravani, Alessio; Sansaro, Daniela; Kauhanen, Jussi; Rauramaa, Rainer; de Faire, Ulf; Hamsten, Anders; Smit, Andries J.; Mannarino, Elmo; Humphries, Steve E.; Giral, Philippe; Veglia, Fabrizio; Sirtori, Cesare R.; Franceschini, Guido; Tremoli, Elena

    2011-01-01

    Lecithin:cholesterol acyltransferase (LCAT) is the enzyme responsible for cholesterol esterification in plasma. LCAT is a major factor in HDL remodeling and metabolism, and it has long been believed to play a critical role in macrophage reverse cholesterol transport (RCT). The effect of LCAT on human atherogenesis is still controversial. In the present study, the plasma LCAT concentration was measured in all subjects (n = 540) not on drug treatment at the time of enrollment in the multicenter, longitudinal, observational IMPROVE study. Mean and maximum intima-media thickness (IMT) of the whole carotid tree was measured by B-mode ultrasonography in all subjects. In the entire cohort, LCAT quartiles were not associated with carotid mean and maximum IMT (P for trend 0.95 and 0.18, respectively), also after adjustment for age, gender, HDL-cholesterol (HDL-C), and triglycerides. No association between carotid IMT and LCAT quartiles was observed in men (P=0.30 and P=0.99 for mean and maximum IMT, respectively), whereas carotid IMT increased with LCAT quartiles in women (P for trend 0.14 and 0.019 for mean and maximum IMT, respectively). The present findings support the concept that LCAT is not required for an efficient reverse cholesterol transport and that a low plasma LCAT concentration and activity is not associated with increased atherosclerosis. PMID:21596929

  16. Synthesis and characterisation of 5-acyl-6,7-dihydrothieno[3,2-c]pyridine inhibitors of Hedgehog acyltransferase

    PubMed Central

    Lanyon-Hogg, Thomas; Masumoto, Naoko; Bodakh, George; Konitsiotis, Antonio D.; Thinon, Emmanuelle; Rodgers, Ursula R.; Owens, Raymond J.; Magee, Anthony I.; Tate, Edward W.

    2016-01-01

    In this data article we describe synthetic and characterisation data for four members of the 5-acyl-6,7-dihydrothieno[3,2-c]pyridine (termed “RU-SKI”) class of inhibitors of Hedgehog acyltransferase, including associated NMR spectra for final compounds. RU-SKI compounds were selected for synthesis based on their published high potencies against the enzyme target. RU-SKI 41 (9a), RU-SKI 43 (9b), RU-SKI 101 (9c), and RU-SKI 201 (9d) were profiled for activity in the related article “Click chemistry armed enzyme linked immunosorbent assay to measure palmitoylation by Hedgehog acyltransferase” (Lanyon-Hogg et al., 2015) [1]. 1H NMR spectral data indicate different amide conformational ratios between the RU-SKI inhibitors, as has been observed in other 5-acyl-6,7-dihydrothieno[3,2-c]pyridines. The synthetic and characterisation data supplied in the current article provide validated access to the class of RU-SKI inhibitors. PMID:27077078

  17. Mouse lysocardiolipin acyltransferase controls the development of hematopoietic and endothelial lineages during in vitro embryonic stem-cell differentiation

    PubMed Central

    Wang, Chengyan; Faloon, Patrick W.; Tan, Zhijia; Lv, Yaxin; Zhang, Pengbo; Ge, Yu; Deng, Hongkui

    2007-01-01

    The blast colony-forming cell (BL-CFC) was identified as an equivalent to the hemangioblast during in vitro embryonic stem (ES) cell differentiation. However, the molecular mechanisms underlying the generation of the BL-CFC remain largely unknown. Here we report the isolation of mouse lysocardiolipin acyltransferase (Lycat) based on homology to zebrafish lycat, a candidate gene for the cloche locus. Mouse Lycat is expressed in hematopoietic organs and is enriched in the Lin−C-Kit+Sca-1+ hematopoietic stem cells in bone marrow and in the Flk1+/hCD4+(Scl+) hemangioblast population in embryoid bodies. The forced Lycat transgene leads to increased messenger RNA expression of hematopoietic and endothelial genes as well as increased blast colonies and their progenies, endothelial and hematopoietic lineages. The Lycat small interfering RNA transgene leads to a decrease expression of hematopoietic and endothelial genes. An unbiased genomewide microarray analysis further substantiates that the forced Lycat transgene specifically up-regulates a set of genes related to hemangioblasts and hematopoietic and endothelial lineages. Therefore, mouse Lycat plays an important role in the early specification of hematopoietic and endothelial cells, probably acting at the level of the hemangioblast. PMID:17675553

  18. Glycerol-3-Phosphate Acyltransferase Contributes to Triacylglycerol Biosynthesis, Lipid Droplet Formation, and Host Invasion in Metarhizium robertsii

    PubMed Central

    Gao, Qiang; Shang, Yanfang; Huang, Wei

    2013-01-01

    Enzymes involved in the triacylglycerol (TAG) biosynthesis have been well studied in the model organisms of yeasts and animals. Among these, the isoforms of glycerol-3-phosphate acyltransferase (GPAT) redundantly catalyze the first and rate-limiting step in glycerolipid synthesis. Here, we report the functions of mrGAT, a GPAT ortholog, in an insect-pathogenic fungus, Metarhizium robertsii. Unlike in yeasts and animals, a single copy of the mrGAT gene is present in the fungal genome and the gene deletion mutant is viable. Compared to the wild type and the gene-rescued mutant, the ΔmrGAT mutant demonstrated reduced abilities to produce conidia and synthesize TAG, glycerol, and total lipids. More importantly, we found that mrGAT is localized to the endoplasmic reticulum and directly linked to the formation of lipid droplets (LDs) in fungal cells. Insect bioassay results showed that mrGAT is required for full fungal virulence by aiding fungal penetration of host cuticles. Data from this study not only advance our understanding of GPAT functions in fungi but also suggest that filamentous fungi such as M. robertsii can serve as a good model to elucidate the role of the glycerol phosphate pathway in fungal physiology, particularly to determine the mechanistic connection of GPAT to LD formation. PMID:24077712

  19. Structure-based analysis of the molecular interactions between acyltransferase and acyl carrier protein in vicenistatin biosynthesis.

    PubMed

    Miyanaga, Akimasa; Iwasawa, Shohei; Shinohara, Yuji; Kudo, Fumitaka; Eguchi, Tadashi

    2016-02-16

    Acyltransferases (ATs) are key determinants of building block specificity in polyketide biosynthesis. Despite the importance of protein-protein interactions between AT and acyl carrier protein (ACP) during the acyltransfer reaction, the mechanism of ACP recognition by AT is not understood in detail. Herein, we report the crystal structure of AT VinK, which transfers a dipeptide group between two ACPs, VinL and VinP1LdACP, in vicenistatin biosynthesis. The isolated VinK structure showed a unique substrate-binding pocket for the dipeptide group linked to ACP. To gain greater insight into the mechanism of ACP recognition, we attempted to crystallize the VinK-ACP complexes. Because transient enzyme-ACP complexes are difficult to crystallize, we developed a covalent cross-linking strategy using a bifunctional maleimide reagent to trap the VinK-ACP complexes, allowing the determination of the crystal structure of the VinK-VinL complex. In the complex structure, Arg-153, Met-206, and Arg-299 of VinK interact with the negatively charged helix II region of VinL. The VinK-VinL complex structure allows, to our knowledge, the first visualization of the interaction between AT and ACP and provides detailed mechanistic insights into ACP recognition by AT. PMID:26831085

  20. Structure-based analysis of the molecular interactions between acyltransferase and acyl carrier protein in vicenistatin biosynthesis

    PubMed Central

    Miyanaga, Akimasa; Iwasawa, Shohei; Shinohara, Yuji; Kudo, Fumitaka; Eguchi, Tadashi

    2016-01-01

    Acyltransferases (ATs) are key determinants of building block specificity in polyketide biosynthesis. Despite the importance of protein–protein interactions between AT and acyl carrier protein (ACP) during the acyltransfer reaction, the mechanism of ACP recognition by AT is not understood in detail. Herein, we report the crystal structure of AT VinK, which transfers a dipeptide group between two ACPs, VinL and VinP1LdACP, in vicenistatin biosynthesis. The isolated VinK structure showed a unique substrate-binding pocket for the dipeptide group linked to ACP. To gain greater insight into the mechanism of ACP recognition, we attempted to crystallize the VinK–ACP complexes. Because transient enzyme–ACP complexes are difficult to crystallize, we developed a covalent cross-linking strategy using a bifunctional maleimide reagent to trap the VinK–ACP complexes, allowing the determination of the crystal structure of the VinK–VinL complex. In the complex structure, Arg-153, Met-206, and Arg-299 of VinK interact with the negatively charged helix II region of VinL. The VinK–VinL complex structure allows, to our knowledge, the first visualization of the interaction between AT and ACP and provides detailed mechanistic insights into ACP recognition by AT. PMID:26831085

  1. The acyltransferase GPAT5 is required for the synthesis of suberin in seed coat and root of Arabidopsis.

    PubMed

    Beisson, Fred; Li, Yonghua; Bonaventure, Gustavo; Pollard, Mike; Ohlrogge, John B

    2007-01-01

    Suberin and cutin are fatty acid- and glycerol-based plant polymers that act as pathogen barriers and function in the control of water and solute transport. However, despite important physiological roles, their biosynthetic pathways, including the acyl transfer reactions, remain hypothetical. We report the characterization of two suberin mutants (gpat5-1 and gpat5-2) of Arabidopsis thaliana GPAT5, encoding a protein with acyl-CoA:glycerol-3-phosphate acyltransferase activity. RT-PCR and beta-glucuronidase-promoter fusion analyses demonstrated GPAT5 expression in seed coat, root, hypocotyl, and anther. The gpat5 plants showed a 50% decrease in aliphatic suberin in young roots and produced seed coats with a severalfold reduction in very long chain dicarboxylic acid and omega-hydroxy fatty acids typical of suberin but no change in the composition or content of membrane or storage glycerolipids or surface waxes. Consistent with their altered suberin, seed coats of gpat5 mutants had a steep increase in permeability to tetrazolium salts compared with wild-type seed coats. Furthermore, the germination rate of gpat5 seeds under high salt was reduced, and gpat5 seedlings had lower tolerance to salt stress. These results provide evidence for a critical role of GPAT5 in polyester biogenesis in seed coats and roots and for the importance of lipid polymer structures in the normal function of these organs. PMID:17259262

  2. Alteration of seed fatty acid composition by an ethyl methanesulfonate-induced mutation in Arabidopsis thaliana affecting diacylglycerol acyltransferase activity.

    PubMed Central

    Katavic, V; Reed, D W; Taylor, D C; Giblin, E M; Barton, D L; Zou, J; Mackenzie, S L; Covello, P S; Kunst, L

    1995-01-01

    In characterizing the enzymes involved in the formation of very long-chain fatty acids (VLCFAs) in the Brassicaceae, we have generated a series of mutants of Arabidopsis thaliana that have reduced VLCFA content. Here we report the characterization of a seed lipid mutant, AS11, which, in comparison to wild type (WT), has reduced levels of 20:1 and 18:1 and accumulates 18:3 as the major fatty acid in triacylglycerols. Proportions of 18:2 remain similar to WT. Genetic analyses indicate that the fatty acid phenotype is caused by a semidominant mutation in a single nuclear gene, designated TAG1, located on chromosome 2. Biochemical analyses have shown that the AS11 phenotype is not due to a deficiency in the capacity to elongate 18:1 or to an increase in the relative delta 15 or delta 12 desaturase activities. Indeed, the ratio of desaturase/elongase activities measured in vitro is virtually identical in developing WT and AS11 seed homogenates. Rather, the fatty acid phenotype of AS11 is the result of reduced diacylglycerol acyltransferase activity throughout development, such that triacylglycerol biosynthesis is reduced. This leads to a reduction in 20:1 biosynthesis during seed development, leaving more 18:1 available for desaturation. Thus, we have demonstrated that changes to triacylglycerol biosynthesis can result in dramatic changes in fatty acid composition and, in particular, in the accumulation of VLCFAs in seed storage lipids. PMID:7784510

  3. Cloning, heterologous expression and biochemical characterization of plastidial sn-glycerol-3-phosphate acyltransferase from Helianthus annuus.

    PubMed

    Payá-Milans, Miriam; Venegas-Calerón, Mónica; Salas, Joaquín J; Garcés, Rafael; Martínez-Force, Enrique

    2015-03-01

    The acyl-[acyl carrier protein]:sn-1-glycerol-3-phosphate acyltransferase (GPAT; E.C. 2.3.1.15) catalyzes the first step of glycerolipid assembly within the stroma of the chloroplast. In the present study, the sunflower (Helianthus annuus, L.) stromal GPAT was cloned, sequenced and characterized. We identified a single ORF of 1344base pairs that encoded a GPAT sharing strong sequence homology with the plastidial GPAT from Arabidopsis thaliana (ATS1, At1g32200). Gene expression studies showed that the highest transcript levels occurred in green tissues in which chloroplasts are abundant. The corresponding mature protein was heterologously overexpressed in Escherichia coli for purification and biochemical characterization. In vitro assays using radiolabelled acyl-ACPs and glycerol-3-phosphate as substrates revealed a strong preference for oleic versus palmitic acid, and weak activity towards stearic acid. The positional fatty acid composition of relevant chloroplast phospholipids from sunflower leaves did not reflect the in vitro GPAT specificity, suggesting a more complex scenario with mixed substrates at different concentrations, competition with other acyl-ACP consuming enzymatic reactions, etc. In summary, this study has confirmed the affinity of this enzyme which would partly explain the resistance to cold temperatures observed in sunflower plants. PMID:25618244

  4. Phospholipid: diacylglycerol acyltransferase contributes to the conversion of membrane lipids into triacylglycerol in Myrmecia incisa during the nitrogen starvation stress

    PubMed Central

    Liu, Xiao-Yu; Ouyang, Long-Ling; Zhou, Zhi-Gang

    2016-01-01

    In addition to the Kennedy pathway for de novo biosynthesis, triacylglycerol (TAG), the most important stock for microalgae-based biodiesel production, can be synthesized by phospholipid: diacylglycerol acyltransferase (PDAT) that transfers an acyl group from phospholipids (PLs) to diacylglycerol (DAG). This study presents a novel gene that encodes PDAT from the green microalga Myrmecia incisa Reisigl H4301 (designated MiPDAT ). MiPDAT is localized on the plasma membrane (PM) via the agroinfiltration of tobacco leaves with a green fluorescent protein-fused construct. MiPDAT synthesizes TAG based on functional complementary experiments in the mutant yeast strain H1246 and the membrane lipid phosphatidylcholine (PC) is preferentially used as substrates as revealed by in vitro enzyme activity assay. The gradually increased transcription levels of MiPDAT in M. incisa during the cultivation under nitrogen starvation conditions is proposed to be responsible for the decrease and increase of the PC and TAG levels, respectively, as detected by liquid chromatography-mass spectrometry after 4 d of nitrogen starvation. In addition, the mechanism by which MiPDAT in this microalga uses PC to yield TAG is discussed. Accordingly, it is concluded that this PM-located PDAT contributes to the conversion of membrane lipids into TAG in M. incisa during the nitrogen starvation stress. PMID:27216435

  5. Altered chloroplast structure and function in a mutant of Arabidopsis deficient in plastid glycerol-3-phosphate acyltransferase activity

    SciTech Connect

    Kunst, L.; Somerville, C. ); Browse, J. )

    1989-07-01

    Mutants of Arabidopsis thaliana deficient in plastid glycerol-3-phosphate acyltransferase activity have altered chloroplast membrane lipid composition. This caused an increase in the number of regions of appressed membrane per chloroplast and a decrease in the average number of thylakoid membranes in the appressed regions. The net effect was a significant decrease in the ratio of appressed to nonappressed membranes. A comparison of 77 K fluorescence emission spectra of thylakoid membranes from the mutant and wild type indicated that the ultrastructural changes were associated with an altered distribution of excitation energy transfer from antenna chlorophyll to photosystem II and photosystem I in the mutant. The changes in leaf lipid composition did not significantly affect growth or development of the mutant under standard conditions. However, at temperatures above 28{degree}C the mutant grew slightly more rapidly than the wild type, and measurements of temperature-induced fluorescence yield enhancement suggested an increased thermal stability of the photosynthetic apparatus of the mutant. These effects are consistent with other evidence suggesting that membrane lipid composition is an important determinant of chloroplast structure but has relatively minor direct effects on the function of the membrane proteins associated with photosynthetic electron transport.

  6. The dihydrolipoyl acyltransferase gene BCE2 participates in basal resistance against Phytophthora infestans in potato and Nicotiana benthamiana.

    PubMed

    Wang, Hongyang; Sun, Chunlian; Jiang, Rui; He, Qin; Yang, Yu; Tian, Zhejuan; Tian, Zhendong; Xie, Conghua

    2014-07-01

    Dihydrolipoyl acyltransferase (EC 2.3.1.12), a branched-chain α-ketoacid dehydrogenase E2 subunit (BCE2), catalyzes the transfer of the acyl group from the lipoyl moiety to coenzyme A. However, the role of BCE2 responding to biotic stress in plant is not clear. In this study, we cloned and characterized a BCE2 gene from potato, namely StBCE2, which was previously suggested to be involved in Phytophthora infestans-potato interaction. We found that the expression of StBCE2 was strongly induced by both P. infestans isolate HB09-14-2 and salicylic acid. Besides, when the homolog of StBCE2 in Nicotiana benthamiana named NbBCE2 was silenced, plants showed increased susceptibility to P. infestans and reduced accumulation of hydrogen peroxide (H2O2). Furthermore, we found that a marker gene NbrbohB involved in the production of reactive oxygen species, was also suppressed in NbBCE2-silenced plants. However, silencing of NbBCE2 had no significant effect on the hypersensitive responses trigged by INF1, R3a-AVR3a(KI) pair or Rpi-vnt1.1-AVR-vnt1.1 pair. Our results suggest that BCE2 is associated with the basal resistance to P. infestans by regulating H2O2 production. PMID:24913048

  7. Phospholipid: diacylglycerol acyltransferase contributes to the conversion of membrane lipids into triacylglycerol in Myrmecia incisa during the nitrogen starvation stress.

    PubMed

    Liu, Xiao-Yu; Ouyang, Long-Ling; Zhou, Zhi-Gang

    2016-01-01

    In addition to the Kennedy pathway for de novo biosynthesis, triacylglycerol (TAG), the most important stock for microalgae-based biodiesel production, can be synthesized by phospholipid: diacylglycerol acyltransferase (PDAT) that transfers an acyl group from phospholipids (PLs) to diacylglycerol (DAG). This study presents a novel gene that encodes PDAT from the green microalga Myrmecia incisa Reisigl H4301 (designated MiPDAT ). MiPDAT is localized on the plasma membrane (PM) via the agroinfiltration of tobacco leaves with a green fluorescent protein-fused construct. MiPDAT synthesizes TAG based on functional complementary experiments in the mutant yeast strain H1246 and the membrane lipid phosphatidylcholine (PC) is preferentially used as substrates as revealed by in vitro enzyme activity assay. The gradually increased transcription levels of MiPDAT in M. incisa during the cultivation under nitrogen starvation conditions is proposed to be responsible for the decrease and increase of the PC and TAG levels, respectively, as detected by liquid chromatography-mass spectrometry after 4 d of nitrogen starvation. In addition, the mechanism by which MiPDAT in this microalga uses PC to yield TAG is discussed. Accordingly, it is concluded that this PM-located PDAT contributes to the conversion of membrane lipids into TAG in M. incisa during the nitrogen starvation stress. PMID:27216435

  8. The Palmitoyl Acyltransferase DHHC2 Regulates Recycling Endosome Exocytosis and Synaptic Potentiation through Palmitoylation of AKAP79/150

    PubMed Central

    Woolfrey, Kevin M.; Sanderson, Jennifer L.

    2015-01-01

    Phosphorylation and dephosphorylation of AMPA-type ionotropic glutamate receptors (AMPARs) by kinases and phosphatases and interactions with scaffold proteins play essential roles in regulating channel biophysical properties and trafficking events that control synaptic strength during NMDA receptor-dependent synaptic plasticity, such as LTP and LTD. We previously demonstrated that palmitoylation of the AMPAR-linked scaffold protein A-kinase anchoring protein (AKAP) 79/150 is required for its targeting to recycling endosomes in dendrites, where it regulates exocytosis from these compartments that is required for LTP-stimulated enlargement of postsynaptic dendritic spines, delivery of AMPARs to the plasma membrane, and maintenance of synaptic potentiation. Here, we report that the recycling endosome-resident palmitoyl acyltransferase DHHC2 interacts with and palmitoylates AKAP79/150 to regulate these plasticity signaling mechanisms. In particular, RNAi-mediated knockdown of DHHC2 expression in rat hippocampal neurons disrupted stimulation of exocytosis from recycling endosomes, enlargement of dendritic spines, AKAP recruitment to spines, and potentiation of AMPAR-mediated synaptic currents that occur during LTP. Importantly, expression of a palmitoylation-independent lipidated AKAP mutant in DHHC2-deficient neurons largely restored normal plasticity regulation. Thus, we conclude that DHHC2-AKAP79/150 signaling is an essential regulator of dendritic recycling endosome exocytosis that controls both structural and functional plasticity at excitatory synapses. PMID:25589740

  9. Cloning, characterization and functional analysis of two type 1 diacylglycerol acyltransferases (DGAT1s) from Tetraena mongolica.

    PubMed

    Li, Minchun; Zhao, Mingming; Wu, Hanying; Wu, Wang; Xu, Yinong

    2013-06-01

    Two cDNAs encoding putative type 1 acyl-CoA: diacylglycerol acyltransferases (DGAT1, EC 2.3.1.20), were cloned from Tetraena mongolica, an extreme xerophyte with high oil content in the stems. The 1 488-bp and 1 485-bp of the open reading frame (ORF) of the two cDNAs, designated as TmDGAT1a and TmDGAT1b, were both predicted to encode proteins of 495 and 494 amino acids, respectively. Southern blot analysis revealed that TmDGAT1a and TmDGAT1b both had low copy numbers in the T. mongolica genome. In addition to ubiquitous expression with different intensity in different tissues, including stems, leaves and roots, TmDGAT1a and TmDGAT1b, were found to be strongly induced by high salinity, drought and osmotic stress, resulting in a remarkable increase of triacylglycerol (TAG) accumulation in T. mongolica plantlets. TmDGAT1a and TmDGAT1b activities were confirmed in the yeast H1246 quadruple mutant (DGA1, LRO1, ARE1, ARE2) by restoring DGAT activity of the mutant host to produce TAG. Overexpression of TmDGAT1a and TmDGAT1b in soybean hairy roots as well as in T. mongolica calli both resulted in an increase in oil content (ranging from 37% to 108%), accompanied by altered fatty acid profiles. PMID:23480422

  10. Biodiesel production from crude jatropha oil catalyzed by immobilized lipase/acyltransferase from Candida parapsilosis in aqueous medium.

    PubMed

    Rodrigues, Joana; Perrier, Véronique; Lecomte, Jérôme; Dubreucq, Eric; Ferreira-Dias, Suzana

    2016-10-01

    The lipase/acyltransferase from Candida parapsilosis (CpLIP2) immobilized on two synthetic resins (Accurel MP 1000 and Lewatit VP OC 1600) was used as catalyst for the production of biodiesel (fatty acid methyl esters, FAME) by transesterification of jatropha oil with methanol, in a lipid/aqueous system. The oil was dispersed in a buffer solution (pH 6.5) containing methanol in excess (2M in the biphasic system; molar ratio methanol/acyl chains 2:1). Transesterification was carried out at 30°C, under magnetic stirring, using 10% (w/w) of immobilized enzyme in relation to oil. The maximum FAME yields were attained after 8h reaction time: 80.5% and 93.8%, when CpLIP2 immobilized on Accurel MP 1000 or on Lewatit VP OC 1600 were used, respectively. CpLIP2 on both Accurel MP 1000 and Lewatit VP OC 1600 showed high operational stability along 5 consecutive 8h batches. PMID:27474957

  11. Plant Acyl-CoA:Lysophosphatidylcholine Acyltransferases (LPCATs) Have Different Specificities in Their Forward and Reverse Reactions*

    PubMed Central

    Lager, Ida; Yilmaz, Jenny Lindberg; Zhou, Xue-Rong; Jasieniecka, Katarzyna; Kazachkov, Michael; Wang, Peng; Zou, Jitao; Weselake, Randall; Smith, Mark A.; Bayon, Shen; Dyer, John M.; Shockey, Jay M.; Heinz, Ernst; Green, Allan; Banas, Antoni; Stymne, Sten

    2013-01-01

    Acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT) enzymes have central roles in acyl editing of phosphatidylcholine (PC). Plant LPCAT genes were expressed in yeast and characterized biochemically in microsomal preparations of the cells. Specificities for different acyl-CoAs were similar for seven LPCATs from five different species, including species accumulating hydroxylated acyl groups in their seed oil, with a preference for C18-unsaturated acyl-CoA and low activity with palmitoyl-CoA and ricinoleoyl (12-hydroxyoctadec-9-enoyl)-CoA. We showed that Arabidopsis LPCAT1 and LPCAT2 enzymes catalyzed the acylation and de-acylation of both sn positions of PC, with a preference for the sn-2 position. When acyl specificities of the Arabidopsis LPCATs were measured in the reverse reaction, sn-2-bound oleoyl, linoleoyl, and linolenoyl groups from PC were transferred to acyl-CoA to a similar extent. However, a ricinoleoyl group at the sn-2-position of PC was removed 4–6-fold faster than an oleoyl group in the reverse reaction, despite poor utilization in the forward reaction. The data presented, taken together with earlier published reports on in vivo lipid metabolism, support the hypothesis that plant LPCAT enzymes play an important role in regulating the acyl-CoA composition in plant cells by transferring polyunsaturated and hydroxy fatty acids produced on PC directly to the acyl-CoA pool for further metabolism or catabolism. PMID:24189065

  12. Sterol O-Acyltransferase 2-Driven Cholesterol Esterification Opposes Liver X Receptor-Stimulated Fecal Neutral Sterol Loss.

    PubMed

    Warrier, Manya; Zhang, Jun; Bura, Kanwardeep; Kelley, Kathryn; Wilson, Martha D; Rudel, Lawrence L; Brown, J Mark

    2016-02-01

    Statin drugs have proven a successful and relatively safe therapy for the treatment of atherosclerotic cardiovascular disease (CVD). However, even with the substantial low-density lipoprotein (LDL) cholesterol lowering achieved with statin treatment, CVD remains the top cause of death in developed countries. Selective inhibitors of the cholesterol esterifying enzyme sterol-O acyltransferase 2 (SOAT2) hold great promise as effective CVD therapeutics. In mouse models, previous work has demonstrated that either antisense oligonucleotide (ASO) or small molecule inhibitors of SOAT2 can effectively reduce CVD progression, and even promote regression of established CVD. Although it is well known that SOAT2-driven cholesterol esterification can alter both the packaging and retention of atherogenic apoB-containing lipoproteins, here we set out to determine whether SOAT2-driven cholesterol esterification can also impact basal and liver X receptor (LXR)-stimulated fecal neutral sterol loss. These studies demonstrate that SOAT2 is a negative regulator of LXR-stimulated fecal neutral sterol loss in mice. PMID:26729489

  13. Alcohol and the Intestine

    PubMed Central

    Patel, Sheena; Behara, Rama; Swanson, Garth R.; Forsyth, Christopher B.; Voigt, Robin M.; Keshavarzian, Ali

    2015-01-01

    Alcohol abuse is a significant contributor to the global burden of disease and can lead to tissue damage and organ dysfunction in a subset of alcoholics. However, a subset of alcoholics without any of these predisposing factors can develop alcohol-mediated organ injury. The gastrointestinal tract (GI) could be an important source of inflammation in alcohol-mediated organ damage. The purpose of review was to evaluate mechanisms of alcohol-induced endotoxemia (including dysbiosis and gut leakiness), and highlight the predisposing factors for alcohol-induced dysbiosis and gut leakiness to endotoxins. Barriers, including immunologic, physical, and biochemical can regulate the passage of toxins into the portal and systemic circulation. In addition, a host of environmental interactions including those influenced by circadian rhythms can impact alcohol-induced organ pathology. There appears to be a role for therapeutic measures to mitigate alcohol-induced organ damage by normalizing intestinal dysbiosis and/or improving intestinal barrier integrity. Ultimately, the inflammatory process that drives progression into organ damage from alcohol appears to be multifactorial. Understanding the role of the intestine in the pathogenesis of alcoholic liver disease can pose further avenues for pathogenic and treatment approaches. PMID:26501334

  14. Alcohol's effect on lactation.

    PubMed

    Mennella, J

    2001-01-01

    Although pregnant women are discouraged from drinking alcohol because of alcohol's detrimental effect on fetal development, the lore of many cultures encourages lactating women to drink alcohol to optimize breast milk production and infant nutrition. In contrast to this folklore, however, studies demonstrate that maternal alcohol consumption may slightly reduce milk production. Furthermore, some of the alcohol consumed by a lactating woman is transferred to her milk and thus consumed by the infant. This alcohol consumption may adversely affect the infant's sleep and gross motor development and influence early learning about alcohol. Based on this science, it would seem that the recommendation for a nursing mother to drink a glass of beer or wine shortly before nursing may actually be counterproductive. PMID:11810962

  15. Alcoholic and non-alcoholic steatohepatitis.

    PubMed

    Neuman, Manuela G; French, Samuel W; French, Barbara A; Seitz, Helmut K; Cohen, Lawrence B; Mueller, Sebastian; Osna, Natalia A; Kharbanda, Kusum K; Seth, Devanshi; Bautista, Abraham; Thompson, Kyle J; McKillop, Iain H; Kirpich, Irina A; McClain, Craig J; Bataller, Ramon; Nanau, Radu M; Voiculescu, Mihai; Opris, Mihai; Shen, Hong; Tillman, Brittany; Li, Jun; Liu, Hui; Thomes, Paul G; Ganesan, Murali; Malnick, Steve

    2014-12-01

    This paper is based upon the "Charles Lieber Satellite Symposia" organized by Manuela G. Neuman at the Research Society on Alcoholism (RSA) Annual Meetings, 2013 and 2014. The present review includes pre-clinical, translational and clinical research that characterize alcoholic liver disease (ALD) and non-alcoholic steatohepatitis (NASH). In addition, a literature search in the discussed area was performed. Strong clinical and experimental evidence lead to recognition of the key toxic role of alcohol in the pathogenesis of ALD. The liver biopsy can confirm the etiology of NASH or alcoholic steatohepatitis (ASH) and assess structural alterations of cells, their organelles, as well as inflammatory activity. Three histological stages of ALD are simple steatosis, ASH, and chronic hepatitis with hepatic fibrosis or cirrhosis. These latter stages may also be associated with a number of cellular and histological changes, including the presence of Mallory's hyaline, megamitochondria, or perivenular and perisinusoidal fibrosis. Genetic polymorphisms of ethanol metabolizing enzymes such as cytochrome p450 (CYP) 2E1 activation may change the severity of ASH and NASH. Alcohol mediated hepatocarcinogenesis, immune response to alcohol in ASH, as well as the role of other risk factors such as its co-morbidities with chronic viral hepatitis in the presence or absence of human immunodeficiency virus are discussed. Dysregulation of hepatic methylation, as result of ethanol exposure, in hepatocytes transfected with hepatitis C virus (HCV), illustrates an impaired interferon signaling. The hepatotoxic effects of ethanol undermine the contribution of malnutrition to the liver injury. Dietary interventions such as micro and macronutrients, as well as changes to the microbiota are suggested. The clinical aspects of NASH, as part of metabolic syndrome in the aging population, are offered. The integrative symposia investigate different aspects of alcohol-induced liver damage and possible

  16. Alcoholic and non-alcoholic steatohepatitis

    PubMed Central

    Neuman, Manuela G.; French, Samuel W.; French, Barbara A.; Seitz, Helmut K.; Cohen, Lawrence B.; Mueller, Sebastian; Osna, Natalia A.; Kharbanda, Kusum K.; Seth, Devanshi; Bautista, Abraham; Thompson, Kyle J.; McKillop, Iain H.; Kirpich, Irina A.; McClain, Craig J.; Bataller, Ramon; Nanau, Radu M.; Voiculescu, Mihai; Opris, Mihai; Shen, Hong; Tillman, Brittany; Li, Jun; Liu, Hui; Thomas, Paul G.; Ganesan, Murali; Malnick, Steve

    2015-01-01

    This paper is based upon the “Charles Lieber Satellite Symposia” organized by Manuela G. Neuman at the Research Society on Alcoholism (RSA) Annual Meetings, 2013 and 2014. The present review includes pre-clinical, translational and clinical research that characterize alcoholic liver disease (ALD) and non-alcoholic steatohepatitis (NASH). In addition, a literature search in the discussed area was performed. Strong clinical and experimental evidence lead to recognition of the key toxic role of alcohol in the pathogenesis of ALD. The liver biopsy can confirm the etiology of NASH or alcoholic steatohepatitis (ASH) and assess structural alterations of cells, their organelles, as well as inflammatory activity. Three histological stages of ALD are simple steatosis, ASH, and chronic hepatitis with hepatic fibrosis or cirrhosis. These latter stages may also be associated with a number of cellular and histological changes, including the presence of Mallory's hyaline, megamitochondria, or perivenular and perisinusoidal fibrosis. Genetic polymorphisms of ethanol metabolizing enzymes such as cytochrome p450 (CYP) 2E1 activation may change the severity of ASH and NASH. Alcohol mediated hepatocarcinogenesis, immune response to alcohol in ASH, as well as the role of other risk factors such as its comorbidities with chronic viral hepatitis in the presence or absence of human deficiency virus are discussed. Dysregulation of hepatic methylation, as result of ethanol exposure, in hepatocytes transfected with hepatitis C virus (HCV), illustrates an impaired interferon signaling. The hepatotoxic effects of ethanol undermine the contribution of malnutrition to the liver injury. Dietary interventions such as micro and macronutrients, as well as changes to the microbiota are suggested. The clinical aspects of NASH, as part of metabolic syndrome in the aging population, are offered. The integrative symposia investigate different aspects of alcohol-induced liver damage and possible

  17. Alcohol disrupts sleep homeostasis.

    PubMed

    Thakkar, Mahesh M; Sharma, Rishi; Sahota, Pradeep

    2015-06-01

    Alcohol is a potent somnogen and one of the most commonly used "over the counter" sleep aids. In healthy non-alcoholics, acute alcohol decreases sleep latency, consolidates and increases the quality (delta power) and quantity of NREM sleep during the first half of the night. However, sleep is disrupted during the second half. Alcoholics, both during drinking periods and during abstinences, suffer from a multitude of sleep disruptions manifested by profound insomnia, excessive daytime sleepiness, and altered sleep architecture. Furthermore, subjective and objective indicators of sleep disturbances are predictors of relapse. Finally, within the USA, it is estimated that societal costs of alcohol-related sleep disorders exceeds $18 billion. Thus, although alcohol-associated sleep problems have significant economic and clinical consequences, very little is known about how and where alcohol acts to affect sleep. In this review, we have described our attempts to unravel the mechanism of alcohol-induced sleep disruptions. We have conducted a series of experiments using two different species, rats and mice, as animal models. We performed microdialysis, immunohistochemical, pharmacological, sleep deprivation and lesion studies which suggest that the sleep-promoting effects of alcohol may be mediated via alcohol's action on the mediators of sleep homeostasis: adenosine (AD) and the wake-promoting cholinergic neurons of the basal forebrain (BF). Alcohol, via its action on AD uptake, increases extracellular AD resulting in the inhibition of BF wake-promoting neurons. Since binge alcohol consumption is a highly prevalent pattern of alcohol consumption and disrupts sleep, we examined the effects of binge drinking on sleep-wakefulness. Our results suggest that disrupted sleep homeostasis may be the primary cause of sleep disruption observed following binge drinking. Finally, we have also shown that sleep disruptions observed during acute withdrawal, are caused due to impaired

  18. Women's alcohol use and alcoholism in Korea.

    PubMed

    Kim, Wooksoo; Kim, Sungjae

    2008-07-01

    Recently South Korean society has experienced an increase in alcohol use related problems, as well as alcohol use among women. The purpose of this paper is to describe the cultural context of and to summarize the current state of knowledge of women's drinking in South Korea. Subscribing to Confucian principles, traditional Korean society has allowed drinking for men, but not for women. However, as society has changed, contemporary women drink at a younger age and consume larger amounts of alcohol than their prior generations. The current trends suggest an urgent need for research on the etiology and trajectory of women's alcohol use among various populations and the need to develop intervention programs tailored to the specific needs of women. PMID:18649231

  19. Neurobiology of Alcohol Dependence

    PubMed Central

    Gilpin, Nicholas W.; Koob, George F.

    2008-01-01

    Alcoholism is a debilitating disorder for the individual and very costly for society. A major goal of alcohol research is to understand the neural underpinnings associated with the transition from alcohol use to alcohol dependence. Positive reinforcement is important in the early stages of alcohol use and abuse. Negative reinforcement can be important early in alcohol use by people self-medicating coexisting affective disorders, but its role likely increases following the transition to dependence. Chronic exposure to alcohol induces changes in neural circuits that control motivational processes, including arousal, reward, and stress. These changes affect systems utilizing the signaling molecules dopamine, opioid peptides, γ-aminobutyric acid, glutamate, and serotonin, as well as systems modulating the brain’s stress response. These neuroadaptations produce changes in sensitivity to alcohol’s effects following repeated exposure (i.e., sensitization and tolerance) and a withdrawal state following discontinuation of alcohol use. Chronic alcohol exposure also results in persistent neural deficits, some of which may fully recover following extended periods of abstinence. However, the organism remains susceptible to relapse, even after long periods of abstinence. Recent research focusing on brain arousal, reward, and stress systems is accelerating our understanding of the components of alcohol dependence and contributing to the development of new treatment strategies. PMID:19881886

  20. ADOLESCENTS AND ALCOHOL

    PubMed Central

    Spear, Linda Patia

    2014-01-01

    The high levels of alcohol consumption characteristic of adolescence may be in part biologically based, given that elevated consumption levels are also evident during this developmental transition in other mammalian species as well. Studies conducted using a simple animal model of adolescence in the rat has shown adolescents to be more sensitive than adults to social facilitatory and rewarding effects of alcohol, but less sensitive to numerous alcohol effects that may serve as cues to limit intake. These age-specific alcohol sensitivities appear related to differential rates of development of neural systems underlying different alcohol effects as well as to an ontogenetic decline in rapid brain compensations to alcohol, termed “acute tolerance”. In contrast, these adolescent-typical sensitivities to alcohol do not appear to be notably influenced by pubertally-related increases in gonadal hormones. Although data are sparse, there are hints that similar alcohol sensitivities may also be seen in human adolescents, with this developmentally decreased sensitivity to alcohol’s intoxicating effects possibly exacerbated by genetic vulnerabilities also characterized by an insensitivity to alcohol intoxication, thereby perhaps permitting especially high levels of alcohol consumption among vulnerable youth. PMID:25309054

  1. Neuropharmacology of alcohol addiction.

    PubMed

    Vengeliene, V; Bilbao, A; Molander, A; Spanagel, R

    2008-05-01

    Despite the generally held view that alcohol is an unspecific pharmacological agent, recent molecular pharmacology studies demonstrated that alcohol has only a few known primary targets. These are the NMDA, GABA(A), glycine, 5-hydroxytryptamine 3 (serotonin) and nicotinic ACh receptors as well as L-type Ca(2+) channels and G-protein-activated inwardly rectifying K(+) channels. Following this first hit of alcohol on specific targets in the brain, a second wave of indirect effects on a variety of neurotransmitter/neuropeptide systems is initiated that leads subsequently to the typical acute behavioural effects of alcohol, ranging from disinhibition to sedation and even hypnosis, with increasing concentrations of alcohol. Besides these acute pharmacodynamic aspects of alcohol, we discuss the neurochemical substrates that are involved in the initiation and maintenance phase of an alcohol drinking behaviour. Finally, addictive behaviour towards alcohol as measured by alcohol-seeking and relapse behaviour is reviewed in the context of specific neurotransmitter/neuropeptide systems and their signalling pathways. The activity of the mesolimbic dopaminergic system plays a crucial role during the initiation phase of alcohol consumption. Following long-term, chronic alcohol consumption virtually all brain neurotransmission seems to be affected, making it difficult to define which of the systems contributes the most to the transition from controlled to compulsive alcohol use. However, compulsive alcohol drinking is characterized by a decrease in the function of the reward neurocircuitry and a recruitment of antireward/stress mechanisms comes into place, with a hypertrophic corticotropin-releasing factor system and a hyperfunctional glutamatergic system being the most important ones. PMID:18311194

  2. Alcohol Expectancies in Young Adult Sons of Alcoholics and Controls.

    ERIC Educational Resources Information Center

    Brown, Sandra A.; And Others

    Adolescent offspring of alcoholics have been found to have higher alcohol reinforcement expectancies than do teenagers from nonalcoholic families. In particular, those with a positive family history of alcoholism expect more cognitive and motor enhancement with alcohol consumption. This study examined the alcohol expectancies of 58 matched pairs…

  3. Exposure to Televised Alcohol Ads and Subsequent Adolescent Alcohol Use

    ERIC Educational Resources Information Center

    Stacy, Alan W.; Zogg, Jennifer B.; Unger, Jennifer B.; Dent, Clyde W.

    2004-01-01

    Objective : To assess the impact of televised alcohol commercials on adolescents' alcohol use. Methods : Adolescents completed questionnaires about alcohol commercials and alcohol use in a prospective study. Results : A one standard deviation increase in viewing television programs containing alcohol commercials in seventh grade was associated…

  4. The 3D model of the lipase/acyltransferase from Candida parapsilosis, a tool for the elucidation of structural determinants in CAL-A lipase superfamily.

    PubMed

    Subileau, Maeva; Jan, Anne-Hélène; Nozac'h, Hervé; Pérez-Gordo, Marina; Perrier, Véronique; Dubreucq, Eric

    2015-10-01

    Because lipids are hydrophobic, the development of efficient bioconversions in aqueous media free of organic solvents is particularly challenging for green oleochemistry. Within this aim, enzymes exhibiting various abilities to catalyze acyltransfer reaction in water/lipid systems have been identified. Among these, CpLIP2 from Candida parapsilosis has been characterized as a lipase/acyltransferase, able to catalyze acyltransfer reactions preferentially to hydrolysis in the presence of particularly low acyl acceptor concentration and high thermodynamic activity of water (aw>0.9). Lipase/acyltransferases are thus of great interest, being able to produce new esters at concentrations above the thermodynamic equilibrium of hydrolysis/esterification with limited to no release of free fatty acids. Here, we present a 3D model of CpLIP2 based on homologies with crystallographic structures of Pseudozyma antarctica lipase A. Indeed, the two enzymes have 31% of identity in their primary sequence, yielding a same general structure, but different catalytic properties. The quality of the calculated CpLIP2 model was confirmed by several methods. Limited proteolysis confirmed the location of some loops at the surface of the protein 3D model. Directed mutagenesis also supported the structural model constructed on CAL-A template: the functional properties of various mutants were consistent with their structure-based putative involvement in the oxyanion hole, substrate specificity, acyltransfer or hydrolysis catalysis and structural stability. The CpLIP2 3D model, in comparison with CAL-A 3D structure, brings insights for the elucidation and improvement of the structural determinants involved in the exceptional acyltransferase properties of this promising biocatalyst and of homologous enzymes of the same family. PMID:26123263

  5. Genetic Evidence for the Reduction of Brassinosteroid Levels by a BAHD Acyltransferase-Like Protein in Arabidopsis1[W][OA

    PubMed Central

    Roh, Hyungmin; Jeong, Cheol Woong; Fujioka, Shozo; Kim, Youn Kyung; Lee, Sookjin; Ahn, Ji Hoon; Do Choi, Yang; Lee, Jong Seob

    2012-01-01

    Brassinosteroids (BRs) are a group of steroidal hormones involved in plant development. Although the BR biosynthesis pathways are well characterized, the BR inactivation process, which contributes to BR homeostasis, is less understood. Here, we show that a member of the BAHD (for benzylalcohol O-acetyltransferase, anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoyltransferase, and deacetylvindoline 4-O-acetyltransferase) acyltransferase family may play a role in BR homeostasis in Arabidopsis (Arabidopsis thaliana). We isolated two gain-of-function mutants, brassinosteroid inactivator1-1Dominant (bia1-1D) and bia1-2D, in which a novel BAHD acyltransferase-like protein was transcriptionally activated. Both mutants exhibited dwarfism, reduced male fertility, and deetiolation in darkness, which are typical phenotypes of plants defective in BR biosynthesis. Exogenous BR treatment rescued the phenotypes of the bia1-1D mutant. Endogenous levels of BRs were reduced in the bia1-1D mutant, demonstrating that BIA1 regulates endogenous BR levels. When grown in darkness, the bia1 loss-of-function mutant showed a longer hypocotyl phenotype and was more responsive to exogenous BR treatment than the wild-type plant. BIA1 expression was predominantly observed in the root, where low levels of BRs were detected. These results indicate that the BAHD acyltransferase family member encoded by BIA1 plays a role in controlling BR levels, particularly in the root and hypocotyl in darkness. Taken together, our study provides new insights into a mechanism that maintains BR homeostasis in Arabidopsis, likely via acyl conjugation of BRs. PMID:22544867

  6. [Accidental methyl alcohol poisoning].

    PubMed

    Xiao, J H

    1990-05-01

    An accidental poisoning due to drinking methyl alcohol in Chaoyang county is reported, analysing the accident. The poison came from the "retail white spirit" which was contaminated with methyl alcohol. Twenty-nine persons drank the wine, fourteen of them died, two of them became blind. After drinking this "retail white spirit" the drinkers showed symptoms of vertigo, headache, weakness, vomiting, night sweat, dyspnea and blurring of vision etc. within 6-120 hours. On examining the remaining spirit, we found the content of methyl alcohol to be between 16.6 and 40.69 g/100 ml. Some of the patients' urine and blood also contained methyl alcohol. We reckoned that each one of the twenty patients had taken more than 27 g of methyl alcohol and each of the ten dead drank more than 40 ml of the alcohol. PMID:2253526

  7. [Upgrade on alcohol abuse].

    PubMed

    Bordini, L; Riboldi, L

    2010-01-01

    Problematic use of alcohol configures an element of interest in the context of preventive interventions aimed to ensuring the performance of any work in safety conditions. To contrast the acute alcohol abuse in the workplace the existing legislation provides alcoholimeters controls and prohibition of recruitment and administration of alcohol. Recent legislation (D.Lgs. 81/08) establishes health surveillance for alcohol dependence and appears still incomplete and difficult to apply. Clinical diagnostic tools available to the physician for alcohol dependence identification are well-defined and recently improved thanks to new laboratory markers with high sensitivity and specificity (CDT) and self-administered questionnaires. In this contest we are awaiting for legislative action to specify conditions and procedures for inspections in the workplace in order to face the problem of alcohol dependence without excessive bureaucracy and with more attention to preventive aspects. PMID:21438261

  8. Update on Alcoholic Hepatitis

    PubMed Central

    Torok, Natalie J.

    2015-01-01

    Alcoholic liver disease is one of the most prevalent liver diseases worldwide, and a major cause of morbidity and mortality. Alcoholic hepatitis is a severe form of liver injury in patients with alcohol abuse, can present as an acute on chronic liver failure associated with a rapid decline in liver synthetic function, and consequent increase in mortality. Despite therapy, about 30%–50% of patients with severe alcoholic hepatitis eventually die. The pathogenic pathways that lead to the development of alcoholic hepatitis are complex and involve oxidative stress, gut dysbiosis, and dysregulation of the innate and adaptive immune system with injury to the parenchymal cells and activation of hepatic stellate cells. As accepted treatment approaches are currently limited, a better understanding of the pathophysiology would be required to generate new approaches that improve outcomes. This review focuses on recent advances in the diagnosis, pathogenesis of alcoholic hepatitis and novel treatment strategies. PMID:26540078

  9. Alcoholic liver disease: Treatment

    PubMed Central

    Suk, Ki Tae; Kim, Moon Young; Baik, Soon Koo

    2014-01-01

    The excess consumption of alcohol is associated with alcoholic liver diseases (ALD). ALD is a major healthcare problem, personal and social burden, and significant reason for economic loss worldwide. The ALD spectrum includes alcoholic fatty liver, alcoholic hepatitis, cirrhosis, and the development of hepatocellular carcinoma. The diagnosis of ALD is based on a combination of clinical features, including a history of significant alcohol intake, evidence of liver disease, and laboratory findings. Abstinence is the most important treatment for ALD and the treatment plan varies according to the stage of the disease. Various treatments including abstinence, nutritional therapy, pharmacological therapy, psychotherapy, and surgery are currently available. For severe alcoholic hepatitis, corticosteroid or pentoxifylline are recommended based on the guidelines. In addition, new therapeutic targets are being under investigation. PMID:25278689

  10. Biochemistry and Comparative Genomics of SxxK Superfamily Acyltransferases Offer a Clue to the Mycobacterial Paradox: Presence of Penicillin-Susceptible Target Proteins versus Lack of Efficiency of Penicillin as Therapeutic Agent

    PubMed Central

    Goffin, Colette; Ghuysen, Jean-Marie

    2002-01-01

    The bacterial acyltransferases of the SxxK superfamily vary enormously in sequence and function, with conservation of particular amino acid groups and all-α and α/β folds. They occur as independent entities (free-standing polypeptides) and as modules linked to other polypeptides (protein fusions). They can be classified into three groups. The group I SxxK d,d-acyltransferases are ubiquitous in the bacterial world. They invariably bear the motifs SxxK, SxN(D), and KT(S)G. Anchored in the plasma membrane with the bulk of the polypeptide chain exposed on the outer face of it, they are implicated in the synthesis of wall peptidoglycans of the most frequently encountered (4→3) type. They are inactivated by penicillin and other β-lactam antibiotics acting as suicide carbonyl donors in the form of penicillin-binding proteins (PBPs). They are components of a morphogenetic apparatus which, as a whole, controls multiple parameters such as shape and size and allows the bacterial cells to enlarge and duplicate their particular pattern. Class A PBP fusions comprise a glycosyltransferase module fused to an SxxK acyltransferase of class A. Class B PBP fusions comprise a linker, i.e., protein recognition, module fused to an SxxK acyltransferase of class B. They ensure the remodeling of the (4→3) peptidoglycans in a cell cycle-dependent manner. The free-standing PBPs hydrolyze d,d peptide bonds. The group II SxxK acyltransferases frequently have a partially modified bar code, but the SxxK motif is invariant. They react with penicillin in various ways and illustrate the great plasticity of the catalytic centers. The secreted free-standing PBPs, the serine β-lactamases, and the penicillin sensors of several penicillin sensory transducers help the d,d-acyltransferases of group I escape penicillin action. The group III SxxK acyltransferases are indistinguishable from the PBP fusion proteins of group I in motifs and membrane topology, but they resist penicillin. They are

  11. [Biological markers of alcoholism].

    PubMed

    Marcos Martín, M; Pastor Encinas, I; Laso Guzmán, F J

    2005-09-01

    Diagnosis of alcoholism is very important, given its high prevalence and possibility of influencing the disease course. For this reason, the so-called biological markers of alcoholism are useful. These are analytic parameters that alter in the presence of excessive alcohol consumption. The two most relevant markers are the gamma-glutamyltranspeptidase and carbohydrate deficient transferrin. With this clinical comment, we aim to contribute to the knowledge of these tests and promote its use in the clinical practice. PMID:16194480

  12. Attendance at Alcohol-Free and Alcohol-Service Parties and Alcohol Consumption among College Students

    PubMed Central

    Wei, Jill; Barnett, Nancy P.; Clark, Melissa

    2010-01-01

    Objective To examine attendance at alcohol-service and alcohol-free parties among college students, and to compare alcohol consumption on nights of these parties. Method A random sample of 556 students (38.6% male) completed a web survey that measured past-semester alcohol use, alcohol-service party attendance, alcohol-free party attendance, and alcohol consumed on the nights of recent parties. Results Participants were twice as likely to attend alcohol-service parties as they were to attend alcohol-free parties (90% vs. 44%). First-year students and Black students were more likely than other students to attend alcohol-free parties. Alcohol use was higher in students who attended alcohol-service parties but there were no differences in levels of alcohol use between students who attended alcohol-free parties and those who did not. Pre-gaming was more prevalent, but number of drinks and intoxication were lower on nights of alcohol-free parties than on nights of alcohol-service parties. Conclusions The lack of association between attendance at alcohol-free parties and alcohol use indicates both heavy and light drinkers attend these parties. The lower drinking and intoxication on alcohol-free party nights suggests alcohol-free programming should be investigated to determine if it may reduce alcohol use on college campuses. PMID:20188482

  13. A thraustochytrid diacylglycerol acyltransferase 2 with broad substrate specificity strongly increases oleic acid content in engineered Arabidopsis thaliana seeds

    PubMed Central

    Zhang, Chunyu; Iskandarov, Umidjon; Cahoon, Edgar B.

    2013-01-01

    Diacylglycerol acyltransferase (DGAT) catalyses the last step in acyl-CoA-dependent triacylglycerol (TAG) biosynthesis and is an important determinant of cellular oil content and quality. In this study, a gene, designated TaDGAT2, encoding a type 2 DGAT (DGAT2)-related enzyme was identified from the oleaginous marine protist Thraustochytrium aureum. The deduced TaDGAT2 sequence contains a ~460 amino acid domain most closely related to DGAT2s from Dictyostelium sp. (45–50% identity). Recombinant TaDGAT2 restored TAG biosynthesis to the Saccharomyces cerevisiae H1246 TAG-deficient mutant, and microsomes from the complemented mutant displayed DGAT activity with C16 and C18 saturated and unsaturated fatty acyl-CoA and diacylglycerol substrates. To examine its biotechnological potential, TaDGAT2 was expressed under control of a strong seed-specific promoter in wild-type Arabidopsis thaliana and the high linoleic acid fad3fae1 mutant. In both backgrounds, little change was detected in seed oil content, but a striking increase in oleic acid content of seeds was observed. This increase was greatest in fad3fae1 seeds, where relative amounts of oleic acid increased nearly 2-fold to >50% of total fatty acids. In addition, >2-fold increase in oleic acid levels was detected in the triacylglycerol sn-2 position and in the major seed phospholipid phosphatidylcholine. These results suggest that increased seed oleic acid content mediated by TaDGAT2 is influenced in part by the fatty acid composition of host cells and occurs not by enhancing oleic acid content at the TAG sn-3 position directly but by increasing total oleic acid levels in seeds, presumably by limiting flux through phosphatidylcholine-based desaturation reactions. PMID:23814277

  14. Two types of soybean diacylglycerol acyltransferases are differentially involved in triacylglycerol biosynthesis and response to environmental stresses and hormones

    PubMed Central

    Chen, BeiBei; Wang, Junejie; Zhang, Gaoyang; Liu, Jiaqi; Manan, Sehrish; Hu, Honghong; Zhao, Jian

    2016-01-01

    Diacylglycerol acyltransferases (DGATs) play a key role in plant triacylglycerol (TAG) biosynthesis. Two type 1 and 2 DGATs from soybean were characterized for their functions in TAG biosynthesis and physiological roles. GmDGAT1A is highly expressed in seeds while GmDGAT2D is mainly expressed in flower tissues. They showed different expression patterns in response to biotic and abiotic stresses. GmDGAT2D was up-regulated by cold and heat stress and ABA signaling, and repressed by insect biting and jasmonate, whereas GmDGAT1A show fewer responses. Both GmDGAT1A and GmDGAT2D were localized to the endoplasmic reticulum and complemented the TAG deficiency of a yeast mutant H1246. GmDGAT2D-transgenic hairy roots synthesized more 18:2- or 18:1-TAG, whereas GmDGAT1A prefers to use 18:3-acyl CoA for TAG synthesis. Overexpression of both GmDGATs in Arabidopsis seeds enhanced the TAG production; GmDGAT2D promoted 18:2-TAG in wild-type but enhanced 18:1-TAG production in rod1 mutant seeds, with a decreased 18:3-TAG. However, GmDGAT1A enhanced 18:3-TAG and reduced 20:1-TAG contents. The different substrate preferences of two DGATs may confer diverse fatty acid profiles in soybean oils. While GmDGAT1A may play a role in usual seed TAG production and GmDGAT2D is also involved in usual TAG biosynthesis in other tissues in responses to environmental and hormonal cues. PMID:27345221

  15. Pharmacological Inhibition of Monoacylglycerol O-Acyltransferase 2 Improves Hyperlipidemia, Obesity, and Diabetes by Change in Intestinal Fat Utilization

    PubMed Central

    Take, Kazumi; Mochida, Taisuke; Maki, Toshiyuki; Satomi, Yoshinori; Hirayama, Megumi; Nakakariya, Masanori; Amano, Nobuyuki; Adachi, Ryutaro; Sato, Kenjiro; Kitazaki, Tomoyuki; Takekawa, Shiro

    2016-01-01

    Monoacylglycerol O-acyltransferase 2 (MGAT2) catalyzes the synthesis of diacylglycerol (DG), a triacylglycerol precursor and potential peripheral target for novel anti-obesity therapeutics. High-throughput screening identified lead compounds with MGAT2 inhibitory activity. Through structural modification, a potent, selective, and orally bioavailable MGAT2 inhibitor, compound A (compA), was discovered. CompA dose-dependently inhibited postprandial increases in plasma triglyceride (TG) levels. Metabolic flux analysis revealed that compA inhibited triglyceride/diacylglycerol resynthesis in the small intestine and increased free fatty acid and acyl-carnitine with shorter acyl chains than originally labelled fatty acid. CompA decreased high-fat diet (HFD) intake in C57BL/6J mice. MGAT2-null mice showed a similar phenotype as compA-treated mice and compA did not suppress a food intake in MGAT2 KO mice, indicating that the anorectic effects were dependent on MGAT2 inhibition. Chronic administration of compA significantly prevented body weight gain and fat accumulation in mice fed HFD. MGAT2 inhibition by CompA under severe diabetes ameliorated hyperglycemia and fatty liver in HFD-streptozotocin (STZ)-treated mice. Homeostatic model assessments (HOMA-IR) revealed that compA treatment significantly improved insulin sensitivity. The proximal half of the small intestine displayed weight gain following compA treatment. A similar phenomenon has been observed in Roux-en-Y gastric bypass-treated animals and some studies have reported that this intestinal remodeling is essential to the anti-diabetic effects of bariatric surgery. These results clearly demonstrated that MGAT2 inhibition improved dyslipidemia, obesity, and diabetes, suggesting that compA is an effective therapeutic for obesity-related metabolic disorders. PMID:26938273

  16. Cloning and functional analysis of human acyl coenzyme A: Cholesterol acyltransferase1 gene P1 promoter.

    PubMed

    Ge, Jing; Cheng, Bei; Qi, Benling; Peng, Wen; Wen, Hui; Bai, Lijuan; Liu, Yun; Zhai, Wei

    2016-07-01

    Acyl-coenzyme A: cholesterol acyltransferase 1 (ACAT1) catalyzes the conversion of free cholesterol (FC) to cholesterol ester. The human ACAT1 gene P1 promoter has been cloned. However, the activity and specificity of the ACAT1 gene P1 promoter in diverse cell types remains unclear. The P1 promoter fragment was digested with KpnI/XhoI from a P1 promoter cloning vector, and was subcloned into the multiple cloning site of the Firefly luciferase vector pGL3‑Enhancer to obtain the construct P1E‑1. According to the analysis of biological information, the P1E‑1 plasmid was used to generate deletions of the ACAT1 gene P1 promoter with varying 5' ends and an identical 3' end at +65 by polymerase chain reaction (PCR). All the 5'‑deletion constructs of the P1 promoter were identified by PCR, restriction enzyme digestion mapping and DNA sequencing. The transcriptional activity of each construct was detected after transient transfection into THP‑1, HepG2, HEK293 and Hela cells using DEAE‑dextran and Lipofectamine 2000 liposome transfection reagent. Results showed that the transcriptional activity of the ACAT1 gene P1 promoter and deletions of P1 promoter in THP‑1 and HepG2 cells was higher than that in HEK293 and HeLa cells. Moreover, the transcriptional activity of P1E‑9 was higher compared with those of other deletions in THP‑1, HepG2, HEK293 and HeLa cells. These findings indicate that the transcriptional activity of the P1 promoter and the effects of deletions vary with different cell lines. Thus, the P1 promoter may drive ACAT1 gene expression with cell‑type specificity. In addition, the core sequence of ACAT1 gene P1 promoter was suggested to be between -125 and +65 bp. PMID:27220725

  17. The Glycerol-3-Phosphate Acyltransferase GPAT6 from Tomato Plays a Central Role in Fruit Cutin Biosynthesis.

    PubMed

    Petit, Johann; Bres, Cécile; Mauxion, Jean-Philippe; Tai, Fabienne Wong Jun; Martin, Laetitia B B; Fich, Eric A; Joubès, Jérôme; Rose, Jocelyn K C; Domergue, Frédéric; Rothan, Christophe

    2016-06-01

    The thick cuticle covering and embedding the epidermal cells of tomato (Solanum lycopersicum) fruit acts not only as a protective barrier against pathogens and water loss but also influences quality traits such as brightness and postharvest shelf-life. In a recent study, we screened a mutant collection of the miniature tomato cultivar Micro-Tom and isolated several glossy fruit mutants in which the abundance of cutin, the polyester component of the cuticle, was strongly reduced. We employed a newly developed mapping-by-sequencing strategy to identify the causal mutation underlying the cutin deficiency in a mutant thereafter named gpat6-a (for glycerol-3-phosphate acyltransferase6). To this end, a backcross population (BC1F2) segregating for the glossy trait was phenotyped. Individuals displaying either a wild-type or a glossy fruit trait were then pooled into bulked populations and submitted to whole-genome sequencing prior to mutation frequency analysis. This revealed that the causal point mutation in the gpat6-a mutant introduces a charged amino acid adjacent to the active site of a GPAT6 enzyme. We further showed that this mutation completely abolished the GPAT activity of the recombinant protein. The gpat6-a mutant showed perturbed pollen formation but, unlike a gpat6 mutant of Arabidopsis (Arabidopsis thaliana), was not male sterile. The most striking phenotype was observed in the mutant fruit, where cuticle thickness, composition, and properties were altered. RNA sequencing analysis highlighted the main processes and pathways that were affected by the mutation at the transcriptional level, which included those associated with lipid, secondary metabolite, and cell wall biosynthesis. PMID:27208295

  18. Coexpressing Escherichia coli Cyclopropane Synthase with Sterculia foetida Lysophosphatidic Acid Acyltransferase Enhances Cyclopropane Fatty Acid Accumulation1[W][OPEN

    PubMed Central

    Yu, Xiao-Hong; Prakash, Richa Rawat; Sweet, Marie; Shanklin, John

    2014-01-01

    Cyclopropane fatty acids (CPAs) are desirable as renewable chemical feedstocks for the production of paints, plastics, and lubricants. Toward our goal of creating a CPA-accumulating crop, we expressed nine higher plant cyclopropane synthase (CPS) enzymes in the seeds of fad2fae1 Arabidopsis (Arabidopsis thaliana) and observed accumulation of less than 1% CPA. Surprisingly, expression of the Escherichia coli CPS gene resulted in the accumulation of up to 9.1% CPA in the seed. Coexpression of a Sterculia foetida lysophosphatidic acid acyltransferase (SfLPAT) increases CPA accumulation up to 35% in individual T1 seeds. However, seeds with more than 9% CPA exhibit wrinkled seed morphology and reduced size and oil accumulation. Seeds with more than 11% CPA exhibit strongly decreased seed germination and establishment, and no seeds with CPA more than 15% germinated. That previous reports suggest that plant CPS prefers the stereospecific numbering (sn)-1 position whereas E. coli CPS acts on sn-2 of phospholipids prompted us to investigate the preferred positions of CPS on phosphatidylcholine (PC) and triacylglycerol. Unexpectedly, in planta, E. coli CPS acts primarily on the sn-1 position of PC; coexpression of SfLPAT results in the incorporation of CPA at the sn-2 position of lysophosphatidic acid. This enables a cycle that enriches CPA at both sn-1 and sn-2 positions of PC and results in increased accumulation of CPA. These data provide proof of principle that CPA can accumulate to high levels in transgenic seeds and sets the stage for the identification of factors that will facilitate the movement of CPA from PC into triacylglycerol to produce viable seeds with additional CPA accumulation. PMID:24204024

  19. Membrane topology of human monoacylglycerol acyltransferase-2 and identification of regions important for its localization to the endoplasmic reticulum.

    PubMed

    McFie, Pamela J; Izzard, Sabrina; Vu, Huyen; Jin, Youzhi; Beauchamp, Erwan; Berthiaume, Luc G; Stone, Scot J

    2016-09-01

    Acyl CoA:2-monoacylglycerol acyltransferase (MGAT)-2 has an important role in dietary fat absorption in the intestine. MGAT2 resides in the endoplasmic reticulum and catalyzes the synthesis of diacylglycerol which is then utilized as a substrate for triacylglycerol synthesis. This triacylglycerol is then incorporated into chylomicrons which are released into the circulation. In this study, we determined the membrane topology of human MGAT2. Protease protection experiments showed that the C-terminus is exposed to the cytosol, while the N-terminus is partially buried in the ER membrane. MGAT2, like murine DGAT2, was found to have two transmembrane domains. We also identified a region of MGAT2 associated with the ER membrane that contains the histidine-proline-histidine-glycine sequence present in all DGAT2 family members that is thought to comprise the active site. Proteolysis experiments demonstrated that digestion of total cellular membranes from cells expressing MGAT2 with trypsin abolished MGAT activity, indicating that domains that are important for catalysis face the cytosol. We also explored the role that the five cysteines residues present in MGAT2 have in catalysis. MGAT activity was sensitive to two thiol modifiers, N-ethylmaleimide and 5,5'-dithiobis-(2-nitrobenzoic acid). Furthermore, mutation of four cysteines resulted in a reduction in MGAT activity. However, when the C-terminal cysteine (C334) was mutated, MGAT activity was actually higher than that of wild-type FL-MGAT2. Lastly, we determined that both transmembrane domains of MGAT2 are important for its ER localization, and that MGAT2 is present in mitochondrial-associated membranes. PMID:27373844

  20. Pharmacological Inhibition of Monoacylglycerol O-Acyltransferase 2 Improves Hyperlipidemia, Obesity, and Diabetes by Change in Intestinal Fat Utilization.

    PubMed

    Take, Kazumi; Mochida, Taisuke; Maki, Toshiyuki; Satomi, Yoshinori; Hirayama, Megumi; Nakakariya, Masanori; Amano, Nobuyuki; Adachi, Ryutaro; Sato, Kenjiro; Kitazaki, Tomoyuki; Takekawa, Shiro

    2016-01-01

    Monoacylglycerol O-acyltransferase 2 (MGAT2) catalyzes the synthesis of diacylglycerol (DG), a triacylglycerol precursor and potential peripheral target for novel anti-obesity therapeutics. High-throughput screening identified lead compounds with MGAT2 inhibitory activity. Through structural modification, a potent, selective, and orally bioavailable MGAT2 inhibitor, compound A (compA), was discovered. CompA dose-dependently inhibited postprandial increases in plasma triglyceride (TG) levels. Metabolic flux analysis revealed that compA inhibited triglyceride/diacylglycerol resynthesis in the small intestine and increased free fatty acid and acyl-carnitine with shorter acyl chains than originally labelled fatty acid. CompA decreased high-fat diet (HFD) intake in C57BL/6J mice. MGAT2-null mice showed a similar phenotype as compA-treated mice and compA did not suppress a food intake in MGAT2 KO mice, indicating that the anorectic effects were dependent on MGAT2 inhibition. Chronic administration of compA significantly prevented body weight gain and fat accumulation in mice fed HFD. MGAT2 inhibition by CompA under severe diabetes ameliorated hyperglycemia and fatty liver in HFD-streptozotocin (STZ)-treated mice. Homeostatic model assessments (HOMA-IR) revealed that compA treatment significantly improved insulin sensitivity. The proximal half of the small intestine displayed weight gain following compA treatment. A similar phenomenon has been observed in Roux-en-Y gastric bypass-treated animals and some studies have reported that this intestinal remodeling is essential to the anti-diabetic effects of bariatric surgery. These results clearly demonstrated that MGAT2 inhibition improved dyslipidemia, obesity, and diabetes, suggesting that compA is an effective therapeutic for obesity-related metabolic disorders. PMID:26938273

  1. Brain Mapping of Ghrelin O-Acyltransferase in Goldfish (Carassius Auratus): Novel Roles for the Ghrelinergic System in Fish?

    PubMed

    Blanco, Ayelén M; Sánchez-Bretaño, Aída; Delgado, María J; Valenciano, Ana I

    2016-06-01

    Ghrelin O-acyltransferase (GOAT) is the enzyme responsible for acylation of ghrelin, a gut-brain hormone with important roles in many physiological functions in vertebrates. Many aspects of GOAT remain to be elucidated, especially in fish, and particularly its anatomical distribution within the different brain areas has never been reported to date. The present study aimed to characterize the brain mapping of GOAT using RT-qPCR and immunohistochemistry in a teleost, the goldfish (Carassius auratus). Results show that goat transcripts are expressed in different brain areas of the goldfish, with the highest levels in the vagal lobe. Using immunohistochemistry, we also report the presence of GOAT immunoreactive cells in different encephalic areas, including the telencephalon, some hypothalamic nuclei, pineal gland, optic tectum and cerebellum, although they are especially abundant in the hindbrain. Particularly, an important signal is observed in the vagal lobe and some fiber tracts of the brainstem, such as the medial longitudinal fasciculus, Mauthneri fasciculus, secondary gustatory tract and spinothalamic tract. Most of the forebrain areas where GOAT is detected, particularly the hypothalamic nuclei, also express the ghs-r1a ghrelin receptor and other appetite-regulating hormones (e.g., orexin and NPY), supporting the role of ghrelin as a modulator of food intake and energy balance in fish. Present results are the first report on the presence of GOAT in the brain using imaging techniques. The high presence of GOAT in the hindbrain is a novelty, and point to possible new functions for the ghrelinergic system in fish. Anat Rec, 299:748-758, 2016. © 2016 Wiley Periodicals, Inc. PMID:27064922

  2. Glycerol-3-phosphate Acyltransferase Isoform-4 (GPAT4) Limits Oxidation of Exogenous Fatty Acids in Brown Adipocytes.

    PubMed

    Cooper, Daniel E; Grevengoed, Trisha J; Klett, Eric L; Coleman, Rosalind A

    2015-06-12

    Glycerol-3-phosphate acyltransferase-4 (GPAT4) null pups grew poorly during the suckling period and, as adults, were protected from high fat diet-induced obesity. To determine why Gpat4(-/-) mice failed to gain weight during these two periods of high fat feeding, we examined energy metabolism. Compared with controls, the metabolic rate of Gpat4(-/-) mice fed a 45% fat diet was 12% higher. Core body temperature was 1 ºC higher after high fat feeding. Food intake, fat absorption, and activity were similar in both genotypes. Impaired weight gain in Gpat4(-/-) mice did not result from increased heat loss, because both cold tolerance and response to a β3-adrenergic agonist were similar in both genotypes. Because GPAT4 comprises 65% of the total GPAT activity in brown adipose tissue (BAT), we characterized BAT function. A 45% fat diet increased the Gpat4(-/-) BAT expression of peroxisome proliferator-activated receptor α (PPAR) target genes, Cpt1α, Pgc1α, and Ucp1, and BAT mitochondria oxidized oleate and pyruvate at higher rates than controls, suggesting that fatty acid signaling and flux through the TCA cycle were enhanced. To assess the role of GPAT4 directly, neonatal BAT preadipocytes were differentiated to adipocytes. Compared with controls, Gpat4(-/-) brown adipocytes incorporated 33% less fatty acid into triacylglycerol and 46% more into the pathway of β-oxidation. The increased oxidation rate was due solely to an increase in the oxidation of exogenous fatty acids. These data suggest that in the absence of cold exposure, GPAT4 limits excessive fatty acid oxidation and the detrimental induction of a hypermetabolic state. PMID:25918168

  3. Regulation of high density lipoprotein receptors in cultured macrophages: role of acyl-CoA:cholesterol acyltransferase.

    PubMed Central

    Schmitz, G; Niemann, R; Brennhausen, B; Krause, R; Assmann, G

    1985-01-01

    The interaction of human serum high density lipoproteins (HDL) with mouse peritoneal macrophages and human blood monocytes was studied. Saturation curves for binding of apolipoprotein E-free [125I]HDL3 showed at least two components: non-specific binding and specific binding that saturated at approximately 40 micrograms HDL protein/ml. Scatchard analysis of specific binding of apo E-free [125I]-HDL3 to cultured macrophages yielded linear plots indicative of a single class of specific binding sites. Pretreatment of [125I]HDL3 with various apolipoprotein antibodies (anti apo A-I, anti apo A-II, anti apo C-II, anti apo C-III and anti apo E) and preincubation of the cells with anti-idiotype antibodies against apo A-I and apo A-II prior to the HDL binding studies revealed apolipoprotein A-I as the ligand involved in specific binding of HDL. Cellular cholesterol accumulation via incubation with acetylated LDL led to an increase in HDL binding sites as well as an increase in the activity of the cytoplasmic cholesterol esterifying enzyme acyl-CoA:cholesterol acyltransferase (ACAT). Incubation of the cholesterol-loaded cells in the presence of various ACAT inhibitors (Sandoz 58.035, Octimibate-Nattermann, progesterone) revealed a time- and dose-dependent amplification in HDL binding and HDL-mediated cholesterol efflux. It is concluded that the homeostasis of cellular cholesterol in macrophages is regulated in part by the number of HDL binding sites and that ACAT inhibitors enhance HDL-mediated cholesterol efflux from peripheral cells. Images Fig. 4. PMID:2998754

  4. Altered lipid composition and enhanced lipid production in green microalga by introduction of brassica diacylglycerol acyltransferase 2.

    PubMed

    Ahmad, Irshad; Sharma, Anil K; Daniell, Henry; Kumar, Shashi

    2015-05-01

    Higher lipid biosynthesis and accumulation are important to achieve economic viability of biofuel production via microalgae. To enhance lipid content, Chlamydomonas reinhardtii was genetically engineered with a key enzyme diacylglycerol acyltransferase (BnDGAT2) from Brassica napus, responsible for neutral lipid biosynthesis. The transformed colonies harbouring aph7 gene, screened on hygromycin-supplemented medium, achieved transformation frequency of ~120 ± 10 colonies/1 × 10(6) cells. Transgene integration and expression were confirmed by PCR, Southern blots, staining lipid droplets, proteins and spectro-fluorometric analysis of Nile red-stained cells. The neutral lipid is a major class (over 80% of total lipids) and most significant requirement for biodiesel production; this was remarkably higher in the transformed alga than the untransformed control. The levels of saturated fatty acids in the transformed alga decreased to about 7% while unsaturated fatty acids increased proportionately when compared to wild type cells. Polyunsaturated fatty acids, especially α-linolenic acid, an essential omega-3 fatty acid, were enhanced up to 12% in the transformed line. Nile red staining confirmed formation of a large number of lipid globules in the transformed alga. Evaluation of long-term stability and vitality of the transgenic alga revealed that cryopreservation produced significantly higher quantity of lipid than those maintained continuously over 128 generations on solid medium. The overexpression of BnDGAT2 significantly altered the fatty acids profile in the transformed alga. Results of this study offer a valuable strategy of genetic manipulation for enhancing polyunsaturated fatty acids and neutral lipids for biofuel production in algae. PMID:25403771

  5. Transcriptional and biochemical responses of monoacylglycerol acyltransferase-mediated oil synthesis and associated senescence-like responses in Nicotiana benthamiana

    PubMed Central

    Divi, Uday K.; El Tahchy, Anna; Vanhercke, Thomas; Petrie, James R.; Robles-Martinez, Jose A.; Singh, Surinder P.

    2014-01-01

    Triacylglycerol (TAG) accumulates in plant seeds as a major renewable source of carbon for food, fuel and industrial feedstock. Approaches to enhance TAG content by altering lipid pathways and genes in vegetative parts have gained significant attention for biofuel and other applications. However, consequences of these modifications are not always studied in detail. In an attempt to increase TAG levels in leaves we previously demonstrated that a novel substrate, monoacylglycerol (MAG), can be used for the biosynthesis of diacylglycerol (DAG) and TAG. Transient expression of the Mus musculus monoacylglycerol acyltransferases MGAT1 and 2 in the model plant Nicotiana benthamiana increased TAG levels at 5 days post-infiltration (dpi). Here we show that increased TAG and DAG levels can be achieved as early as 2 dpi. In addition, the MGAT1 infiltrated areas showed senescence-like symptoms from 3 dpi onwards. To unravel underlying molecular mechanisms, Illumina deep sequencing was carried out (a) for de-novo assembling and annotation of N. benthamiana leaf transcripts and (b) to characterize MGAT1-responsive transcriptome. We found that MGAT1-responsive genes are involved in several processes including TAG biosynthesis, photosynthesis, cell-wall, cutin, suberin, wax and mucilage biosynthesis, lipid and hormone metabolism. Comparative analysis with transcript profiles from other senescence studies identified characteristic gene expression changes involved in senescence induction. We confirmed that increased TAG and observed senescence-symptoms are due to the MAG depletion caused by MGAT1 activity and suggest a mechanism for MGAT1 induced TAG increase and senescence-like symptoms. The data generated will serve as a valuable resource for oil and senescence related studies and for future N. benthamiana transcriptome studies. PMID:24904604

  6. Transcriptional and biochemical responses of monoacylglycerol acyltransferase-mediated oil synthesis and associated senescence-like responses in Nicotiana benthamiana.

    PubMed

    Divi, Uday K; El Tahchy, Anna; Vanhercke, Thomas; Petrie, James R; Robles-Martinez, Jose A; Singh, Surinder P

    2014-01-01

    Triacylglycerol (TAG) accumulates in plant seeds as a major renewable source of carbon for food, fuel and industrial feedstock. Approaches to enhance TAG content by altering lipid pathways and genes in vegetative parts have gained significant attention for biofuel and other applications. However, consequences of these modifications are not always studied in detail. In an attempt to increase TAG levels in leaves we previously demonstrated that a novel substrate, monoacylglycerol (MAG), can be used for the biosynthesis of diacylglycerol (DAG) and TAG. Transient expression of the Mus musculus monoacylglycerol acyltransferases MGAT1 and 2 in the model plant Nicotiana benthamiana increased TAG levels at 5 days post-infiltration (dpi). Here we show that increased TAG and DAG levels can be achieved as early as 2 dpi. In addition, the MGAT1 infiltrated areas showed senescence-like symptoms from 3 dpi onwards. To unravel underlying molecular mechanisms, Illumina deep sequencing was carried out (a) for de-novo assembling and annotation of N. benthamiana leaf transcripts and (b) to characterize MGAT1-responsive transcriptome. We found that MGAT1-responsive genes are involved in several processes including TAG biosynthesis, photosynthesis, cell-wall, cutin, suberin, wax and mucilage biosynthesis, lipid and hormone metabolism. Comparative analysis with transcript profiles from other senescence studies identified characteristic gene expression changes involved in senescence induction. We confirmed that increased TAG and observed senescence-symptoms are due to the MAG depletion caused by MGAT1 activity and suggest a mechanism for MGAT1 induced TAG increase and senescence-like symptoms. The data generated will serve as a valuable resource for oil and senescence related studies and for future N. benthamiana transcriptome studies. PMID:24904604

  7. Altered lipid composition and enhanced lipid production in green microalga by introduction of brassica diacylglycerol acyltransferase 2

    PubMed Central

    Ahmad, Irshad; Sharma, Anil K.; Daniell, Henry; Kumar, Shashi

    2015-01-01

    Summary Higher lipid biosynthesis and accumulation are important to achieve economic viability of biofuel production via microalgae. To enhance lipid content, Chlamydomonas reinhardtii was genetically engineered with a key enzyme diacylglycerol acyltransferase (BnDGAT2) from Brassica napus, responsible for neutral lipid biosynthesis. The transformed colonies harbouring aph7 gene, screened on hygromycin-supplemented medium, achieved transformation frequency of ~120 ± 10 colonies/1 × 106 cells. Transgene integration and expression were confirmed by PCR, Southern blots, staining lipid droplets, proteins and spectro-fluorometric analysis of Nile red-stained cells. The neutral lipid is a major class (over 80% of total lipids) and most significant requirement for biodiesel production; this was remarkably higher in the transformed alga than the untransformed control. The levels of saturated fatty acids in the transformed alga decreased to about 7% while unsaturated fatty acids increased proportionately when compared to wild type cells. Polyunsaturated fatty acids, especially α-linolenic acid, an essential omega-3 fatty acid, were enhanced up to 12% in the transformed line. Nile red staining confirmed formation of a large number of lipid globules in the transformed alga. Evaluation of long-term stability and vitality of the transgenic alga revealed that cryopreservation produced significantly higher quantity of lipid than those maintained continuously over 128 generations on solid medium. The overexpression of BnDGAT2 significantly altered the fatty acids profile in the transformed alga. Results of this study offer a valuable strategy of genetic manipulation for enhancing polyunsaturated fatty acids and neutral lipids for biofuel production in algae. PMID:25403771

  8. Lecithin:Cholesterol Acyltransferase (LCAT) Deficiency Promotes Differentiation of Satellite Cells to Brown Adipocytes in a Cholesterol-dependent Manner.

    PubMed

    Nesan, Dinushan; Tavallaee, Ghazaleh; Koh, Deborah; Bashiri, Amir; Abdin, Rawand; Ng, Dominic S

    2015-12-18

    Our laboratory previously reported that lecithin:cholesterol acyltransferase (LCAT) and LDL receptor double knock-out mice (Ldlr(-/-)xLcat(-/-) or DKO) spontaneously develop functioning ectopic brown adipose tissue (BAT) in skeletal muscle, putatively contributing to protection from the diet-induced obesity phenotype. Here we further investigated their developmental origin and the mechanistic role of LCAT deficiency. Gene profiling of skeletal muscle in DKO newborns and adults revealed a classical lineage. Primary quiescent satellite cells (SC) from chow-fed DKO mice, not in Ldlr(-/-)xLcat(+/+) single-knock-out (SKO) or C57BL/6 wild type, were found to (i) express exclusively classical BAT-selective genes, (ii) be primed to express key functional BAT genes, and (iii) exhibit markedly increased ex vivo adipogenic differentiation into brown adipocytes. This gene priming effect was abrogated upon feeding the mice a 2% high cholesterol diet in association with accumulation of excess intracellular cholesterol. Ex vivo cholesterol loading of chow-fed DKO SC recapitulated the effect, indicating that cellular cholesterol is a key regulator of SC-to-BAT differentiation. Comparing adipogenicity of Ldlr(+/+)xLcat(-/-) (LCAT-KO) SC with DKO SC identified a role for LCAT deficiency in priming SC to express BAT genes. Additionally, we found that reduced cellular cholesterol is important for adipogenic differentiation, evidenced by increased induction of adipogenesis in cholesterol-depleted SC from both LCAT-KO and SKO mice. Taken together, we conclude that ectopic BAT in DKO mice is classical in origin, and its development begins in utero. We further showed complementary roles of LCAT deficiency and cellular cholesterol reduction in the SC-to-BAT adipogenesis. PMID:26494623

  9. Characterisation of the influence of genetic variations on the enzyme activity of a recombinant human glycine N-acyltransferase.

    PubMed

    van der Sluis, Rencia; Badenhorst, Christoffel P S; van der Westhuizen, Francois H; van Dijk, Alberdina A

    2013-02-25

    Human glycine N-acyltransferase (human GLYAT) detoxifies a wide range of endogenous and xenobiotic metabolites, including benzoate and salicylate. Significant inter-individual variation exists in glycine conjugation capacity. The molecular basis for this variability is not known. To investigate the influence of single nucleotide polymorphisms (SNPs) in the GLYAT coding sequence on enzyme activity, we expressed and characterised a recombinant human GLYAT. Site-directed mutagenesis was used to generate six non-synonymous SNP variants of the enzyme (K16N; S17T; R131H; N156S; F168L; R199C). The variants were expressed, purified, and enzymatically characterised. The enzyme activities of the K16N, S17T and R131H variants were similar to that of the wild-type, whereas the N156S variant was more active, the F168L variant less active, and the R199C variant was inactive. We also generated an E227Q mutant, which lacks the catalytic residue proposed by Badenhorst et al. (2012). This mutant was inactive compared to the wild-type recombinant human GLYAT. A molecular model of human GLYAT containing coenzyme A (CoA) was generated which revealed that the inactivity of the R199C variant could be due to the substitution of the highly conserved Arg(199) and destabilisation of an α-loop-α motif which is important for substrate binding in the GNAT superfamily. The finding that SNP variations in the human GLYAT gene influence the kinetic properties of the enzyme may explain some of the inter-individual variation in glycine conjugation capacity, which is relevant to the metabolism of xenobiotics such as aspirin and the industrial solvent xylene, and to the treatment of some metabolic disorders. PMID:23237781

  10. Pharmacological glycerol-3-phosphate acyltransferase inhibition decreases food intake and adiposity and increases insulin sensitivity in diet-induced obesity

    PubMed Central

    Kuhajda, Francis P.; Tu, Yajun; Han, Wan Fang; Medghalchi, Susan M.; El Meskini, Rajaa; Landree, Leslie E.; Peterson, Jonathan M.; Daniels, Khadija; Wong, Kody; Wydysh, Edward A.; Townsend, Craig A.; Ronnett, Gabriele V.

    2011-01-01

    Storage of excess calories as triglycerides is central to obesity and its associated disorders. Glycerol-3-phosphate acyltransferases (GPATs) catalyze the initial step in acylglyceride syntheses, including triglyceride synthesis. We utilized a novel small-molecule GPAT inhibitor, FSG67, to investigate metabolic consequences of systemic pharmacological GPAT inhibition in lean and diet-induced obese (DIO) mice. FSG67 administered intraperitoneally decreased body weight and energy intake, without producing conditioned taste aversion. Daily FSG67 (5 mg/kg, 15.3 μmol/kg) produced gradual 12% weight loss in DIO mice beyond that due to transient 9- to 10-day hypophagia (6% weight loss in pair-fed controls). Continued FSG67 maintained the weight loss despite return to baseline energy intake. Weight was lost specifically from fat mass. Indirect calorimetry showed partial protection by FSG67 against decreased rates of oxygen consumption seen with hypophagia. Despite low respiratory exchange ratio due to a high-fat diet, FSG67-treated mice showed further decreased respiratory exchange ratio, beyond pair-fed controls, indicating enhanced fat oxidation. Chronic FSG67 increased glucose tolerance and insulin sensitivity in DIO mice. Chronic FSG67 decreased gene expression for lipogenic enzymes in white adipose tissue and liver and decreased lipid accumulation in white adipose, brown adipose, and liver tissues without signs of damage. RT-PCR showed decreased gene expression for orexigenic hypothalamic neuropeptides AgRP or NPY after acute and chronic systemic FSG67. FSG67 given intracerebroventricularly (100 and 320 nmol icv) produced 24-h weight loss and feeding suppression, indicating contributions from direct central nervous system sites of action. Together, these data point to GPAT as a new potential therapeutic target for the management of obesity and its comorbidities. PMID:21490364

  11. Estrogen Decreases Atherosclerosis In Part By Reducing Hepatic Acyl-CoA:Cholesterol Acyltransferase 2 (ACAT2) In Monkeys

    PubMed Central

    Kavanagh, Kylie; Davis, Matthew A.; Zhang, Li; Wilson, Martha D.; Register, Thomas C.; Adams, Michael R.; Rudel, Lawrence L.; Wagner, Janice D.

    2009-01-01

    Objective Estrogens decrease atherosclerosis progression, mediated in part through changes in plasma lipids and lipoproteins. This study aimed to determine estrogen-induced changes in hepatic cholesterol metabolism, plasma lipoproteins, and the relationship of these changes to atherosclerosis extent. Methods and Results Ovariectomized monkeys (n=34) consumed atherogenic diets for 30 months which contained either no hormones (control, n=17) or conjugated equine estrogens (CEE, n=17) at a human dose equivalent of 0.625 mg/d. Hepatic cholesterol content, low-density lipoprotein (LDL) receptor expression, cholesterol 7α-hydroxylase and acyl-coenzyme A:cholesterol acyltransferase (ACAT) activity and expression levels were determined. CEE treatment resulted in lower plasma concentrations of very-low- and intermediate density lipoprotein cholesterol (V+IDLC; p=0.01), smaller LDL particles (p=0.002) and 50% lower hepatic cholesterol content (total, free and esterified; p<0.05 for all). Total ACAT activity was significantly lower (p=0.01), explained primarily by reductions in the activity of ACAT2. Estrogen regulation of enzymatic activity was at the protein level as both ACAT1 and 2 protein, but not mRNA levels, were lower (p=0.02 and <0.0001, respectively). ACAT2 activity was significantly associated with hepatic total cholesterol, plasma V+IDLC cholesterol, and atherosclerosis. Conclusions Atheroprotective effects of estrogen therapy may be related to reduced hepatic secretion of ACAT2-derived cholesteryl esters in plasma lipoproteins. Condensed Abstract Estrogen inhibits atherogenesis. We demonstrate in ovariectorized monkeys that estrogen therapy led to lower hepatic and circulating lipoprotein cholesterol, and lower ACAT2 protein and associated activity levels as compared to controls. Hepatic ACAT2 activity was highly correlated with, and was an independent predictor of coronary artery atherosclerosis extent. PMID:19759374

  12. Myeloid Acyl-CoA:Cholesterol Acyltransferase 1 Deficiency Reduces Lesion Macrophage Content and Suppresses Atherosclerosis Progression.

    PubMed

    Huang, Li-Hao; Melton, Elaina M; Li, Haibo; Sohn, Paul; Rogers, Maximillian A; Mulligan-Kehoe, Mary Jo; Fiering, Steven N; Hickey, William F; Chang, Catherine C Y; Chang, Ta-Yuan

    2016-03-18

    Acyl-CoA:cholesterol acyltransferase 1 (Acat1) converts cellular cholesterol to cholesteryl esters and is considered a drug target for treating atherosclerosis. However, in mouse models for atherosclerosis, global Acat1 knockout (Acat1(-/-)) did not prevent lesion development. Acat1(-/-) increased apoptosis within lesions and led to several additional undesirable phenotypes, including hair loss, dry eye, leukocytosis, xanthomatosis, and a reduced life span. To determine the roles of Acat1 in monocytes/macrophages in atherosclerosis, we produced a myeloid-specific Acat1 knockout (Acat1(-M/-M)) mouse and showed that, in the Apoe knockout (Apoe(-/-)) mouse model for atherosclerosis, Acat1(-M/-M) decreased the plaque area and reduced lesion size without causing leukocytosis, dry eye, hair loss, or a reduced life span. Acat1(-M/-M) enhanced xanthomatosis in apoe(-/-) mice, a skin disease that is not associated with diet-induced atherosclerosis in humans. Analyses of atherosclerotic lesions showed that Acat1(-M/-M) reduced macrophage numbers and diminished the cholesterol and cholesteryl ester load without causing detectable apoptotic cell death. Leukocyte migration analysis in vivo showed that Acat1(-M/-M) caused much fewer leukocytes to appear at the activated endothelium. Studies in inflammatory (Ly6C(hi)-positive) monocytes and in cultured macrophages showed that inhibiting ACAT1 by gene knockout or by pharmacological inhibition caused a significant decrease in integrin β 1 (CD29) expression in activated monocytes/macrophages. The sparse presence of lesion macrophages without Acat1 can therefore, in part, be attributed to decreased interaction between inflammatory monocytes/macrophages lacking Acat1 and the activated endothelium. We conclude that targeting ACAT1 in a myeloid cell lineage suppresses atherosclerosis progression while avoiding many of the undesirable side effects caused by global Acat1 inhibition. PMID:26801614

  13. The Glycerol-3-Phosphate Acyltransferase GPAT6 from Tomato Plays a Central Role in Fruit Cutin Biosynthesis1[OPEN

    PubMed Central

    Petit, Johann; Mauxion, Jean-Philippe; Tai, Fabienne Wong Jun; Fich, Eric A.; Joubès, Jérôme; Rothan, Christophe

    2016-01-01

    The thick cuticle covering and embedding the epidermal cells of tomato (Solanum lycopersicum) fruit acts not only as a protective barrier against pathogens and water loss but also influences quality traits such as brightness and postharvest shelf-life. In a recent study, we screened a mutant collection of the miniature tomato cultivar Micro-Tom and isolated several glossy fruit mutants in which the abundance of cutin, the polyester component of the cuticle, was strongly reduced. We employed a newly developed mapping-by-sequencing strategy to identify the causal mutation underlying the cutin deficiency in a mutant thereafter named gpat6-a (for glycerol-3-phosphate acyltransferase6). To this end, a backcross population (BC1F2) segregating for the glossy trait was phenotyped. Individuals displaying either a wild-type or a glossy fruit trait were then pooled into bulked populations and submitted to whole-genome sequencing prior to mutation frequency analysis. This revealed that the causal point mutation in the gpat6-a mutant introduces a charged amino acid adjacent to the active site of a GPAT6 enzyme. We further showed that this mutation completely abolished the GPAT activity of the recombinant protein. The gpat6-a mutant showed perturbed pollen formation but, unlike a gpat6 mutant of Arabidopsis (Arabidopsis thaliana), was not male sterile. The most striking phenotype was observed in the mutant fruit, where cuticle thickness, composition, and properties were altered. RNA sequencing analysis highlighted the main processes and pathways that were affected by the mutation at the transcriptional level, which included those associated with lipid, secondary metabolite, and cell wall biosynthesis. PMID:27208295

  14. Two types of soybean diacylglycerol acyltransferases are differentially involved in triacylglycerol biosynthesis and response to environmental stresses and hormones.

    PubMed

    Chen, BeiBei; Wang, Junejie; Zhang, Gaoyang; Liu, Jiaqi; Manan, Sehrish; Hu, Honghong; Zhao, Jian

    2016-01-01

    Diacylglycerol acyltransferases (DGATs) play a key role in plant triacylglycerol (TAG) biosynthesis. Two type 1 and 2 DGATs from soybean were characterized for their functions in TAG biosynthesis and physiological roles. GmDGAT1A is highly expressed in seeds while GmDGAT2D is mainly expressed in flower tissues. They showed different expression patterns in response to biotic and abiotic stresses. GmDGAT2D was up-regulated by cold and heat stress and ABA signaling, and repressed by insect biting and jasmonate, whereas GmDGAT1A show fewer responses. Both GmDGAT1A and GmDGAT2D were localized to the endoplasmic reticulum and complemented the TAG deficiency of a yeast mutant H1246. GmDGAT2D-transgenic hairy roots synthesized more 18:2- or 18:1-TAG, whereas GmDGAT1A prefers to use 18:3-acyl CoA for TAG synthesis. Overexpression of both GmDGATs in Arabidopsis seeds enhanced the TAG production; GmDGAT2D promoted 18:2-TAG in wild-type but enhanced 18:1-TAG production in rod1 mutant seeds, with a decreased 18:3-TAG. However, GmDGAT1A enhanced 18:3-TAG and reduced 20:1-TAG contents. The different substrate preferences of two DGATs may confer diverse fatty acid profiles in soybean oils. While GmDGAT1A may play a role in usual seed TAG production and GmDGAT2D is also involved in usual TAG biosynthesis in other tissues in responses to environmental and hormonal cues. PMID:27345221

  15. Characterization of type 2 diacylglycerol acyltransferases in Chlamydomonas reinhardtii reveals their distinct substrate specificities and functions in triacylglycerol biosynthesis.

    PubMed

    Liu, Jin; Han, Danxiang; Yoon, Kangsup; Hu, Qiang; Li, Yantao

    2016-04-01

    Diacylglycerol acyltransferases (DGATs) catalyze a rate-limiting step of triacylglycerol (TAG) biosynthesis in higher plants and yeast. The genome of the green alga Chlamydomonas reinhardtii has multiple genes encoding type 2 DGATs (DGTTs). Here we present detailed functional and biochemical analyses of Chlamydomonas DGTTs. In vitro enzyme analysis using a radiolabel-free assay revealed distinct substrate specificities of three DGTTs: CrDGTT1 preferred polyunsaturated acyl CoAs, CrDGTT2 preferred monounsaturated acyl CoAs, and CrDGTT3 preferred C16 CoAs. When diacylglycerol was used as the substrate, CrDGTT1 preferred C16 over C18 in the sn-2 position of the glycerol backbone, but CrDGTT2 and CrDGTT3 preferred C18 over C16. In vivo knockdown of CrDGTT1, CrDGTT2 or CrDGTT3 resulted in 20-35% decreases in TAG content and a reduction of specific TAG fatty acids, in agreement with the findings of the in vitro assay and fatty acid feeding test. These results demonstrate that CrDGTT1, CrDGTT2 and CrDGTT3 possess distinct specificities toward acyl CoAs and diacylglycerols, and may work in concert spatially and temporally to synthesize diverse TAG species in C. reinhardtii. CrDGTT1 was shown to prefer prokaryotic lipid substrates and probably resides in both the endoplasmic reticulum and chloroplast envelope, indicating its role in prokaryotic and eukaryotic TAG biosynthesis. Based on these findings, we propose a working model for the role of CrDGTT1 in TAG biosynthesis. This work provides insight into TAG biosynthesis in C. reinhardtii, and paves the way for engineering microalgae for production of biofuels and high-value bioproducts. PMID:26919811

  16. Purification and characterization of thiol-reagent-sensitive glycerol-3-phosphate acyltransferase from the membrane fraction of an oleaginous fungus.

    PubMed Central

    Mishra, S; Kamisaka, Y

    2001-01-01

    Glycerol-3-phosphate acyltransferase (GPAT), responsible for the first committed, rate-limiting, step of glycerolipid synthesis, was purified to homogeneity from the membrane fraction of an oleaginous fungus, Mortierella ramanniana var. angulispora. The enzyme was solubilized from the membrane fraction by pretreatment with 0.05% Triton X-100 and treatment of the resulting pellet with 0.3% Triton X-100. The enzyme was subsequently purified by column chromatography on heparin-Sepharose, Yellow 86 agarose, a second heparin-Sepharose column, Superdex-200 and hydroxylapatite Bio-Gel. Enzyme activity was finally enriched 1308-fold over that of the starting membrane fraction. SDS/PAGE of the purified fraction revealed a single band with a molecular mass of 45 kDa. Native PAGE showed a major band that corresponded to GPAT activity. Enzyme activity was inhibited by thiol reagents, suggesting that it originated from microsomes rather than mitochondria. Purified GPAT depended on exogenous oleoyl-CoA and sn-glycerol-3-phosphate, with the highest activity at approx. 50 and 250 microM, respectively, and preferred oleoyl-CoA 5.4-fold over palmitoyl-CoA as an acyl donor. Anionic phospholipids, such as phosphatidic acid and phosphatidylserine, were absolutely required for activity of the purified enzyme, and their ability to activate GPAT was influenced by the purity of the GPAT preparation. Bivalent cations, such as Mg(2+) and Ca(2+), inhibited purified GPAT activity, whereas 5 mM Mn(2+) elevated activity approx. 2-fold. These results provide new insights into the molecular characterization of microsomal GPAT, which has not been well characterized compared with mitochondrial and plastidic GPAT. PMID:11284717

  17. Probing the chemical mechanism and critical regulatory amino acid residues of Drosophila melanogaster arylalkylamine N-acyltransferase like 2.

    PubMed

    Dempsey, Daniel R; Carpenter, Anne-Marie; Ospina, Santiago Rodriguez; Merkler, David J

    2015-11-01

    Arylalkylamine N-acyltransferase like 2 (AANATL2) catalyzes the formation of N-acylarylalkylamides from the corresponding acyl-CoA and arylalkylamine. The N-acylation of biogenic amines in Drosophila melanogaster is a critical step for the inactivation of neurotransmitters, cuticle sclerotization, and melatonin biosynthesis. In addition, D. melanogaster has been used as a model system to evaluate the biosynthesis of fatty acid amides: a family of potent cell signaling lipids. We have previously showed that AANATL2 catalyzes the formation of N-acylarylakylamides, including long-chain N-acylserotonins and N-acyldopamines. Herein, we define the kinetic mechanism for AANATL2 as an ordered sequential mechanism with acetyl-CoA binding first followed by tyramine to generate the ternary complex prior to catalysis. Bell shaped kcat,app - acetyl-CoA and (kcat/Km)app - acetyl-CoA pH-rate profiles identified two apparent pKa,app values of ∼7.4 and ∼8.9 that are critical to catalysis, suggesting the AANATL2-catalyzed formation of N-acetyltyramine occurs through an acid/base chemical mechanism. Site-directed mutagenesis of a conserved glutamate that corresponds to the catalytic base for other D. melanogaster AANATL enzymes did not produce a substantial depression in the kcat,app value nor did it abolish the pKa,app value attributed to the general base in catalysis (pKa ∼7.4). These data suggest that AANATL2 catalyzes the formation of N-acylarylalkylamides using either different catalytic residues or a different chemical mechanism relative to other D. melanogaster AANATL enzymes. In addition, we constructed other site-directed mutants of AANATL2 to help define the role of targeted amino acids in substrate binding and/or enzyme catalysis. PMID:26476413

  18. Comparative Analysis of the Substrate Specificity of trans- versus cis-Acyltransferases of Assembly Line Polyketide Synthases

    PubMed Central

    2015-01-01

    Due to their pivotal role in extender unit selection during polyketide biosynthesis, acyltransferase (AT) domains are important engineering targets. A subset of assembly line polyketide synthases (PKSs) are serviced by discrete, trans-acting ATs. Theoretically, these trans-ATs can complement an inactivated cis-AT, promoting introduction of a noncognate extender unit. This approach requires a better understanding of the substrate specificity and catalytic mechanism of naturally occurring trans-ATs. We kinetically analyzed trans-ATs from the disorazole and kirromycin synthases and compared them to a representative cis-AT from the 6-deoxyerythronolide B synthase (DEBS). During transacylation, the disorazole AT favored malonyl-CoA over methylmalonyl-CoA by >40000-fold, whereas the kirromycin AT favored ethylmalonyl-CoA over methylmalonyl-CoA by 20-fold. Conversely, the disorazole AT had broader specificity than its kirromycin counterpart for acyl carrier protein (ACP) substrates. The presence of the ACP had little effect on the specificity (kcat/KM) of the cis-AT domain for carboxyacyl-CoA substrates but had a marked influence on the corresponding specificity parameters for the trans-ATs, suggesting that these enzymes do not act strictly by a canonical ping-pong mechanism. To investigate the relevance of the kinetic analysis of isolated ATs in the context of intact PKSs, we complemented an in vitro AT-null DEBS assembly line with either trans-AT. Whereas the disorazole AT efficiently complemented the mutant PKS at substoichiometric protein ratios, the kirromycin AT was considerably less effective. Our findings suggest that knowledge of both carboxyacyl-CoA and ACP specificity is critical to the choice of a trans-AT in combination with a mutant PKS to generate novel polyketides. PMID:24871074

  19. Three Aspects of Alcoholism: The Recovering Alcoholic, Adult Child of an Alcoholic, and Mother of an Alcoholic.

    ERIC Educational Resources Information Center

    Briles, Amanda

    This paper focuses on shedding light on three aspects--or faces--of alcoholism. The paper, in an interview format, presents the perspectives of the recovering alcoholic, a mother of the recovering alcoholic, and the adult child of an alcoholic. It also provides brief medical definitions of the various types of alcoholism. The paper points out that…

  20. Tobacco, Alcohol, Drugs, and Pregnancy

    MedlinePlus

    ... What are fetal alcohol spectrum disorders? • What is fetal alcohol syndrome? • What amounts of alcohol can cause FAS? • Is ... disabilities that can last a lifetime. What is fetal alcohol syndrome? Fetal alcohol syndrome (FAS) is the most severe ...

  1. Fetal Alcohol Syndrome "Chemical Genocide."

    ERIC Educational Resources Information Center

    Asetoyer, Charon

    In the Northern Plains of the United States, 100% of Indian reservations are affected by alcohol related problems. Approximately 90% of Native American adults are currently alcohol users or abusers or are recovering from alcohol abuse. Alcohol consumption has a devastating effect on the unborn. Fetal Alcohol Syndrome (FAS) is an irreversible birth…

  2. Affordability of alcohol and alcohol-related mortality in Belarus.

    PubMed

    Razvodovsky, Yury E

    2013-01-01

    Alcohol abuse has numerous adverse health and social consequences. The consumer response to changes in alcohol affordability is an important issue on alcohol policy debates. Studies from many countries have shown an inverse relationship between alcohol prices and alcohol consumption in the population. There are, however, suggestions that increasing the price of alcohol by rising taxes may have limited effect on alcohol-related problems, associated with long-term heavy drinking. The aim of the present study was to evaluate the relationship between alcohol affordability and alcohol-related mortality rates in post-Soviet Belarus. For this purpose trends in alcohol-related mortality rates (mortality from liver cirrhosis, pancreatitis, alcoholism and alcohol psychoses) and affordability of vodka between 1990 and 2010 were compared. The time series analysis revealed that 1% increase in vodka affordability is associated with an increase in liver cirrhosis mortality of 0,77%, an increase in pancreatitis mortality of 0.53%, an increase in mortality from alcoholism and alcohol psychoses of 0,70%. The major conclusion emerging from this study is that affordability of alcohol is one of the most important predictor of alcohol-related problems in a population. These findings provide additional evidence that decreasing in affordability of alcohol is an effective strategy for reducing alcohol consumption and alcohol-related harm. PMID:23748944

  3. Older Adults and Alcohol

    MedlinePlus

    ... Disorders Publications & Multimedia Brochures & Fact Sheets NIAAA Journal Alcohol Alert Bulletin Professional Education Materials Classroom Resources Presentations & Videocasts Video Bank Publicaciones ...

  4. Alcohol and Sexual Assault

    PubMed Central

    Abbey, Antonia; Zawacki, Tina; Buck, Philip O.; Clinton, A. Monique; McAuslan, Pam

    2015-01-01

    Conservative estimates of sexual assault prevalence suggest that 25 percent of American women have experienced sexual assault, including rape. Approximately one-half of those cases involve alcohol consumption by the perpetrator, victim, or both. Alcohol contributes to sexual assault through multiple pathways, often exacerbating existing risk factors. Beliefs about alcohol’s effects on sexual and aggressive behavior, stereotypes about drinking women, and alcohol’s effects on cognitive and motor skills contribute to alcohol-involved sexual assault. Despite advances in researchers’ understanding of the relationships between alcohol consumption and sexual assault, many questions still need to be addressed in future studies. PMID:11496965

  5. Alcohol disrupts sleep homeostasis

    PubMed Central

    Thakkar, Mahesh M.; Sharma, Rishi; Sahota, Pradeep

    2014-01-01

    Alcohol is a potent somnogen and one of the most commonly used “over the counter” sleep aids. In healthy non-alcoholics, acute alcohol decreases sleep latency, consolidates and increases the quality (delta power) and quantity of NREM sleep during the first half of the night. However, sleep is disrupted during the second half. Alcoholics, both during drinking periods and during abstinences, suffer from a multitude of sleep disruptions manifested by profound insomnia, excessive daytime sleepiness, and altered sleep architecture. Furthermore, subjective and objective indicators of sleep disturbances are predictors of relapse. Finally, within the USA, it is estimated that societal costs of alcohol-related sleep disorders exceeds $18 billion. Thus, although alcohol-associated sleep problems have significant economic and clinical consequences, very little is known about how and where alcohol acts to affect sleep. In this review, we have described our attempts to understand how and where alcohol acts to affect sleep. We have conducted a series of experiments using two different species, rats and mice, as animal models, and a combination of multi-disciplinary experimental methodologies to examine and understand anatomical and cellular substrates mediating the effects of acute and chronic alcohol exposure on sleep-wakefulness. The results of our studies suggest that the sleep-promoting effects of alcohol may be mediated via alcohol’s action on the mediators of sleep homeostasis: adenosine (AD) and the wake-promoting cholinergic neurons of the basal forebrain (BF). Alcohol, via its action on AD uptake, increases extracellular AD resulting in the inhibition of BF wake-promoting neurons. Lesions of the BF cholinergic neurons or blockade of AD A1 receptors results in attenuation of alcohol-induced sleep promotion, suggesting that AD and BF cholinergic neurons are critical for sleep-promoting effects of alcohol. Since binge alcohol consumption is a highly prevalent pattern

  6. Alcoholic leukopenic pneumococcal sepsis.

    PubMed

    Alraiyes, Abdul Hamid; Shaheen, Khaldoon; Alraies, M Chadi

    2013-04-01

    Alcohol abuse has been associated with an increased mortality and morbidity due to increased aspiration, delirium tremens, and seizures. The association of pneumococcal lung infections and leukopenia in the setting of alcohol abuse are rarely reported; however, when present, severe lung infections can happen with severe lung injury and poor response to conventional therapy and ultimately, death. We are reporting a case of 55-year-old-man presented with shortness of breath, cough and altered mental status and eventually found with severe pneumococcal lung infection in the setting of leukopenia and long-term alcohol abuse representing alcoholic leukopenic pneumococcal sepsis syndrome. PMID:23930244

  7. [Doctors' alcohol problems].

    PubMed

    Florkowski, Antoni; Gruszczyński, Wojciech; Gałecki, Piotr; Szubert, Sławomir; Klus, Marek; Zboralski, Krzysztof

    2008-01-01

    An overusing and an addiction to alcoholic drinks are important problems in a medical society. The studies made in the United States had documented that about 8-12% doctors were addicted to alcohol. In many cases the doctors are able to keep their problem as a secret and their activity is satisfied up to the moment when a decrease is noticed. Some factors--such as a high level of stress--predispose doctors to alcoholic problems especially surgeons. Alcohol problems should be identified as early as possible, and therapy ought to be given as well. There is no reason to hide the problem. PMID:19025048

  8. [Alcohol and myocarditis].

    PubMed

    Wilke, A; Kaiser, A; Ferency, I; Maisch, B

    1996-08-01

    The direct toxic effect of alcohol and its metabolite acetaldehyde has been demonstrated both in laboratory animals and in humans. Alterations in the mitochondrial ultrastructure and the dilatation of the sarcoplasmatic reticulum have been shown after an acute infusion of alcohol in the heart. These changes correlate with decreased mitochondrial function, defects in protein synthesis and the occurrence of arrhythmias. The risk of developing alcoholic cardiomyopathy is related to both the mean daily alcohol intake and the duration of drinking, but there is much individual susceptibility to the toxic effect of alcohol. Most patients, in whom alcoholic cardiomyopathy develops, have been drinking over 80 g/d for more than 5 years. The clinical diagnosis of alcoholic cardiomyopathy reflects the coexistence of global myocardial dysfunction in a heavy drinker in whom no other cause for myocardial disease was found. In studies focussing on alcoholic cardiomyopathy the surprising histologic findings in endomyocardial biopsy in about 30% of all cases was myocarditis with a lymphocytic infiltrate in association with myocyte degeneration or focal necrosis. In myocarditis, the network of microtubules and intermediate filaments is also disrupted by the inflammatory reaction which involves resident cells (myocytes, fibroblasts, endothel cells) and systemic cells (granulocytes, macrophages, monocytes, lymphocytes). Changes in the cardiac cytoskeleton and the extracellular matrix may affect contractile function, since the cytoskeleton organizes the intra- and intercellular architecture. After all, in patients with alcohol abuse and myocarditis the immune functioning appears to be compromised. Several studies suggest that heavy drinking alters both lymphocyte and granulocyte production and function. Alcohol consumption per se might harm the immune system. Furthermore, the myocardial damage due to alcohol consumption could initiate autoreactive mechanisms comparable to those in viral

  9. Alcohol-Related Liver Disease

    MedlinePlus

    ... to run events. Please support us. Donate | Volunteer Alcohol-Related Liver Disease Discussion on Inspire Support Community ... Liver > Liver Disease Information > Alcohol-Related Liver Disease Alcohol-Related Liver Disease Explore this section to learn ...

  10. Alcohol and Choice.

    ERIC Educational Resources Information Center

    Kraushaar, Kevin W.

    Increased constraints on access to alcohol resulted from the closure of the sole hotels in two "experimental" towns. This afforded a natural experiment to study the effects of the change in availability of alcohol on consumption. Dependent measures were derived from public records of liquor sales by all licensed premises, and from computerized…

  11. Weight loss and alcohol

    MedlinePlus

    ... weight gain in a couple of ways. First, alcohol is high in calories. Some mixed drinks can contain as many calories as a meal, but without the nutrients. You also may make poor food choices ... to cut out all alcohol if you are trying to lose weight, you ...

  12. Breath alcohol test

    MedlinePlus

    ... in the tube change colors (from yellow to green), depending on the alcohol content. Carefully read the ... When 1 band is green, it means that the blood-alcohol level is 0.05% or lower. 2 green bands mean levels of 0.05% ...

  13. Alcohol on wheels.

    PubMed

    McDermott, F T

    1986-01-01

    Alcohol misuse remains the single most important contributing factor to road accident deaths and injuries in Australia. The results of compulsory blood alcohol tests on road casualties have shown that probationary licensed drivers have a threefold increased risk of road accident injury compared to fully licensed drivers and are additionally over-represented in alcohol-related crashes. These findings led the Victorian Road Trauma Committee to campaign for a zero blood alcohol limit for learner and probationary drivers and motorcyclists. In May 1984, zero blood alcohol legislation was enacted in Victoria. The present legislation applies to learner and first year probationary licence holders. For the first time we have evidence of a moderate reduction in alcohol-related road trauma in Victoria. Between 1977 and 1983 there has been a significant reduction in the proportion of driver casualties admitted to hospital with illegal blood alcohol concentrations and in the number of driver fatalities with blood alcohol concentrations in excess of 0.15 g%. An evaluation of the following recommended drink driver countermeasures is presented: improved driver education, increased penalties, re-education--rehabilitation programmes for convicted drink drivers, interlock devices and an increase in the legal drinking age. PMID:3461765

  14. Occupational therapy in alcoholism.

    PubMed

    Rotert, D A

    1989-01-01

    Gorski describes "abstinence plus a full return to biopsychosocial functioning as the indicator of successful recovery," and "relapse ... as the process of becoming dysfunctional in recovery." Occupational therapy supports a biopsychosocial premise in assisting the alcoholic to establish a sober lifestyle for recovery as a part of treatment. Adolph Meyer said, "If the goal of alcoholism treatment is abstinence, then the alcoholic patient must be instructed and guided to organize his time and build up habits of work and leisure which are free of alcohol." In order to attain satisfaction in recovery, the alcoholic must develop a balanced lifestyle. This balanced lifestyle will be for competent role performance in all roles. Sobriety can restore something the alcoholic has lost. The alcoholic can be a contributing member of society; have feelings of self respect; participate in relationships with family, friends, and coworkers; and return to work, social, and leisure environments. Zackon identified lifestyle rehabilitation as the second track of recovery. He also listed the key tasks of secondary recovery as deaddiction, learning new pleasures, social integration, and creating new goals. It is in these key tasks that occupational therapy can provide significant input and feedback to the alcoholic. PMID:2658155

  15. Molecular basis of alcoholism.

    PubMed

    Most, Dana; Ferguson, Laura; Harris, R Adron

    2014-01-01

    Acute alcohol intoxication causes cellular changes in the brain that last for hours, while chronic alcohol use induces widespread neuroadaptations in the nervous system that can last a lifetime. Chronic alcohol use and the progression into dependence involve the remodeling of synapses caused by changes in gene expression produced by alcohol. The progression of alcohol use, abuse, and dependence can be divided into stages, which include intoxication, withdrawal, and craving. Each stage is associated with specific changes in gene expression, cellular function, brain circuits, and ultimately behavior. What are the molecular mechanisms underlying the transition from recreational use (acute) to dependence (chronic)? What cellular adaptations result in drug memory retention, leading to the persistence of addictive behaviors, even after prolonged drug abstinence? Research into the neurobiology of alcoholism aims to answer these questions. This chapter will describe the molecular adaptations caused by alcohol use and dependence, and will outline key neurochemical participants in alcoholism at the molecular level, which are also potential targets for therapy. PMID:25307570

  16. Fetal alcohol syndrome

    MedlinePlus

    Fetal alcohol syndrome is growth, mental, and physical problems that may occur in a baby when a mother drinks ... A baby with fetal alcohol syndrome may have the following symptoms: Poor growth while the baby is in the womb and after birth Decreased muscle ...

  17. The Fetal Alcohol Syndrome.

    ERIC Educational Resources Information Center

    Umbreit, John; Ostrow, Lisa S.

    1980-01-01

    Fetal alcohol syndrome is a pattern of altered growth and morphogenesis found in about half the offspring of severely and chronically alcoholic women who continue drinking throughout their pregnancy. Of children studied, mild to moderate mental retardation was the most common disorder, occurring in 44 percent of the cases. (PHR)

  18. Fetal Alcohol Syndrome.

    ERIC Educational Resources Information Center

    Zerrer, Peggy

    The paper reviews Fetal Alcohol Syndrome (FAS), a series of effects seen in children whose mothers drink alcohol to excess during pregnancy. The identification of FAS and its recognition as a major health problem in need of prevention are traced. Characteristics of children with FAS are described and resultant growth retardation, abnormal physical…

  19. Fetal Alcohol Spectrum Disorder

    ERIC Educational Resources Information Center

    Caley, Linda M.; Kramer, Charlotte; Robinson, Luther K.

    2005-01-01

    Fetal alcohol spectrum disorder (FASD) is a serious and widespread problem in this country. Positioned within the community with links to children, families, and healthcare systems, school nurses are a critical element in the prevention and treatment of those affected by fetal alcohol spectrum disorder. Although most school nurses are familiar…

  20. Alcoholism: A Developmental Disorder.

    ERIC Educational Resources Information Center

    Tarter, Ralph E.; Vanyukov, Michael

    1994-01-01

    Alcoholism etiology is discussed from developmental behavior genetic perspective. Temperament features that appear to be associated with heightened risk for alcoholism are examined. Their interactions with the environment during course of development are considered within epigenetic framework and, as discussed, have ramifications for improving…

  1. Cardiovascular effects of alcohol.

    PubMed Central

    Davidson, D M

    1989-01-01

    The effects of alcohol on the heart include modification of the risk of coronary artery disease, the development of alcoholic cardiomyopathy, exacerbation of conduction disorders, atrial and ventricular dysrhythmias, and an increased risk of hypertension, hemorrhagic stroke, infectious endocarditis, and fetal heart abnormalities. PMID:2686174

  2. Type I Diacylglycerol Acyltransferase (MtDGAT1) from Macadamia tetraphylla: Cloning, Characterization, and Impact of Its Heterologous Expression on Triacylglycerol Composition in Yeast.

    PubMed

    Arroyo-Caro, José María; Mañas-Fernández, Aurora; Alonso, Diego López; García-Maroto, Federico

    2016-01-13

    Acyltransferase enzymes have been reported as useful biotechnological tools in order to increase oil yield and modify fatty acid composition. Macadamia species are able to accumulate unusually high levels of palmitoleic acid that besides oleic acid amounts to over 80% of monounsaturated fatty acids in the seed oil. In this work, a gene encoding a type 1 acyl-CoA:diacylglycerol acyltransferase (DGAT1) was cloned from M. tetraphylla. DGAT activity of the protein encoded by MtDGAT1 was confirmed by heterologous expression in a yeast mutant. Fatty acid composition of triacylglycerols synthesized by MtDGAT1 was compared to that of DGAT1 enzymes from Arabidopsis and Echium, with the results suggesting a substrate preference for monounsaturated over polyunsaturated fatty acids. Characteristics of MtDGAT1 may contribute to biochemical mechanisms determining the particular fatty acid composition of Macadamia oil and also indicate the possibility of using this enzyme in biotechnological approaches where a reduction of polyunsaturated fatty acids in the oil is desired. PMID:26666454

  3. Essential oil of Pinus koraiensis leaves exerts antihyperlipidemic effects via up-regulation of low-density lipoprotein receptor and inhibition of acyl-coenzyme A: cholesterol acyltransferase.

    PubMed

    Kim, Ji-Hyun; Lee, Hyo-Jung; Jeong, Soo-Jin; Lee, Min-Ho; Kim, Sung-Hoon

    2012-09-01

    Hyperlipidemia is an important factor to induce metabolic syndrome such as obesity, diabetes and cardiovascular diseases. Recently, some antihyperlipidemic agents from herbal medicines have been in the spotlight in the medical science field. Thus, the present study evaluated the antihyperlipidemic activities of the essential oil from the leaves of Pinus koraiensis SIEB (EOPK) that has been used as a folk remedy for heart disease. The reverse transcription polymerase chain reaction (RT-PCR) revealed that EOPK up-regulated low density lipoprotein receptor (LDLR) at the mRNA level as well as negatively suppressed the expression of sterol regulatory element-binding protein (SREBP)-1c, SREBP-2, 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR), fatty acid synthase (FAS) and glycerol-3-phosphate acyltransferase (GPAT) involved in lipid metabolism in HepG2 cells. Also, western blotting showed that EOPK activated LDLR and attenuated the expression of FAS at the protein level in the cells. Consistently, EOPK significantly inhibited the level of human acylcoenzyme A: cholesterol acyltransferase (hACAT)1 and 2 and reduced the low-density lipoprotein (LDL) oxidation activity. Furthermore, chromatography-mass spectrometry (GC-MS) analysis showed that EOPK, an essential oil mixture, contained camphene (21.11%), d-limonene (21.01%), α-pinene (16.74%) and borneol (11.52%). Overall, the findings suggest that EOPK can be a potent pharmaceutical agent for the prevention and treatment of hyperlipidemia. PMID:22275303

  4. YPR139c/LOA1 encodes a novel lysophosphatidic acid acyltransferase associated with lipid droplets and involved in TAG homeostasis

    PubMed Central

    Ayciriex, Sophie; Le Guédard, Marina; Camougrand, Nadine; Velours, Gisèle; Schoene, Mario; Leone, Sebastien; Wattelet-Boyer, Valerie; Dupuy, Jean-William; Shevchenko, Andrej; Schmitter, Jean-Marie; Lessire, René; Bessoule, Jean-Jacques; Testet, Eric

    2012-01-01

    For many years, lipid droplets (LDs) were considered to be an inert store of lipids. However, recent data showed that LDs are dynamic organelles playing an important role in storage and mobilization of neutral lipids. In this paper, we report the characterization of LOA1 (alias VPS66, alias YPR139c), a yeast member of the glycerolipid acyltransferase family. LOA1 mutants show abnormalities in LD morphology. As previously reported, cells lacking LOA1 contain more LDs. Conversely, we showed that overexpression results in fewer LDs. We then compared the lipidome of loa1Δ mutant and wild-type strains. Steady-state metabolic labeling of loa1Δ revealed a significant reduction in triacylglycerol content, while phospholipid (PL) composition remained unchanged. Interestingly, lipidomic analysis indicates that both PLs and glycerolipids are qualitatively affected by the mutation, suggesting that Loa1p is a lysophosphatidic acid acyltransferase (LPA AT) with a preference for oleoyl-CoA. This hypothesis was tested by in vitro assays using both membranes of Escherichia coli cells expressing LOA1 and purified proteins as enzyme sources. Our results from purification of subcellular compartments and proteomic studies show that Loa1p is associated with LD and active in this compartment. Loa1p is therefore a novel LPA AT and plays a role in LD formation. PMID:22090344

  5. Dual Role for Phospholipid:Diacylglycerol Acyltransferase: Enhancing Fatty Acid Synthesis and Diverting Fatty Acids from Membrane Lipids to Triacylglycerol in Arabidopsis Leaves[C][W

    PubMed Central

    Fan, Jilian; Yan, Chengshi; Zhang, Xuebin; Xu, Changcheng

    2013-01-01

    There is growing interest in engineering green biomass to expand the production of plant oils as feed and biofuels. Here, we show that PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE1 (PDAT1) is a critical enzyme involved in triacylglycerol (TAG) synthesis in leaves. Overexpression of PDAT1 increases leaf TAG accumulation, leading to oil droplet overexpansion through fusion. Ectopic expression of oleosin promotes the clustering of small oil droplets. Coexpression of PDAT1 with oleosin boosts leaf TAG content by up to 6.4% of the dry weight without affecting membrane lipid composition and plant growth. PDAT1 overexpression stimulates fatty acid synthesis (FAS) and increases fatty acid flux toward the prokaryotic glycerolipid pathway. In the trigalactosyldiacylglycerol1-1 mutant, which is defective in eukaryotic thylakoid lipid synthesis, the combined overexpression of PDAT1 with oleosin increases leaf TAG content to 8.6% of the dry weight and total leaf lipid by fourfold. In the plastidic glycerol-3-phosphate acyltransferase1 mutant, which is defective in the prokaryotic glycerolipid pathway, PDAT1 overexpression enhances TAG content at the expense of thylakoid membrane lipids, leading to defects in chloroplast division and thylakoid biogenesis. Collectively, these results reveal a dual role for PDAT1 in enhancing fatty acid and TAG synthesis in leaves and suggest that increasing FAS is the key to engineering high levels of TAG accumulation in green biomass. PMID:24076979

  6. Improvement of neutral lipid and polyunsaturated fatty acid biosynthesis by overexpressing a type 2 diacylglycerol acyltransferase in marine diatom Phaeodactylum tricornutum.

    PubMed

    Niu, Ying-Fang; Zhang, Meng-Han; Li, Da-Wei; Yang, Wei-Dong; Liu, Jie-Sheng; Bai, Wei-Bin; Li, Hong-Ye

    2013-11-01

    Microalgae have been emerging as an important source for the production of bioactive compounds. Marine diatoms can store high amounts of lipid and grow quite quickly. However, the genetic and biochemical characteristics of fatty acid biosynthesis in diatoms remain unclear. Glycerophospholipids are integral as structural and functional components of cellular membranes, as well as precursors of various lipid mediators. In addition, diacylglycerol acyltransferase (DGAT) is a key enzyme that catalyzes the last step of triacylglyceride (TAG) biosynthesis. However, a comprehensive sequence-structure and functional analysis of DGAT in diatoms is lacking. In this study, an isoform of diacylglycerol acyltransferase type 2 of the marine diatom Phaeodactylum tricornutum was characterized. Surprisingly, DGAT2 overexpression in P. tricornutum stimulated more oil bodies, and the neutral lipid content increased by 35%. The fatty acid composition showed a significant increase in the proportion of polyunsaturated fatty acids; in particular, EPA was increased by 76.2%. Moreover, the growth rate of transgenic microalgae remained similar, thereby maintaining a high biomass. Our results suggest that increased DGAT2 expression could alter fatty acid profile in the diatom, and the results thus represent a valuable strategy for polyunsaturated fatty acid production by genetic manipulation. PMID:24232669

  7. Cloning of a coconut endosperm cDNA encoding a 1-acyl-sn-glycerol-3-phosphate acyltransferase that accepts medium-chain-length substrates.

    PubMed Central

    Knutzon, D S; Lardizabal, K D; Nelsen, J S; Bleibaum, J L; Davies, H M; Metz, J G

    1995-01-01

    Immature coconut (Cocos nucifera) endosperm contains a 1-acyl-sn-glycerol-3-phosphate acyltransferase (LPAAT) activity that shows a preference for medium-chain-length fatty acyl-coenzyme A substrates (H.M. Davies, D.J. Hawkins, J.S. Nelsen [1995] Phytochemistry 39:989-996). Beginning with solubilized membrane preparations, we have used chromatographic separations to identify a polypeptide with an apparent molecular mass of 29 kD, whose presence in various column fractions correlates with the acyltransferase activity detected in those same fractions. Amino acid sequence data obtained from several peptides generated from this protein were used to isolate a full-length clone from a coconut endosperm cDNA library. Clone pCGN5503 contains a 1325-bp cDNA insert with an open reading frame encoding a 308-amino acid protein with a calculated molecular mass of 34.8 kD. Comparison of the deduced amino acid sequence of pCGN5503 to sequences in the data banks revealed significant homology to other putative LPAAT sequences. Expression of the coconut cDNA in Escherichia coli conferred upon those cells a novel LPAAT activity whose substrate activity profile matched that of the coconut enzyme. PMID:8552723

  8. [Changing alcohol abuse patterns].

    PubMed

    Batel, Philippe

    2011-12-01

    While it has been steadily declining since the 1960s, though at a slower pace over the last 5 years, the average alcohol consumption per capita and per year in France remains one of the highest in Europe. The available general population surveys reveal that the most visible change is the type of alcohol abuse. Two emerging trends have been observed over the last ten years, and seem to be worsening: the transfer from daily drinking to weekend drinking, and the increase in isolated risk-taking related to acute alcoholization associated with more-or-less conscious inebriation episodes. These changes require adapting prevention messages, the development of alcohol risk screening strategies in emergency units and the assessment of therapeutic programs aiming at reducing the risks of alcohol consumption rather than maintaining abstinence. PMID:22288346

  9. Phytotherapy of alcoholism.

    PubMed

    Tomczyk, Michał; Zovko-Koncić, Marijana; Chrostek, Lech

    2012-02-01

    Alcoholism is a medical, social, and economic problem where treatment methods mostly include difficult and long-lasting psychotherapy and, in some cases, quite controversial pharmacological approaches. A number of medicinal plants and pure natural compounds are reported to have preventive and therapeutic effects on alcoholism and alcohol dependency, but their constituents, efficacy and mechanism of action are mostly unknown so far. Recently, kudzu [Pueraria lobata (Willd.) Ohwi], St. John's wort (Hypericum perforatum L.), danshen (Salvia miltiorrhiza Bge.), ginseng (Panax ginseng C.A. Mey.), Japanese raisin tree (Hovenia dulcis Thunb.), ibogaine (Tabernanthe iboga H. Bn.), evening primrose (Oenothera biennis L.), prickly pear fruit (Opuntia ficus indica (L.) Mill.), purple passionflower (Passiflora incarnata L.), thyme (Thymus vulgaris L.), fenugreek seed (Trigonella foenum-graecum L.), ginger (Zingiber officinale Roscoe) and many others drew the attention of researchers. Can, therefore, drugs of natural origin be helpful in the treatment of alcoholism or in decreasing alcohol consumption? PMID:22474979

  10. Requirement of catalytic-triad and related amino acids for the acyltransferase activity of Tanacetum cinerariifolium GDSL lipase/esterase TcGLIP for ester-bond formation in pyrethrin biosynthesis.

    PubMed

    Kikuta, Yukio; Yamada, Gen; Mitsumori, Tomonori; Takeuchi, Takayuki; Nakayama, Koji; Katsuda, Yoshio; Hatanaka, Akikazu; Matsuda, Kazuhiko

    2013-01-01

    We have recently discovered that a GDSL lipase/esterase (TcGLIP) in Tanacetum cinerariifolium catalyzed acyltransferase activity to form an ester bond in the natural insecticide, pyrethrin. TcGLIP contained Ser40 in Block I, Gly64 in Block II, Asn168 in Block III and Asp318 and His321 in Block V, suggesting underlying hydrolase activity, although little is known about their role in acyltransferase activity. We expressed TcGLIP here in Esherichia coli as a fusion with maltose-binding protein (MBP), part of the fusion being cleaved with a protease to obtain MBP-free TcGLIP. A kinetic analysis revealed that the MBP moiety scarcely influenced the kinetic parameters. The effects on acyltransferase activity of mutations of Gly64, Asn168, Asp318 and His321 were investigated by using MBP-fused TcGLIP. Mutations of these amino acids markedly reduced the acyltransferase activity, suggesting their critical role in the production of pyrethrins. PMID:24018659

  11. 78 FR 42530 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-16

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial Review..., Ph.D., Scientific Review Officer, National Institute on Alcohol Abuse & Alcoholism,...

  12. 76 FR 26308 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-06

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  13. 75 FR 10291 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

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    2010-03-05

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  14. 77 FR 70171 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

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    2012-11-23

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  15. 77 FR 22794 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

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    2012-04-17

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  16. 77 FR 22794 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

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    2012-04-17

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  17. 75 FR 38533 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

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    2010-07-02

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  18. 76 FR 78014 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

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    2011-12-15

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  19. 75 FR 10808 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

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    2010-03-09

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  20. 78 FR 42529 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

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    2013-07-16

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  1. 76 FR 77841 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-14

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial Review..., Ph.D., Scientific Review Officer, National Institute on Alcohol Abuse & Alcoholism,...

  2. 75 FR 57473 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

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  3. 75 FR 24961 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-06

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  4. 75 FR 63494 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-15

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  5. Alcohol Alert: Link Between Stress and Alcohol

    MedlinePlus

    ... people continue to try and deal with its effects by drinking alcohol. Instead of “calming your nerves,” long-term, heavy ... pleasure” systems. Researchers believe this may contribute to alcohol’s reinforcing effects, motivating the drinker to consume higher levels of ...

  6. Structurally divergent lysophosphatidic acid acyltransferases with high selectivity for saturated medium chain fatty acids from Cuphea seeds.

    PubMed

    Kim, Hae Jin; Silva, Jillian E; Iskandarov, Umidjon; Andersson, Mariette; Cahoon, Rebecca E; Mockaitis, Keithanne; Cahoon, Edgar B

    2015-12-01

    Lysophosphatidic acid acyltransferase (LPAT) catalyzes acylation of the sn-2 position on lysophosphatidic acid by an acyl CoA substrate to produce the phosphatidic acid precursor of polar glycerolipids and triacylglycerols (TAGs). In the case of TAGs, this reaction is typically catalyzed by an LPAT2 from microsomal LPAT class A that has high specificity for C18 fatty acids containing Δ9 unsaturation. Because of this specificity, the occurrence of saturated fatty acids in the TAG sn-2 position is infrequent in seed oils. To identify LPATs with variant substrate specificities, deep transcriptomic mining was performed on seeds of two Cuphea species producing TAGs that are highly enriched in saturated C8 and C10 fatty acids. From these analyses, cDNAs for seven previously unreported LPATs were identified, including cDNAs from Cuphea viscosissima (CvLPAT2) and Cuphea avigera var. pulcherrima (CpuLPAT2a) encoding microsomal, seed-specific class A LPAT2s and a cDNA from C. avigera var. pulcherrima (CpuLPATB) encoding a microsomal, seed-specific LPAT from the bacterial-type class B. The activities of these enzymes were characterized in Camelina sativa by seed-specific co-expression with cDNAs for various Cuphea FatB acyl-acyl carrier protein thioesterases (FatB) that produce a variety of saturated medium-chain fatty acids. CvLPAT2 and CpuLPAT2a expression resulted in accumulation of 10:0 fatty acids in the Camelina sativa TAG sn-2 position, indicating a 10:0 CoA specificity that has not been previously described for plant LPATs. CpuLPATB expression generated TAGs with 14:0 at the sn-2 position, but not 10:0. Identification of these LPATs provides tools for understanding the structural basis of LPAT substrate specificity and for generating altered oil functionalities. PMID:26505880

  7. Expression of the Acyl-Coenzyme A: Cholesterol Acyltransferase GFP Fusion Protein in Sf21 Insect Cells

    NASA Technical Reports Server (NTRS)

    Mahtani, H. K.; Richmond, R. C.; Chang, T. Y.; Chang, C. C. Y.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    The enzyme acyl-coenzyme A:cholesterol acyltransferase (ACAT) is an important contributor to the pathological expression of plaque leading to artherosclerosis n a major health problem. Adequate knowledge of the structure of this protein will enable pharmaceutical companies to design drugs specific to the enzyme. ACAT is a membrane protein located in the endoplasmic reticulum.t The protein has never been purified to homogeneity.T.Y. Chang's laboratory at Dartmouth College provided a 4-kb cDNA clone (K1) coding for a structural gene of the protein. We have modified the gene sequence and inserted the cDNA into the BioGreen His Baculovirus transfer vector. This was successfully expressed in Sf2l insect cells as a GFP-labeled ACAT protein. The advantage to this ACAT-GFP fusion protein (abbreviated GCAT) is that one can easily monitor its expression as a function of GFP excitation at 395 nm and emission at 509 nm. Moreover, the fusion protein GCAT can be detected on Western blots with the use of commercially available GFP antibodies. Antibodies against ACAT are not readily available. The presence of the 6xHis tag in the transfer vector facilitates purification of the recombinant protein since 6xHis fusion proteins bind with high affinity to Ni-NTA agarose. Obtaining highly pure protein in large quantities is essential for subsequent crystallization. The purified GCAT fusion protein can readily be cleaved into distinct GFP and ACAT proteins in the presence of thrombin. Thrombin digests the 6xHis tag linking the two protein sequences. Preliminary experiments have indicated that both GCAT and ACAT are expressed as functional proteins. The ultimate aim is to obtain large quantities of the ACAT protein in pure and functional form appropriate for protein crystal growth. Determining protein structure is the key to the design and development of effective drugs. X-ray analysis requires large homogeneous crystals that are difficult to obtain in the gravity environment of earth

  8. Utilizing Alcohol Expectancies in the Treatment of Alcoholism.

    ERIC Educational Resources Information Center

    Brown, Sandra A.

    The heterogeneity of alcoholic populations may be one reason that few specific therapeutic approaches to the treatment of alcoholism have been consistently demonstrated to improve treatment outome across studies. To individualize alcoholism treatment, dimensions which are linked to drinking or relapse and along which alcoholics display significant…

  9. Supported metal catalysts for alcohol/sugar alcohol steam reforming

    SciTech Connect

    Davidson, Stephen; Zhang, He; Sun, Junming; Wang, Yong

    2014-08-21

    Despite extensive studies on hydrogen production via steam reforming of alcohols and sugar alcohols, catalysts typically suffer a variety of issues from poor hydrogen selectivity to rapid deactivation. Here, we summarize recent advances in fundamental understanding of functionality and structure of catalysts for alcohol/sugar alcohol steam reforming, and provide perspectives on further development required to design highly efficient steam reforming catalysts.

  10. Does Alcohol Education Prevent Alcohol Problems?: Need for Evaluation.

    ERIC Educational Resources Information Center

    Cooper, A. Mitch; Sobell, Mark B.

    1979-01-01

    Examined evidence for the alleged failure of alcohol education to prevent alcohol problems among children and adolescents. Concluded that there is need for investigations of the effectiveness of alcohol education. Recommendations regarding methodological characteristics of an adequate test of effectiveness of alcohol education were presented and…

  11. Alcohol Alert: Alcohol's Damaging Effects on the Brain

    MedlinePlus

    ... Crews, F.T. , and Nixon, K. Alcohol, neural stem cells, and adult neurogenesis. Alcohol Research & Health 27(2): 197–204, 2003. (31) Nixon, ... Miller, M.W.; Ma, W.; et al. Neural stem cells and alcohol. Alcoholism: Clinical and Experimental Research 27(2):324–335, 2003. (34) Oscar–Berman, ...

  12. Unhealthy Alcohol Use.

    PubMed

    Holt, Stephen; Tetrault, Jeanette

    2016-08-01

    Unhealthy alcohol use is common and routine screening is essential to identify patients and initiate appropriate treatment. At-risk or hazardous drinking is best managed with brief interventions, which can be performed by any provider and are designed to enhance patients' motivations and promote behavioral change. Alcohol withdrawal can be managed, preferably with benzodiazepines, using a symptom-triggered approach. Twelve-step programs and provider-driven behavioral therapies have robust data supporting their effectiveness and patients with alcohol use disorder should be referred for these services. Research now support the use of several FDA-approved medications that aid in promoting abstinence and reducing heavy drinking. PMID:27373607

  13. Alcohol induced liver disease.

    PubMed Central

    Fleming, K A; McGee, J O

    1984-01-01

    Alcohol induces a variety of changes in the liver: fatty change, hepatitis, fibrosis, and cirrhosis. The histopathological appearances of these conditions are discussed, with special attention to differential diagnosis. Many forms of alcoholic liver disease are associated with Mallory body formation and fibrosis. Mallory bodies are formed, at least in part, from intermediate filaments. Associated changes in intermediate filament organisation in alcoholic liver disease also occur. Their significance in the pathogenesis of hepatocyte death may be related to abnormalities in messenger RNA function. The mechanisms underlying hepatic fibrogenesis are also discussed. Images PMID:6086722

  14. [Alcohol and working life].

    PubMed

    Kaarne, Tiina; Aalto, Mauri

    2009-01-01

    Alcohol-related harm constitutes a significant factor decreasing work productivity. Of heavy alcohol users, most participate in working life. According to labour contract law, a person attending the workplace inebriated can be fired. If the employer applies a deferral to treatment practice, the drug- or alcohol-addicted person can be provided with the choice of therapy and rehabilitation instead of terminating the employment. According to the recent recommendation by the trade unions, organizations should have a program for preventing substance abuse. The employer should take care of the worker's intoxicant education and train the foremen to intervene in the situations on time. PMID:19492706

  15. Marital Interaction in Alcoholic and Nonalcoholic Couples: Alcoholic Subtype Variations and Wives’ Alcoholism Status

    PubMed Central

    Floyd, Frank J.; Daugherty, Michelle Klotz; Fitzgerald, Hiram H.; Cranford, James A.; Zucker, Robert A.

    2008-01-01

    The authors examined problem-solving marital interactions of alcoholic and nonalcoholic couples (N = 132). Four alcoholic groups (husband alcoholic with antisocial personality disorder or not, paired with alcoholic or nonalcoholic wives) were compared with each other and with a both-spouses-nonalcoholic group. Consistent with the alcoholic subtypes hypothesis, couples with an antisocial alcoholic husband had higher levels of hostile behavior regardless of wives’ alcoholism status. In contrast, rates of positive behaviors and the ratio of positive to negative behaviors were greatest among couples in which either both or neither of the spouses had alcoholic diagnoses and were lowest among alcoholic husbands with nonalcoholic wives. Discussion focuses on possible mechanisms linking antisocial alcoholism and discrepant alcoholic diagnoses to poorer marital outcomes. PMID:16492103

  16. Alcohol and Staff Leisure Time.

    ERIC Educational Resources Information Center

    Camping Magazine, 1992

    1992-01-01

    Discusses the problem of alcohol use and abuse by camp staff. Describes alcohol policies of two different camps. Camp Highlands allows responsible drinking but not intoxication. Camp Olympia requires total abstinence from alcohol. A policy that clearly expresses the camp's philosophy toward alcohol and spells out all expectations and results is…

  17. Theories of the Alcoholic Personality.

    ERIC Educational Resources Information Center

    Cox, W. Miles

    Several theories of the alcoholic personality have been devised to determine the relationship between the clusters of personality characteristics of alcoholics and their abuse of alcohol. The oldest and probably best known theory is the dependency theory, formulated in the tradition of classical psychoanalysis, which associates the alcoholic's…

  18. Alcohol Policies on College Campuses.

    ERIC Educational Resources Information Center

    Mitchell, Rebecca J.; Toomey, Traci L.; Erickson, Darin

    2005-01-01

    State and local alcohol policies can minimize opportunities for people to use alcohol, thereby reducing consumption and alcohol-related problems. Little is known, however, about the prevalence of campus policies aimed at reducing college students' alcohol use and related problems. The authors surveyed school administrators in Minnesota and…

  19. Alcohol in Suicides and Homicides.

    ERIC Educational Resources Information Center

    Goodwin, Donald W.

    This paper discusses research findings about 2 sources of violent death associated with alcohol -- suicide and homicide. After depression, alcoholism is the 2nd most common psychiatric diagnosis among suicide victims. Suicide attempters also are frequently alcoholic. The association between alcoholism and suicide, however, may only apply to white…

  20. Alcohol use disorder

    MedlinePlus

    ... be a combination of a person's: Genes Environment Psychology, such as being impulsive or having low self- ... using alcohol. This is called abstinence. Having strong social and family support can help make it easier ...

  1. Fetal Alcohol Syndrome

    MedlinePlus

    ... drink other beverages instead, such as water, fruit juices or milk. Questions to Ask Your Doctor If your baby was born with fetal alcohol syndrome: What health problems does my baby have? Does my baby ...

  2. Alcohol and Migraine

    MedlinePlus

    ... tension-type headache. Cluster headache patients have higher alcohol sensitivity (about 50-80%). In a forward-looking study (PAMINA) published in 2007 Austrian researchers examined a large number of factors related to ...

  3. Inpatient alcohol withdrawal syndrome.

    PubMed

    Monte-Secades, R; Rabuñal-Rey, R; Guerrero-Sande, H

    2015-03-01

    A 55-year-old man was admitted for a femur fracture; an alcohol fetor was noted on admission. The following day, the patient began to experience tremors and nervousness. Intravenous haloperidol was administered. Shortly afterwards, the patient experienced two generalized seizures and then began to experience delirium and uncontrollable agitation. The patient was diagnosed with alcohol withdrawal syndrome; high doses of intravenous midazolam were prescribed and infused. A few hours later, the patient presented signs of respiratory depression, requiring a transfer to the intensive care unit. After a review of the medical history, it was determined that the patient had been admitted on 3 previous occasions due to alcohol withdrawal and had progressed to delirium tremens after experiencing seizures. Can the risk of alcohol withdrawal syndrome and the need for prophylactic treatment be assessed on admission? Were appropriate monitoring and treatment measures employed? Would it have been possible to change his outcome? PMID:25559647

  4. Indian Alcoholism and Education.

    ERIC Educational Resources Information Center

    Mitchell, Wayne; Patch, Kenneth

    1981-01-01

    Educational programs about alcohol should be presented in the formal school setting for Indian youth and in the communities for the general population. The primary outcome of these programs would be the development of self-management skills. (Author)

  5. Calorie count - Alcoholic beverages

    MedlinePlus

    ... want to watch how much you drink. Cocktails mixed with soda, cream, or ice cream can have especially high calorie counts. If you find you are having trouble cutting back on alcohol , talk with your doctor. Here is a list ...

  6. Alcohol and Cirrhosis

    MedlinePlus

    ... that a non-drinker with hepatitis C has. Alcohol and hepatitis C both damage the liver, so together, the risk of serious liver damage (cirrhosis) is much higher than with either alone. < Previous Living with Hepatitis ...

  7. [Prevention of alcohol dependence].

    PubMed

    Trova, A C; Paparrigopoulos, Th; Liappas, I; Ginieri-Coccossis, M

    2015-01-01

    With the exception of cardiovascular diseases, no other medical condition causes more serious dysfunction or premature deaths than alcohol-related problems. Research results indicate that alcohol dependent individuals present an exceptionally poor level of quality of life. This is an outcome that highlights the necessity of planning and implementing preventive interventions on biological, psychological or social level, to be provided to individuals who make alcohol abuse, as well as to their families. Preventive interventions can be considered on three levels of prevention: (a) primary prevention, which is focused on the protection of healthy individuals from alcohol abuse and dependence, and may be provided on a universal, selective or indicated level, (b) secondary prevention, which aims at the prevention of deterioration regarding alcoholic dependence and relapse, in the cases of individuals already diagnosed with the condition and (c) tertiary prevention, which is focused at minimizing deterioration of functioning in chronically sufferers from alcoholic dependence. The term "quaternary prevention" can be used for the prevention of relapse. As for primary prevention, interventions focus on assessing the risk of falling into problematic use, enhancing protective factors and providing information and health education in general. These interventions can be delivered in schools or in places of work and recreation for young people. In this context, various programs have been applied in different countries, including Greece with positive results (Preventure, Alcolocks, LST, SFP, Alcohol Ignition Interlock Device). Secondary prevention includes counseling and structured help with the delivery of programs in schools and in high risk groups for alcohol dependence (SAP, LST). These programs aim at the development of alcohol refusal skills and behaviors, the adoption of models of behaviors resisting alcohol use, as well as reinforcement of general social skills. In the

  8. Analysis of Alcohols.

    ERIC Educational Resources Information Center

    McCullough, Brother Thomas

    1984-01-01

    Presents a novel approach to identification of unknown alcohols using experimental measurements of boiling point and viscosity which are easily obtained without expensive equipment of instrumentation. Provides instructions for preparing capillary viscometer, listing special hints for obtaining good results. (JM)

  9. Alcoholic cardiomyopathy: Pathophysiologic insights

    PubMed Central

    Piano, Mariann R.; Phillips, Shane A.

    2014-01-01

    Alcoholic cardiomyopathy is a specific heart muscle disease found in individuals with a history of long-term heavy alcohol consumption. Alcoholic cardiomyopathy is associated with a number of adverse histological, cellular, and structural changes within the myocardium. Several mechanisms are implicated in mediating the adverse effects of ethanol, including the generation of oxidative stress, apoptotic cell death, impaired mitochondrial bioenergetics/stress, derangements in fatty acid metabolism and transport, and accelerated protein catabolism. In this review, we discuss the evidence for such mechanisms and present the potential importance of drinking patterns, genetic susceptibility, nutritional factors, race, and sex. The purpose of this review is to provide a mechanistic paradigm for future research in the area of alcoholic cardiomyopathy. PMID:24671642

  10. Alcohol and Hepatitis C

    MedlinePlus

    ... Combat Veterans & their Families Readjustment Counseling (Vet Centers) War Related Illness & Injury Study Center Homeless Veterans Returning ... break of 1 hour between drinks. Drink soda, water, or juice after a drink with alcohol. Do ...

  11. Myths about drinking alcohol

    MedlinePlus

    ... time to break down the alcohol in your system. The caffeine in coffee may help you stay awake. However, it will not improve your coordination or decision-making skills. These can be impaired for several hours ...

  12. Alcohol Facts and Statistics

    MedlinePlus

    ... to a range of acute consequences, including injuries, sexual assaults, and even deaths—including those from car crashes. ... of 18 and 24 report experiencing alcohol-related sexual assault or date rape. 28 Roughly 20 percent of ...

  13. Alcohol Facts and Statistics

    MedlinePlus

    ... deaths (31 percent of overall driving fatalities). 11 Economic Burden: In 2010, alcohol misuse problems cost the ... teenage years could interfere with normal adolescent brain development and increase the risk of developing an AUD. ...

  14. Electrophysiological studies in alcoholism

    PubMed Central

    Blackstock, Eileen; Rushworth, Geoffrey; Gath, Dennis

    1972-01-01

    Using a range of electrophysiological techniques, it has been possible to demonstrate impaired function in smaller calibre motor fibres and in distal large cutaneous sensory nerve fibres in both alcoholic patients without neuropathy and in those alcoholics with clinical manifestations of peripheral nerve disease. Evidence of more proximal involvement of Ia sensory fibres was obtained, but in the majority of our patients, large motor fibres functioned normally. The nature of the underlying pathological process is discussed. Images PMID:4338445

  15. Novel Lysophospholipid Acyltransferase PLAT1 of Aurantiochytrium limacinum F26-b Responsible for Generation of Palmitate-Docosahexaenoate-Phosphatidylcholine and Phosphatidylethanolamine

    PubMed Central

    Abe, Eriko; Ikeda, Kazutaka; Nutahara, Eri; Hayashi, Masahiro; Yamashita, Atsushi; Taguchi, Ryo; Doi, Kosaku; Honda, Daiske; Okino, Nozomu; Ito, Makoto

    2014-01-01

    N-3 polyunsaturated fatty acids (PUFA), such as docosahexaenoic acid (DHA, 22:6n-3), have been reported to play roles in preventing cardiovascular diseases. The major source of DHA is fish oils but a recent increase in the global demand of DHA and decrease in fish stocks require a substitute. Thraustochytrids, unicellular marine protists belonging to the Chromista kingdom, can synthesize large amounts of DHA, and, thus, are expected to be an alternative to fish oils. DHA is found in the acyl chain(s) of phospholipids as well as triacylglycerols in thraustochytrids; however, how thraustochytrids incorporate DHA into phospholipids remains unknown. We report here a novel lysophospholipid acyltransferase (PLAT1), which is responsible for the generation of DHA-containing phosphatidylcholine and phosphatidylethanolamine in thraustochytrids. The PLAT1 gene, which was isolated from the genomic DNA of Aurantiochytrium limacinum F26-b, was expressed in Saccharomyces cerevisiae, and the FLAG-tagged recombinant enzyme was characterized after purification with anti-FLAG affinity gel. PLAT1 shows wide specificity for donor substrates as well as acceptor substrates in vitro, i.e, the enzyme can adopt lysophosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylserine and lysophosphatidylinositol as acceptor substrates, and 15:0/16:0-CoA and DHA-CoA as donor substrates. In contrast to the in vitro experiment, only lysophosphatidylcholine acyltransferase and lysophosphatidylethanolamine acyltransferase activities were decreased in plat1-knockout mutants, resulting in a decrease of 16:0-DHA-phosphatidylcholine (PC) [PC(38∶6)] and 16:0-DHA-phosphatidylethanolamine (PE) [PE(38∶6)], which are two major DHA-containing phospholipids in A. limacinum F26-b. However, the amounts of other phospholipid species including DHA-DHA-PC [PC(44∶12)] and DHA-DHA-PE [PE(44∶12)] were almost the same in plat-knockout mutants and the wild-type. These results indicate that PLAT1 is the

  16. Novel lysophospholipid acyltransferase PLAT1 of Aurantiochytrium limacinum F26-b responsible for generation of palmitate-docosahexaenoate-phosphatidylcholine and phosphatidylethanolamine.

    PubMed

    Abe, Eriko; Ikeda, Kazutaka; Nutahara, Eri; Hayashi, Masahiro; Yamashita, Atsushi; Taguchi, Ryo; Doi, Kosaku; Honda, Daiske; Okino, Nozomu; Ito, Makoto

    2014-01-01

    N-3 polyunsaturated fatty acids (PUFA), such as docosahexaenoic acid (DHA, 22:6n-3), have been reported to play roles in preventing cardiovascular diseases. The major source of DHA is fish oils but a recent increase in the global demand of DHA and decrease in fish stocks require a substitute. Thraustochytrids, unicellular marine protists belonging to the Chromista kingdom, can synthesize large amounts of DHA, and, thus, are expected to be an alternative to fish oils. DHA is found in the acyl chain(s) of phospholipids as well as triacylglycerols in thraustochytrids; however, how thraustochytrids incorporate DHA into phospholipids remains unknown. We report here a novel lysophospholipid acyltransferase (PLAT1), which is responsible for the generation of DHA-containing phosphatidylcholine and phosphatidylethanolamine in thraustochytrids. The PLAT1 gene, which was isolated from the genomic DNA of Aurantiochytrium limacinum F26-b, was expressed in Saccharomyces cerevisiae, and the FLAG-tagged recombinant enzyme was characterized after purification with anti-FLAG affinity gel. PLAT1 shows wide specificity for donor substrates as well as acceptor substrates in vitro, i.e, the enzyme can adopt lysophosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylserine and lysophosphatidylinositol as acceptor substrates, and 15:0/16:0-CoA and DHA-CoA as donor substrates. In contrast to the in vitro experiment, only lysophosphatidylcholine acyltransferase and lysophosphatidylethanolamine acyltransferase activities were decreased in plat1-knockout mutants, resulting in a decrease of 16:0-DHA-phosphatidylcholine (PC) [PC(38:6)] and 16:0-DHA-phosphatidylethanolamine (PE) [PE(38:6)], which are two major DHA-containing phospholipids in A. limacinum F26-b. However, the amounts of other phospholipid species including DHA-DHA-PC [PC(44:12)] and DHA-DHA-PE [PE(44:12)] were almost the same in plat-knockout mutants and the wild-type. These results indicate that PLAT1 is the enzyme

  17. Stress and Alcohol

    PubMed Central

    Keyes, KM.; Hatzenbuehler, ML.; Grant, Bridget F.; Hasin, Deborah S.

    2012-01-01

    Exposure to stress often is psychologically distressing. The impact of stress on alcohol use and the risk of alcohol use disorders (AUDs) depends on the type, timing during the life course, duration, and severity of the stress experienced. Four important categories of stressors that can influence alcohol consumption are general life stress, catastrophic/fateful stress, childhood maltreatment, and minority stress. General life stressors, including divorce and job loss, increase the risk for AUDs. Exposure to terrorism or other disasters causes population-level increases in overall alcohol consumption but little increase in the incidence of AUDs. However, individuals with a history of AUDs are more likely to drink to cope with the traumatic event. Early onset of drinking in adolescence, as well as adult AUDs, are more common among people who experience childhood maltreatment. Finally, both perceptions and objective indicators of discrimination are associated with alcohol use and AUDs among racial/ethnic and sexual minorities. These observations demonstrate that exposure to stress in many forms is related to subsequent alcohol consumption and AUDs. However, many areas of this research remain to be studied, including greater attention to the role of various stressors in the course of AUDs and potential risk moderators when individuals are exposed to stressors. PMID:23584105

  18. Neuropathology of alcoholism.

    PubMed

    Sutherland, Greg T; Sheedy, Donna; Kril, Jillian J

    2014-01-01

    Chronic alcohol consumption results in structural changes to the brain. In alcoholics without coexisting thiamine deficiency or liver disease this is largely restricted to a loss of white-matter volume. When it occurs, neuronal loss is limited in anatomic distribution and only detected with quantitative techniques. This relative paucity of neurodegeneration is reflected in studies of gene and protein expression in postmortem brain where findings are subtle and discordant between studies. In alcoholics with coexisting pathologies, neuronal loss is more marked and affects a wider range of anatomic regions, especially subcortical nuclei. Although this more widespread damage may reflect a more severe drinking history, there is evidence linking thiamine deficiency and the consequences of liver disease to the pathogenesis of alcohol-related brain damage. Furthermore, a range of other factors, such as cigarette smoking and mood disorders, that are common in alcoholics, have the potential to influence studies of brain pathology and should be considered in further studies of the neuropathology of alcoholism. PMID:25307599

  19. Perspectives on the neuroscience of alcohol from the National Institute on Alcohol Abuse and Alcoholism.

    PubMed

    Reilly, Matthew T; Noronha, Antonio; Warren, Kenneth

    2014-01-01

    Mounting evidence over the last 40 years clearly indicates that alcoholism (alcohol dependence) is a disorder of the brain. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) has taken significant steps to advance research into the neuroscience of alcohol. The Division of Neuroscience and Behavior (DNB) was formed within NIAAA in 2002 to oversee, fund, and direct all research areas that examine the effects of alcohol on the brain, the genetic underpinnings of alcohol dependence, the neuroadaptations resulting from excessive alcohol consumption, advanced behavioral models of the various stages of the addiction cycle, and preclinical medications development. This research portfolio has produced important discoveries in the etiology, treatment, and prevention of alcohol abuse and dependence. Several of these salient discoveries are highlighted and future areas of neuroscience research on alcohol are presented. PMID:25307566

  20. Discovery of a potent and orally available acyl-CoA: cholesterol acyltransferase inhibitor as an anti-atherosclerotic agent: (4-phenylcoumarin)acetanilide derivatives.

    PubMed

    Ogino, Masaki; Fukui, Seiji; Nakada, Yoshihisa; Tokunoh, Ryosuke; Itokawa, Shigekazu; Kakoi, Yuichi; Nishimura, Satoshi; Sanada, Tsukasa; Fuse, Hiromitsu; Kubo, Kazuki; Wada, Takeo; Marui, Shogo

    2011-01-01

    Acyl-CoA: cholesterol acyltransferase (ACAT) is an intracellular enzyme that catalyzes cholesterol esterification. ACAT inhibitors are expected to be potent therapeutic agents for the treatment of atherosclerosis. A series of potent ACAT inhibitors based on an (4-phenylcoumarin)acetanilide scaffold was identified. Evaluation of the structure-activity relationships of a substituent on this scaffold, with an emphasis on improving the pharmacokinetic profile led to the discovery of 2-[7-chloro-4-(3-chlorophenyl)-6-methyl-2-oxo-2H-chromen-3-yl]-N-[4-chloro-2-(trifluoromethyl)phenyl]acetamide (23), which exhibited potent ACAT inhibitory activity (IC50=12 nM) and good pharmacokinetic profile in mice. Compound 23 also showed regressive effects on atherosclerotic plaques in apolipoprotein (apo)E knock out (KO) mice at a dose of 0.3 mg/kg per os (p.o.). PMID:21963637

  1. The solid phase synthesis of a protein activator for lecithin-cholesterol acyltransferase corresponding to human plasma apoC-I.

    PubMed Central

    Sigler, G F; Soutar, A K; Smith, L C; Gotto, A M; Sparrow, J T

    1976-01-01

    Apolipoprotein C-I, a protein constituent of the very low density lipoproteins of human plasma, consists of a single chain of 57 amino acids. The total synthesis of a protein corresponding to apolipoprotein C-I in physical properties and compositions was accomplished by solid phase techniques employing a modified polystrene incorporating spacer groups between the point of attachment of the first residue and the polymer matrix. The synthetic apoprotein was shown to activate lecithin:cholesterol acyltransferase to the same extent as the native protein. Comparative lipid-binding studies with dimyristoyl phosphatidylcholine gave complexes for native and synthetic apoprotein which floated at the same density after ultracentrifugation in KBr gradients and had virtually the same lipid:protein ratios. Images PMID:179085

  2. The solid phase synthesis of a protein activator for lecithin-cholesterol acyltransferase corresponding to human plasma apoC-I.

    PubMed

    Sigler, G F; Soutar, A K; Smith, L C; Gotto, A M; Sparrow, J T

    1976-05-01

    Apolipoprotein C-I, a protein constituent of the very low density lipoproteins of human plasma, consists of a single chain of 57 amino acids. The total synthesis of a protein corresponding to apolipoprotein C-I in physical properties and compositions was accomplished by solid phase techniques employing a modified polystrene incorporating spacer groups between the point of attachment of the first residue and the polymer matrix. The synthetic apoprotein was shown to activate lecithin:cholesterol acyltransferase to the same extent as the native protein. Comparative lipid-binding studies with dimyristoyl phosphatidylcholine gave complexes for native and synthetic apoprotein which floated at the same density after ultracentrifugation in KBr gradients and had virtually the same lipid:protein ratios. PMID:179085

  3. Penicillium griseofulvum F1959, high-production strain of pyripyropene a, specific inhibitor of acyl-CoA: cholesterol acyltransferase 2.

    PubMed

    Choi, Jung Ho; Rho, Mun-Chual; Lee, Seung Woong; Choi, Ji Na; Lee, Hee Jeong; Bae, Kyung Sook; Kim, Koanhoi; Kim, Young Kook

    2008-10-01

    Acyl-coenzyme A: cholesterol acyltransferase (ACAT) catalyzes cholesterol esterification and plays an important role in the intestinal absorption of cholesterol, hepatic production of lipoproteins, and accumulation of cholesteryl ester within cells. During the course of screening to find ACAT inhibitors from microbial sources, the present authors isolated pyripyropene A from Penicillium griseofulvum F1959. Pyripyropene A, an ACAT2-specific inhibitor, has already been produced from Aspergillus fumigatus. Yet, Aspergillus fumigatus is a pathogen and only produces a limited amount of pyripyropene A, making the isolation of pyripyropene A troublesome. In contrast, Penicillium griseofulvum F1959 was found to produce approximately 28 times more pyripyropene A than Aspergillus fumigatus, plus this report also describes the ideal conditions for the production of pyripyropene A by Penicillium griseofulvum F1959 and its subsequent purification. PMID:18955816

  4. The role of lecithin cholesterol acyltransferase and organic substances from coal in the etiology of Balkan endemic nephropathy: A new hypothesis

    USGS Publications Warehouse

    Pavlovic, N.M.; Orem, W.H.; Tatu, C.A.; Lerch, H.E.; Bunnell, J.E.; Feder, G.L.; Kostic, E.N.; Ordodi, V.L.

    2008-01-01

    Balkan endemic nephropathy (BEN) occurs in Serbia, Bulgaria, Romania, Bosnia and Herzegovina, and Croatia. BEN has been characterized as a chronic, slowly progressive renal disease of unknown etiology. In this study, we examined the influence of soluble organic compounds in drinking water leached from Pliocene lignite from BEN-endemic areas on plasma lecithin-cholesterol acyltransferase (LCAT) activity. We found that changes for all samples were the most prominent for the dilution category containing 90% plasma and 10% of diluting media. Water samples from BEN villages from Serbia and Romania showed higher LCAT inhibiting activity (p = 0.02) and (p = 0.003), respectively, compared to deionised water and non-endemic water. A secondary LCAT deficiency could result from this inhibitory effect of the organic compounds found in endemic water supplies and provide an ethiopathogenic basis for the development of BEN in the susceptible population. ?? 2007 Elsevier Ltd. All rights reserved.

  5. Acute alcohol consumption, alcohol outlets, and gun suicide.

    PubMed

    Branas, Charles C; Richmond, Therese S; Ten Have, Thomas R; Wiebe, Douglas J

    2011-01-01

    A case-control study of 149 intentionally self-inflicted gun injury cases (including completed gun suicides) and 302 population-based controls was conducted from 2003 to 2006 in a major US city. Two focal independent variables, acute alcohol consumption and alcohol outlet availability, were measured. Conditional logistic regression was adjusted for confounding variables. Gun suicide risk to individuals in areas of high alcohol outlet availability was less than the gun suicide risk they incurred from acute alcohol consumption, especially to excess. This corroborates prior work but also uncovers new information about the relationships between acute alcohol consumption, alcohol outlets, and gun suicide. Study limitations and implications are discussed. PMID:21929327

  6. WOMEN ALCOHOLICS : ARE THEY DIFFERENT FROM MEN ALCOHOLICS ?

    PubMed Central

    Selvaraj, V.; Suveera, Prasad; Ashok, M.V.; Appaya, M.P.

    1997-01-01

    Women alcoholics seeking psychiatric help have been increasing steadily over the years. The data on this subgroup however, is limited. Eighteen women alcoholics who presented to us over one year have been compared to twenty-eight men alcoholics who presented to us over one calendar month. Gender differences in the functions and effects of problem drinking were found. Men and women alcoholics differed in marital and occupational status, initiating and maintaining factors for drinking, course of alcoholism and alcohol related damage. PMID:21584094

  7. Acute Alcohol Consumption, Alcohol Outlets, and Gun Suicide

    PubMed Central

    Branas, Charles C.; Richmond, Therese S.; Ten Have, Thomas R.; Wiebe, Douglas J.

    2014-01-01

    A case–control study of 149 intentionally self-inflicted gun injury cases (including completed gun suicides) and 302 population-based controls was conducted from 2003 to 2006 in a major US city. Two focal independent variables, acute alcohol consumption and alcohol outlet availability, were measured. Conditional logistic regression was adjusted for confounding variables. Gun suicide risk to individuals in areas of high alcohol outlet availability was less than the gun suicide risk they incurred from acute alcohol consumption, especially to excess. This corroborates prior work but also uncovers new information about the relationships between acute alcohol consumption, alcohol outlets, and gun suicide. Study limitations and implications are discussed. PMID:21929327

  8. The influence of alcohol-specific communication on adolescent alcohol use and alcohol-related consequences.

    PubMed

    Reimuller, Alison; Hussong, Andrea; Ennett, Susan T

    2011-12-01

    Alcohol-specific communication, a direct conversation between an adult and an adolescent regarding alcohol use, contains messages about alcohol relayed from the adult to the child. The current study examined the construct of alcohol-specific communication and the effect of messages on adolescent alcohol use and alcohol-related consequences. Parent-adolescent dyads were assessed biannually for 3 years (grades 9-11 at wave 6) to examine these relations in a large longitudinal study of adolescents initially in grades 6 through 8. An exploratory factor analysis identified two factors among alcohol-specific communication items, permissive messages and negative alcohol messages. Results showed previous level of adolescent alcohol use moderated the relation between permissive messages and alcohol use outcomes. Plotting of these interactions showed greater alcohol use and consequences with increasing permissive messages in adolescents with higher versus lower levels of previous alcohol use. Results suggest that parental messages regarding alcohol use may impact adolescent alcohol use beyond the effect of general parenting style and parental alcohol use. PMID:21667141

  9. Molecular Characterization of the Elaeis guineensis Medium-Chain Fatty Acid Diacylglycerol Acyltransferase DGAT1-1 by Heterologous Expression in Yarrowia lipolytica

    PubMed Central

    Aymé, Laure; Jolivet, Pascale; Nicaud, Jean-Marc; Chardot, Thierry

    2015-01-01

    Diacylglycerol acyltransferases (DGAT) are involved in the acylation of sn-1,2-diacylglycerol. Palm kernel oil, extracted from Elaeis guineensis (oil palm) seeds, has a high content of medium-chain fatty acids mainly lauric acid (C12:0). A putative E. guineensis diacylglycerol acyltransferase gene (EgDGAT1-1) is expressed at the onset of lauric acid accumulation in the seed endosperm suggesting that it is a determinant of medium-chain triacylglycerol storage. To test this hypothesis, we thoroughly characterized EgDGAT1-1 activity through functional complementation of a Yarrowia lipolytica mutant strain devoid of neutral lipids. EgDGAT1-1 expression is sufficient to restore triacylglycerol accumulation in neosynthesized lipid droplets. A comparative functional study with Arabidopsis thaliana DGAT1 highlighted contrasting substrate specificities when the recombinant yeast was cultured in lauric acid supplemented medium. The EgDGAT1-1 expressing strain preferentially accumulated medium-chain triacylglycerols whereas AtDGAT1 expression induced long-chain triacylglycerol storage in Y. lipolytica. EgDGAT1-1 localized to the endoplasmic reticulum where TAG biosynthesis takes place. Reestablishing neutral lipid accumulation in the Y. lipolytica mutant strain did not induce major reorganization of the yeast microsomal proteome. Overall, our findings demonstrate that EgDGAT1-1 is an endoplasmic reticulum DGAT with preference for medium-chain fatty acid substrates, in line with its physiological role in palm kernel. The characterized EgDGAT1-1 could be used to promote medium-chain triacylglycerol accumulation in microbial-produced oil for industrial chemicals and cosmetics. PMID:26581109

  10. Identification of a Pair of Phospholipid:Diacylglycerol Acyltransferases from Developing Flax (Linum usitatissimum L.) Seed Catalyzing the Selective Production of Trilinolenin*

    PubMed Central

    Pan, Xue; Siloto, Rodrigo M. P.; Wickramarathna, Aruna D.; Mietkiewska, Elzbieta; Weselake, Randall J.

    2013-01-01

    The oil from flax (Linum usitatissimum L.) has high amounts of α-linolenic acid (ALA; 18:3cisΔ9,12,15) and is one of the richest sources of omega-3 polyunsaturated fatty acids (ω-3-PUFAs). To produce ∼57% ALA in triacylglycerol (TAG), it is likely that flax contains enzymes that can efficiently transfer ALA to TAG. To test this hypothesis, we conducted a systematic characterization of TAG-synthesizing enzymes from flax. We identified several genes encoding acyl-CoA:diacylglycerol acyltransferases (DGATs) and phospholipid:diacylglycerol acyltransferases (PDATs) from the flax genome database. Due to recent genome duplication, duplicated gene pairs have been identified for all genes except DGAT2-2. Analysis of gene expression indicated that two DGAT1, two DGAT2, and four PDAT genes were preferentially expressed in flax embryos. Yeast functional analysis showed that DGAT1, DGAT2, and two PDAT enzymes restored TAG synthesis when produced recombinantly in yeast H1246 strain. The activity of particular PDAT enzymes (LuPDAT1 and LuPDAT2) was stimulated by the presence of ALA. Further seed-specific expression of flax genes in Arabidopsis thaliana indicated that DGAT1, PDAT1, and PDAT2 had significant effects on seed oil phenotype. Overall, this study indicated the existence of unique PDAT enzymes from flax that are able to preferentially catalyze the synthesis of TAG containing ALA acyl moieties. The identified LuPDATs may have practical applications for increasing the accumulation of ALA and other polyunsaturated fatty acids in oilseeds for food and industrial applications. PMID:23824186

  11. Identification of a Novel Sequence Motif Recognized by the Ankyrin Repeat Domain of zDHHC17/13 S-Acyltransferases.

    PubMed

    Lemonidis, Kimon; Sanchez-Perez, Maria C; Chamberlain, Luke H

    2015-09-01

    S-Acylation is a major post-translational modification affecting several cellular processes. It is particularly important for neuronal functions. This modification is catalyzed by a family of transmembrane S-acyltransferases that contain a conserved zinc finger DHHC (zDHHC) domain. Typically, eukaryote genomes encode for 7-24 distinct zDHHC enzymes, with two members also harboring an ankyrin repeat (AR) domain at their cytosolic N termini. The AR domain of zDHHC enzymes is predicted to engage in numerous interactions and facilitates both substrate recruitment and S-acylation-independent functions; however, the sequence/structural features recognized by this module remain unknown. The two mammalian AR-containing S-acyltransferases are the Golgi-localized zDHHC17 and zDHHC13, also known as Huntingtin-interacting proteins 14 and 14-like, respectively; they are highly expressed in brain, and their loss in mice leads to neuropathological deficits that are reminiscent of Huntington's disease. Here, we report that zDHHC17 and zDHHC13 recognize, via their AR domain, evolutionary conserved and closely related sequences of a [VIAP][VIT]XXQP consensus in SNAP25, SNAP23, cysteine string protein, Huntingtin, cytoplasmic linker protein 3, and microtubule-associated protein 6. This novel AR-binding sequence motif is found in regions predicted to be unstructured and is present in a number of zDHHC17 substrates and zDHHC17/13-interacting S-acylated proteins. This is the first study to identify a motif recognized by AR-containing zDHHCs. PMID:26198635

  12. Synthesis of phosphatidylcholines in ozone-exposed alveolar type II cells isolated from adult rat lung: is glycerolphosphate acyltransferase a rate-limiting enzyme

    SciTech Connect

    Haagsman, H.P.; Schuurmans, E.A.; Batenburg, J.J.; van Golde, L.M.

    1988-01-01

    Type II cells were exposed to ozone by gas diffusion through the thin Teflon bottom of culture dishes. The rate of phosphatidylcholine synthesis by type II cells, monitored by the incorporation of (Me-/sup 14/C)choline, was impaired by ozone at concentrations that did not affect other cellular parameters. The enzymes choline kinase and cholinephosphate cytidylyltransferase were not susceptible to inactivation by ozone at concentrations at which the activity of glycerolphosphate acyltransferase was decreased. The enzyme activity of lactate dehydrogenase increased after ozone exposure. The specific activity of choline kinase in the cytosolic fraction of type II cells was fivefold that in whole lung. The metabolism of (Me-/sup 14/C)choline was studied as a function of the choline concentration. Maximal rates of phosphatidylcholine synthesis were already attained at a concentration of 20 microM choline. Exposure of type II cells to ozone did not affect the recovery of label from (Me-/sup 14/C)choline in choline phosphate and CDP choline. However, the maximal rate of phosphatidylcholine synthesis decreased after ozone exposure, which indicates that the decreased apparent activity of glycerolphosphate acyltransferase limits the supply of diacylglycerols and thereby the rate of phosphatidylcholine synthesis. If the flux through the diacylglycerol pathway was stimulated by the addition of palmitic acid, a higher maximal rate of phosphatidylcholine synthesis was observed. The uptake of (Me-/sup 14/C)choline and the recovery of label in CDPcholine were not altered by the addition of different concentrations of palmitate. It is concluded that type II cells take up choline very efficiently, probably due to the high specific activity of choline kinase. At low choline concentrations the rate of phosphatidylcholine synthesis is determined by the supply of CDPcholine.

  13. The enzyme lecithin-cholesterol acyltransferase esterifies cerebrosterol and limits the toxic effect of this oxysterol on SH-SY5Y cells.

    PubMed

    La Marca, Valeria; Spagnuolo, Maria Stefania; Cigliano, Luisa; Marasco, Daniela; Abrescia, Paolo

    2014-07-01

    Cholesterol is mostly removed from the CNS by its conversion to cerebrosterol (24(S)-hydroxycholesterol, 24(S)OH-C), which is transported to the circulation for bile formation in liver. A neurotoxic role of this oxysterol was previously demonstrated in cell culture. Here, we provide evidence that the enzyme lecithin-cholesterol acyltransferase, long known to esterify cholesterol, also produces monoesters of 24(S)OH-C. Proteoliposomes containing apolipoprotein A-I or apolipoprotein E were used to stimulate the enzyme activity and entrap the formed esters. Proteoliposomes with apolipoprotein A-I were found to be more active than those with apolipoprotein E in stimulating the production of oxysteryl esters. Cholesterol and 24(S)OH-C were found to compete for enzyme activity. High levels of haptoglobin, as those circulating during the acute inflammatory phase, inhibited 24(S)OH-C esterification. When highly neurotoxic 24(S)OH-C was treated with enzyme and proteoliposomes before incubation with differentiated SH-SY5Y cells, the neuron survival improved. The esters of 24(S)OH-C, embedded into proteoliposomes by the enzyme and isolated from unesterified 24(S)OH-C by gel filtration chromatography, did not enter the neurons in culture. These results suggest that the enzyme, in the presence of the apolipoproteins, converts 24(S)OH-C into esters restricted to the extracellular environment, thus preventing or limiting oxysterol-induced neurotoxic injuries to neurons in culture. 24-hydroxycholesterol (24(S)OH-C) is neurotoxic. The enzyme lecithin-cholesterol acyltransferase (LCAT) synthesizes monoesters of 24(S)OH-C in reaction mixtures with proteoliposomes containing phospholipids and apolipoprotein A-I or apolipoprotein E. The esters, also produced by incubation of cerebrospinal fluid only with tritiated 24(S)OH-C, are embedded into lipoproteins that do not enter neurons in culture. The enzyme activity limits the toxicity of 24-hydroxycholesterol in neuron culture. PMID

  14. Molecular Characterization of the Elaeis guineensis Medium-Chain Fatty Acid Diacylglycerol Acyltransferase DGAT1-1 by Heterologous Expression in Yarrowia lipolytica.

    PubMed

    Aymé, Laure; Jolivet, Pascale; Nicaud, Jean-Marc; Chardot, Thierry

    2015-01-01

    Diacylglycerol acyltransferases (DGAT) are involved in the acylation of sn-1,2-diacylglycerol. Palm kernel oil, extracted from Elaeis guineensis (oil palm) seeds, has a high content of medium-chain fatty acids mainly lauric acid (C12:0). A putative E. guineensis diacylglycerol acyltransferase gene (EgDGAT1-1) is expressed at the onset of lauric acid accumulation in the seed endosperm suggesting that it is a determinant of medium-chain triacylglycerol storage. To test this hypothesis, we thoroughly characterized EgDGAT1-1 activity through functional complementation of a Yarrowia lipolytica mutant strain devoid of neutral lipids. EgDGAT1-1 expression is sufficient to restore triacylglycerol accumulation in neosynthesized lipid droplets. A comparative functional study with Arabidopsis thaliana DGAT1 highlighted contrasting substrate specificities when the recombinant yeast was cultured in lauric acid supplemented medium. The EgDGAT1-1 expressing strain preferentially accumulated medium-chain triacylglycerols whereas AtDGAT1 expression induced long-chain triacylglycerol storage in Y. lipolytica. EgDGAT1-1 localized to the endoplasmic reticulum where TAG biosynthesis takes place. Reestablishing neutral lipid accumulation in the Y. lipolytica mutant strain did not induce major reorganization of the yeast microsomal proteome. Overall, our findings demonstrate that EgDGAT1-1 is an endoplasmic reticulum DGAT with preference for medium-chain fatty acid substrates, in line with its physiological role in palm kernel. The characterized EgDGAT1-1 could be used to promote medium-chain triacylglycerol accumulation in microbial-produced oil for industrial chemicals and cosmetics. PMID:26581109

  15. Exposure to Alcohol Advertisements and Teenage Alcohol-Related Problems

    PubMed Central

    Dent, Clyde W.; Stacy, Alan W.

    2013-01-01

    OBJECTIVE: This study used prospective data to test the hypothesis that exposure to alcohol advertising contributes to an increase in underage drinking and that an increase in underage drinking then leads to problems associated with drinking alcohol. METHODS: A total of 3890 students were surveyed once per year across 4 years from the 7th through the 10th grades. Assessments included several measures of exposure to alcohol advertising, alcohol use, problems related to alcohol use, and a range of covariates, such as age, drinking by peers, drinking by close adults, playing sports, general TV watching, acculturation, parents’ jobs, and parents’ education. RESULTS: Structural equation modeling of alcohol consumption showed that exposure to alcohol ads and/or liking of those ads in seventh grade were predictive of the latent growth factors for alcohol use (past 30 days and past 6 months) after controlling for covariates. In addition, there was a significant total effect for boys and a significant mediated effect for girls of exposure to alcohol ads and liking of those ads in 7th grade through latent growth factors for alcohol use on alcohol-related problems in 10th grade. CONCLUSIONS: Younger adolescents appear to be susceptible to the persuasive messages contained in alcohol commercials broadcast on TV, which sometimes results in a positive affective reaction to the ads. Alcohol ad exposure and the affective reaction to those ads influence some youth to drink more and experience drinking-related problems later in adolescence. PMID:23359585

  16. Alcohol and porphyrin metabolism.

    PubMed

    Doss, M O; Kühnel, A; Gross, U

    2000-01-01

    Alcohol is a porphyrinogenic agent which may cause disturbances in porphyrin metabolism in healthy persons as well as biochemical and clinical manifestations of acute and chronic hepatic porphyrias. After excessive consumption of alcohol, a temporary, clinically asymptomatic secondary hepatic coproporphyrinuria is observable, which can become persistent in cases of alcohol-induced liver damage. Nowadays, the alcohol-liver-porphyrinuria syndrome is the first to be mentioned in secondary hepatic disturbances of porphyrin metabolism. Acute hepatic porphyrias (acute intermittent porphyria, variegate porphyria and hereditary coproporphyria) are considered to be molecular regulatory diseases, in contrast to non-acute, chronic hepatic porphyria, clinically appearing as porphyria cutanea tarda (PCT). Porphyrins do not accumulate in the liver in acute porphyrias, whereas in chronic hepatic porphyrias they do. Thus, chronic hepatic porphyria is a porphyrin-accumulation disease, whereas acute hepatic porphyrias are haem-pathway-dysregulation diseases, characterized in general by induction of delta-aminolevulinic acid synthase in the liver and excessive stimulation of the pathway without storage of porphyrins in the liver. The clinical expression of acute hepatic porphyrias can be triggered by alcohol, because alcohol augments the inducibility of delta-aminolevulinic acid synthase. In chronic hepatic porphyrias, however, which are already associated with liver damage, alcohol potentiates the disturbance of the decarboxylation of uro- and heptacarboxyporphyrinogen, which is followed by a hepatic accumulation of uro- and heptacarboxyporphyrin and their sometimes extreme urinary excretion. Especially in persons with a genetic deficiency of uroporphyrinogen decarboxylase, but also in patients with the so-called sporadic variety of PCT, alcohol is able to transform an asymptomatic coproporphyrinuria into PCT. Alcohol has many biochemical and clinical effects on porphyrin and haem

  17. Spectrum of Alcoholic Liver Disease.

    PubMed

    Chacko, Kristina Rachel; Reinus, John

    2016-08-01

    Liver disease from excessive alcohol consumption is an important cause of morbidity and mortality worldwide. There is a clear relationship between alcohol and a variety of health and socioeconomic problems. According to the World Health Organization, 3.3 million people die of alcohol-related causes annually. Despite public knowledge of its potential adverse effects, alcohol consumption and the morbidity and mortality from alcoholic liver disease (ALD) have increased. ALD comprises a spectrum of injury, including simple steatosis, acute alcoholic hepatitis, and cirrhosis. Rather than being distinct disease entities, these pathologic processes frequently overlap. PMID:27373606

  18. Consumption of Alcohol Surrogates Among Alcohol-Dependent Women.

    PubMed

    Razvodovsky, Yury Evgeny

    2015-01-01

    This is the first in-depth study of alcohol and surrogate drinking patterns, types, reasons, and correlates among alcohol-dependent women in Belarus. The structured interviews were performed in 2013 with 103 alcohol-dependent women admitted to a narcological clinic in Grodno, Belarus. The results suggest that at least 30.3% of alcohol-dependent women regularly consume samogon (moonshine) and 10.8% of women use surrogates, the most popular among which are medications with a high percentage of ethanol and industrial spirits. The belief that samogon exceeds licensed vodka in quality is the main motive for its consumption. The results from the present study confirm that noncommercial alcohol use is common among alcohol-dependent women although its use may be underreported. These findings emphasize that the implementation of a comprehensive alcohol policy must take fully into account the consumption of alcohol from illicit sources. PMID:26549001

  19. The economics of alcohol abuse and alcohol-control policies.

    PubMed

    Cook, Philip J; Moore, Michael J

    2002-01-01

    Economic research has contributed to the evaluation of alcohol policy through empirical analysis of the effects of alcohol-control measures on alcohol consumption and its consequences. It has also provided an accounting framework for defining and comparing costs and benefits of alcohol consumption and related policy interventions, including excise taxes. The most important finding from the economics literature is that consumers tend to drink less ethanol, and have fewer alcohol-related problems, when alcoholic beverage prices are increased or alcohol availability is restricted. That set of findings is relevant for policy purposes because alcohol abuse imposes large "external" costs on others. Important challenges remain, including developing a better understanding of the effects of drinking on labor-market productivity. PMID:11900152

  20. Alcoholism and Alcohol Abuse - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Alcoholism and Alcohol Abuse URL of this page: https://medlineplus.gov/languages/alcoholismandalcoholabuse.html Other topics A-Z A B ...

  1. Alcoholism and Alcohol Abuse - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Alcoholism and Alcohol Abuse URL ... this page: https://www.nlm.nih.gov/medlineplus/languages/alcoholismandalcoholabuse.html Other topics A-Z A B ...

  2. 78 FR 65347 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Special Emphasis... Abuse and Alcoholism, 5635 Fishers Lane (Teleconference), Rockville, MD 20855. Contact Person:...

  3. 78 FR 21615 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial ] Review... Foster, Ph.D., Scientific Review Administrator, National Institutes on Alcohol Abuse &...

  4. 78 FR 38353 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-26

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Special Emphasis Panel; Review of Applications on HIV- AIDS/Alcohol Comparative Effectiveness & Implementation...

  5. Doxasozin for Alcoholism

    PubMed Central

    Leggio, Lorenzo; Kenna, George A.

    2016-01-01

    Recent preclinical and clinical evidence using prazosin indicates that a1-blockade may represent a new approach to treat alcohol dependence (AD). While most of the alcohol research on a1-blockade has been conducted testing prazosin, O’Neil and colleagues recently performed a set of preclinical experiments testing another a1-blocker, i.e. doxazosin that has a longer half-life that may enhance clinical utility. Doxazosin and prazosin share the same chemical structure, in which the central element is a piperazine ring. O’Neil et al.’s main results are that doxazosin significantly reduced alcohol intake without affecting locomotor activity. As such, O’Neil and colleagues provide the first preclinical evidence of the possible role of doxazosin in AD. Additional translational research is needed to further test this hypothesis. PMID:23278505

  6. Neuroplasticity in Human Alcoholism

    PubMed Central

    Fein, George; Cardenas, Valerie A.

    2015-01-01

    Alcoholism is characterized by a lack of control over excessive alcohol consumption despite significant negative consequences. This impulsive and compulsive behavior may be related to functional abnormalities within networks of brain regions responsible for how we make decisions. The abnormalities may result in strengthened networks related to appetitive drive—or the need to fulfill desires—and simultaneously weakened networks that exercise control over behaviors. Studies using functional magnetic resonance imaging (fMRI) in abstinent alcoholics suggest that abstinence is associated with changes in the tone of such networks, decreasing resting tone in appetitive drive networks, and increasing resting tone in inhibitory control networks to support continued abstinence. Identifying electroencephalographic (EEG) measures of resting tone in these networks initially identified using fMRI, and establishing in longitudinal studies that these abstinence-related changes in network tone are progressive would motivate treatment initiatives to facilitate these changes in network tone, thereby supporting successful ongoing abstinence. PMID:26259093

  7. High alcohol intake in female Sardinian alcohol-preferring rats.

    PubMed

    Loi, Barbara; Colombo, Giancarlo; Maccioni, Paola; Carai, Mauro A M; Franconi, Flavia; Gessa, Gian Luigi

    2014-06-01

    Sardinian alcohol-preferring (sP) rats have been selectively bred for high alcohol preference and consumption. When exposed to the standard, home cage 2-bottle "alcohol (10%, v/v) vs. water" choice regimen with continuous access, male sP rats consume daily approximately 6 g/kg alcohol. Conversely, when exposed to the intermittent (once every other day) access to 2 bottles containing alcohol (20%, v/v) and water, respectively, male sP rats display marked increases in daily alcohol intake and signs of alcohol intoxication and "behavioral" dependence. The present study was designed to assess alcohol intake in female sP rats exposed, under the 2-bottle choice regimen, to (a) 10% (v/v) alcohol with continuous access (CA10%), (b) 10% (v/v) alcohol with intermittent access (IA10%), (c) 20% (v/v) alcohol with continuous access (CA20%), and (d) 20% (v/v) alcohol with intermittent access (IA20%). Male sP rats (exposed to CA10% and IA20% conditions) were included for comparison. Over 20 daily drinking sessions, daily alcohol intake in female CA10% and IA20% rats averaged 7.0 and 9.6 g/kg, respectively. The rank of alcohol intake was IA20% > IA10% = CA20% > CA10%. Conversely, daily alcohol intake in male CA10% and IA20% rats averaged 6.0 and 8.2 g/kg, respectively. Comparison of female and male rats yielded the following rank of alcohol intake: female IA20% > male IA20% > female CA10% ≥ male CA10%. An additional experiment found that alcohol drinking during the first hour of the drinking session produced mean blood alcohol levels of 35-40 mg% and 85-100 mg% in the CA10% and IA20% rats, respectively. These results (a) extend to female sP rats previous data demonstrating the capacity of the IA20% condition to markedly escalate alcohol drinking, and (b) demonstrate that female sP rats consume more alcohol than male sP rats. This sex difference is more evident under the IA20% condition, suggesting that female sP rats are highly sensitive to the promoting effect

  8. Interactions of several genetic polymorphisms and alcohol consumption on blood pressure levels.

    PubMed

    Yin, Rui-Xing; Aung, Lynn Htet Htet; Long, Xing-Jiang; Yan, Ting-Ting; Cao, Xiao-Li; Huang, Feng; Wu, Jin-Zhen; Yang, De-Zhai; Lin, Wei-Xiong; Pan, Shang-Ling

    2015-01-01

    This study aimed to detect the interactions of several single nucleotide polymorphisms (SNPs) and alcohol consumption on blood pressure levels. Genotypes of 10 SNPs in the ATP-binding cassette transporter A1 (ABCA-1), acyl-CoA:cholesterol acyltransferase-1 (ACAT-1), low density lipoprotein receptor (LDLR), hepatic lipase gene (LIPC), endothelial lipase gene (LIPG), methylenetetrahydrofolate reductase (MTHFR), the E3 ubiquitin ligase myosin regulatory light chain-interacting protein (MYLIP), proprotein convertase subtilisin-like kexin type 9 (PCSK9), peroxisome proliferator-activated receptor delta (PPARD), and Scavenger receptor class B type 1 (SCARB1) genes were determined in 616 nondrinkers and 608 drinkers. The genotypic frequencies of LDLR rs5925, LIPC rs2070895, MTHFR rs1801133, and MYLIP rs3757354 SNPs were significantly different between nondrinkers and drinkers. The levels of systolic blood pressure (ABCA-1 rs2066715 and rs2070895), diastolic blood pressure (rs2070895), and pulse pressure (PP) (rs2066715, ACAT-1 rs1044925, and rs1801133) in nondrinkers, and systolic blood pressure (rs1044925 and SCARB1 rs5888), diastolic blood pressure (rs1044925 and LIPG rs2000813), and PP (PCSK9 rs505151 and rs5888) in drinkers were different among the genotypes (P < 0.005-0.001). The interactions of several SNPs and alcohol consumption on systolic blood pressure (rs2066715, rs1044925, rs5925, rs2070895, rs1801133, rs3757354, PPARD rs2016520, and rs5888), diastolic blood pressure (rs2066715, rs1044925, rs5925, rs2000813, rs3757354, and rs2016520), and PP (rs1044925, rs2070895, rs1801133, rs3757354, rs505151, and rs5888) were observed (P < 0.005-0.001). The differences in blood pressure levels between the nondrinkers and drinkers might be partially attributed to the interactions of these SNPs and alcohol consumption. PMID:26354227

  9. Antiatherogenic and antiperoxidative effects of garlic and soy proteins in alcohol fed rats.

    PubMed

    Rajasree, C R; Rajmohan, T; Augusti, K T

    2009-03-01

    Rats fed with alcohol (18%) at 3.76 g/day for 45 days showed significant reduction in body weight, glutathione (GSH) content and activities of superoxide dismutase (SOD) and catalase in liver. Lecithin cholesterol acyltransferase (LCAT) in plasma, levels of HDL cholesterol in serum, hepatic bile acid production and fecal excretion of neutral sterols also showed significant reduction. Simultaneous feeding of garlic protein (GP) or soy protein (SP) (500 mg/kg body weight/day for 45 days) to alcohol fed groups increased each of above parameters significantly towards normal values. Increase in GSH content and catalase activity in liver, was significantly higher for SP treated group than for GP treated group. However, increase in plasma LCAT was significantly higher for GP treated group than for SP treated group. Alcohol fed rats showed significant increase in liver weight, serum and tissue cholesterol, serum triacylglycerol (TAG), phospholipids (PL) and free fatty acid (FFA) levels and activity of HMGCoA reductase in liver and intestine. Lipid peroxidation, glucose-6 phosphate dehydrogenase (G6PD), glutathione peroxidase (GPx) and glutathione reductase (GR) in liver and incorporation of labeled acetate into liver cholesterol also showed significant increase. GP and SP treated rats showed decrease in these values towards normal. GP feeding showed a better effect than SP in lowering serum and heart total cholesterol, and in maintaining GPx at near normal level, while SP feeding showed a better effect in lowering serum FFA level and maintaining GR activity at near normal level. In suppressing incorporation of labeled acetate into serum cholesterol, GP feeding showed a better effect than SP. Antiatherogenic and antiperoxidative effects of these proteins may be due to lower lysine/arginine ratio. PMID:19405381

  10. [Pathogenesis of alcoholic chronic hepatitis].

    PubMed

    Hayashi, Nobuhiko; Saito, Takashi; Kakuda, Masahiro; Matsue, Yasuhiro; Minato, Takashiro; Fukumura, Atsushi; Ozaki, Kazuaki; Tsuchisima, Mutsumi; Tsutsumi, Mikihiro

    2014-10-01

    In 1983, Nei et al. reported that alcoholic chronic hepatitis (ACH)(chronic hepatitis induced tal area. Recently, the number of alcoholics patients diagnosed with ACH has been increased In this review, we discussed the characteristics of liver histopathology and blood chemistry of ACH patients. In ACH, pericellular fibrosis, ballooned hepatocytes and/or bridging fibrosis, and infiltration of mononuclear lymphocytes is decreased after 6 to 8 weeks of abstinence from results suggest that ACH could be one type of alcoholic liver disease. The precise mechanism by alcohol) as one type of alcoholic liver disease. Since then, it has been discussed whether alcohol abuse, suggesting that alcohol may play a role in the infiltration of mononuclear lym ACH is one type of alcoholic liver disease, because there could be infection of unknown hepatitis virus in alcoholics and it is not clear why mononuclear lymphocytes infiltrate into the porphocytes in portal region. After abstinence of alcohol, serum levels of AST, ALT, and γ-GTP in patients with ACH returned to normal as in other types of alcoholic liver disease such as alcoholic fatty liver, alcoholic fibrosis, alcoholic hepatitis and alcoholic liver cirrhosis. These results suggest that ACH could be one type of alcoholic liver disease. The precise mechanism of the infiltration of mononuclear lymphocytes into portal areas of ACH patients is not known. We propose that the reason for the infiltration of natural killer (T) cells into portal areas could be due to the influx of endotoxin into portal vein resulting from the increased permeability of gut induced by alcohol. PMID:25651616

  11. Managing alcoholic liver disease

    PubMed Central

    2015-01-01

    Alcoholic liver disease continues to be a significant cause of liver-related morbidity and mortality throughout the world. A number of diagnostic and prognostic models have been developed in the management of this condition, although specific roles for liver biopsy still remain particularly in the setting of alcoholic hepatitis. Despite a large number of recent treatment trials, the ideal pharmacotherapy approach remains undefined. Most essential is the supportive care and focus on abstinence and nutrition. Owing in part to a great deal of attention from governmental funding sources, a number of new treatment approaches are undergoing rigorous evaluation, hopefully providing future treatment options in this very severe condition. PMID:26523266

  12. Fermentative alcohol production

    DOEpatents

    Wilke, Charles R.; Maiorella, Brian L.; Blanch, Harvey W.; Cysewski, Gerald R.

    1982-01-01

    An improved fermentation process for producing alcohol which includes the combination of vacuum fermentation and vacuum distillation. Preferably, the vacuum distillation is carried out in two phases, one a fermentor proper operated at atmospheric pressure and a flash phase operated at reduced pressure with recycle of fermentation brew having a reduced alcohol content to the fermentor, using vapor recompression heating of the flash-pot recycle stream to heat the flash-pot or the distillation step, and using "water load balancing" (i.e., the molar ratio of water in the fermentor feed is the same as the molar ratio of water in the distillation overhead).

  13. Acute Alcoholic Hepatitis: Therapy.

    PubMed

    Phillips, Paulina K; Lucey, Michael R

    2016-08-01

    Alcoholic hepatitis (AH) causes great morbidity and mortality in the United States and throughout the world. Advances in therapy have proven difficult. In part, this reflects challenges in diagnosis, including the distinction between AH and acute-on-chronic liver failure. Liver biopsy is the best method to clarify the cause in circumstances whereby conflicting clinical data confound the diagnosis. All treatment of AH begins with abstinence from alcohol. All patients with AH should be given sufficient nutrition. Prednisolone has become the principal agent for treating patients with severe AH. PMID:27373613

  14. Alcohol fuel from sugarbeets

    SciTech Connect

    Doney, D.L.; Theurer, J.C.

    1980-05-01

    Sugarbeets are a prime candidate for alcohol fuel production because they store their energy and much of their biomass as sucrose, a fermentable sugar. At the present time, it is uneconomical to produce alcohol from sugarbeets and the balance is marginal. A number of approaches could improve both the economic and the energy situation: 1) increasing production per acre; 2) reducing conversion costs; 3) integrating sugarbeet - sweet sorghum crops; and 4) utilizing low priority sources such as geothermal, coal, bagasse and solar for the energy of conversion.

  15. Information on Blood Alcohol Concentration: Evaluation of Two Alcohol Nomograms.

    ERIC Educational Resources Information Center

    Werch, Chudley E.

    1988-01-01

    Compared utility of two common alcohol nomograms on impacting decisions regarding drinking, driving after drinking, knowledge of relationship between personal alcohol consumption and the legal level of intoxication, and consumer evaluation measures, to utility of alcohol information warning card. Nomograms were no more effective than cards warning…

  16. Relationship between Alcohol Consumption and Alcohol Problems in Young Adults.

    ERIC Educational Resources Information Center

    Werch, Chudley E.; And Others

    1987-01-01

    Examined relationship among alcohol problems and alcohol consumption variables in 410 college students. Total alcohol-related problems, drinking and driving problems, and school problems increased significantly when subjects drank moderately. Physical illness problems increased during light drinking, while interpersonal and legal problems…

  17. Alcohol Promotional Clothing Items and Alcohol Use by Underage Consumers.

    ERIC Educational Resources Information Center

    Workman, Jane E.

    2003-01-01

    Of 154 female and 106 male adolescents, 76.3% had tried alcohol; more than 36% owned alcohol promotional clothing and more than half had seen such clothing at school. Ownership increased with alcohol use status. Those who received such clothing from their parents were more likely to perceive parental approval of their drinking. (Contains 59…

  18. Information on Blood Alcohol Concentration: Evaluation of Two Alcohol Nomograms.

    ERIC Educational Resources Information Center

    Werch, Chudley E.

    The purpose of this study was to compare with an alcohol information warning card the utility of two common alcohol nomograms (statistical information tables) in impacting decisions regarding drinking, driving after drinking, the development of knowledge of the relations between personal alcohol consumption and the legal level of intoxication, and…

  19. Fetal Alcohol Syndrome and Fetal Alcohol Effects: Principles for Educators.

    ERIC Educational Resources Information Center

    Burgess,Donna M.; Streissguth, Ann P.

    1992-01-01

    Fetal alcohol syndrome (FAS), the leading cause of mental retardation, often goes unrecognized because of social and emotional taboos about alcohol and alcoholism. This article describes medical and behavioral characteristics of FAS children and describes guiding principles for educators, based on early intervention, teaching communication and…

  20. Fetal Alcohol Syndrome and Fetal Alcohol Effects in Child Development.

    ERIC Educational Resources Information Center

    Pancratz, Diane R.

    This literature review defines Fetal Alcohol Syndrome (FAS) and Fetal Alcohol Effects (FAE) and considers their causes, diagnoses, prevalence, and educational ramifications. Effects of alcohol during each of the trimesters of pregnancy are summarized. Specific diagnostic characteristics of FAS are listed: (1) growth deficiency, (2) a…