XB001: Shortening of membrane lipid acyl chains compensates for phosphatidylcholine deficiency in choline‐auxotroph yeast
Ontology highlight
ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE75725 | GEO | 2021/08/04
REPOSITORIES: GEO
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Project description:Fatty acid transport protein 4 (FATP4) is an acyl-CoA synthetase that is required for normal permeability barrier in mammalian skin. FATP4 (SLC27A4) mutations cause ichthyosis prematurity syndrome, a nonlethal disorder. In contrast, Fatp4<sup>-/-</sup> mice die neonatally from a defective barrier. Here we used electron microscopy and lipidomics to characterize defects in Fatp4<sup>-/-</sup> mice. Mutants showed lamellar body, corneocyte lipid envelope, and cornified envelope abnormalities. Lipidomics identified two lipids previously speculated to be present in mouse epidermis, sphingosine β-hydroxyceramide and monoacylglycerol; mutants displayed decreased proportions of these and the two ceramide classes that carry ultralong-chain, amide-linked fatty acids (FAs) thought to be critical for barrier function, unbound ω-O-acylceramide and bound ω-hydroxyceramide, the latter constituting the major component of the corneocyte lipid envelope. Other abnormalities included elevated amounts of sphingosine α-hydroxyceramide, phytosphingosine non-hydroxyceramide, and 1-O-acylceramide. Acyl chain length alterations in ceramides also suggested roles for FATP4 in esterifying saturated non-hydroxy and β-hydroxy FAs with at least 25 carbons and saturated or unsaturated ω-hydroxy FAs with at least 30 carbons to CoA. Our lipidomic analysis is the most thorough such study of the Fatp4<sup>-/-</sup> mouse skin barrier to date, providing information about how FATP4 can contribute to barrier function by regulating fatty acyl moieties in various barrier lipids.
2021-07-15 | MTBLS1138 | MetaboLights
Project description:vanEunen2013 - Network dynamics of fatty acid β-oxidation (time-course model)
Lipid metabolism plays an important role in the development of metabolic syndrome, a major risk factor for cardiovascular disease and diabetes. This model gives insights into the response of lipid oxidation to dietart and medical interventions. The model predicts the rate of lipid oxidation and the time course of most acyl carnitines. There are two models described in the paper, (i) steady-state model [ BIOMD0000000505
], (ii) time-course model [ BIOMD0000000506
]. This model corresponds to the time-course model.
This model is described in the article:
Biochemical competition makes fatty-acid β-oxidation vulnerable to substrate overload.
van Eunen K, Simons SM, Gerding A, Bleeker A, den Besten G, Touw CM, Houten SM, Groen BK, Krab K, Reijngoud DJ, Bakker BM.
PLoS Comput Biol. 2013;9(8):e1003186.
Abstract:
Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid β-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and saturable enzyme-kinetic equations and experimentally determined parameters for rat-liver enzymes. It was validated by adding palmitoyl CoA or palmitoyl carnitine to isolated rat-liver mitochondria: without refitting of measured parameters, the model correctly predicted the β-oxidation flux as well as the time profiles of most acyl-carnitine concentrations. Subsequently, we simulated the condition of obesity by increasing the palmitoyl-CoA concentration. At a high concentration of palmitoyl CoA the β-oxidation became overloaded: the flux dropped and metabolites accumulated. This behavior originated from the competition between acyl CoAs of different chain lengths for a set of acyl-CoA dehydrogenases with overlapping substrate specificity. This effectively induced competitive feedforward inhibition and thereby led to accumulation of CoA-ester intermediates and depletion of free CoA (CoASH). The mitochondrial [NAD⁺]/[NADH] ratio modulated the sensitivity to substrate overload, revealing a tight interplay between regulation of β-oxidation and mitochondrial respiration.
This model is hosted on BioModels Database
and identified
by: BIOMD0000000506
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource
for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to the public
domain worldwide. Please refer to CC0 Public Domain
Dedication
for more information.
2024-09-02 | BIOMD0000000506 | BioModels
Project description:vanEunen2013 - Network dynamics of fatty acid β-oxidation (steady-state model)
Lipid metabolism plays an important role in the development of metabolic syndrome, a major risk factor for cardiovascular disease and diabetes. This model gives insights into the response of lipid oxidation to dietart and medical interventions. The model predicts the rate of lipid oxidation and the time course of most acyl carnitines. There are two models described in the paper, (i) steady-state model [ BIOMD0000000505
], (ii) time-course model [ BIOMD0000000506
]. This model corresponds to the steady-state model.
This model is described in the article:
Biochemical competition makes fatty-acid β-oxidation vulnerable to substrate overload.
van Eunen K, Simons SM, Gerding A, Bleeker A, den Besten G, Touw CM, Houten SM, Groen BK, Krab K, Reijngoud DJ, Bakker BM.
PLoS Comput Biol. 2013;9(8):e1003186.
Abstract:
Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid β-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and saturable enzyme-kinetic equations and experimentally determined parameters for rat-liver enzymes. It was validated by adding palmitoyl CoA or palmitoyl carnitine to isolated rat-liver mitochondria: without refitting of measured parameters, the model correctly predicted the β-oxidation flux as well as the time profiles of most acyl-carnitine concentrations. Subsequently, we simulated the condition of obesity by increasing the palmitoyl-CoA concentration. At a high concentration of palmitoyl CoA the β-oxidation became overloaded: the flux dropped and metabolites accumulated. This behavior originated from the competition between acyl CoAs of different chain lengths for a set of acyl-CoA dehydrogenases with overlapping substrate specificity. This effectively induced competitive feedforward inhibition and thereby led to accumulation of CoA-ester intermediates and depletion of free CoA (CoASH). The mitochondrial [NAD⁺]/[NADH] ratio modulated the sensitivity to substrate overload, revealing a tight interplay between regulation of β-oxidation and mitochondrial respiration.
This model is hosted on BioModels Database
and identified
by: BIOMD0000000505
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource
for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to the public
domain worldwide. Please refer to CC0 Public Domain
Dedication
for more information.
2024-09-02 | BIOMD0000000505 | BioModels
Project description:We have identified that these two organisms have quite distinct phospholipid structures - S. pombe phospholipids display canonical symmetric long acyl chains (18 and/ or 16 carbon atoms), and in S. japonicus significant fraction of phospholipids are asymmetrical - one acyl chain is 18 carbon atoms and second one is short - only 10 carbon atoms. Medium chain fatty acid like C10:0 are critical for S. japonicus physiology and are synthesised by the cytosolic fatty acid synthase (FAS) complex. Such findings lead us to address the functional role of these asymmetric lipids and we exchanged FAS between the two fission yeast species. We observed that in S. pombe expressing solely japonicus FAS, the membrane is functionally impaired in a number of ways (e.g. endocytosis, mitosis etc etc) and moreover, it seems that at lower temperatures (such as 24C) the phenotype is more severe compared to the higher temperatures like 30 and 36. We believe that comparative transcriptomic analysis will shed light on what is going on in S. pombe cells with exchanged FAS and therefore displaying an altered lipidome.
2019-12-07 | GSE141579 | GEO
Project description:The translational efficiency of mRNAs in cells progressing synchronously through the mitotic cell cycle and having to meet their growth requirements for cell division has not been interrogated. Here, we used ribosome profiling of a cell-size series from the time of cell birth, to identify for the first time yeast mRNAs under periodic translational control. Late in the cell cycle, there was coordinate translational activation of mRNAs encoding lipid biosynthesis enzymes. An upstream open reading frame (uORF) mediates the translational control of ACC1, the mRNA encoding the rate-limiting enzyme acetyl-CoA carboxylase. The ACC1 uORF also adjusts Acc1p protein levels in different nutrients. Mutating the ACC1 uORF delayed cell cycle progression, reduced cell size and suppressed the replicative longevity of cells lacking the Sch9p protein kinase, the yeast S6 kinase ortholog. These findings reveal unexpected links between lipogenesis and protein synthesis in mitotic cell divisions
2017-01-09 | GSE81932 | GEO
Project description:Acyl-CoA synthetase medium-chain family member 3 (ACSM3) is one member of ACSM family and localized on the outer membrane of mitochondria, which catalyzes the activation of medium-chain (C4-C14) length FAs and xenobiotic carboxylic acids. We found that ACSM3 was lower expressed in the metabolic syndrome (MetS) patients and mice. ACSM3 mainly expressed in the liver. We speculated that ACSM3 deficiency may participated in the MetS progression and then constructed Acsm3 global knockout mice (C57BL/6J background) by CRISPR/Cas9 system. The knockout mice exhibited profound depletion of Acsm3 expression in liver extracts. Male mice are more sensitive to diet-induced MetS than female mice, and thus male mice were used in this study. The phenotype of Acsm3 knockout mice was analyzed with wild type littermates as controls. 12 weeks, livers from three male Acsm3 knockout mice and three male control mice were removed for RNA sequencing.
2023-11-12 | GSE247290 | GEO
Project description:Lipid remodeling is crucial for plant responses to abiotic stress and metabolic disturbances. A key aspect of this process involves the modification of phosphatidylcholine (PC) acyl chains by lysophosphatidylcholine: acyl-CoA acyltransferases (LPCATs). To understand their role in lipid homeostasis, we studied the trigalactosyldiacylglycerol1 (tgd1) mutant, which exhibits significant increases in fatty acid synthesis and flux through PC due to disrupted inter-organelle lipid trafficking. We discovered that the elevated fatty acid synthesis in tgd1 is due to the posttranslational activation of plastidic acetyl-coenzyme A carboxylase (ACCase). Global transcriptomic profiling revealed 62 significantly upregulated genes in tgd1, with 27 (44%) involved in RNA and DNA modifications, suggesting a role for posttranscriptional mechanisms in adapting to lipid trafficking disruptions. Additionally, transcript levels of LPCATs and several genes regulating ACCase were moderately increased in tgd1. Genetic analysis showed that knocking out LPCAT1 and LPCAT2 was lethal in the tgd1 background. Furthermore, plants homozygous for lpcat2 and heterozygous for lpcat1 in the tgd1 background displayed reduced levels of PC and TAG, along with altered fatty acid compositions. Our findings provide mechanistic insights into fatty acid synthesis regulation and highlight the critical role of LPCATs in maintaining cellular lipid homeostasis when fatty acid production exceeds the cellular demand for membrane lipid synthesis.
2024-09-16 | PXD054661 | Pride
Project description:Nudix hydrolase 7 (NUDT7) is a peroxisomal (acyl-)CoA-degrading enzyme that is highly expressed in the liver. We previously showed that liver-specific NUDT7 overexpression affects peroxisomal lipid metabolism, but does not prevent the increase in total liver CoA levels that occurs with fasting. Herein, we show that deletion of Nudt7 alters the composition of the hepatic acyl-CoA pool in mice fed a low fat diet, but only in males fed a western diet does the lack of NUDT7 increase total liver CoA levels. This effect is driven by the accumulation of medium-chain dicarboxylic acyl-CoAs, which are products of the oxidation of dicarboxylic fatty acids in the peroxisomes. We also show that, under conditions of increased cholesterol intake and elevated bile acid synthesis, Nudt7 deletion increases the production of tauro-muricholic acids, decreasing the hydrophobicity index of the intestinal bile acid pool and increasing fecal cholesterol excretion. Collectively, our findings reveal a key role for NUDT7 in the regulation of the final products of bile acid synthesis and dicarboxylic fatty acid oxidation
2022-11-25 | GSE207914 | GEO
Project description:RNAseq analysis was conducted to complement the targeted and untargeted metabolomics analysis of livers overexpressing the CoA-degrading enzyme Nudt7 or GFP (control). Lipid metabolism requires coenzyme A (CoA), which is found in multiple subcellular compartments including the peroxisomes. In the liver, CoA levels are dynamically adjusted between the fed and fasted states. The elevation in CoA levels that occurs during fasting is driven by increased synthesis but also correlates with decreased expression of Nudt7, the major CoA-degrading enzyme in the liver. Nudt7 resides in the peroxisomes and we overexpressed this enzyme in mouse livers to determine its effect on the size and composition of the hepatic CoA pool in the fed and fasted states. Nudt7 overexpression did not change total CoA levels but decreased the concentration of short-chain acyl-CoAs and choloyl-CoA in fasted livers, when endogenous Nudt7 activity was lowest. The effect on these acyl-CoAs correlated with a significant decrease in the hepatic bile acid content and in the rate of peroxisomal fatty acid oxidation, as estimated by targeted and untargeted metabolomics, combined with the measurement of fatty acid oxidation in intact hepatocytes. Identification of the CoA species and metabolic pathways affected the overexpression on Nudt7 in vivo supports the conclusion that the nutritionally-driven modulation of Nudt7 activity could contribute to the regulation of the peroxisomal CoA pool and peroxisomal lipid metabolism.
2019-03-08 | GSE125237 | GEO
Project description:Overexpression of Long Chain Acyl CoA Synthetase 1 effects on Lipid Metabolism in Sheep adipocytes
| PRJNA595792 | ENA