Low-temperature effects on docosahexaenoic acid biosynthesis in Schizochytrium sp. TIO01 and its proposed underlying mechanism

Abstract Background Schizochytrium species are known for their abundant production of docosahexaenoic acid (DHA). Low temperatures can promote the biosynthesis of polyunsaturated fatty acids (PUFAs) in many species. This study investigates low-temperature effects on DHA biosynthesis in Schizochytrium sp. TIO01 and its underlying mechanism. Results The Schizochytrium fatty acid biosynthesis pathway was evaluated based on de novo genome assembly (contig N50 = 2.86 Mb) and iTRAQ-based protein identification. Our findings revealed that desaturases, involved in DHA synthesis via the fatty acid synthase (FAS) pathway, were completely absent. The polyketide synthase (PKS) pathway and the FAS pathway are, respectively, responsible for DHA and saturated fatty acid synthesis in Schizochytrium. Analysis of fatty acid composition profiles indicates that low temperature has a significant impact on the production of DHA in Schizochytrium, increasing the DHA content from 43 to 65% of total fatty acids. However, the expression levels of PKS pathway genes were not significantly regulated as the DHA content increased. Further, gene expression analysis showed that pathways related to the production of substrates (acetyl-CoA and NADPH) for fatty acid synthesis (the branched-chain amino acid degradation pathway and the pentose phosphate pathway) and genes related to saturated fatty acid biosynthesis (the FAS pathway genes and malic enzyme) were, respectively, upregulated and downregulated. These results indicate that low temperatures increase the DHA content by likely promoting the entry of relatively large amounts of substrates into the PKS pathway. Conclusions In this study, we provide genomic, proteomic, and transcriptomic evidence for the fatty acid synthesis pathway in Schizochytrium and propose a mechanism by which low temperatures promote the accumulation of DHA in Schizochytrium. The high-quality and nearly complete genome sequence of Schizochytrium provides a valuable reference for investigating the regulation of polyunsaturated fatty acid biosynthesis and the evolutionary characteristics of Thraustochytriidae species.

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The effects of low temperature on docosahexaenoic acid biosynthesis in Schizochytrium sp TIO01 and the underlying mechanism

10.21203/rs.2.22487/v1 ◽

2020 ◽

Author(s):

Fan Hu ◽

April L. Clevenger ◽

Peng Zheng ◽

Qiongye Huang ◽

Zhaokai Wang

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Low Temperature ◽

Saturated Fatty Acid ◽

Fatty Acid Synthesis ◽

Low Temperatures ◽

Underlying Mechanism ◽

Acid Synthesis ◽

Acid Biosynthesis ◽

Fas Pathway

Abstract Background Schizochytrium are known for their abundant production of docosahexaenoic acid (DHA). Low temperatures can promote the biosynthesis of polyunsaturated fatty acids in many species. In this study, the effects of low temperature on the biosynthesis of DHA in Schizochytrium sp TIO01 and the underlying mechanism was investigated. Results Based on the de novo genome assembly (contig N50=2.86 Mb) and iTRAQ-based protein identification, we first reconstructed the detailed Schizochytrium fatty acid biosynthesis pathway. Our findings revealed that desaturases, involved in DHA synthesis via the fatty acid synthase (FAS) pathway, were completely absent. The polyketide synthase (PKS) pathway and the FAS pathway are separately responsible for DHA and saturated fatty acid synthesis in Schizochytrium . Analysis of fatty acid composition profiles indicates that low temperature has a significant impact on the production of DHA in Schizochytrium, increasing the DHA content and overall total fatty acids from 43% to 65%. The increased DHA content, however, was not a result of the expression of the PKS pathway genes. Further gene expression analysis indicated that low temperatures may promote DHA accumulation by the up-regulation of both the pentose phosphate pathway and the branched-chain amino acid degradation pathway (increasing the production of the substrates for polyunsaturated fatty acid synthesis: acetyl-CoA and NADPH). In addition, low temerpatures result in a down-regulation of the FAS pathway (reducing the consumption of the substrates for saturated fatty acid synthesis) and malic enzyme, leading to a decreased saturated fatty acid content. Conclusions These findings elucidate the detailed fatty acid synthesis pathway of Schizochytrium, revealing an underlying mechanism by which low temperatures promote the accumulation of DHA in Schizochytrium. The high-quality and nearly complete genome sequence of Schizochytrium provides a valuable reference for further investigation of the regulation of polyunsaturated fatty acids biosynthesisand the evolutionary characteristics in Thraustochytriidae species.

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Mechanistic diversity and regulation of Type II fatty acid synthesis

Biochemical Society Transactions ◽

10.1042/bst0301050 ◽

2002 ◽

Vol 30 (6) ◽

pp. 1050-1055 ◽

Cited By ~ 76

Author(s):

H. Marrakchi ◽

Y.-M. Zhang ◽

C. O. Rock

Keyword(s):

Fatty Acid ◽

Fatty Acid Synthesis ◽

Unsaturated Fatty Acid ◽

Fatty Acid Synthase ◽

Fatty Acid Biosynthesis ◽

Specific Interaction ◽

Acid Synthesis ◽

Protein Crystal ◽

Type Ii ◽

Acid Biosynthesis

Fatty acid biosynthesis is catalysed in most bacteria by a group of highly conserved proteins known as the Type II fatty acid synthase (FAS) system. The Type II system organization is distinct from its mammalian counterpart and offers several unique sites for selective inhibition by antibacterial agents. There has been remarkable progress in the understanding of the genetics, biochemistry and regulation of Type II FASs. One important advance is the discovery of the interaction between the fatty acid degradation regulator, FadR, and the fatty acid biosynthesis regulator, FabR, in the transcriptional control of unsaturated fatty acid synthesis in Escherichia coli. The availability of genomic sequences and high-resolution protein crystal structures has expanded our understanding of Type II FASs beyond the E. coli model system to a number of pathogens. The molecular diversity among the pathway enzymes is illustrated by the discovery of a new type of enoyl-reductase in Streptococcus pneumoniae [enoyl-acyl carrier protein (ACP) reductase II, FabK], the presence of two enoyl-reductases in Bacillus subtilis (enoyl-ACP reductases I and III, FabI and FabL), and the use of a new mechanism for unsaturated fatty acid formation in S. pneumoniae (trans-2-cis-3-enoyl-ACP isomerase, FabM). The solution structure of ACP from Mycobacterium tuberculosis revealed features common to all ACPs, but its extended C-terminal domain may reflect a specific interaction with very-long-chain intermediates.

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Lipogenic enzymes in rat maternal adipose tissue in the perinatal period

Biochemical Journal ◽

10.1042/bj1860937 ◽

1980 ◽

Vol 186 (3) ◽

pp. 937-944 ◽

Cited By ~ 13

Author(s):

P A Sinnett-Smith ◽

R G Vernon ◽

R J Mayer

Keyword(s):

Adipose Tissue ◽

Fatty Acid ◽

Fatty Acid Synthesis ◽

Pyruvate Dehydrogenase ◽

Fatty Acid Biosynthesis ◽

Specific Activity ◽

Fatty Acid Synthetase ◽

Acid Synthesis ◽

Acetyl Coa Carboxylase ◽

Acid Biosynthesis

1. The specific activities of fatty acid synthetase, acetyl-CoA carboxylase and pyruvate dehydrogenase were measured in rat adipose-tissue extracts in pregnancy and lactation. Fatty acid synthetase specific activity correlates very closely with the rate of fatty acid synthesis, the enzyme specific activity decreasing after mid-pregnancy in a manner very similar to the rate of fatty acid synthesis. Acetyl-CoA carboxylase specific activity also decreases dramatically after mid-pregnancy. Initial pyruvate dehydrogenase specific activity shows a decrease between 2 days pre partum and 2 days post partum, but total enzyme activity shows no significant change in the same period. 2. Immunotitrations of fatty acid synthetase and pyruvate dehydrogenase activities were carried out; the titrations showed that the change in the fatty acid synthetase activity is due to a change in the enzyme amount; the amount of pyruvate dyhydrogenase does not change. Therefore the decrease in fatty acid biosynthesis in subcutaneous and parametrial adipose tissue in late pregnancy and early lactation is associated with a decrease in the amount of at least one of the enzymes involved in fatty acid biosynthesis. The correlation of these events with known hormonal changes is discussed.

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Role and Regulation of Fatty Acid Biosynthesis in the Response of Shewanella piezotolerans WP3 to Different Temperatures and Pressures

Journal of Bacteriology ◽

10.1128/jb.00498-08 ◽

2009 ◽

Vol 191 (8) ◽

pp. 2574-2584 ◽

Cited By ~ 75

Author(s):

Feng Wang ◽

Xiang Xiao ◽

Hong-Yu Ou ◽

Yingbao Gai ◽

Fengping Wang

Keyword(s):

Fatty Acids ◽

High Pressure ◽

Fatty Acid ◽

Low Temperature ◽

Gene Cluster ◽

Fatty Acid Synthesis ◽

Fatty Acid Biosynthesis ◽

Acid Synthesis ◽

Different Temperatures ◽

Branched Chain

ABSTRACT Members of the genus Shewanella inhabit various environments; they are capable of synthesizing various types of low-melting-point fatty acids, including monounsaturated fatty acids (MUFA) and branched-chain fatty acids (BCFA) with and without eicosapentanoic acid (EPA). The genes involved in fatty acid synthesis in 15 whole-genome-sequenced Shewanella strains were identified and compared. A typical type II fatty acid synthesis pathway in Shewanella was constructed. A complete EPA synthesis gene cluster was found in all of the Shewanella genomes, although only a few of them were found to produce EPA. The roles and regulation of fatty acids synthesis in Shewanella were further elucidated in the Shewanella piezotolerans WP3 response to different temperatures and pressures. The EPA and BCFA contents of WP3 significantly increased when it was grown at low temperature and/or under high pressure. EPA, but not MUFA, was determined to be crucial for its growth at low temperature and high pressure. A gene cluster for a branched-chain amino acid ABC transporter (LIV-I) was found to be upregulated at low temperature. Combined approaches, including mutagenesis and an isotopic-tracer method, revealed that the LIV-I transporter played an important role in the regulation of BCFA synthesis in WP3. The LIV-I transporter was identified only in the cold-adapted Shewanella species and was assumed to supply an important strategy for Shewanella cold adaptation. This is the first time the molecular mechanism of BCFA regulation in bacteria has been elucidated.

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Morphological Features and Cold-Response Gene Expression in Mesophilic Bacillus cereus Group and Psychrotolerant Bacillus cereus Group under Low Temperature

Microorganisms ◽

10.3390/microorganisms9061255 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1255

Author(s):

Kyung-Min Park ◽

Hyun-Jung Kim ◽

Min-Sun Kim ◽

Minseon Koo

Keyword(s):

Gene Expression ◽

Fatty Acid ◽

Low Temperature ◽

Bacillus Cereus ◽

Low Temperatures ◽

Fatty Acid Biosynthesis ◽

Morphological Changes ◽

Growth Strategies ◽

Acid Biosynthesis ◽

Bacillus Cereus Group

At low temperatures, psychrotolerant B. cereus group strains exhibit a higher growth rate than mesophilic strains do. However, the different survival responses of the psychrotolerant strain (BCG34) and the mesophilic strain (BCGT) at low temperatures are unclear. We investigated the morphological and genomic features of BCGT and BCG34 to characterize their growth strategies at low temperatures. At low temperatures, morphological changes were observed only in BCGT. These morphological changes included the elongation of rod-shaped cells, whereas the cell shape in BCG34 was unchanged at the low temperature. A transcriptomic analysis revealed that both species exhibited different growth-related traits during low-temperature growth. The BCGT strain induces fatty acid biosynthesis, sulfur assimilation, and methionine and cysteine biosynthesis as a survival mechanism in cold systems. Increases in energy metabolism and fatty acid biosynthesis in the mesophilic B. cereus group strain might explain its ability to grow at low temperatures. Several pathways involved in carbohydrate mechanisms were downregulated to conserve the energy required for growth. Peptidoglycan biosynthesis was upregulated, implying that a change of gene expression in both RNA-Seq and RT-qPCR contributed to sustaining its growth and rod shape at low temperatures. These results improve our understanding of the growth response of the B. cereus group, including psychrotolerant B. cereus group strains, at low temperatures and provide information for improving bacterial inhibition strategies in the food industry.

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Transcriptional Profiles of Long Non-coding RNAs Involved in Fatty Acid Biosynthesis at Filling Stage of Soybean Pods

10.21203/rs.3.rs-853545/v1 ◽

2021 ◽

Author(s):

Bohan Ma ◽

Yue Li ◽

Mohamed Khalifa ◽

Meng Teng ◽

Aijing Zhang ◽

...

Keyword(s):

Fatty Acid ◽

Fatty Acid Synthesis ◽

High Throughput Sequencing ◽

Target Genes ◽

Fatty Acid Biosynthesis ◽

Acid Synthesis ◽

Published Data ◽

Acid Biosynthesis ◽

Non Coding Rnas ◽

Low Linolenic

Abstract Background: Long non-coding RNAs (lncRNAs) are non-coding RNAs of more than 200 nucleotides. To date, the roles of lncRNAs in soybean fatty acid synthesis have not been fully studied. Here, the low-linolenic acid ‘mutant 72’ (MT72) and the wild-type control ‘JiNong 18’(JN18) were used. Based on the previously published data on lncRNAs related RNA-seq in young pods of soybean 30 d to 40 d after flowering, lncRNAs and mRNAs from soybean pods 50 d after flowering were identified using high-throughput sequencing. The possible target genes of lncRNAs were predicted, and the functions related to fatty acid synthesis were analyzed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG).Results: A total of 10,500 lncRNAs and 54,370 mRNAs were identified, and 115 possible target genes of 1,805 differentially expressed lncRNAs were found to be involved in fatty acid synthesis. A network of lncRNAs and mRNAs was constructed, and a total of 604 lncRNAs and 1,484 mRNAs had regulatory relationships. Among them, 115 target genes of 77 lncRNAs were directly or indirectly involved in fatty acid biosynthesis.Conclusions: The function related to fatty acid synthesis was predicted by differential expression of the target gene mRNAs interacting with lncRNAs. In conclusion, our results provide a theoretical basis for studies on fatty acid synthesis of lncRNAs in soybean.

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Genome-Wide Mapping of Histone H3 Lysine 4 Trimethylation (H3K4me3) and Its Involvement in Fatty Acid Biosynthesis in Sunflower Developing Seeds

Plants ◽

10.3390/plants10040706 ◽

2021 ◽

Vol 10 (4) ◽

pp. 706

Author(s):

Antonio J. Moreno-Pérez ◽

Raquel Martins-Noguerol ◽

Cristina DeAndrés-Gil ◽

Mónica Venegas-Calerón ◽

Rosario Sánchez ◽

...

Keyword(s):

Fatty Acid ◽

Chromatin Remodeling ◽

Molecular Mechanisms ◽

Acid Metabolism ◽

Fatty Acid Biosynthesis ◽

Acid Synthesis ◽

Sunflower Seeds ◽

Acid Biosynthesis ◽

Functional Regions ◽

Genome Wide

Histone modifications are of paramount importance during plant development. Investigating chromatin remodeling in developing oilseeds sheds light on the molecular mechanisms controlling fatty acid metabolism and facilitates the identification of new functional regions in oil crop genomes. The present study characterizes the epigenetic modifications H3K4me3 in relationship with the expression of fatty acid-related genes and transcription factors in developing sunflower seeds. Two master transcriptional regulators identified in this analysis, VIV1 (homologous to Arabidopsis ABI3) and FUS3, cooperate in the regulation of WRINKLED 1, a transcriptional factor regulating glycolysis, and fatty acid synthesis in developing oilseeds.

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Effects of glucagon and insulin on fatty acid synthesis and glycogen degradation in the perfused liver of normal and genetically obese (ob/ob) mice

Biochemical Journal ◽

10.1042/bj1740761 ◽

1978 ◽

Vol 174 (3) ◽

pp. 761-768 ◽

Cited By ~ 16

Author(s):

G Y Ma ◽

C D Gove ◽

D A Hems

Keyword(s):

Fatty Acid ◽

Food Deprivation ◽

Fatty Acid Synthesis ◽

Fatty Acid Biosynthesis ◽

Glycogen Metabolism ◽

Acid Synthesis ◽

Significant Inhibition ◽

Perfused Liver ◽

Glucagon And Insulin ◽

Glycogen Breakdown

1. Rapid effects of hormones on glycogen metabolism and fatty acid synthesis in the perfused liver of the mouse were studied. 2. In perfusions lasting 2h, of livers from normal mice, glucagon in successive doses, each producing concentrations of 10(-10) or 10(-9)M, inhibited fatty acid and cholesterol synthesis. In perfusions lasting 40–50 min, in which medium was not recycled, inhibition of fatty acid synthesis was only observed with glucagon at concentrations greater than 10(-9)M. This concentration was about two orders of magnitude higher than that required for the stimulation of glycogen breakdown. Glucagon did not inhibit the activity of acetyl-CoA carboxylase, assayed 10 or 20 min after addition of glucagon (10(-9) or 10(-10)M). It is proposed that the action of glucagon on hepatic fatty acid biosynthesis could be secondary in time to depletion of glycogen. Insulin prevented the effect of glucagon (10(-10)M) on glycogenolysis, but not that of vasopressin. 3. Livers of genetically obese (ob/ob) mice did not show significant inhibition of lipid biosynthesis in response to glucagon, although there was normal acceleration of glycogen breakdown. This resistance to glucagon action was not reversed by food deprivation. Livers of obese mice exhibited resistance to the counteraction by insulin of glucagon-stimulated glycogenolysis, which was reversible by partial food deprivation.

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