scholarly journals Fatty acid biosynthesis in the leaves of barley, wheat and pea

1978 ◽  
Vol 174 (1) ◽  
pp. 163-169 ◽  
Author(s):  
J Wharfe ◽  
J L Harwood
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Pulse Labelling ◽  
Acid Biosynthesis ◽  
Single Experiment ◽  
Acyl Lipids

1. The incorporation of radioactivity from [1-14C]acetate into the leaf lipids of barley, pea and wheat has been studied in pulse-labelling experiments. 2. There was little increase in the total labelling of lipids after the leaves were transferred to non-radioactive medium. However, there was an increase in the relative labelling of unsaturated fatty acids. In addition, there was an increase in the relative labelling of diacylgalactosylglycerol. 3. The principal radioactively labelled acyl lipids were diacylgalactosylglycerol and phosphatidylcholine. Phosphatidylcholine showed a decreasing proportion of [14C]oleate and an increasing amount of [14C]linoleate with time. Diacylgalactosylglycerol also had decreasing amounts of [14C]oleate but, in addition, had an increasing proportion of [14C]linolenate with time. 4. The absence of significant amounts of [14C]linolenate in phosphatidylcholine appeared to exclude a role for this phospholipid in linoleate desaturation. 5. The specific radioactivities of oleate and linoleate in phosphatidylcholine, diacylgalactosylglycerol and diacylgalabiosylglycerol were very similar in any single experiment. It was concluded that these fatty acids can rapidly exchange between the three intact lipids.

scholarly journals The same rat Δ6-desaturase not only acts on 18- but also on 24-carbon fatty acids in very-long-chain polyunsaturated fatty acid biosynthesis

2002 ◽  
Vol 364 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Sabine D'ANDREA ◽  
Hervé GUILLOU ◽  
Sophie JAN ◽  
Daniel CATHELINE ◽  
Jean-Noël THIBAULT ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Chain Polyunsaturated Fatty Acid ◽  
Acid Biosynthesis ◽  
Highly Unsaturated Fatty Acids ◽  
Long Chain ◽  
Δ6 Desaturase

The recently cloned Δ6-desaturase is known to catalyse the first step in very-long-chain polyunsaturated fatty acid biosynthesis, i.e. the desaturation of linoleic and α-linolenic acids. The hypothesis that this enzyme could also catalyse the terminal desaturation step, i.e. the desaturation of 24-carbon highly unsaturated fatty acids, has never been elucidated. To test this hypothesis, the activity of rat Δ6-desaturase expressed in COS-7 cells was investigated. Recombinant Δ6-desaturase expression was analysed by Western blot, revealing a single band at 45kDa. The putative involvement of this enzyme in the Δ6-desaturation of C24:5n-3 to C24:6n-3 was measured by incubating transfected cells with C22:5n-3. Whereas both transfected and non-transfected COS-7 cells were able to synthesize C24:5n-3 by elongation of C22:5n-3, only cells expressing Δ6-desaturase were also able to produce C24:6n-3. In addition, Δ6-desaturation of [1-14C]C24:5n-3 was assayed invitro in homogenates from COS-7 cells expressing Δ6-desaturase or not, showing that Δ6-desaturase catalyses the conversion of C24:5n-3 to C24:6n-3. Evidence is therefore presented that the same rat Δ6-desaturase catalyses not only the conversion of C18:3n-3 to C18:4n-3, but also the conversion of C24:5n-3 to C24:6n-3. A similar mechanism in the n-6 series is strongly suggested.

scholarly journals Identification of genes associated with the biosynthesis of unsaturated fatty acid and oil accumulation in herbaceous peony ‘Hangshao’ (Paeonia lactiflora ‘Hangshao’) seeds based on transcriptome analysis

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jia-Song Meng ◽  
Yu-Han Tang ◽  
Jing Sun ◽  
Da-Qiu Zhao ◽  
Ke-Liang Zhang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Unsaturated Fatty Acid ◽  
Molecular Mechanisms ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Paeonia Lactiflora ◽  
Acid Biosynthesis ◽  
Oil Accumulation ◽  
Herbaceous Peony

Abstract Background Paeonia lactiflora ‘Hangshao’ is widely cultivated in China as a traditional Chinese medicine ‘Radix Paeoniae Alba’. Due to the abundant unsaturated fatty acids in its seed, it can also be regarded as a new oilseed plant. However, the process of the biosynthesis of unsaturated fatty acids in it has remained unknown. Therefore, transcriptome analysis is helpful to better understand the underlying molecular mechanisms. Results Five main fatty acids were detected, including stearic acid, palmitic acid, oleic acid, linoleic acid and α-linolenic acid, and their absolute contents first increased and then decreased during seed development. A total of 150,156 unigenes were obtained by transcriptome sequencing. There were 15,005 unigenes annotated in the seven functional databases, including NR, NT, GO, KOG, KEGG, Swiss-Prot and InterPro. Based on the KEGG database, 1766 unigenes were annotated in the lipid metabolism. There were 4635, 12,304, and 18,291 DEGs in Group I (60 vs 30 DAF), Group II (90 vs 60 DAF) and Group III (90 vs 30 DAF), respectively. A total of 1480 DEGs were detected in the intersection of the three groups. In 14 KEGG pathways of lipid metabolism, 503 DEGs were found, belonging to 111 enzymes. We screened out 123 DEGs involved in fatty acid biosynthesis (39 DEGs), fatty acid elongation (33 DEGs), biosynthesis of unsaturated fatty acid (24 DEGs), TAG assembly (17 DEGs) and lipid storage (10 DEGs). Furthermore, qRT-PCR was used to analyze the expression patterns of 16 genes, including BBCP, BC, MCAT, KASIII, KASII, FATA, FATB, KCR, SAD, FAD2, FAD3, FAD7, GPAT, DGAT, OLE and CLO, most of which showed the highest expression at 45 DAF, except for DGAT, OLE and CLO, which showed the highest expression at 75 DAF. Conclusions We predicted that MCAT, KASIII, FATA, SAD, FAD2, FAD3, DGAT and OLE were the key genes in the unsaturated fatty acid biosynthesis and oil accumulation in herbaceous peony seed. This study provides the first comprehensive genomic resources characterizing herbaceous peony seed gene expression at the transcriptional level. These data lay the foundation for elucidating the molecular mechanisms of fatty acid biosynthesis and oil accumulation for herbaceous peony.

scholarly journals Competence-associated peptide BriC alters fatty acid biosynthesis in Streptococcus pneumoniae

2021 ◽  
Author(s):  
Surya D. Aggarwal ◽  
Jessica M. Gullett ◽  
Tara Fedder ◽  
J. Pedro F. Safi ◽  
Charles O. Rock ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Cell Communication ◽  
Host Adaptation ◽  
Acid Biosynthesis ◽  
Biofilm Development ◽  
Cell Cell

ABSTRACTMembrane lipid homeostasis is required for bacteria to survive in a spectrum of host environments. This homeostasis is achieved by regulation of fatty acid chain length and of the ratio of saturated to unsaturated fatty acids. In the pathogen Streptococcus pneumoniae, fatty acid biosynthesis is encoded by a cluster of fatty acid biosynthesis (fab) genes (FASII locus) whose expression is controlled by the FabT repressor. Encoded immediately downstream of the FASII locus is BriC, a competence-induced, cell-cell communication peptide that promotes biofilm development as well as nasopharyngeal colonization in a murine model of pneumococcal carriage. Here, we demonstrate that briC is co-transcribed with genes of the fab gene cluster and that a reduction of briC levels, caused by decoupling its transcription from fab gene cluster, negatively impacts biofilm development. BriC elevates fabT transcription, which is predicted to alter the balance of saturated and unsaturated fatty acids produced by the pathway. We find that briC inactivation results in a decreased production of unsaturated fatty acids that impact the membrane properties by decreasing the abundance of di-unsaturated phosphatidylglycerol molecular species. We propose that the link between BriC, FabT and phospholipid composition contributes to the ability of S. pneumoniae to alter membrane homeostasis in response to the production of a quorum-sensing peptide.IMPORTANCEAdaptation of bacteria to their host environment is a key component of colonization and pathogenesis. As an essential component of bacterial membranes, fatty acid composition contributes to host adaptation. Similarly, so does cell-cell communication, which serves as a mechanism for population levels responses. While much is known about the pathways that control the biosynthesis of fatty acids, many questions remain regarding regulation of these pathways and consequently the factors that impacts the balance between saturated and unsaturated fatty acids. We find that BriC, a cell-cell communication peptide implicated in biofilm regulation and colonization, is both influenced by a fatty acid biosynthesis pathway and impacts this same pathway. This study identified a link between cell-cell communication, fatty acid composition, and biofilms and, in doing so, suggests that these pathways are integrated into the networks that control pneumococcal colonization and host adaptation.

scholarly journals Transformation with Oncogenic Ras and the Simian Virus 40 T Antigens Induces Caspase-Dependent Sensitivity to Fatty Acid Biosynthetic Inhibition

2015 ◽  
Vol 89 (12) ◽  
pp. 6406-6417 ◽  
Author(s):  
Shihao Xu ◽  
Cody M. Spencer ◽  
Joshua Munger
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigens ◽  
Acid Biosynthesis ◽  
Oncogenic Ras ◽  
Cancerous Cells

ABSTRACTOncogenesis is frequently accompanied by the activation of specific metabolic pathways. One such pathway is fatty acid biosynthesis, whose induction is observed upon transformation of a wide variety of cell types. Here, we explored how defined oncogenic alleles, specifically the simian virus 40 (SV40) T antigens and oncogenic Ras12V, affect fatty acid metabolism. Our results indicate that SV40/Ras12V-mediated transformation of fibroblasts induces fatty acid biosynthesis in the absence of significant changes in the concentration of fatty acid biosynthetic enzymes. This oncogene-induced activation of fatty acid biosynthesis was found to be mammalian target of rapamycin (mTOR) dependent, as it was attenuated by rapamycin treatment. Furthermore, SV40/Ras12V-mediated transformation induced sensitivity to treatment with fatty acid biosynthetic inhibitors. Pharmaceutical inhibition of acetyl-coenzyme A (CoA) carboxylase (ACC), a key fatty acid biosynthetic enzyme, induced caspase-dependent cell death in oncogene-transduced cells. In contrast, isogenic nontransformed cells were resistant to fatty acid biosynthetic inhibition. This oncogene-induced sensitivity to fatty acid biosynthetic inhibition was independent of the cells' growth rates and could be attenuated by supplementing the medium with unsaturated fatty acids. Both the activation of fatty acid biosynthesis and the sensitivity to fatty acid biosynthetic inhibition could be conveyed to nontransformed breast epithelial cells through transduction with oncogenic Ras12V. Similar to what was observed in the transformed fibroblasts, the Ras12V-induced sensitivity to fatty acid biosynthetic inhibition was independent of the proliferative status and could be attenuated by supplementing the medium with unsaturated fatty acids. Combined, our results indicate that specific oncogenic alleles can directly confer sensitivity to inhibitors of fatty acid biosynthesis.IMPORTANCEViral oncoproteins and cellular mutations drive the transformation of normal cells to the cancerous state. These oncogenic alterations induce metabolic changes and dependencies that can be targeted to kill cancerous cells. Here, we find that the cellular transformation resulting from combined expression of the SV40 early region with an oncogenic Ras allele is sufficient to induce cellular susceptibility to fatty acid biosynthetic inhibition. Inhibition of fatty acid biosynthesis in these cells resulted in programmed cell death, which could be rescued by supplementing the medium with nonsaturated fatty acids. Similar results were observed with the expression of oncogenic Ras in nontransformed breast epithelial cells. Combined, our results suggest that specific oncogenic alleles induce metabolic dependencies that can be exploited to selectively kill cancerous cells.

scholarly journals NodFE-Dependent Fatty Acids That Lack an α-β Unsaturation Are Subject to Differential Transfer, Leading to Novel Phospholipids

1998 ◽  
Vol 11 (1) ◽  
pp. 33-44 ◽  
Author(s):  
Otto Geiger ◽  
John Glushka ◽  
Ben J. J. Lugtenberg ◽  
Herman P. Spaink ◽  
Jane E. Thomas-Oates
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Rhizobium Leguminosarum ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Fatty Acyl Chain ◽  
Acid Biosynthesis ◽  
Fatty Acid Trans

In Rhizobium leguminosarum, the nodABC and nodFEL operons are involved in the production of lipo-chitin oligosaccharide signals that mediate host specificity. A nodFE-determined, highly unsaturated C18:4 fatty acid (trans-2, trans-4, trans-6, cis-11-octadecatetraenoic acid) is essential for the ability of the signals to induce nodule meristems and pre-infection thread structures on the host plant Vicia sativa. Of the nod genes, induction of only nodFE is sufficient to modify fatty acid biosynthesis to yield trans-2, trans-4, trans-6, cis-11-octadeca-tetraenoic acid, with an absorbance maximum of 303 nm. This unusual C18:4 fatty acid is not only found in the lipo-chitin oligosaccharides but is also associated with the phospholipids (O. Geiger, J. E. Thomas-Oates, J. Glushka, H. P. Spaink, and B. J. J. Lugtenberg, 1994, J. Biol. Chem. 269:11090-11097). Here we report that the phospholipids can contain other nodFE-derived fatty acids, a C18:3 trans-4, trans-6, cis-11-octadecatrienoic acid that has a characteristic absorption maximum at 225 nm, and a C18:2 octadecadienoic acid. Neither this C18:3 nor this C18:2 fatty acid has to date been observed attached to lipo-chitin oligosaccharides, suggesting that an as yet unknown acyl transferase (presumably NodA), responsible for the transfer of the fatty acyl chain to the glycan backbone of the lipo-chitin oligosaccharides, does not transfer all fatty acids synthesized by the action of NodFE to the lipo-chitin oligosaccharides. Rather, it must have a preference for α-β unsaturated fatty acids during transfer.

scholarly journals A kinetic rationale for functional redundancy in fatty acid biosynthesis

2020 ◽  
Vol 117 (38) ◽  
pp. 23557-23564
Author(s):  
Alex Ruppe ◽  
Kathryn Mains ◽  
Jerome M. Fox
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Average Length ◽  
Functional Redundancy ◽  
Experimental Investigations ◽  
Total Production

Cells build fatty acids with biocatalytic assembly lines in which a subset of enzymes often exhibit overlapping activities (e.g., two enzymes catalyze one or more identical reactions). Although the discrete enzymes that make up fatty acid pathways are well characterized, the importance of catalytic overlap between them is poorly understood. We developed a detailed kinetic model of the fatty acid synthase (FAS) ofEscherichia coliand paired that model with a fully reconstituted in vitro system to examine the capabilities afforded by functional redundancy in fatty acid synthesis. The model captures—and helps explain—the effects of experimental perturbations to FAS systems and provides a powerful tool for guiding experimental investigations of fatty acid assembly. Compositional analyses carried out in silico and in vitro indicate that FASs with multiple partially redundant enzymes enable tighter (i.e., more independent and/or broader range) control of distinct biochemical objectives—the total production, unsaturated fraction, and average length of fatty acids—than FASs with only a single multifunctional version of each enzyme (i.e., one enzyme with the catalytic capabilities of two partially redundant enzymes). Maximal production of unsaturated fatty acids, for example, requires a second dehydratase that is not essential for their synthesis. This work provides a kinetic, control-theoretic rationale for the inclusion of partially redundant enzymes in fatty acid pathways and supplies a valuable framework for carrying out detailed studies of FAS kinetics.

SYNTHESIS OF FATTY ACIDS BY TESTICULAR TISSUE IN VITRO

1963 ◽  
Vol 41 (1) ◽  
pp. 1267-1274
Author(s):  
Peter F. Hall ◽  
Edward E. Nishizawa ◽  
Kristen B. Eik-Nes
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Fatty Acid Fraction ◽  
Testicular Tissue ◽  
Acid Biosynthesis ◽  
Adrenal Tissue ◽  
Substrate Fatty Acid

The fatty acids palmitic, palmitoleic, stearic, and oleic have been isolated from rabbit testis and evidence for the synthesis of palmitic and stearic acids de novo from acetate-1-C14is presented. ICSH did not produce demonstrable stimulation of the synthesis of these acids in vitro although the hormone stimulated the production of testosterone-C14by the same tissue. Adrenal tissue was shown to contain palmitic, stearic, and oleic acids, and ACTH did not increase the incorporation of acetate-1-C14into a fatty acid fraction extracted following incubation of adrenal tissue in the presence of this substrate. Fatty acid biosynthesis, therefore, is probably not influenced by the mechanisms by which tropic hormones increase steroid formation.

scholarly journals Fatty acid biosynthesis revisited: structure elucidation and metabolic engineering

2015 ◽  
Vol 11 (1) ◽  
pp. 38-59 ◽  
Author(s):  
Joris Beld ◽  
D. John Lee ◽  
Michael D. Burkart
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Metabolic Engineering ◽  
Structure Elucidation ◽  
Fatty Acid Biosynthesis ◽  
Acid Biosynthesis ◽  
Primary Metabolites ◽  
Biosynthetic Machinery

Fatty acids are primary metabolites synthesized by complex, elegant, and essential biosynthetic machinery.

Thiocarbamate Inhibition of Fatty Acid Biosynthesis in Isolated Spinach Chloroplasts

Weed Science ◽  
1975 ◽  
Vol 23 (2) ◽  
pp. 100-104 ◽  
Author(s):  
R. E. Wilkinson ◽  
A. E. Smith
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
Spinacia Oleracea ◽  
Lipid Synthesis ◽  
Metabolic Effects ◽  
Acid Biosynthesis ◽  
Spinach Chloroplasts ◽  
Physiological Range

EPTC (S-ethyl dipropylthiocarbamate) (33μM) and diallate [S-(2,3-dichloroallyl)diisopropylthiocarbamate] (90μM) inhibited the incorporation of 6 mM acetate-2-14C (Ac∗) by 80% and 65%, respectively, and the incorporation of 0.5μM malonate-2-14C (Mal∗) by 32% and 26%, respectively, into the lipids of spinach (Spinacia oleraceaL.) chloroplasts. The inhibition of Ac∗or Mal∗incorporation into lipids was not observed in the presence of excess Ac∗or Mal∗, respectively. Incorporation of palmitate-1-14C and oleate-1-14C into chloroplast lipids was inhibited by EPTC and diallate. Mal∗incorporation into dienoic fatty acids was inhibited by EPTC and diallate. The concentration of EPTC and diallate inhibiting lipid synthesis falls into the physiological range of these herbicides, explains some metabolic effects of these compounds, and fits as the mode of activity of these herbicides.

Effect of Thiolactomycin on de novo Fatty Acid Biosynthesis in Plants

1990 ◽  
Vol 45 (5) ◽  
pp. 518-520 ◽  
Author(s):  
Manfred Focke ◽  
Andrea Feld ◽  
Hartmut K. Lichtenthaler
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Fatty Acid Synthetase ◽  
Acetate Incorporation ◽  
Acid Biosynthesis ◽  
Acetyl Coa ◽  
Malonyl Coa ◽  
Total Fatty Acids

Thiolactomycin was shown to be a potent inhibitor of de novo fatty acid biosynthesis in intact isolated chloroplasts (measured as [14C]acetate incorporation into total fatty acids). In our attempt to further localize the inhibition site we confirmed the inhibition with a fatty acid synthetase preparation, measuring the incorporation of [14C]malonyl-CoA into total fatty acids. From the two proposed enzymic targets of the fatty acid synthetase by thiolactomycin we could exclude the acetyl-CoA: ACP transacetylase. It appears that the inhibition by thiolactomycin occurs on the level of the condensing enzymes, i.e. the 3-oxoacyl-ACP synthases. We also demonstrated that the two starting enzymes of de novo fatty acid biosynthesis, the acetyl-CoA synthetase and the acetyl-CoA carboxylase, are not affected by thiolactomycin.

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