Novel fatty acid elongases and their use for the reconstitution of docosahexaenoic acid biosynthesis

Meyer, Astrid; Kirsch, Helene; Domergue, Frédéric; Abbadi, Amine; Sperling, Petra; Bauer, Jörg; Cirpus, Petra; Zank, T.; Moreau, Hervé; Roscoe, Thomas; Zähringer, Ulrich; Heinz, Ernst

doi:10.1194/jlr.m400181-jlr200

Cited by 169 publications

(199 citation statements)

References 32 publications

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“…18:3n3, 20:5n3, or 22:5n3 can be converted to VLC-PUFA through consecutive enzymatic activities of desaturases and elongases. Although some elongases are specific for a single step, others are nonspecific or multifunctional and act at several steps (e.g., human ELOVL5 and murine ELOVL2) (11). We propose that ELOVL4 is essential for elongation of saturated 26:0 to 28:0 and of 26:5n3 to 28:5n3.…”

Section: Discussionmentioning

confidence: 99%

“…For example, the yeast microsomal Elo1p is responsible for elongation of carbon chains between 14:0 and 16:0 (9). Yeast Elo2p and Elo3p, and mammalian ELOVL1, 2, 3, and 5 have been shown to be involved in elongation of saturated, monounsaturated, or polyunsaturated fatty acids (PUFA) from 18 to 26 carbons (10)(11)(12). However, a role for ELOVL4 protein in fatty acid elongation and the specific step(s) it may catalyze have remained elusive (13,14).…”

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confidence: 99%

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Role of Stargardt-3 macular dystrophy protein (ELOVL4) in the biosynthesis of very long chain fatty acids

Agbaga

Brush

Mandal

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

241

346

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Stargardt-like macular dystrophy (STGD3) is a dominantly inherited juvenile macular degeneration that eventually leads to loss of vision. Three independent mutations causing STGD3 have been identified in exon six of a gene named Elongation of very long chain fatty acids 4 (ELOVL4). The ELOVL4 protein was predicted to be involved in fatty acid elongation, although evidence for this and the specific step(s) it may catalyze have remained elusive. Here, using a gain-of-function approach, we provide direct and compelling evidence that ELOVL4 is required for the synthesis of C28 and C30 saturated fatty acids (VLC-FA) and of C28-C38 very long chain polyunsaturated fatty acids (VLC-PUFA), the latter being uniquely expressed in retina, sperm, and brain. Rat neonatal cardiomyocytes and a human retinal epithelium cell line (ARPE-19) were transduced with recombinant adenovirus type 5 carrying mouse Elovl4 and supplemented with 24:0, 20:5n3, or 22:5n3. The 24:0 was elongated to 28:0 and 30:0; 20:5n3 and 22:5n3 were elongated to a series of C28-C38 PUFA. Because retinal degeneration is the only known phenotype in STGD3 disease, we propose that reduced VLC-PUFA in the retinas of these patients may be the cause of photoreceptor cell death.fatty acid biosynthesis ͉ macular degeneration T hree independent mutations in the last exon (exon-VI) of the ELOVL4 gene are associated with dominant Stargardt-like macular dystrophy (STGD3) in humans (1-4). These mutations cause a frame-shift that introduces a stop codon, resulting in premature termination of the protein and removal of the signal sequence for targeting the protein to its putative cellular location, the endoplasmic reticulum (1, 4). As a result, the mutant protein mis-localizes and aggregates (3,5,6), and, when coexpressed with the wild type protein, the mutant and wild-type proteins associate and mis-localize (3, 7). Based on sequence homology with a group of functional yeast genes and other mammalian ELOVLs, the ELOVL4 protein was predicted to be involved in elongation of very long chain fatty acids (1,5,8). For example, the yeast microsomal Elo1p is responsible for elongation of carbon chains between 14:0 and 16:0 (9). Yeast Elo2p and Elo3p, and mammalian ELOVL1, 2, 3, and 5 have been shown to be involved in elongation of saturated, monounsaturated, or polyunsaturated fatty acids (PUFA) from 18 to 26 carbons (10-12). However, a role for ELOVL4 protein in fatty acid elongation and the specific step(s) it may catalyze have remained elusive (13,14). Based on the abundant expression of ELOVL4 protein in photoreceptor cells of the retina (15-17) and to lesser extents in brain, testis, and skin (17), it was first hypothesized that ELOVL4 may be involved in the biosynthetic pathway of docosahexaenoic acid (22:6n3, DHA), the most abundant PUFA in the retina and the brain (1,16,18). A series of experiments carried out in our laboratory (unpublished data) does not support this hypothesis.Recent reports establish ELOVL4 as an essential protein for growth and development, as neonatal ...

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Role of Stargardt-3 macular dystrophy protein (ELOVL4) in the biosynthesis of very long chain fatty acids

Agbaga

Brush

Mandal

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

241

346

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“…As the first step towards generation of transgenic marine fish, we cloned and over-expressed a masu salmon (Oncorhynchus masou) MELO gene in the model species zebrafish (Danio rerio). Based on the predicted topology, consensus sequences, and sequence homologies, MELO are in excellent agreement with expected structural traits of elongases (Leonard et al, 2002;Hasting et al, 2004;Meyer et al, 2004;Agaba et al, 2004Agaba et al, , 2005.…”

Section: Transgenic Fish Carrying Melo Genementioning

confidence: 51%

Over-Expression of Gene Encoding Fatty Acid Metabolic Enzymes in Fish

Alimuddin

Yoshizaki

Takeuchi

et al. 2008

Indonesian Aquaculture Journal

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Eicosapentaenoic acid (EPA, and docosahexaenoic acid (DHA, 22:6n-3) have important nutritional benefits in humans. EPA and DHA are mainly derived from fish, but the decline in the stocks of major marine capture fishes could result in these fatty acids being consumed less. Farmed fish could serve as promising sources of EPA and DHA, but they need these fatty acids in their diets. Generation of fish strains that are capable of synthesizing enough amounts of EPA/DHA from the conversion of α-linolenic acid (LNA, 18:3n-3) rich oils can supply a new EPA/DHA source. This may be achieved by over-expression of genes encoding enzymes involved in HUFA biosynthesis. In aquaculture, the successful of this technique would open the possibility to reduce the enrichment of live food with fish oils for marine fish larvae, and to completely substitute fish oils with plant oils without reducing the quality of flesh in terms of EPA and DHA contents. Here, three genes, i.e. Δ6-desaturase-like (OmΔ6FAD), Δ5-desaturase-like (OmΔ5FAD) and elongase-like (MELO) encoding EPA/ DHA metabolic enzymes derived from masu salmon (Oncorhynchus masou) were individually transferred into zebrafish (Danio rerio) as a model to increase its ability for synthesizing EPA and DHA. Fatty acid analysis showed that EPA content in whole body of the second transgenic fish generation over-expressing OmΔ6FAD gene was 1.4 fold and that of DHA was 2.1 fold higher (P<0.05) than those in non-transgenic fish. The EPA content in whole body of transgenic fish over-expressing OmΔ5FAD gene was 1.21-fold, and that of DHA was 1.24-fold higher (P<0.05) than those in nontransgenic fish. The same patterns were obtained in transgenic fish over-expressing MELO gene. EPA content was increased by 1.30-fold and DHA content by 1.33-fold higher (P<0.05) than those in non-transgenic fish. The results of studies demonstrated that fatty acid content of fish can be enhanced by over-expressing gene encoding enzymes involved in fatty acid biosynthesis, and perhaps this could be applied to tailor farmed fish as even better sources of valuable human food.

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“…The low specificity of PUFA elongases appears to be common in vertebrates. In contrast, ELO-like PUFA elongases from lower eukaryotes are able to discriminate between C18 and C20 acyl-CoA and the position of the first double bond of substrates (14,29).…”

Section: Aerobic Pathwaymentioning

confidence: 99%

“…The diatom Thalassiosira pseudonana synthesizes DHA by the action of D6, D5 and D4 front-end desaturases and C18 D6 and C20 D5 elongases. All corresponding genes were cloned and the encoded products functionally characterized, including an exceptional type I D11 desaturase, specific for 16:0, which contains an N-terminal cytochrome b5 domain (29,38). As mentioned before, Schizochytrium synthesizes PUFAs by PKS, whereas Thraustochytrium contains at least D5 and D4 desaturases (30), indicating that both the aerobic and anaerobic routes can coexist in the same group of organisms.…”

Section: Pathways Found In Lower Eukaryotesmentioning

confidence: 99%

Biosynthesis of polyunsaturated fatty acids in lower eukaryotes

Uttaro

2006

IUBMB Life

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SummaryPolyunsaturated fatty acids have important structural roles in cell membranes. They are also intermediates in the synthesis of biologically active molecules such as eicosanoids, which mediate fever, inflammation, blood pressure and neurotransmission. Arachidonic and docosahexaenoic acids are essential components of brain tissues and, through their involvement in the development of neural and retinal functions, important dietary nutrients for neonatal babies. Lower eukaryotes are particularly rich in C20-22 polyunsaturated fatty acids. Fungi and marine microalgae are currently used to produce nutraceutic oils. Other protists and algae are being studied because of the variability in their enzymes involved in polyunsaturated fatty acid biosynthesis. Such enzymes could be used as source for the production of transgenic organisms able to synthesize designed oils for human diet or, in the case of parasitic protozoa, they might be identified as putative chemotherapeutic targets. Polyunsaturated fatty acids can be synthesized by two different pathways: an anaerobic one, by using polyketide synthase related enzymes, and an aerobic one, which involves the action of elongases and oxygen dependent desaturases. Desaturases can be classified into three main types, depending on which of the consecutive steps of polyunsaturated fatty acid synthesis they are involved with. The enzymes may be specialized to act on: saturated substrates (type I); mono-and di-unsaturated fatty acids by introducing additional double bonds at the methyl-end site of the existing double bonds (type II); or the carboxy half ('front-end') of polyunsaturated ones (type III). Type III desaturases require the alternating action of elongases. A description of the enzymes that have been isolated and functionally characterized is provided, in order to highlight the different pathways found in lower eukaryotes.

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Novel fatty acid elongases and their use for the reconstitution of docosahexaenoic acid biosynthesis

Cited by 169 publications

References 32 publications

Role of Stargardt-3 macular dystrophy protein (ELOVL4) in the biosynthesis of very long chain fatty acids

Role of Stargardt-3 macular dystrophy protein (ELOVL4) in the biosynthesis of very long chain fatty acids

Over-Expression of Gene Encoding Fatty Acid Metabolic Enzymes in Fish

Biosynthesis of polyunsaturated fatty acids in lower eukaryotes

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