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Smirnova EO, Lantsova NV, Hamberg M, Toporkova YY, Grechkin AN. The versatile CYP74 clan enzyme CYP440A19 from the European lancelet Branchiostoma lanceolatum biosynthesizes novel macrolactone, epoxydiene, and related oxylipins. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159507. [PMID: 38740178 DOI: 10.1016/j.bbalip.2024.159507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/23/2024] [Accepted: 05/08/2024] [Indexed: 05/16/2024]
Abstract
The present work reports the detection and cloning of a new CYP74 clan gene of the European lancelet (Branchiostoma lanceolatum) and the biochemical characterization of the recombinant protein CYP440A19. CYP440A19 possessed epoxyalcohol synthase (EAS) activity towards the 13-hydroperoxides of linoleic and α-linolenic acids, which were converted into oxiranylcarbinols, i.e., (11S,12R,13S)-11-hydroxy-12,13-epoxy derivatives. The conversion of 9-hydroperoxides produced distinct products. Linoleic acid 9(S)-hydroperoxide (9-HPOD) was mainly converted into 9,14-diol (10E,12E)-9,14-dihydroxy-10,12-octadecadienoic acid and macrolactone 9(S),10(R)-epoxy-11(E)-octadecen-13(S)-olide. In addition, (8Z)-colneleic acid was formed. Brief incubations of the enzyme with 9-HPOD in a biphasic system of hexane-water enabled the isolation of the short-lived 9,10-epoxydiene (9S,10R,11E,13E)-9,10-epoxy-11,13-octadecadienoic acid. The structure and stereochemistry of the epoxyalcohols, macrolactone, (8Z)-colneleic acid (Me), and 9,10-epoxydiene (Me) were confirmed by 1H-NMR, 1H-1H-COSY, 1H-13C-HSQC, and 1H-13C-HMBC spectroscopy. Macrolactone and cis-9,10-epoxydiene are novel products. The 9-hydroperoxide of α-linolenic acid was mainly converted into macrolactone 9(S),10(R)-epoxy-11(E),15(Z)-octadecadiene-13(S)-olide and a minority of divinyl ethers, particularly (8Z)-colnelenic acid. The versatility of enzyme catalysis, as well as the diversity of CYP74s and other enzymes involved in oxylipin biosynthesis, demonstrates the complexity of the lipoxygenase pathway in lancelets.
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Affiliation(s)
- Elena O Smirnova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, P.O. Box 261, 420111 Kazan, Russia.
| | - Natalia V Lantsova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, P.O. Box 261, 420111 Kazan, Russia
| | - Mats Hamberg
- Unit of Integrative Metabolomics, Institute of Environmental Medicine, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Yana Y Toporkova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, P.O. Box 261, 420111 Kazan, Russia
| | - Alexander N Grechkin
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, P.O. Box 261, 420111 Kazan, Russia.
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Shen Y, Li L, Luo X, Huang M, Ke C, You W, Li W. Prostaglandin E2 involvement in the reproduction of small abalone, Haliotis diversicolor. AQUACULTURE AND FISHERIES 2023. [DOI: 10.1016/j.aaf.2022.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Functional Characterization of Novel Bony Fish Lipoxygenase Isoforms and Their Possible Involvement in Inflammation. Int J Mol Sci 2022; 23:ijms232416026. [PMID: 36555666 PMCID: PMC9787790 DOI: 10.3390/ijms232416026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/10/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Eicosanoids and related compounds are pleiotropic lipid mediators, which are biosynthesized in mammals via three distinct metabolic pathways (cyclooxygenase pathway, lipoxygenase pathway, epoxygenase pathway). These mediators have been implicated in the pathogenesis of inflammatory diseases and drugs interfering with eicosanoid signaling are currently available as antiphlogistics. Eicosanoid biosynthesis has well been explored in mammals including men, but much less detailed information is currently available on eicosanoid biosynthesis in other vertebrates including bony fish. There are a few reports in the literature describing the expression of arachidonic acid lipoxygenases (ALOX isoforms) in several bony fish species but except for two zebrafish ALOX-isoforms (zfALOX1 and zfALOX2) bony fish eicosanoid biosynthesizing enzymes have not been characterized. To fill this gap and to explore the possible roles of ALOX15 orthologs in bony fish inflammation we cloned and expressed putative ALOX15 orthologs from three different bony fish species (N. furzeri, P. nyererei, S. formosus) as recombinant N-terminal his-tag fusion proteins and characterized the corresponding enzymes with respect to their catalytic properties (temperature-dependence, activation energy, pH-dependence, substrate affinity and substrate specificity with different polyenoic fatty acids). Furthermore, we identified the chemical structure of the dominant oxygenation products formed by the recombinant enzymes from different free fatty acids and from more complex lipid substrates. Taken together, our data indicate that functional ALOX isoforms occur in bony fish but that their catalytic properties are different from those of mammalian enzymes. The possible roles of these ALOX-isoforms in bony fish inflammation are discussed.
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Daniel D, Nunes B. Evaluation of single and combined effects of two pharmaceuticals on the marine gastropod Phorcus lineatus enzymatic activity under two different exposure periods. ECOTOXICOLOGY (LONDON, ENGLAND) 2021; 30:756-765. [PMID: 33829385 DOI: 10.1007/s10646-021-02396-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
Pharmaceutical drugs are among the most used chemicals for human and veterinary medicines, aquaculture and agriculture. Pharmaceuticals are environmentally persistent, biologically active molecules, thereby having the potential to exert biological effects on non-target species. Among the most used pharmaceuticals, one may find salicylic acid (SA), a non-steroid anti-inflammatory drug (NSAID) that acts by inhibiting the enzymes cyclooxigenases; it is also possible to identify acetazolamide (ACZ), a diuretic that acts by inhibiting the activity of carbonic anhydrase (CA). In this work, the effects of both single and combined effects of these drugs were assessed on the marine gastropod Phorcus lineatus, by measuring key enzymatic activities, namely carbonic anhydrase (CA) and cyclooxygenase (COX), under two different exposure periods (14 and 28 days). We observed no straightforward pattern of enzymatic response in all treatments of both pharmaceuticals, on both analyzed tissues (gut and gills), and for both exposure regimes. We assume that this species is not responsive to the hereby tested pharmaceuticals, a finding that may be due to general mechanisms of response to adverse conditions, such as reduction of metabolism, of heart rate, of filtration rates, and to the increase production of mucus. All these functional adaptations can mitigate the deleterious effects caused by adverse conditions, without triggering biochemical responses. In conclusion, the species P. lineatus seems not to be sensitive in terms of these specific enzymatic pathways to these contaminants, under the adopted conditions.
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Affiliation(s)
- David Daniel
- Departamento de Biologia, Universidade de Aveiro, Campus de Santiago, 3810-193, Aveiro, Portugal
| | - Bruno Nunes
- Departamento de Biologia, Universidade de Aveiro, Campus de Santiago, 3810-193, Aveiro, Portugal.
- Centro de Estudos do Ambiente e do Mar (CESAM), Universidade de Aveiro, Campus de Santiago, 3810-193, Aveiro, Portugal.
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Biochemical characterization of the cyclooxygenase enzyme in penaeid shrimp. PLoS One 2021; 16:e0250276. [PMID: 33886622 PMCID: PMC8062024 DOI: 10.1371/journal.pone.0250276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 04/01/2021] [Indexed: 11/24/2022] Open
Abstract
Cyclooxygenase (COX) is a two-step enzyme that converts arachidonic acid into prostaglandin H2, a labile intermediate used in the production of prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α). In vertebrates and corals, COX must be N-glycosylated on at least two asparagine residues in the N-(X)-S/T motif to be catalytically active. Although COX glycosylation requirement is well-characterized in many species, whether crustacean COXs require N-glycosylation for their enzymatic function have not been investigated. In this study, a 1,842-base pair cox gene was obtained from ovarian cDNA of the black tiger shrimp Penaeus monodon. Sequence analysis revealed that essential catalytic residues and putative catalytic domains of P. monodon COX (PmCOX) were well-conserved in relation to other vertebrate and crustacean COXs. Expression of PmCOX in 293T cells increased levels of secreted PGE2 and PGF2α up to 60- and 77-fold, respectively, compared to control cells. Incubation of purified PmCOX with endoglycosidase H, which cleaves oligosaccharides from N-linked glycoproteins, reduced the molecular mass of PmCOX. Similarly, addition of tunicamycin, which inhibits N-linked glycosylation, in PmCOX-expressing cells resulted in PmCOX protein with lower molecular mass than those obtained from untreated cells, suggesting that PmCOX was N-glycosylated. Three potential glycosylation sites of PmCOX were identified at N79, N170 and N424. Mutational analysis revealed that although all three residues were glycosylated, only mutations at N170 and N424 completely abolished catalytic function. Inhibition of COX activity by ibuprofen treatment also decreased the levels of PGE2 in shrimp haemolymph. This study not only establishes the presence of the COX enzyme in penaeid shrimp, but also reveals that N-glycosylation sites are highly conserved and required for COX function in crustaceans.
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Dionísio R, Daniel D, Arenas F, Campos JC, Costa PC, Nunes B, Correia AT. Effects of pH on salicylic acid toxicity in terms of biomarkers determined in the marine gastropod Gibbula umbilicalis. MARINE ENVIRONMENTAL RESEARCH 2020; 158:104995. [PMID: 32501266 DOI: 10.1016/j.marenvres.2020.104995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/10/2020] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
Alterations of the physical-chemical properties of the oceans due to anthropogenic activities are, at present, one of the most concerning environmental issues studied by researchers. One of these issues is ocean acidification, mainly caused by overproduction and release of carbon dioxide (CO2) from anthropogenic sources. Another component of environmental degradation is related to the production and release of potential toxic compounds, namely active pharmaceutical ingredients, into the aquatic environment that, combined with oceanic acidification, can cause unpredictable and never before considered deleterious effects on non-target marine organisms. Regarding this issue, the hereby study used predictions of future ocean acidification to simulate realistic scenarios of environmental exposure to a common therapeutic drug, salicylic acid (SA), in the marine gastropod Gibbula umbilicalis under different pH values. This species was exposed to a range of pH values (8.2, 7.9 and 7.6), and to already reported environmentally realistic concentrations (5, 25 and 125 μg/L) of SA. To evaluate the effects of these environmental stressors, key physiological biomarkers (GSTs, CAT, TBARS, AChE and COX) and shell hardness (SH) were quantified. Results from the present study showed that CAT and GSTs activities were enhanced by SA under water acidification; increased lipid peroxidation was also observed in organisms exposed to SA in more acidic media. In addition, the hereby study demonstrated the neurotoxic effects of SA through the inhibition of AChE. Effects were also observed in terms of COX activity, showing that SA absorption may be affected by water acidification. In terms of SH, the obtained data suggest that SA may alter the physical integrity of shells of exposed organisms. It is possible to conclude that the combination of seawater acidification and exposure to toxic xenobiotics (namely to the drug SA) may be strenuous to marine communities, making aquatic biota more susceptible to xenobiotics, and consequently endangering marine life in an unpredictable extent.
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Affiliation(s)
- Ricardo Dionísio
- Departamento de Biologia da Universidade de Aveiro (DBIO-UA), Campus de Santiago, 3810-193 Aveiro, Portugal; Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos S/N, 4450-208, Matosinhos, Portugal
| | - David Daniel
- Departamento de Biologia da Universidade de Aveiro (DBIO-UA), Campus de Santiago, 3810-193 Aveiro, Portugal; Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos S/N, 4450-208, Matosinhos, Portugal
| | - Francisco Arenas
- Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos S/N, 4450-208, Matosinhos, Portugal
| | - João C Campos
- Unidade de Ciências Biomoleculares Aplicadas (UCIBIO-REQUIMTE), MedTech - Laboratório de Tecnologia Farmacêutica, Departamento de Ciências Farmacêuticas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira 228, 4050-313, Porto, Portugal
| | - Paulo C Costa
- Unidade de Ciências Biomoleculares Aplicadas (UCIBIO-REQUIMTE), MedTech - Laboratório de Tecnologia Farmacêutica, Departamento de Ciências Farmacêuticas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira 228, 4050-313, Porto, Portugal
| | - Bruno Nunes
- Departamento de Biologia da Universidade de Aveiro (DBIO-UA), Campus de Santiago, 3810-193 Aveiro, Portugal; Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193, Aveiro, Portugal.
| | - Alberto Teodorico Correia
- Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos S/N, 4450-208, Matosinhos, Portugal; Faculdade de Ciências da Saúde da Universidade Fernando Pessoa (FCS/UFP), Rua Carlos da Maia 296, 4200-150, Porto, Portugal
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Di Dato V, Barbarinaldi R, Amato A, Di Costanzo F, Fontanarosa C, Perna A, Amoresano A, Esposito F, Cutignano A, Ianora A, Romano G. Variation in prostaglandin metabolism during growth of the diatom Thalassiosira rotula. Sci Rep 2020; 10:5374. [PMID: 32214130 PMCID: PMC7096440 DOI: 10.1038/s41598-020-61967-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 02/28/2020] [Indexed: 02/03/2023] Open
Abstract
Prostaglandins (PGs) are hormone-like mediators in many physiological and pathological processes that are present in all vertebrates, in some terrestrial and aquatic invertebrates, and have also been identified in some macroalgae. They have recently been reported also in marine microalgae but their role as chemical mediators is largely unknown. Here we studied the expression pattern of the PG biosynthetic pathway during different growth phases of the centric diatom Thalassiosira rotula and assessed the release of PGs in the surrounding environment for the first time. We show that enzymes responsible for PGs formation such as cyclooxygenase, prostaglandin E synthase 2-like and prostaglandin F synthase are mainly expressed at the end of the exponential phase and that PGs are released especially during the stationary and senescent phases, suggesting a possible signaling function for these compounds. Phylogenetic analysis of the limiting enzyme, COX, indicate the presence in diatoms of more than one enzyme related to the oxidative metabolism of fatty acids belonging to the peroxidase-cyclooxygenase superfamily. These findings suggest a more complex evolution and diversity of metabolic pathways leading to the synthesis of lipid mediators in diatoms.
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Affiliation(s)
- Valeria Di Dato
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
| | | | - Alberto Amato
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG-LPCV 38054, Grenoble Cedex 9, France
| | | | - Carolina Fontanarosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli, Monte Sant'Angelo, 80126, Napoli, Italy
| | - Anna Perna
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Angela Amoresano
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli, Monte Sant'Angelo, 80126, Napoli, Italy
| | | | - Adele Cutignano
- Istituto di Chimica Biomolecolare-CNR, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli, Italy
| | - Adrianna Ianora
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Giovanna Romano
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
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Ganley JG, Derbyshire ER. Linking Genes to Molecules in Eukaryotic Sources: An Endeavor to Expand Our Biosynthetic Repertoire. Molecules 2020; 25:E625. [PMID: 32023950 PMCID: PMC7036892 DOI: 10.3390/molecules25030625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 01/23/2020] [Accepted: 01/30/2020] [Indexed: 02/06/2023] Open
Abstract
The discovery of natural products continues to interest chemists and biologists for their utility in medicine as well as facilitating our understanding of signaling, pathogenesis, and evolution. Despite an attenuation in the discovery rate of new molecules, the current genomics and transcriptomics revolution has illuminated the untapped biosynthetic potential of many diverse organisms. Today, natural product discovery can be driven by biosynthetic gene cluster (BGC) analysis, which is capable of predicting enzymes that catalyze novel reactions and organisms that synthesize new chemical structures. This approach has been particularly effective in mining bacterial and fungal genomes where it has facilitated the discovery of new molecules, increased the understanding of metabolite assembly, and in some instances uncovered enzymes with intriguing synthetic utility. While relatively less is known about the biosynthetic potential of non-fungal eukaryotes, there is compelling evidence to suggest many encode biosynthetic enzymes that produce molecules with unique bioactivities. In this review, we highlight how the advances in genomics and transcriptomics have aided natural product discovery in sources from eukaryotic lineages. We summarize work that has successfully connected genes to previously identified molecules and how advancing these techniques can lead to genetics-guided discovery of novel chemical structures and reactions distributed throughout the tree of life. Ultimately, we discuss the advantage of increasing the known biosynthetic space to ease access to complex natural and non-natural small molecules.
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Affiliation(s)
- Jack G Ganley
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708-0346, USA
| | - Emily R Derbyshire
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708-0346, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, 213 Research Drive, Durham, NC 27710, USA
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Bouchard C, Michaels J, Brown-Harding H. RNA isolation from corals and other cnidarian species using urea-LiCl as a denaturant. Anal Biochem 2020; 588:113472. [PMID: 31605694 DOI: 10.1016/j.ab.2019.113472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 10/08/2019] [Indexed: 11/28/2022]
Abstract
A method of RNA isolation using a solution of urea-LiCl as a denaturing agent was tested on stony coral. As the method does not require homogenization of tissues prior to their incubation in the denaturant, specimen collected in the field can be immediately transferred to the urea-LiCl solution. The method was also tested on tissues of other cnidarian species. RNA was isolated from fresh tissues of jellyfish and sea anemones using two protocols - that is, incubations in the urea-LiCl solution were either performed on homogenized tissues or on intact tissues or specimen. RNA quality was evaluated on a bioanalyser.
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Affiliation(s)
- Christelle Bouchard
- College of Science and Mathematics, University of South Florida, 8350 N Tamiami Trail, Sarasota, FL, 34243, USA.
| | - Jay Michaels
- College of Science and Mathematics, University of South Florida, 8350 N Tamiami Trail, Sarasota, FL, 34243, USA
| | - Heather Brown-Harding
- Department of Biology and Center for Molecular Signaling, Wake Forest University, 455 Vine Street, Winston Salem, NC, 27101, USA
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Eicosanoid Diversity of Stony Corals. Mar Drugs 2018; 16:md16010010. [PMID: 29301345 PMCID: PMC5793058 DOI: 10.3390/md16010010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/13/2017] [Accepted: 12/20/2017] [Indexed: 02/07/2023] Open
Abstract
Oxylipins are well-established lipid mediators in plants and animals. In mammals, arachidonic acid (AA)-derived eicosanoids control inflammation, fever, blood coagulation, pain perception and labor, and, accordingly, are used as drugs, while lipoxygenases (LOX), as well as cyclooxygenases (COX) serve as therapeutic targets for drug development. In soft corals, eicosanoids are synthesized on demand from AA by LOX, COX, and catalase-related allene oxide synthase-lipoxygenase (cAOS-LOX) and hydroperoxide lyase-lipoxygenase (cHPL-LOX) fusion proteins. Reef-building stony corals are used as model organisms for the stress-related genomic studies of corals. Yet, the eicosanoid synthesis capability and AA-derived lipid mediator profiles of stony corals have not been determined. In the current study, the genomic and transcriptomic data about stony coral LOXs, AOS-LOXs, and COXs were analyzed and the eicosanoid profiles and AA metabolites of three stony corals, Acropora millepora, A. cervicornis, and Galaxea fascicularis, were determined by reverse-phase high-performance liquid chromatography (RP-HPLC) coupled with MS-MS and a radiometric detector. Our results confirm that the active LOX and AOS-LOX pathways are present in Acropora sp., which correspond to the genomic/sequence data reported earlier. In addition, LOX, AOS-LOX, and COX products were detected in the closely related species G. fascicularis. In conclusion, the functional 8R-LOX and/or AOS-LOX pathways are abundant among corals, while COXs are restricted to certain soft and stony coral lineages.
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Toporkova YY, Gorina SS, Mukhitova FK, Hamberg M, Ilyina TM, Mukhtarova LS, Grechkin AN. Identification of CYP443D1 (CYP74 clan) of Nematostella vectensis as a first cnidarian epoxyalcohol synthase and insights into its catalytic mechanism. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1099-1109. [PMID: 28774820 DOI: 10.1016/j.bbalip.2017.07.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/16/2017] [Accepted: 07/29/2017] [Indexed: 01/08/2023]
Abstract
The CYP74 clan enzymes are responsible for the biosynthesis of numerous bioactive oxylipins in higher plants, some Proteobacteria, brown and green algae, and Metazoa. A novel putative CYP74 clan gene CYP443D1 of the starlet sea anemone (Nematostella vectensis, Cnidaria) has been cloned, and the properties of the corresponding recombinant protein have been studied in the present work. The recombinant CYP443D1 was incubated with the 9- and 13-hydroperoxides of linoleic and α-linolenic acids (9-HPOD, 13-HPOD, 9-HPOT, and 13-HPOT, respectively), as well as with the 9-hydroperoxide of γ-linolenic acid (γ-9-HPOT) and 15-hydroperoxide of eicosapentaenoic acid (15-HPEPE). The enzyme was active towards all C18-hydroperoxides with some preference to 9-HPOD. In contrast, 15-HPEPE was a poor substrate. The CYP443D1 specifically converted 9-HPOD into the oxiranyl carbinol 1, (9S,10R,11S,12Z)-9,10-epoxy-11-hydroxy-12-octadecenoic acid. Both 18O atoms from [18O2-hydroperoxy]9-HPOD were virtually quantitatively incorporated into product 1. Thus, the CYP443D1 exhibited epoxyalcohol synthase (EAS) activity. The 18O labelling data demonstrated that the reaction mechanism included three sequential steps: (1) hydroperoxyl homolysis, (2) oxy radical rearrangement into epoxyallylic radical, (3) hydroxyl rebound, resulting in oxiranyl carbinol formation. The 9-HPOT and γ-9-HPOT were also specifically converted into the oxiranyl carbinols, 15,16- and 6,7-dehydro analogues of compound 1, respectively. The 13-HPOD was converted into erythro- and threo-isomers of oxiranyl carbinol, as well as oxiranyl vinyl carbinols. The obtained results allow assignment of the name "N. vectensis EAS" (NvEAS) to CYP443D1. The NvEAS is a first EAS detected in Cnidaria.
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Affiliation(s)
- Yana Y Toporkova
- Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111, Russia
| | - Svetlana S Gorina
- Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111, Russia
| | - Fakhima K Mukhitova
- Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111, Russia
| | - Mats Hamberg
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Tatyana M Ilyina
- Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111, Russia
| | - Lucia S Mukhtarova
- Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111, Russia
| | - Alexander N Grechkin
- Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111, Russia.
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Kato Y, Jimbo M, Sakakibara Y, Onizuka R, Takahashi T, Matsuhashi S, Mita H, Amada K, Imahara Y, Tanabe K, Toda A, Kamiya H. Characterization of a novel allergenic protein from the octocoral Scleronephthya gracillima (Kuekenthal) that corresponds to a new GFP-like family named Akane. LUMINESCENCE 2017; 32:1009-1016. [PMID: 28378893 DOI: 10.1002/bio.3284] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/15/2016] [Accepted: 12/28/2016] [Indexed: 11/08/2022]
Abstract
Certain marine organisms have been known to cause allergic reactions among occupational fishermen. We have previously reported that bronchial asthma among the workers engaged in spiny lobster fishing in Japan was caused by octocorals such as Dendronephthya sp. and Scleronephthya gracillima (previously named Alcyonium gracillimum). Now we have found another octocoral, Scleronephthya gracillima (Kuekenthal), which causes the allergic disease in fishermen. The octocoral was characterized as a new green fluorescent protein (GFP)-like family. The new allergen has a molecular mass of 27 kDa in 1D and 2D SDS-PAGE under reduced conditions. The 27 kDa component was determined to be an allergen by western blotting, ECL immune staining method and absorption of patient sera with the antigen. Furthermore, the combination of analysis with LC-ESI-MS/MS and MASCOT search in the NCBInr database concluded the 27 kDa component had the sequence YPADI/LPDYFK, and that the 22 kDa component had the sequence QSFPEGFSWER, which both matched a GFP-like protein in Acropora aculeus and in Montastraea annularis. Further analysis by MALDI-TOF/MS/MS and MASCOT search in the NCBInr database of all 27 kDa eight spot components from 2D SDS-PAGE indicated that the sequence QSFPEGFSWER also matched as GFP-like protein in Lobophyllia hemprichii and Scleractinia sp. To our knowledge, this is the first report of the new allergenic protein that corresponds to a new GFP-like protein named Akane, and which has fluorescent emissions in the red and green part of the spectra at 628 nm and 508 nm, respectively.
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Affiliation(s)
- Yuko Kato
- Electronics Research Laboratory, Comprehensive Research Organization, Fukuoka Institute of Technology, Fukuoka, Japan
| | - Mitsuru Jimbo
- Department of Marine Biosciences, Schools of Marine Biosciences, Kitasato University, Japan
| | - Youichi Sakakibara
- Department of Biochemistry and Applied Biosciences, University of Miyazaki, Japan
| | - Reiko Onizuka
- National Hospital Organization, Miyazaki-Higashi Hospital, Japan
| | - Tatsuya Takahashi
- Department of Internal Medicine, Faculty of Medicine, Saga University, Japan
| | - Sachiko Matsuhashi
- Department of Internal Medicine, Faculty of Medicine, Saga University, Japan
| | - Hajime Mita
- Department of Life, Environment and Materials Science, Faculty of Engineering, Fukuoka Institute of Technology, Japan
| | - Kei Amada
- Department of Life, Environment and Materials Science, Faculty of Engineering, Fukuoka Institute of Technology, Japan
| | | | - Kimiko Tanabe
- Cooperative Research Center, University of Miyazaki, Japan
| | - Akihisa Toda
- Daiichi University of Pharmacy, Department of Health Science and Hygiene, Japan
| | - Hisao Kamiya
- Department of Marine Biosciences, Schools of Marine Biosciences, Kitasato University, Japan
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Seo MJ, Oh DK. Prostaglandin synthases: Molecular characterization and involvement in prostaglandin biosynthesis. Prog Lipid Res 2017; 66:50-68. [DOI: 10.1016/j.plipres.2017.04.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 03/30/2017] [Accepted: 04/01/2017] [Indexed: 01/30/2023]
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14
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Sumpownon C, Engsusophon A, Siangcham T, Sugiyama E, Soonklang N, Meeratana P, Wanichanon C, Hanna PJ, Setou M, Sobhon P. Variation of prostaglandin E2 concentrations in ovaries and its effects on ovarian maturation and oocyte proliferation in the giant fresh water prawn, Macrobrachium rosenbergii. Gen Comp Endocrinol 2015; 223:129-38. [PMID: 25963041 DOI: 10.1016/j.ygcen.2015.04.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 04/16/2015] [Accepted: 04/20/2015] [Indexed: 10/23/2022]
Abstract
Prostaglandins (PGs) are important bioactive mediators for many physiological functions. In some decapod crustaceans, prostaglandin E2 (PGE2) has been detected in reproductive organs, and may play a role in the control of ovarian maturation. However, in the freshwater prawn, Macrobrachium rosenbergii, the presences of PGE2 and key enzymes for PGE2 biosynthesis, as well as its effects on ovarian maturation have not yet been investigated. In this study we reported the presence of PGE2, cyclooxygenase1 (COX1) and prostaglandin E synthase (PGES) in the ovarian tissues of M. rosenbergii, using immunohistochemistry. Intense immunoreactivities of PGE2 (PGE2-ir), COX1 (Cox1-ir) and PGES (PGES-ir) were detected in previtellogenic oocytes (Oc1 and Oc2), while the immunoreactivities were absent in the late vitellogenic oocytes (Oc4). This finding supports the hypothesis that the PGE2 biosynthesis occurs in the ovary of this prawn. To ascertain this finding we used LC-MS/MS to quantitate PGE2 concentrations during ovarian developmental cycle. The levels of PGE2 were significantly higher in the early ovarian stages (St I and II) than in the late stages (St III and IV). Moreover, we found that administration of PGE2 stimulated the ovarian maturation in this species by shortening the length of the ovarian cycle, increasing ovarian-somatic index, oocyte proliferation, and vitellogenin (Vg) level in the hemolymph.
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Affiliation(s)
- Chanudporn Sumpownon
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand.
| | - Attakorn Engsusophon
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand
| | - Tanapan Siangcham
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand
| | - Eiji Sugiyama
- Department of Cell Biology and Anatomy, School of Medicine, Hamamatsu University, Hamamatsu, Shizuoka, Japan
| | - Nantawan Soonklang
- Department of Preclinical Science, Faculty of Medicine, Thammasat University, Pathumthani 12120, Thailand
| | - Prasert Meeratana
- Deparment of Biomedical Sciences, Faculty of Allied Health Sciences, Burapha University, Chonburi 20131, Thailand
| | - Chaitip Wanichanon
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand
| | - Peter J Hanna
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand; Pro Vice-Chancellor's Office, Faculty of Science and Technology, Deakin University, Locked Bag 2000, Geelong, Victoria 3220, Australia
| | - Mitsutoshi Setou
- Department of Cell Biology and Anatomy, School of Medicine, Hamamatsu University, Hamamatsu, Shizuoka, Japan
| | - Prasert Sobhon
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand.
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15
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Havird JC, Kocot KM, Brannock PM, Cannon JT, Waits DS, Weese DA, Santos SR, Halanych KM. Reconstruction of cyclooxygenase evolution in animals suggests variable, lineage-specific duplications, and homologs with low sequence identity. J Mol Evol 2015; 80:193-208. [PMID: 25758350 DOI: 10.1007/s00239-015-9670-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 03/02/2015] [Indexed: 11/30/2022]
Abstract
Cyclooxygenase (COX) enzymatically converts arachidonic acid into prostaglandin G/H in animals and has importance during pregnancy, digestion, and other physiological functions in mammals. COX genes have mainly been described from vertebrates, where gene duplications are common, but few studies have examined COX in invertebrates. Given the increasing ease in generating genomic data, as well as recent, although incomplete descriptions of potential COX sequences in Mollusca, Crustacea, and Insecta, assessing COX evolution across Metazoa is now possible. Here, we recover 40 putative COX orthologs by searching publicly available genomic resources as well as ~250 novel invertebrate transcriptomic datasets. Results suggest the common ancestor of Cnidaria and Bilateria possessed a COX homolog similar to those of vertebrates, although such homologs were not found in poriferan and ctenophore genomes. COX was found in most crustaceans and the majority of molluscs examined, but only specific taxa/lineages within Cnidaria and Annelida. For example, all octocorallians appear to have COX, while no COX homologs were found in hexacorallian datasets. Most species examined had a single homolog, although species-specific COX duplications were found in members of Annelida, Mollusca, and Cnidaria. Additionally, COX genes were not found in Hemichordata, Echinodermata, or Platyhelminthes, and the few previously described COX genes in Insecta lacked appreciable sequence homology (although structural analyses suggest these may still be functional COX enzymes). This analysis provides a benchmark for identifying COX homologs in future genomic and transcriptomic datasets, and identifies lineages for future studies of COX.
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Affiliation(s)
- Justin C Havird
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, USA,
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16
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Bacterial and algal orthologs of prostaglandin H₂synthase: novel insights into the evolution of an integral membrane protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:83-94. [PMID: 25281773 DOI: 10.1016/j.bbamem.2014.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 09/09/2014] [Accepted: 09/23/2014] [Indexed: 01/01/2023]
Abstract
Prostaglandin H₂synthase (PGHS; EC 1.14.99.1), a bi-functional heme enzyme that contains cyclooxygenase and peroxidase activities, plays a central role in the inflammatory response, pain, and blood clotting in higher eukaryotes. In this review, we discuss the progenitors of the mammalian enzyme by using modern bioinformatics and homology modeling to draw comparisons between this well-studied system and its orthologs from algae and bacterial sources. A clade of bacterial and algal orthologs is described that have salient structural features distinct from eukaryotic counterparts, including the lack of a dimerization and EGF-like domains, the absence of gene duplicates, and minimal membrane-binding domains. The functional implications of shared and variant features are discussed.
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Hansen K, Varvas K, Järving I, Samel N. Novel membrane-associated prostaglandin E synthase-2 from crustacean arthropods. Comp Biochem Physiol B Biochem Mol Biol 2014; 174:45-52. [DOI: 10.1016/j.cbpb.2014.05.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/29/2014] [Accepted: 05/30/2014] [Indexed: 11/30/2022]
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18
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Mohamed ME, Lazarus CM. Production of prostaglandins in transgenic Arabidopsis thaliana. PHYTOCHEMISTRY 2014; 102:74-79. [PMID: 24629803 DOI: 10.1016/j.phytochem.2014.02.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/05/2014] [Accepted: 02/10/2014] [Indexed: 06/03/2023]
Abstract
Plants do not naturally produce the very-long-chain polyunsaturated fatty acids that are the precursors of prostaglandins, but in previous studies Arabidopsis thaliana had been transformed sequentially with genes encoding a Δ(9)-elongase and a Δ(8)-desaturase to produce dihomo-γ-linolenic acid (DGLA) and eicosatetraenoic acid (ETA), and subsequently with a gene encoding a Δ(5)-desaturase to produce arachidonic acid (AA) and eicosapentaenoic acid (EPA). Transformation of A. thaliana with the first two genes consolidated on a single binary vector yielded transformants producing high levels of DGLA, and these plants were further transformed with mouse prostaglandin H synthase (PGH) genes to produce prostaglandins. Mouse PGHS-1 and PGHS-2 cDNAs were amplified for expression as three isoforms: PGHS-1 (complete coding sequence with signal peptide), PGHS-1-Ma (mature PGHS-1 sequence, without signal peptide) and PGHS-2 (complete coding sequence with signal peptide). PGHS-1 transformants showed the highest activity, followed by PGHS-2 transformants, whereas removal of the signal peptide resulted in almost complete loss of PGHS-1 activity. In order to produce a physiologically active prostaglandin, the Trypanosoma brucei prostaglandin F synthase gene was combined with the mouse PGHS-1 gene and the Mortierella alpina Δ(5)-desaturase on a binary vector. Transformation of DGLA-producing A. thaliana with this construct yielded transformants that successfully produced prostaglandin F.
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Affiliation(s)
- Maged E Mohamed
- School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, United Kingdom; College of Clinical Pharmacy, King Faisal University, P.O. 380, Ahsaa 31982, Saudi Arabia.
| | - Colin M Lazarus
- School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, United Kingdom
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19
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Yuan D, Zou Q, Yu T, Song C, Huang S, Chen S, Ren Z, Xu A. Ancestral genetic complexity of arachidonic acid metabolism in Metazoa. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:1272-84. [PMID: 24801744 DOI: 10.1016/j.bbalip.2014.04.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 04/23/2014] [Accepted: 04/28/2014] [Indexed: 01/09/2023]
Abstract
Eicosanoids play an important role in inducing complex and crucial physiological processes in animals. Eicosanoid biosynthesis in animals is widely reported; however, eicosanoid production in invertebrate tissue is remarkably different to vertebrates and in certain respects remains elusive. We, for the first time, compared the orthologs involved in arachidonic acid (AA) metabolism in 14 species of invertebrates and 3 species of vertebrates. Based on parsimony, a complex AA-metabolic system may have existed in the common ancestor of the Metazoa, and then expanded and diversified through invertebrate lineages. A primary vertebrate-like AA-metabolic system via cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) pathways was further identified in the basal chordate, amphioxus. The expression profiling of AA-metabolic enzymes and lipidomic analysis of eicosanoid production in the tissues of amphioxus supported our supposition. Thus, we proposed that the ancestral complexity of AA-metabolic network diversified with the different lineages of invertebrates, adapting with the diversity of body plans and ecological opportunity, and arriving at the vertebrate-like pattern in the basal chordate, amphioxus.
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Affiliation(s)
- Dongjuan Yuan
- Department of Biochemistry, College of Life Sciences, State Key Laboratory of Biocontrol, National Engineering Research Center of South China Sea Marine Biotechnology, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China
| | - Qiuqiong Zou
- Department of Biochemistry, College of Life Sciences, State Key Laboratory of Biocontrol, National Engineering Research Center of South China Sea Marine Biotechnology, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China
| | - Ting Yu
- Department of Biochemistry, College of Life Sciences, State Key Laboratory of Biocontrol, National Engineering Research Center of South China Sea Marine Biotechnology, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China
| | - Cuikai Song
- Department of Biochemistry, College of Life Sciences, State Key Laboratory of Biocontrol, National Engineering Research Center of South China Sea Marine Biotechnology, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China
| | - Shengfeng Huang
- Department of Biochemistry, College of Life Sciences, State Key Laboratory of Biocontrol, National Engineering Research Center of South China Sea Marine Biotechnology, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China
| | - Shangwu Chen
- Department of Biochemistry, College of Life Sciences, State Key Laboratory of Biocontrol, National Engineering Research Center of South China Sea Marine Biotechnology, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China
| | - Zhenghua Ren
- Department of Biochemistry, College of Life Sciences, State Key Laboratory of Biocontrol, National Engineering Research Center of South China Sea Marine Biotechnology, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China
| | - Anlong Xu
- Department of Biochemistry, College of Life Sciences, State Key Laboratory of Biocontrol, National Engineering Research Center of South China Sea Marine Biotechnology, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China; Beijing University of Chinese Medicine, 11 Bei San Huang Dong Road, Chao-yang District, Beijing, 100029, People's Republic of China.
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20
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Why do a wide variety of animals retain multiple isoforms of cyclooxygenase? Prostaglandins Other Lipid Mediat 2014; 109-111:14-22. [PMID: 24721150 DOI: 10.1016/j.prostaglandins.2014.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 03/10/2014] [Accepted: 03/26/2014] [Indexed: 12/14/2022]
Abstract
Cyclooxygenase (COX) has been cloned from the phyla Cnidaria, Mollusca, Arthropoda, and Chordata of the animal kingdom. Many organisms have multiple COX isoforms that have arisen from gene duplication. It is not well understood why there are multiple COX isoforms in the same organism, or when duplication of the COX gene occurred. Here, we summarize the current knowledge of the evolutionary history of COX in the animal kingdom and discuss the reasons why the multiple COX system has been retained so widely. The phylogenetic analysis suggests that all COX genes in animals may descend from a common ancestor and that the duplication of an ancestral COX gene might occur within each lineage after the divergence of the animal. In most instances, the expressions of multiple COX isoforms are separately regulated and these isoforms play different and important pathophysiological roles in each organism. This may be the reason why multiple COX isoforms are widely retained.
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21
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Lõhelaid H, Teder T, Tõldsepp K, Ekins M, Samel N. Up-regulated expression of AOS-LOXa and increased eicosanoid synthesis in response to coral wounding. PLoS One 2014; 9:e89215. [PMID: 24551239 PMCID: PMC3925239 DOI: 10.1371/journal.pone.0089215] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 01/17/2014] [Indexed: 12/31/2022] Open
Abstract
In octocorals, a catalase-like allene oxide synthase (AOS) and an 8R-lipoxygenase (LOX) gene are fused together encoding for a single AOS-LOX fusion protein. Although the AOS-LOX pathway is central to the arachidonate metabolism in corals, its biological function in coral homeostasis is unclear. Using an acute incision wound model in the soft coral Capnella imbricata, we here test whether LOX pathway, similar to its role in plants, can contribute to the coral damage response and regeneration. Analysis of metabolites formed from exogenous arachidonate before and after fixed time intervals following wounding indicated a significant increase in AOS-LOX activity in response to mechanical injury. Two AOS-LOX isoforms, AOS-LOXa and AOS-LOXb, were cloned and expressed in bacterial expression system as active fusion proteins. Transcription levels of corresponding genes were measured in normal and stressed coral by qPCR. After wounding, AOS-LOXa was markedly up-regulated in both, the tissue adjacent to the incision and distal parts of a coral colony (with the maximum reached at 1 h and 6 h post wounding, respectively), while AOS-LOXb was stable. According to mRNA expression analysis, combined with detection of eicosanoid product formation for the first time, the AOS-LOX was identified as an early stress response gene which is induced by mechanical injury in coral.
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Affiliation(s)
- Helike Lõhelaid
- Department of Chemistry, Tallinn University of Technology, Tallinn, Estonia
| | - Tarvi Teder
- Department of Chemistry, Tallinn University of Technology, Tallinn, Estonia
| | - Kadri Tõldsepp
- Department of Chemistry, Tallinn University of Technology, Tallinn, Estonia
| | - Merrick Ekins
- Sessile Marine Invertebrates, Queensland Museum, Brisbane, Queensland, Australia
| | - Nigulas Samel
- Department of Chemistry, Tallinn University of Technology, Tallinn, Estonia
- * E-mail:
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22
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Dong L, Sharma NP, Jurban BJ, Smith WL. Pre-existent asymmetry in the human cyclooxygenase-2 sequence homodimer. J Biol Chem 2013; 288:28641-55. [PMID: 23955344 DOI: 10.1074/jbc.m113.505503] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Prostaglandin endoperoxide H synthase-2 (PGHS-2), also known as cyclooxygenase-2 (COX-2), is a sequence homodimer. However, the enzyme exhibits half-site heme and inhibitor binding and functions as a conformational heterodimer having a catalytic subunit (Ecat) with heme bound and an allosteric subunit (Eallo) lacking heme. Some recombinant heterodimers composed of a COX-deficient mutant subunit and a native subunit (i.e. Mutant/Native PGHS-2) have COX activities similar to native PGHS-2. This suggests that the presence of heme plus substrate leads to the subunits becoming lodged in a semi-stable Eallo-mutant/Ecat-Native∼heme form during catalysis. We examined this concept using human PGHS-2 dimers composed of combinations of Y385F, R120Q, R120A, and S530A mutant or native subunits. With some heterodimers (e.g. Y385F/Native PGHS-2), heme binds with significantly higher affinity to the native subunit. This correlates with near native COX activity for the heterodimer. With other heterodimers (e.g. S530A/Native PGHS-2), heme binds with similar affinities to both subunits, and the COX activity approximates that expected for an enzyme in which each monomer contributes equally to the net COX activity. With or without heme, aspirin acetylates one-half of the subunits of the native PGHS-2 dimer, the Ecat subunits. Subunits having an S530A mutation are refractory to acetylation. Curiously, aspirin acetylates only one-quarter of the monomers of S530A/Native PGHS-2 with or without heme. This implies that there are comparable amounts of two noninterchangeable species of apoenzymes, Eallo-S530A/Ecat-Native and Eallo-Native/Ecat-S530A. These results suggest that native PGHS-2 assumes a reasonably stable, asymmetric Eallo/Ecat form during its folding and processing.
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Affiliation(s)
- Liang Dong
- From the Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109
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23
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Varvas K, Kasvandik S, Hansen K, Järving I, Morell I, Samel N. Structural and catalytic insights into the algal prostaglandin H synthase reveal atypical features of the first non-animal cyclooxygenase. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:863-71. [DOI: 10.1016/j.bbalip.2012.11.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 11/06/2012] [Accepted: 11/27/2012] [Indexed: 10/27/2022]
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24
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Purification and characterization of the recombinant human prostaglandin H synthase-2 expressed in Pichia pastoris. Protein Expr Purif 2012; 83:182-9. [DOI: 10.1016/j.pep.2012.03.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 03/28/2012] [Accepted: 03/29/2012] [Indexed: 11/17/2022]
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25
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Jin J, Boeglin WE, Cha JK, Brash AR. 8R-Lipoxygenase-catalyzed synthesis of a prominent cis-epoxyalcohol from dihomo-γ-linolenic acid: a distinctive transformation compared with S-lipoxygenases. J Lipid Res 2011; 53:292-9. [PMID: 22158855 DOI: 10.1194/jlr.m022863] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Conversion of fatty acid hydroperoxides to epoxyalcohols is a well known secondary reaction of lipoxygenases, described for S-specific lipoxygenases forming epoxyalcohols with a trans-epoxide configuration. Here we report on R-specific lipoxygenase synthesis of a cis-epoxyalcohol. Although arachidonic and dihomo-γ-linolenic acids are metabolized by extracts of the Caribbean coral Plexaura homomalla via 8R-lipoxygenase and allene oxide synthase activities, 20:3ω6 forms an additional prominent product, identified using UV, GC-MS, and NMR in comparison to synthetic standards as 8R,9S-cis-epoxy-10S-erythro-hydroxy-eicosa-11Z,14Z-dienoic acid. Both oxygens of (18)O-labeled 8R-hydroperoxide are retained in the product, indicating a hydroperoxide isomerase activity. Recombinant allene oxide synthase formed only allene epoxide from 8R-hydroperoxy-20:3ω6, whereas two different 8R-lipoxygenases selectively produced the epoxyalcohol.A biosynthetic scheme is proposed in which a partial rotation of the reacting intermediate is required to give the observed erythro epoxyalcohol product. This characteristic and the synthesis of cis-epoxy epoxyalcohol may be a feature of R-specific lipoxygenases.
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Affiliation(s)
- Jing Jin
- Department of Pharmacology, and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
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Kanamoto H, Takemura M, Ohyama K. Identification of a cyclooxygenase gene from the red alga Gracilaria vermiculophylla and bioconversion of arachidonic acid to PGF(2α) in engineered Escherichia coli. Appl Microbiol Biotechnol 2011; 91:1121-9. [PMID: 21637939 DOI: 10.1007/s00253-011-3349-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 04/15/2011] [Accepted: 04/20/2011] [Indexed: 10/18/2022]
Abstract
Prostaglandins (PGs) are important local messenger molecules in many tissues and organs of animals including human. For applications in medicine and animal care, PGs are mostly purified from animal tissues or chemically synthesized. To generate a clean, reliable, and inexpensive source for PGs, we have now engineered expression of a suitable cyclooxygenase gene in Escherichia coli and achieved production levels of up to 2.7 mg l(-1) PGF(2α). The cyclooxygenase gene cloned from the red alga Gracilaria vermiculophylla appears to be fully functional without any eukaryotic modifications in E. coli. A crude extract of the recombinant E. coli cells is able to convert in vitro the substrate arachidonic acid (AA) to PGF(2α). Furthermore, these E. coli cells produced PGF(2α) in a medium supplemented with AA and secreted the PGF(2α) product. To our knowledge, this is the first report of the functional expression of a cyclooxygenase gene and concomitant production of PGF(2α) in E. coli. The successful microbial synthesis of PGs with reliable yields promises a novel pharmaceutical tool to produce PGF(2α) at significantly reduced prices and greater purity.
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Affiliation(s)
- Hirosuke Kanamoto
- Laboratory of Plant Gene Technology, Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi-machi, Ishikawa 921-8836, Japan
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Cubero-Leon E, Ciocan CM, Hill EM, Osada M, Kishida M, Itoh N, Kondo R, Minier C, Rotchell JM. Estrogens disrupt serotonin receptor and cyclooxygenase mRNA expression in the gonads of mussels (Mytilus edulis). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2010; 98:178-187. [PMID: 20207427 DOI: 10.1016/j.aquatox.2010.02.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 01/31/2010] [Accepted: 02/02/2010] [Indexed: 05/28/2023]
Abstract
Estrogenic contaminants in the aquatic environment are associated with feminisation of male fish, however their effects on some invertebrate species, such as bivalve molluscs, have yet to be characterised. Gametogenesis represents a critical step in the reproductive process and is subjected to hormonal control by serotonin (5-HT), prostaglandins (synthesised by cyclooxygenases-COX) and steroids such as 17beta-estradiol (E2). Here, we examine the responses of 5-HT receptor and COX mRNA expression in mussels, Mytilus edulis, exposed to estrogenic compounds during different stages of their reproductive cycle. In mature mussels, 5-HT receptor mRNA expression decreased following E2 exposure. The opposite trend was observed in mussels at early gametogenesis stages. COX mRNA expression levels at both stages were generally decreased by E2 exposure. Mussels at early gametogenesis stages were also exposed to ethynylestradiol (EE2) and estradiol benzoate (EB) and a significant increase in 5-HT receptor mRNA expression was observed with both xeno-estrogens. COX expression levels were increased with EB exposure but no significant effects were found with EE2 exposure. These results show that the natural estrogen, E2, as well as the synthetic estrogen, EE2, induce alterations, dependent on reproductive stage, in the mRNA expression levels of 5-HT receptor and/or COX in the marine bivalve M. edulis.
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Affiliation(s)
- Elena Cubero-Leon
- Department of Biology and Environmental Science, University of Sussex, BN1 9QJ Falmer, Brighton, UK
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28
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Varvas K, Kurg R, Hansen K, Järving R, Järving I, Valmsen K, Lõhelaid H, Samel N. Direct evidence of the cyclooxygenase pathway of prostaglandin synthesis in arthropods: genetic and biochemical characterization of two crustacean cyclooxygenases. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2009; 39:851-860. [PMID: 19854273 DOI: 10.1016/j.ibmb.2009.10.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Revised: 10/05/2009] [Accepted: 10/07/2009] [Indexed: 05/28/2023]
Abstract
Prostaglandins, well-known lipid mediators in vertebrate animals, have also shown to play certain regulatory roles in insects and other arthropods acting on reproduction, immune system and ion transport. However, knowledge of their biosynthetic pathways in arthropods is lacking. In the present study, we report the cloning and expression of cyclooxygenase (COX) from amphipod crustaceans Gammarus spp and Caprella spp. The amphipod COX proteins contain key residues shown to be important for cyclooxygenase and peroxidase activities. Differently from all other known cyclooxygenases the N-terminal signal sequence of amphipod enzymes is not cleaved during protein expression in mammalian cells. The C-terminus of amphipod COX is shorter than that of mammalian isoforms and lacks the KDEL(STEL)-type endoplasmic reticulum retention/retrieval signal. Despite that, amphipod COX proteins are N-glycosylated and locate similarly to the vertebrate COX on the endoplasmic reticulum and nuclear envelope. Both amphipod COX mRNAs encode functional cyclooxygenases that catalyze the transformation of arachidonic acid into prostaglandins. Using bioinformatic analysis we identified a COX-like gene from the human body louse Pediculus humanus corporis genome that encodes a protein with about 30% sequence identity with human COX-1 and COX-2. Although the COX gene is known to be absent from genomes of Drosophila sp., Aedes aegypti, Bombyx mori, and other insects, our studies establish the existence of the COX gene in certain lineages within the insect world.
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Affiliation(s)
- Külliki Varvas
- Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
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29
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Reitzel AM, Tarrant AM. Nuclear receptor complement of the cnidarian Nematostella vectensis: phylogenetic relationships and developmental expression patterns. BMC Evol Biol 2009; 9:230. [PMID: 19744329 PMCID: PMC2749838 DOI: 10.1186/1471-2148-9-230] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Accepted: 09/10/2009] [Indexed: 11/15/2022] Open
Abstract
Background Nuclear receptors are a superfamily of metazoan transcription factors that regulate diverse developmental and physiological processes. Sequenced genomes from an increasing number of bilaterians have provided a more complete picture of duplication and loss of nuclear receptors in protostomes and deuterostomes but have left open the question of which nuclear receptors were present in the cnidarian-bilaterian ancestor. In addition, nuclear receptor expression and function are largely uncharacterized within cnidarians, preventing determination of conserved and novel nuclear receptor functions in the context of animal evolution. Results Here we report the first complete set of nuclear receptors from a cnidarian, the starlet sea anemone Nematostella vectensis. Genomic searches using conserved DNA- and ligand-binding domains revealed seventeen nuclear receptors in N. vectensis. Phylogenetic analyses support N. vectensis orthologs of bilaterian nuclear receptors in four nuclear receptor subfamilies within nuclear receptor family 2 (COUP-TF, TLL, HNF4, TR2/4) and one putative ortholog of GCNF (nuclear receptor family 6). Other N. vectensis genes grouped well with nuclear receptor family 2 but represented lineage-specific duplications somewhere within the cnidarian lineage and were not clear orthologs of bilaterian genes. Three nuclear receptors were not well-supported within any particular nuclear receptor family. The seventeen nuclear receptors exhibited distinct developmental expression patterns, with expression of several nuclear receptors limited to a subset of developmental stages. Conclusion N. vectensis contains a diverse complement of nuclear receptors including orthologs of several bilaterian nuclear receptors. Novel nuclear receptors in N. vectensis may be ancient genes lost from triploblastic lineages or may represent cnidarian-specific radiations. Nuclear receptors exhibited distinct developmental expression patterns, which are consistent with diverse regulatory roles for these genes. Understanding the evolutionary relationships and developmental expression of the N. vectensis nuclear receptor complement provides insight into the evolution of the nuclear receptor superfamily and a foundation for mechanistic characterization of cnidarian nuclear receptor function.
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Affiliation(s)
- Adam M Reitzel
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
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30
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Tarrant AM, Reitzel AM, Blomquist CH, Haller F, Tokarz J, Adamski J. Steroid metabolism in cnidarians: insights from Nematostella vectensis. Mol Cell Endocrinol 2009; 301:27-36. [PMID: 18984032 DOI: 10.1016/j.mce.2008.09.037] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2008] [Revised: 09/30/2008] [Accepted: 09/30/2008] [Indexed: 11/17/2022]
Abstract
Cnidarians occupy a key evolutionary position as a sister group to bilaterian animals. While cnidarians contain a diverse complement of steroids, sterols, and other lipid metabolites, relatively little is known of the endogenous steroid metabolism or function in cnidarian tissues. Incubations of cnidarian tissues with steroid substrates have indicated the presence of steroid metabolizing enzymes, particularly enzymes with 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity. Through analysis of the genome of the starlet sea anemone, Nematostella vectensis, we identified a suite of genes in the short chain dehydrogenase/reductase (SDR) superfamily including homologs of genes that metabolize steroids in other animals. A more detailed analysis of Hsd17b4 revealed complex evolutionary relationships, apparent intron loss in several taxa, and predominantly adult expression in N. vectensis. Due to its ease of culture and available molecular tools N. vectensis is an excellent model for investigation of cnidarian steroid metabolism and gene function.
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Affiliation(s)
- Ann M Tarrant
- Biology Department, Woods Hole Oceanographic Institution, 45 Water Street, Woods Hole, MA 02543, USA.
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31
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Tamm T. Plasmids with E2 epitope tags: tagging modules for N- and C-terminal PCR-based gene targeting in both budding and fission yeast, and inducible expression vectors for fission yeast. Yeast 2009; 26:55-66. [DOI: 10.1002/yea.1650] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Environmental sensing and response genes in cnidaria: the chemical defensome in the sea anemone Nematostella vectensis. Cell Biol Toxicol 2008; 24:483-502. [PMID: 18956243 DOI: 10.1007/s10565-008-9107-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Accepted: 10/03/2008] [Indexed: 10/21/2022]
Abstract
The starlet sea anemone Nematostella vectensis has been recently established as a new model system for the study of the evolution of developmental processes, as cnidaria occupy a key evolutionary position at the base of the bilateria. Cnidaria play important roles in estuarine and reef communities, but are exposed to many environmental stressors. Here, I describe the genetic components of a "chemical defensome" in the genome of N. vectensis and review cnidarian molecular toxicology. Gene families that defend against chemical stressors and the transcription factors that regulate these genes have been termed a chemical defensome and include the cytochromes P450 and other oxidases, various conjugating enyzymes, the ATP-dependent efflux transporters, oxidative detoxification proteins, as well as various transcription factors. These genes account for about 1% (266/27,200) of the predicted genes in the sea anemone genome, similar to the proportion observed in tunicates and humans, but lower than that observed in sea urchins. While there are comparable numbers of stress-response genes, the stress sensor genes appear to be reduced in N. vectensis relative to many model protostomes and deuterostomes. Cnidarian toxicology is understudied, especially given the important ecological roles of many cnidarian species. New genomic resources should stimulate the study of chemical stress sensing and response mechanisms in cnidaria and allow us to further illuminate the evolution of chemical defense gene networks.
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Minto RE, Blacklock BJ. Biosynthesis and function of polyacetylenes and allied natural products. Prog Lipid Res 2008; 47:233-306. [PMID: 18387369 PMCID: PMC2515280 DOI: 10.1016/j.plipres.2008.02.002] [Citation(s) in RCA: 242] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 02/25/2008] [Accepted: 02/28/2008] [Indexed: 11/19/2022]
Abstract
Polyacetylenic natural products are a substantial class of often unstable compounds containing a unique carbon-carbon triple bond functionality, that are intriguing for their wide variety of biochemical and ecological functions, economic potential, and surprising mode of biosynthesis. Isotopic tracer experiments between 1960 and 1990 demonstrated that the majority of these compounds are derived from fatty acid and polyketide precursors. During the past decade, research into the metabolism of polyacetylenes has swiftly advanced, driven by the cloning of the first genes responsible for polyacetylene biosynthesis in plants, moss, fungi, and actinomycetes and the initial characterization of the gene products. The current state of knowledge of the biochemistry and molecular genetics of polyacetylenic secondary metabolic pathways will be presented together with an up-to-date survey of new terrestrial and marine natural products, their known biological activities, and a discussion of their likely metabolic origins.
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Affiliation(s)
- Robert E Minto
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, 402 North Blackford Street, Indianapolis, IN 46202, United States.
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34
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Lõhelaid H, Järving R, Valmsen K, Varvas K, Kreen M, Järving I, Samel N. Identification of a functional allene oxide synthase-lipoxygenase fusion protein in the soft coral Gersemia fruticosa suggests the generality of this pathway in octocorals. Biochim Biophys Acta Gen Subj 2008; 1780:315-21. [DOI: 10.1016/j.bbagen.2007.10.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 10/03/2007] [Accepted: 10/15/2007] [Indexed: 10/22/2022]
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35
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Valmsen K, Boeglin WE, Järving R, Järving I, Varvas K, Brash AR, Samel N. A Critical Role of Non-active Site Residues on Cyclooxygenase Helices 5 and 6 in the Control of Prostaglandin Stereochemistry at Carbon 15. J Biol Chem 2007; 282:28157-63. [PMID: 17652088 DOI: 10.1074/jbc.m704950200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The correct stereochemistry of prostaglandins is a prerequisite of their biological activity and thus is under a strict enzymatic control. Recently, we cloned and characterized two cyclooxygenase (COX) isoforms in the coral Plexaura homomalla that share 97% amino acid sequence identity, yet form prostaglandins with opposite stereochemistry at carbon 15. The difference in oxygenation specificity is only partially accounted for by the single amino acid substitution in the active site (Ile or Val at position 349). For further elucidation of residues involved in the C-15 stereocontrol, a series of sequence swapping and site-directed mutagenesis experiments between 15R- and 15S-COX were performed. Our results show that the change in stereochemistry at carbon 15 of prostaglandins relates mainly to five amino acid substitutions on helices 5 and 6 of the coral COX. In COX proteins, these helices form a helix-turn-helix motif that traverses through the entire protein, contributing to the second shell of residues around the oxygenase active site; it constitutes the most highly conserved region where even slight changes result in loss of catalytic activity. The finding that this region is among the least conserved between the P. homomalla 15S- and 15R-specific COX further supports its significance in maintaining the desired prostaglandin stereochemistry at C-15. The results are particularly remarkable because, based on its strong conservation, the conserved middle of helix 5 is considered as central to the core structure of peroxidases, of which COX proteins are derivatives. Now we show that the same parts of the protein are involved in the control of oxygenation with 15R or 15S stereospecificity in the dioxygenase active site.
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Affiliation(s)
- Karin Valmsen
- Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
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36
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Pope EC, Taylor GW, Rowley AF. Biosynthesis and functions of eicosanoids generated by the coelomocytes of the starfish, Asterias rubens. Comp Biochem Physiol B Biochem Mol Biol 2007; 147:657-66. [PMID: 17499535 DOI: 10.1016/j.cbpb.2007.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Revised: 04/05/2007] [Accepted: 04/05/2007] [Indexed: 11/16/2022]
Abstract
Eicosanoids are a group of oxygenated fatty acid derivatives formed from C20 polyunsaturated fatty acids, including arachidonic and eicosapentaenoic acids. The potential of the coelomocytes of the starfish, Asterias rubens, to generate eicosanoids through the cyclooxygenase (COX) and lipoxygenase (LOX) pathways was investigated using reverse-phase high performance liquid chromatography, enzyme immunoassay and gas chromatography-mass spectrometry. The principal LOX product was identified as 8-hydroxyeicosatetraenoic acid (8-HETE) with 8-hydroxyeicosapentaenoic acid (8-HEPE) synthesised at significantly lower levels. No classical prostaglandins (PG), such as PGE2 or PGD2, were found to be generated by ionophore-challenged coelomocytes. Incubation of coelomocytes with lipopolysaccharides from either Escherichia coli or Salmonella abortus failed to induce an increase in generation of LOX products and the presence of 8-HETE (0-25 microM) had no significant effect on the in vitro phagocytic activity of Asterias coelomocytes. Neither indomethacin (a COX inhibitor) or esculetin (a LOX inhibitor) had any effect on the clearance of the bacterium, Vibrio splendidus, from the coelomic cavity of starfish suggesting that products of these enzymes are not involved in such coelomocyte responses to foreign particles.
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Affiliation(s)
- Edward C Pope
- Centre for Sustainable Aquaculture Research, Department of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea, SA2 8PP, UK.
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37
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Machado E, Swevers L, Sdralia N, Medeiros MN, Mello FG, Iatrou K. Prostaglandin signaling and ovarian follicle development in the silkmoth, Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2007; 37:876-85. [PMID: 17628286 DOI: 10.1016/j.ibmb.2007.04.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 03/30/2007] [Accepted: 04/03/2007] [Indexed: 05/16/2023]
Abstract
Previous work on in vitro culturing of silkmoth (Bombyx mori) ovarian follicles has shown that starting from middle vitellogenesis, follicles develop according to an endogenous developmental program that does not require the presence of extra-ovarian factors. In this paper, we are reporting on our investigation for a possible involvement of autocrine/paracrine signaling by prostaglandins in the control of silkmoth ovarian follicle development. Using an initial rapid test that evaluates the formation of a protective eggshell around the oocyte, we are showing that aspirin and indomethacin, potent inhibitors of prostaglandin biosynthesis, block the transition of cultured vitellogenic follicles into choriogenesis. More detailed studies involving analyses of temporal expression patterns of genes known to be expressed in follicular epithelium cells at specific stages of ovarian development revealed that inhibition of prostaglandin biosynthesis arrests stages of follicle development from middle vitellogenesis to late choriogenesis. The arrest could be reversed by the addition of exogenous prostaglandins or cAMP into the culture media leading to the conclusion that the production of prostaglandins triggers cAMP-mediated intracellular signaling that allows the developmental progression of the follicles. Finally, because neither prostaglandins nor cAMP is capable of rescuing a developmental block effected at mid-vitellogenesis by the ecdysone agonist tebufenozide, we are proposing that prostaglandins have a role in the maintenance of normal physiological homeostasis in the ovarian follicles rather than a more specific role in developmental decision-making at distinct stages of follicle development.
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Affiliation(s)
- Ednildo Machado
- Laboratório de Entomologia Médica do Programa de Parasitologia e Biologia Celular, IBCCF, CCS, UFRJ, Cidade Universitária, Ilha do Fundão 21941-590, Rio de Janeiro, RJ, Brazil
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38
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Affiliation(s)
- Bradley S Moore
- Scripps Institution of Oceanography and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA
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39
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Mortimer M, Järving R, Brash AR, Samel N, Järving I. Identification and characterization of an arachidonate 11R-lipoxygenase. Arch Biochem Biophys 2006; 445:147-55. [PMID: 16321357 DOI: 10.1016/j.abb.2005.10.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Revised: 10/22/2005] [Accepted: 10/28/2005] [Indexed: 11/16/2022]
Abstract
11R-Lipoxygenase (11R-LOX) activity has been detected in several marine invertebrates, and here we report the first cloning and expression of the enzyme. The cDNA encoding a protein of 77kDa was isolated by RT-PCR from the soft coral Gersemia fruticosa and expressed in Escherichia coli. Incubations of recombinant enzyme with arachidonic acid yielded a single product, identified by RP-HPLC, GC-MS, and chiral phase-HPLC as 11R-hydroperoxyeicosatetraenoic acid. Other C18, C20, and C22 substrates are also oxygenated, preferentially at the omega10 position. Significantly, both Ca(2+)-ions and a membrane fraction are required for catalytic activity. Calcium effects translocation of the soluble 11R-LOX to the membrane and this association is reversible by Ca(2+) chelation. The enzyme sequence contains some conserved amino acids implicated in calcium activation of mammalian 5-LOX, and with its obligate requirement for membrane interaction the 11R-LOX may thus provide a new model for further analysis of this aspect of lipoxygenase activation.
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Affiliation(s)
- Monika Mortimer
- Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
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40
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Matias I, McPartland JM, Di Marzo V. Occurrence and possible biological role of the endocannabinoid system in the sea squirt Ciona intestinalis. J Neurochem 2005; 93:1141-56. [PMID: 15934935 DOI: 10.1111/j.1471-4159.2005.03103.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A cannabinoid receptor orthologue (CiCBR) has been described in the sea squirt Ciona intestinalis. Here we report that CiCBR mRNA expression is highest in cerebral ganglion, branchial pharynx, heart and testis of C. intestinalis, and that this organism also contains cannabinoid receptor ligands and some of the enzymes for ligand biosynthesis and inactivation. Using liquid chromatography-mass spectrometry, the endocannabinoid anandamide was found in all tissues analysed (0.063-5.423 pmol/mg of lipid extract), with the highest concentrations being found in brain and heart. The endocannabinoid 2-arachidonoylglycerol (2-AG) was fivefold more abundant than anandamide, and was most abundant in stomach and intestine and least abundant in heart and ovaries (2.677-50.607 pmol/mg of lipid extract). Using phylogenomic analysis, we identified orthologues of several endocannabinoid synthesizing and degrading enzymes. In particular, we identified and partly sequenced a fatty acid amide hydrolase (FAAH) orthologue, showing 44% identity with human FAAH and containing nearly all the amino acids necessary for a functional FAAH enzyme. Ciona intestinalis also contained specific binding sites for cannabinoid receptor ligands, and an amidase enzyme with pH-dependency and subcellular/tissue distribution similar to mammalian FAAHs. Finally, a typical C. intestinalis behavioural response, siphon reopening after closure induced by mechanical stimulation, was inhibited by the cannabinoid receptor agonist HU-210, and this effect was significantly attenuated by mammalian cannabinoid receptor antagonists.
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Affiliation(s)
- Isabel Matias
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Pozzuoli (Napoli), Italy
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41
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Rowley AF, Vogan CL, Taylor GW, Clare AS. Prostaglandins in non-insectan invertebrates: recent insights and unsolved problems. J Exp Biol 2005; 208:3-14. [PMID: 15601872 DOI: 10.1242/jeb.01275] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
SUMMARYProstaglandins (PG) are oxygenated derivatives of C20 polyunsaturated fatty acids including arachidonic and eicosapentaenoic acids. In mammals, these compounds have been shown to play key roles in haemostasis, sleep-wake regulation, smooth muscle tone, and vaso-, temperature and immune regulation. In invertebrates, PGs have been reported to perform similar roles and are involved in the control of oogenesis and spermatogenesis, ion transport and defence. Although there is often a detailed understanding of the actions of these compounds in invertebrates such as insects, knowledge of their mechanism of biosynthesis is often lacking. This account provides a critical review of our current knowledge on the structure and modes of biosynthesis of PGs in invertebrates, with particular reference to aquatic invertebrates. It emphasises some of the most recent findings, which suggest that some PGs have been misidentified.Prostaglandins in invertebrates can be categorised into two main types; the classical forms, such as PGE2 and PGD2 that are found in mammals, and novel forms including clavulones, bromo- and iodo-vulones and various PGA2 and PGE2 esters. A significant number of reports of PG identification in invertebrates have relied upon methods such as enzyme immunoassay that do not have the necessary specificity to ensure the validity of the identification. For example, in the barnacle Balanus amphitrite, although there are PG-like compounds that bind to antibodies raised against PGE2, mass spectrometric analysis failed to confirm the presence of this and other classical PGs. Therefore, care should be taken in drawing conclusions about what PGs are formed in invertebrates without employing appropriate analytical methods. Finally, the recent publication of the Ciona genome should facilitate studies on the nature and mode of biosynthesis of PGs in this advanced deuterostomate invertebrate.
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Affiliation(s)
- Andrew F Rowley
- School of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, UK.
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42
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Valmsen K, Boeglin WE, Järving I, Schneider C, Varvas K, Brash AR, Samel N. Structural and functional comparison of 15S- and 15R-specific cyclooxygenases from the coral Plexaura homomalla. ACTA ACUST UNITED AC 2004; 271:3533-8. [PMID: 15317588 DOI: 10.1111/j.0014-2956.2004.04289.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It has been known for 30 years that the gorgonian coral Plexaura homomalla contains either 15S- or 15R-configuration prostaglandins (PGs), depending on its location in the Caribbean. Recently we showed that the 15R-PGs in the R-variety of P. homomalla are formed by a unique cyclooxygenase (COX) with 15R oxygenation specificity [Valmsen, K., Järving, I., Boeglin, W.E., Varvas, K., Koljak, R., Pehk, T., Brash, A.R. & Samel, N. (2001) Proc. Natl. Acad. Sci. USA98, 7700]. Here we describe the cloning and characterization of a closely related COX protein (97% amino acid sequence identity) from the S-variety of P. homomalla. Functional expression of the S-variant COX cDNA in Sf9 insect cells followed by incubation with exogenous arachidonic acid resulted in formation of PG products with > 98% 15S-configuration. Mutational analysis was performed on a suggested active site determinant of C-15 oxygenation specificity, position 349 (Val in all S-specific COX, Ile in 15R-COX). The 15S-COX Val349 to Ile mutant formed 35% 15R-PGs, while the reverse mutation in the 15R-COX (Ile349Val) led to formation of 70% 15S-products. This establishes position 349 as an important determinant of the product stereochemistry at C-15. Our characterization of the enzyme variants demonstrates that very minor sequence divergence accounts for the content of epimeric PGs in the two variants of P. homomalla and that the differences do not arise by isomerization of the products.
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Affiliation(s)
- Karin Valmsen
- Department of Chemistry, Tallinn University of Technology, Estonia
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Järving R, Järving I, Kurg R, Brash AR, Samel N. On the Evolutionary Origin of Cyclooxygenase (COX) Isozymes. J Biol Chem 2004; 279:13624-33. [PMID: 14732711 DOI: 10.1074/jbc.m313258200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In vertebrates, COX-1 and COX-2, two cyclooxygenase isozymes with different physiological functions and gene regulation, catalyze identical reactions in prostaglandin synthesis. It is still not understood why there are multiple forms of COX enzyme in the same cell type and when the evolutionary duplication of the COX gene occurred. Here we report the structure of two genes encoding for COX isozymes in the coral Gersemia fruticosa, the first non-vertebrate organism from which a cyclooxygenase was characterized. Both genes are about 20 kb in size and consist of nine exons. Intron/exon boundaries are well conserved between coral and mammalian COX genes. mRNAs of the previously reported G. fruticosa COX-A (GenBank trade mark accession number AY004222) and the novel COX-B share 94% sequence identity in the coding regions and less than 30% in the 5'- and 3'-untranslated region. Transcripts of both COX genes are detectable in coral cells, although the transcriptional level of COX-A is 2 orders of magnitude higher than COX-B. Expression of both coral genes in mammalian cells gave functional proteins with similar catalytic properties. By data base analyses we also detected and constructed different pairs of COX genes from the primitive chordates, Ciona savignyi and Ciona intestinalis. These two gene pairs encode proteins with 50% intra-species and only 70% cross-species sequence identity. Our results suggest that invertebrate COX gene pairs do not correspond to vertebrate COX-1 and COX-2 and are consistent with duplication of the COX gene having occurred independently in corals, ascidians, and vertebrates. It is evident that due to the importance and complexity of its regulatory role, COX has multiple isoforms in all organisms known to express it, and the genes encoding for the isozymes may to be regulated differently.
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Affiliation(s)
- Reet Järving
- Department of Chemistry, Tallinn Technical University, Akadeemia tee 15, Tallinn 12618
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Seibold SA, Ball T, Hsi LC, Mills DA, Abeysinghe RD, Micielli R, Rieke CJ, Cukier RI, Smith WL. Histidine 386 and its role in cyclooxygenase and peroxidase catalysis by prostaglandin-endoperoxide H synthases. J Biol Chem 2003; 278:46163-70. [PMID: 12952981 DOI: 10.1074/jbc.m306319200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prostaglandin-endoperoxide H synthases (PGHSs) have a cyclooxygenase that forms prostaglandin (PG) G2 from arachidonic acid (AA) plus oxygen and a peroxidase that reduces the PGG2 to PGH2. The peroxidase activates the cyclooxygenase. This involves an initial oxidation of the peroxidase heme group by hydroperoxide, followed by oxidation of Tyr385 to a tyrosyl radical within the cyclooxygenase site. His386 of PGHS-1 is not formally part of either active site, but lies in an extended helix between Tyr385, which protrudes into the cyclooxygenase site, and His388, the proximal ligand of the peroxidase heme. When His386 was substituted with alanine in PGHS-1, the mutant retained <2.5% of the native peroxidase activity, but >20% of the native cyclooxygenase activity. However, peroxidase activity could be restored (10-30%) by treating H386A PGHS-1 with cyclooxygenase inhibitors or AA, but not with linoleic acid; in contrast, mere occupancy of the cyclooxygenase site of native PGHS-1 had no effect on peroxidase activity. Heme titrations indicated that H386A PGHS-1 binds heme less tightly than does native PGHS-1. The low peroxidase activity and decreased affinity for heme of H386A PGHS-1 imply that His386 helps optimize heme binding. Molecular dynamic simulations suggest that this is accomplished in part by a hydrogen bond between the heme D-ring propionate and the N-delta of Asn382 of the extended helix. The structure of the extended helix is, in turn, strongly supported by stable hydrogen bonding between the N-delta of His386 and the backbone carbonyl oxygens of Asn382 and Gln383. We speculate that the binding of cyclooxygenase inhibitors or AA to the cyclooxygenase site of ovine H386A PGHS-1 reopens the constriction in the cyclooxygenase site between the extended helix and a helix containing Gly526 and Ser530 and restores native-like structure to the extended helix. Being less bulky than AA, linoleic acid is apparently unable to reopen this constriction.
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Affiliation(s)
- Steve A Seibold
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109-0606, USA
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Yang T, Forrest SJ, Stine N, Endo Y, Pasumarthy A, Castrop H, Aller S, Forrest JN, Schnermann J, Briggs J. Cyclooxygenase cloning in dogfish shark, Squalus acanthias, and its role in rectal gland Cl secretion. Am J Physiol Regul Integr Comp Physiol 2002; 283:R631-7. [PMID: 12184997 DOI: 10.1152/ajpregu.00743.2001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present studies were carried out with the aims to determine the cDNA sequence for cyclooxygenase (COX) in an elasmobranch species and to study its role in regulation of chloride secretion in the perfused shark rectal gland (SRG). With the use of long primers (43 bp) derived from regions of homology between zebrafish and rainbow trout COX-2 genes, a 600-bp product was amplified from SRG and was found to be almost equally homologous to mammalian COX-1 and COX-2 (65%). The full-length cDNA sequence was obtained by 5'-RACE and by analyzing an EST clone generated by the EST Project of the Mt. Desert Island Biological Laboratory Marine DNA Sequencing Center. The longest open reading frame encodes a 593-amino acid protein that has 68 and 64% homology to mammalian COX-1 and COX-2, respectively. The gene and its protein product is designated as shark COX (sCOX). The key residues in the active site (Try(385), His(388), and Ser(530)) are conserved between the shark and mammalian COX. sCOX contains Val(523) that has been shown to be a key residue determining the sensitivity to COX-2-specific inhibitors including NS-398. The mRNA of sCOX, detected by RT-PCR, was found in all tissues tested, including rectal gland, kidney, spleen, gill, liver, brain, and heart, but not in fin. In the perfused SRG, vasoactive intestinal peptide (VIP) at 5 nM induced rapid and marked Cl(-) secretion (basal: <250 microeq x h(-1) x g(-1); peak response: 3,108 +/- 479 microeq x h(-1) x g(-1)). In the presence of 50 microM NS-398, both the peak response (2,131 +/- 307 microeq x h(-1) x g(-1)) and the sustained response to VIP were significantly reduced. When NS-398 was removed, there was a prompt recovery of chloride secretion to control values. In conclusion, we have cloned the first COX in an elasmobranch species (sCOX) and shown that sCOX inhibition suppresses VIP-stimulated chloride secretion in the perfused SRG.
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Affiliation(s)
- T Yang
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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Schneider C, Brash AR. Lipoxygenase-catalyzed formation of R-configuration hydroperoxides. Prostaglandins Other Lipid Mediat 2002; 68-69:291-301. [PMID: 12432924 DOI: 10.1016/s0090-6980(02)00041-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Prototypical lipoxygenases (LOXs) of animals and plants synthesize hydroperoxy fatty acids of the S stereoconfiguration, yet enzymes forming R-configuration products are found in both the animal and plant kingdoms. R-LOX are widespread in aquatic invertebrates, in some of which their R-HETE products have a defined role in reproductive function. A 12R-LOX has been found recently in humans and mice. The human 12R-LOX product, 12R-HETE, appears to be involved in the pathophysiology of psoriasis and other proliferative skin diseases; a role in normal skin development is implied from the spatial and temporal expression patterns of the 12R-LOX in the mouse embryo. In plants, there are few reports of R-LOX activity and in higher plants this is limited to enzymes that catalyze a significant degree of non-specific oxygenation. There are no obvious amino acid sequence motifs characterizing R-LOXs; and in the phylogenetic tree of the LOX superfamily, the R-LOXs do not group into a specific branch of genes. The mechanistic basis of stereocontrol over the oxygenation reaction performed by LOXs may relate to a changed binding orientation of the fatty acid substrate or to the direction of attack by molecular oxygen. A potentially relevant precedent for switching of R- and S-oxygenation specificity was described recently in studies of prostaglandin C-15 oxygenation during cycloxygenase catalysis; single amino acid changes can invert the oxygenation stereospecificity at C-15. In this case, the evidence suggests that R/S switching can occur with the substrate binding in the normal conformation.
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Affiliation(s)
- Claus Schneider
- Division of Clinical Pharmacology, Vanderbilt University Medical School, Nashville, TN 37232-6602, USA
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Abstract
Allene oxides are unstable epoxides formed by the enzymatic dehydration of the lipoxygenase products of polyunsaturated fatty acids. The allene oxide synthases are of two structurally-unrelated types. In plants, a subfamily of cytochromes P450, designated as CYP74A, use the hydroperoxides of linoleic and linolenic acids as substrate. Both the 9- and 13-hydroperoxides may be converted to allene oxides and subsequently give rise to plant signaling molecules. In corals, a catalase-related hemoprotein functions as the allene oxide synthase. These marine invertebrates, as well as starfish, form allene oxides from the 8R-hydroperoxide of arachidonic acid. The coral allene oxide synthase from Plexaura homomalla occurs as the N-terminal domain of a natural fusion protein with the 8R-lipoxygenase that forms its substrate. This enzyme may be involved in biosynthesis of the cyclopentenone eicosanoids such as the clavulones.
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Affiliation(s)
- Nathalie Tijet
- Department of Pharmacology, Vanderbilt University Medical School, Nashville, TN 37232-6602, USA
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Grosser T, Yusuff S, Cheskis E, Pack MA, FitzGerald GA. Developmental expression of functional cyclooxygenases in zebrafish. Proc Natl Acad Sci U S A 2002; 99:8418-23. [PMID: 12011329 PMCID: PMC123082 DOI: 10.1073/pnas.112217799] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2001] [Accepted: 04/10/2002] [Indexed: 11/18/2022] Open
Abstract
Study of the cyclooxygenases (COXs) has been limited by the role of COX-2 in murine reproduction and renal organogenesis. We sought to characterize COX expression and function in zebrafish (z). Full-length cDNAs of zCOX-1 and zCOX-2 were cloned and assigned to conserved regions of chromosomes 5 and 2, respectively. The deduced proteins are 67% homologous with their human orthologs. Prostaglandin (PG) E(2) is the predominant zCOX product detected by mass spectrometry. Pharmacological inhibitors demonstrate selectivity when directed against heterologously expressed zCOX isoforms. Zebrafish thrombocyte aggregation ex vivo and hemostasis in vivo are sensitive to inhibition of zCOX-1, but not zCOX-2. Both zCOXs were widely expressed during development, and knockdown of zCOX-1 causes growth arrest during early embryogenesis. zCOX-1 is widely evident in the embryonic vasculature, whereas zCOX-2 exhibits a more restricted pattern of expression. Both zCOX isoforms are genetically and functionally homologous to their mammalian orthologs. The zebrafish affords a tractable model system for the study of COX biology and development.
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Affiliation(s)
- Tilo Grosser
- Center for Experimental Therapeutics, University of Pennsylvania School of Medicine, 153 Johnson Pavilion, 3620 Hamilton Walk, Philadelphia, PA 19104, USA
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Valmsen K, Järving I, Boeglin WE, Varvas K, Koljak R, Pehk T, Brash AR, Samel N. The origin of 15R-prostaglandins in the Caribbean coral Plexaura homomalla: molecular cloning and expression of a novel cyclooxygenase. Proc Natl Acad Sci U S A 2001; 98:7700-5. [PMID: 11427702 PMCID: PMC35405 DOI: 10.1073/pnas.131022398] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2001] [Indexed: 11/18/2022] Open
Abstract
The highest concentrations of prostaglandins in nature are found in the Caribbean gorgonian Plexaura homomalla. Depending on its geographical location, this coral contains prostaglandins with typical mammalian stereochemistry (15S-hydroxy) or the unusual 15R-prostaglandins. Their metabolic origin has remained the subject of mechanistic speculations for three decades. Here, we report the structure of a type of cyclooxygenase (COX) that catalyzes transformation of arachidonic acid into 15R-prostaglandins. Using a homology-based reverse transcriptase--PCR strategy, we cloned a cDNA corresponding to a COX protein from the R variety of P. homomalla. The deduced peptide sequence shows 80% identity with the 15S-specific coral COX from the Arctic soft coral Gersemia fruticosa and approximately 50% identity to mammalian COX-1 and COX-2. The predicted tertiary structure shows high homology with mammalian COX isozymes having all of the characteristic structural units and the amino acid residues important in catalysis. Some structural differences are apparent around the peroxidase active site, in the membrane-binding domain, and in the pattern of glycosylation. When expressed in Sf9 cells, the P. homomalla enzyme forms a 15R-prostaglandin endoperoxide together with 11R-hydroxyeicosatetraenoic acid and 15R-hydroxyeicosatetraenoic acid as by-products. The endoperoxide gives rise to 15R-prostaglandins and 12R-hydroxyheptadecatrienoic acid, identified by comparison to authentic standards. Evaluation of the structural differences of this 15R-COX isozyme should provide new insights into the substrate binding and stereospecificity of the dioxygenation reaction of arachidonic acid in the cyclooxygenase active site.
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Affiliation(s)
- K Valmsen
- Department of Bioorganic Chemistry, Institute of Chemistry at Tallinn Technical University, Akadeemia tee 15, Tallinn 12618, Estonia
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