Simultaneous expression of leukocyte-type 12-lipoxygenase and reticulocyte-type 15-lipoxygenase in rabbits 1 1Edited by F. Cohen

Berger, Mario; Schwarz, Kristin; Thiele, Holger; Reimann, Iris; Huth, Antje; Borngräber, Sabine; Kühn, Hartmut; Thiele, B

doi:10.1006/jmbi.1998.1737

Cited by 56 publications

(33 citation statements)

References 46 publications

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“…The only exception was the rabbit. For this species, two distinct ALOX15 cDNAs can be retrieved, and previous studies indicated pronounced differences in the reaction specificity of these ALOX15 isoforms (38).…”

Section: Resultsmentioning

confidence: 91%

“…In this species, a 12-and a 15-lipoxygenating ALOX15 isoform are expressed in a tissue-specific manner. Originally, the existence of two separate ALOX15 genes has been suggested (38), but completion of the rabbit genome did not confirm this suggestion. In fact, the major publically available genome databases [ENSEMBL (www.ensembl.…”

Section: Discussionmentioning

confidence: 99%

“…developed primates such as modern and extinct humans (25,32,33), as well as orangutans (22,34), express 15-lipoxygenating ALOX15 orthologs, whereas less developed mammals (21,(35)(36)(37)(38), including lower primates, have 12-lipoxygenating enzymes. Although no functional data are currently available for most mammalian ALOX15 orthologs, multiple sequence alignments suggested that their reaction specificity was altered during late primate evolution from 12-to 15-lipoxygenation (3).…”

Section: Significancementioning

confidence: 99%

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Evolutionary alteration of ALOX15 specificity optimizes the biosynthesis of antiinflammatory and proresolving lipoxins

Adel

Karst

González‐Lafont

et al. 2016

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

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ALOX15 (12/15-lipoxygenase) orthologs have been implicated in maturational degradation of intracellular organelles and in the biosynthesis of antiinflammatory and proresolving eicosanoids. Here we hypothesized that lower mammals (mice, rats, pigs) express 12-lipoxygenating ALOX15 orthologs. In contrast, 15-lipoxygenating isoforms are found in higher primates (orangutans, men), and these results suggest an evolution of ALOX15 specificity. To test this hypothesis we first cloned and characterized ALOX15 orthologs of selected Catarrhini representing different stages of late primate evolution and found that higher primates (men, chimpanzees) express 15-lipoxygenating orthologs. In contrast, lower primates (baboons, rhesus monkeys) express 12-lipoxygenating enzymes. Gibbons, which are flanked in evolution by rhesus monkeys (12-lipoxygenating ALOX15) and orangutans (15-lipoxygenating ALOX15), express an ALOX15 ortholog with pronounced dual specificity. To explore the driving force for this evolutionary alterations, we quantified the lipoxin synthase activity of 12-lipoxygenating (rhesus monkey, mouse, rat, pig, humIle418Ala) and 15-lipoxygenating (man, chimpanzee, orangutan, rabbit, ratPhe353Ala) ALOX15 variants and found that, when normalized to their arachidonic acid oxygenase activities, the lipoxin synthase activities of 15-lipoxygenating ALOX15 variants were more than fivefold higher (P < 0.01). Comparative molecular dynamics simulations and quantum mechanics/molecular mechanics calculations indicated that, for the 15-lipoxygenating rabbit ALOX15, the energy barrier for C13-hydrogen abstraction (15-lipoxygenation) was 17 kJ/mol lower than for arachidonic acid 12-lipoxygenation. In contrast, for the 12-lipoxygenating Ile418Ala mutant, the energy barrier for 15-lipoxygenation was 10 kJ/mol higher than for 12-lipoxygenation. Taken together, our data suggest an evolution of ALOX15 specificity, which is aimed at optimizing the biosynthetic capacity for antiinflammatory and proresolving lipoxins.

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Section: Resultsmentioning

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Significancementioning

confidence: 99%

See 1 more Smart Citation

Evolutionary alteration of ALOX15 specificity optimizes the biosynthesis of antiinflammatory and proresolving lipoxins

Adel

Karst

González‐Lafont

et al. 2016

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

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“…Most mammalian species (mouse, rats, pigs, cattle, and M. mulatta) express 12-lipoxygenating 12/15-LOX, but in humans and P. pygmaeus, the enzyme constitutes a 15-lipoxygenating isoform. Rabbits are the only animal species for which separate genes encoding for a 12-and a 15-lipoxygenating 12/15-LOX have been described (34). Previous mutagenesis studies on the human 12/15-LOX suggested Ile-418 and Met-419 as sequence determinants for the positional specificity (17), and similar experiments on the rabbit ortholog indicated that Phe-353 (18) and Ile-593 (19) may also play a similar role.…”

Section: Discussionmentioning

confidence: 99%

Applicability of the Triad Concept for the Positional Specificity of Mammalian Lipoxygenases

Vogel

Jansen

Roffeis

et al. 2010

Journal of Biological Chemistry

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The nomenclature of lipoxygenases (LOXs) is partly based on the positional specificity of arachidonic acid oxygenation, but there is no unifying concept explaining the mechanistic basis of this enzyme property. According to the triad model, Phe-353, Ile-418, and Ile-593 of the rabbit 12/15-LOX form the bottom of the substrate-binding pocket, and introduction of less spacefilling residues at either of these positions favors arachidonic acid 12-lipoxygenation. The present study was aimed at exploring the validity of the triad concept for two novel primate 12/15-LOX (Macaca mulatta and Pongo pygmaeus) and for five known members of the mammalian LOX family (human 12/15-LOX, mouse 12/15-LOX, human 15-LOX2, human platelet type 12-LOX, and mouse (12R)-LOX). The enzymes were expressed as N-terminal His tag fusion proteins in E. coli, the potential sequence determinants were mutated, and the specificity of arachidonic acid oxygenation was quantified. Taken together, our data indicate that the triad concept explains the positional specificity of all 12/15-LOXs tested (rabbit, human, M. mulatta, P. pygmaeus, and mouse). For the new enzymes of M. mulatta and P. pygmaeus, the concept had predictive value because the positional specificity predicted on the basis of the amino acid sequence was confirmed experimentally. The specificity of the platelet 12-LOX was partly explained by the triad hypothesis, but the concept was not applicable for 15-LOX2 and (12R)-LOX.

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“…One of these exchanges (Phe353Leu) is responsible for the different positional specificities for oxygenation of the 2 enzymes. 19 Rabbit aorta and cultured ECs convert AA to 15-HPETE and 15-HETE. 5,7,20 However, the cellular expression patterns of the enzyme(s) responsible for the enzymatic properties of aortic 15-LO are still not clear.…”

mentioning

confidence: 99%

Reticulocyte 15-Lipoxygenase-I Is Important in Acetylcholine-Induced Endothelium-Dependent Vasorelaxation in Rabbit Aorta

Tang

Holmes

Nithipatikom

et al. 2006

ATVB

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Objective-Aortic 15-lipoxygenase (15-LO) metabolizes arachidonic acid (AA) to 15-hydroperoxyeicosatetraenoic acid, which is then converted to the vasodilators 15-hydroxy-11,12-epoxyeicosatrienoic acid and 11,12,15-trihydroxyeicosatrienoic acid. These metabolites contribute to endothelium-dependent relaxations of rabbit aorta to AA and acetylcholine. We investigated the identity of rabbit aortic 15-LO and studied its importance in the regulation of vascular tone. Methods and Results-RT-PCR using 12-lipoxygenase/15-LO specific primers resulted in a 572-bp product with a sequence identical to 15-LO-I from rabbit aorta. A RT-PCR/restriction digest strategy excluded expression of 12-lipoxygenase. Immunoblotting revealed 15-LO-I expression in rabbit endothelial and smooth muscle cells. Aortic homogenates and cytosolic fractions metabolize AA to 15(S)-hydroxyeicosatetraenoic acid and linoleic acid to 13(S)-hydroxyoctadecadienoic acid. This activity was blocked by LO inhibitors. The kinetic characteristics (Michaelis constant of aortic 15-LO is 2.2Ϯ0.3 mol/L for AA and 23.5Ϯ3.3 mol/L for linoleic acid) of aortic 15-LO were similar to those of the purified 15-LO-I. An antisense oligonucleotide inhibited 15-LO-I expression in rabbit aorta. Indomethacin and nitro-L-arginine-resistant relaxations to acetylcholine were inhibited by 15-LO-I antisense oligonucleotide but not by the scrambled oligonucleotide. Key Words: endothelium Ⅲ arachidonic acid Ⅲ 15-lipoxygenase Ⅲ endothelium-derived hyperpolarizing factor E ndothelial cells (ECs) release factors that control vascular tone in response to acetylcholine, bradykinin, and other hormones, as well as by shear stress. 1 Some of these vasoactive factors are metabolites of arachidonic acid (AA). In rabbit aortic ECs, AA is metabolized through cyclooxygenase, lipoxygenase (LO), and cytochrome P 450 pathways into bioactive eicosanoids. [2][3][4] Rabbit aorta relaxes to acetylcholine and AA in the presence of indomethacin and L-nitroarginine (L-NA), which block cyclooxygenase and nitric oxide synthase, respectively. 2,5 These relaxation responses are blocked by LO inhibitors, such as nordihydroguaiaretic acid (NDGA), cinnamyl-3,4-dihydroxy-a-cyanocinnamate (CDC), and ebselen. 4 -6 AA is oxidized via the 15-LO pathway to 15(S)-hydroperoxyeicosatetraenoic acid, which is additionally converted to hydroxy-epoxyeicosatrienoic acids (HEETAs) and trihydroxyeicosatrienoic acids (THETAs). Both the HEETA and 11,12,15-THETA relax the rabbit aorta. 7 These studies implicate the aortic 15-LO pathway in the regulation of vascular tone. Thus, the rabbit aortic 15-LO, which initiates the synthesis of these vasodilatory eicosanoids, represents an important regulatory site of vascular eicosanoid metabolism. Conclusions-15-LO-I is expressed in rabbit aortic endothelium and is important in endothelium-In humans, there are 2 15-LO isozymes (15-LO-I and 15-LO-II) originating from 2 different genes. 8,9 15-LO-I was cloned from rabbit reticulocytes 10 and human leukocytes and oxygenates AA to 15(S)-hydrope...

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Simultaneous expression of leukocyte-type 12-lipoxygenase and reticulocyte-type 15-lipoxygenase in rabbits 1 1Edited by F. Cohen

Cited by 56 publications

References 46 publications

Evolutionary alteration of ALOX15 specificity optimizes the biosynthesis of antiinflammatory and proresolving lipoxins

Evolutionary alteration of ALOX15 specificity optimizes the biosynthesis of antiinflammatory and proresolving lipoxins

Applicability of the Triad Concept for the Positional Specificity of Mammalian Lipoxygenases

Reticulocyte 15-Lipoxygenase-I Is Important in Acetylcholine-Induced Endothelium-Dependent Vasorelaxation in Rabbit Aorta

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