Goldstone Jared V.

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Last Name
Goldstone
First Name
Jared V.
ORCID
0000-0002-9618-4961

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  • Preprint
    Cloning a new cytochrome P450 isoform (CYP356A1) from oyster Crassostrea gigas
    ( 2008-02) de Toledo-Silva, Guilherme ; Siebert, Marília N. ; Medeiros, Igor D. ; Sincero, Thaís C. M. ; Moraes, Milton O. ; Goldstone, Jared V. ; Bainy, Afonso C. D.
    We have cloned the full-length cDNA of the first member of a new cytochrome P450 (CYP) family from the Pacific oyster Crassostrea gigas. This new CYP gene was obtained based on an initial 331 bp fragment previously identified among the list of the differentially expressed genes in oysters exposed to untreated domestic sewage. The full-length CYP has an open reading frame of 1500 bp and based on its deduced aminoacid sequence was classified as a member of a new subfamily, CYP356A1. A phylogenetic analysis showed that CYP356A1 is closely related to members of the CYP17 and CYP1 subfamilies. Semiquantitative RT-PCR was performed to analyze the CYP356A1 expression in different tissues of the oyster (digestive gland, gill, mantle and adductor muscle). Results showed slightly higher CYP356A1 expression in digestive gland and mantle, than the other tissues, indicating a possible role of the CYP356A1 in the xenobiotic biotransformation and/or steroid metabolism.
  • Preprint
    Isolation and phylogeny of novel cytochrome P450 genes from tunicates (Ciona spp.) : a CYP3 line in early deuterostomes?
    ( 2006-04-04) Verslycke, Tim A. ; Goldstone, Jared V. ; Stegeman, John J.
    Cytochromes P450 (CYPs) form a gene superfamily involved in the biotransformation of numerous endogenous and exogenous natural and synthetic compounds. In humans, CYP3A4 is regarded as one of the most important CYPs due to its abundance in liver and its capacity to metabolize more than 50% of all clinically used drugs. It has been suggested that all CYP3s arose from a common ancestral gene lineage that diverged between 800 and 1100 million years ago, before the deuterostome-protostome split. While CYP3s are well known in mammals and have been described in lower vertebrates, they have not been reported in non-vertebrate deuterostomes. Members of the genus Ciona belong to the tunicates, whose lineage is thought to be the most basal among the chordates, and from which the vertebrate line diverged. Here we describe the cloning, exon-intron structure, phylogeny, and estimated expression of four novel genes from Ciona intestinalis. We also describe the gene structure and phylogeny of homologous genes in Ciona savignyi. Comparing these genes with other members of the CYP clan 3, show that the Ciona sequences bear remarkable similarity to vertebrate CYP3A genes, and may be an early deuterostome CYP3 line.
  • Article
    Evolution of a major drug metabolizing enzyme defect in the domestic cat and other felidae : phylogenetic timing and the role of hypercarnivory
    (Public Library of Science, 2011-03-28) Shrestha, Binu ; Reed, J. Michael ; Starks, Philip T. ; Kaufman, Gretchen E. ; Goldstone, Jared V. ; Roelke, Melody E. ; O'Brien, Stephen J. ; Koepfli, Klaus-Peter ; Frank, Laurence G. ; Court, Michael H.
    The domestic cat (Felis catus) shows remarkable sensitivity to the adverse effects of phenolic drugs, including acetaminophen and aspirin, as well as structurally-related toxicants found in the diet and environment. This idiosyncrasy results from pseudogenization of the gene encoding UDP-glucuronosyltransferase (UGT) 1A6, the major species-conserved phenol detoxification enzyme. Here, we established the phylogenetic timing of disruptive UGT1A6 mutations and explored the hypothesis that gene inactivation in cats was enabled by minimal exposure to plant-derived toxicants. Fixation of the UGT1A6 pseudogene was estimated to have occurred between 35 and 11 million years ago with all extant Felidae having dysfunctional UGT1A6. Out of 22 additional taxa sampled, representative of most Carnivora families, only brown hyena (Parahyaena brunnea) and northern elephant seal (Mirounga angustirostris) showed inactivating UGT1A6 mutations. A comprehensive literature review of the natural diet of the sampled taxa indicated that all species with defective UGT1A6 were hypercarnivores (>70% dietary animal matter). Furthermore those species with UGT1A6 defects showed evidence for reduced amino acid constraint (increased dN/dS ratios approaching the neutral selection value of 1.0) as compared with species with intact UGT1A6. In contrast, there was no evidence for reduced amino acid constraint for these same species within UGT1A1, the gene encoding the enzyme responsible for detoxification of endogenously generated bilirubin. Our results provide the first evidence suggesting that diet may have played a permissive role in the devolution of a mammalian drug metabolizing enzyme. Further work is needed to establish whether these preliminary findings can be generalized to all Carnivora.
  • Preprint
    Environmental sensing and response genes in cnidaria : the chemical defensome in the sea anemone Nematostella vectensis
    ( 2008-10) Goldstone, Jared V.
    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% (266/27200) 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.
  • Article
    Resistance to Cyp3a induction by polychlorinated biphenyls, including non-dioxin-like PCB153, in gills of killifish (Fundulus heteroclitus) from New Bedford Harbor
    (Elsevier, 2021-01-08) Celander, Malin C. ; Goldstone, Jared V. ; Brun, Nadja R. ; Clark, Bryan W. ; Jayaraman, Saro ; Nacci, Diane E. ; Stegeman, John J.
    Previous reports suggested that non-dioxin-like (NDL) PCB153 effects on cytochrome P450 3A (Cyp3a) expression in Atlantic killifish (Fundulus heteroclitus) gills differed between F0 generation fish from a PCB site (New Bedford Harbor; NBH) and a reference site (Scorton Creek; SC). Here, we examined effects of PCB153, dioxin-like (DL) PCB126, or a mixture of both, on Cyp3a56 mRNA in killifish generations removed from the wild, without environmental PCB exposures. PCB126 effects in liver and gills differed between populations, as expected. Gill Cyp3a56 was not affected by either congener in NBH F2 generation fish, but was induced by PCB153 in SC F1 fish, with females showing a greater response. PCB153 did not affect Cyp3a56 in liver of either population. Results suggest a heritable resistance to NDL-PCBs in killifish from NBH, in addition to that reported for DL PCBs. Induction of Cyp3a56 in gills may be a biomarker of exposure to NDL PCBs in fish populations that are not resistant to PCBs.
  • Preprint
    Proteomic identification, cDNA cloning and enzymatic activity of glutathione S-transferases from the generalist marine gastropod, Cyphoma gibbosum
    ( 2008-06) Whalen, Kristen E. ; Morin, Dexter ; Lin, Ching Yu ; Tjeerdema, Ronald S. ; Goldstone, Jared V. ; Hahn, Mark E.
    Glutathione S-transferases (GST) were characterized from the digestive gland of Cyphoma gibbosum (Mollusca; Gastropoda), to investigate the possible role of these detoxification enzymes in conferring resistance to allelochemicals present in its gorgonian coral diet. We identified the collection of expressed cytosolic Cyphoma GST classes using a proteomic approach involving affinity chromatography, HPLC and nanospray liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two major GST subunits were identified as putative mu-class GSTs; while one minor GST subunit was identified as a putative theta-class GST, apparently the first theta-class GST identified from a mollusc. Two Cyphoma GST cDNAs (CgGSTM1 and CgGSTM2) were isolated by RT-PCR using primers derived from peptide sequences. Phylogenetic analyses established both cDNAs as mu-class GSTs and revealed a mollusc-specific subclass of the GST-mu clade. These results provide new insights into metazoan GST diversity and the biochemical mechanisms used by marine organisms to cope with their chemically defended prey.
  • Preprint
    The new vertebrate CYP1C family : cloning of new subfamily members and phylogenetic analysis
    ( 2005-03-11) Godard, Celine A. J. ; Goldstone, Jared V. ; Said, Maya R. ; Dickerson, Richard L. ; Woodin, Bruce R. ; Stegeman, John J.
    Two novel CYP1 genes from teleost fish constituting a new subfamily have been cloned. These paralogous sequences are designated CYP1C1 and CYP1C2. Both genes were initially obtained from untreated scup Stenotomus chrysops tissues by RT-PCR and RACE. Scup CYP1C1 and CYP1C2 code for 524 and 525 amino acids, respectively, and share 80-81% identity at the nucleotide and amino acid levels. Orthologues of CYP1C1 and CYP1C2 were identified in genome databases for other fish species, and both CYP1B1 and CYP1C1 were cloned from zebrafish (Danio rerio). Phylogenetic analysis shows that CYP1Cs and CYP1Bs constitute a sister clade to the CYP1As. Analysis of sequence domains likely to have functional significance suggests the two CYP1Cs in scup may have catalytic functions and/or substrate specificity that differ from each other and from those of mammalian CYP1Bs or CYP1As. RT-PCR results indicate that CYP1C1 and CYP1C2 are variously expressed in several scup organs.
  • Preprint
    New cytochrome P450 1B1, 1C2 and 1D1 genes in the killifish Fundulus heteroclitus : Basal expression and response of five killifish CYP1s to the AHR agonist PCB126
    ( 2009-04-30) Zanette, Juliano ; Jenny, Matthew J. ; Goldstone, Jared V. ; Woodin, Bruce R. ; Watka, Lauren A. ; Bainy, Afonso C. D. ; Stegeman, John J.
    Knowledge of the complement of cytochrome P450 (CYP) genes is essential to understanding detoxification and bioactivation mechanisms for organic contaminants.We cloned three new CYP1 genes, CYP1B1, CYP1C2 and CYP1D1, from the killifish Fundulus heteroclitus, an important model in environmental toxicology. Expression of the new CYP1s along with previously known CYP1A and CYP1C1 was measured by qPCR in eight different organs. Organ distribution was similar for the two CYP1Cs, but otherwise patterns and extent of expression differed among the genes. The AHR agonist 3,3_,4,4_,5-pentachlorobiphenyl (PCB126) (31 pmol/g fish) induced expression of CYP1A and CYP1B1 in all organs examined, while CYP1C1 was induced in all organs except testis. The largest changes in response to PCB126 were induction of CYP1A in testis (~700-fold) and induction of CYP1C1 in liver (~500-fold). CYP1B1 in liver and gut, CYP1A in brain and CYP1C1 in gill also were induced strongly by PCB126 (>100-fold). CYP1C1 expression levels were higher than CYP1C2 in almost all tissues and CYP1C2 was much less responsive to PCB126. In contrast to the other genes, CYP1D1 was not induced by PCB126 in any of the organs. The organ-specific response of CYP1s to PCB126 implies differential involvement in effects of halogenated aromatic hydrocarbons in different organs. The suite of inducible CYP1s could enhance the use of F. heteroclitus in assessing aquatic contamination by AHR agonists. Determining basal and induced levels of protein and the substrate specificity for all five CYP1s will be necessary to better understand their roles in chemical effects and physiology.
  • Article
    Genome sequence of the metazoan plant-parasitic nematode Meloidogyne incognita
    (Nature Publishing Group, 2008-07-27) Abad, Pierre ; Gouzy, Jerome ; Aury, Jean-Marc ; Castagnone-Sereno, Philippe ; Danchin, Etienne G. J. ; Deleury, Emeline ; Perfus-Barbeoch, Laetitia ; Anthouard, Veronique ; Artiguenave, Francois ; Blok, Vivian C. ; Caillaud, Marie-Cecile ; Coutinho, Pedro M. ; Da Silva, Corinne ; De Luca, Francesca ; Deau, Florence ; Esquibet, Magali ; Flutre, Timothe ; Goldstone, Jared V. ; Hamamouch, Noureddine ; Hewezi, Tarek ; Jaillon, Olivier ; Jubin, Claire ; Leonetti, Paola ; Magliano, Marc ; Maier, Tom R. ; Markov, Gabriel V. ; McVeigh, Paul ; Pesole, Graziano ; Poulain, Julie ; Robinson-Rechavi, Marc ; Sallet, Erika ; Segurens, Beatrice ; Steinbach, Delphine ; Tytgat, Tom ; Ugarte, Edgardo ; van Ghelder, Cyril ; Veronico, Pasqua ; Baum, Thomas J. ; Blaxter, Mark ; Bleve-Zacheo, Teresa ; Davis, Eric L ; Ewbank, Jonathan J. ; Favery, Bruno ; Grenier, Eric ; Henrissat, Bernard ; Jones, John T. ; Laudet, Vincent ; Maule, Aaron G. ; Quesneville, Hadi ; Rosso, Marie-Noelle ; Schiex, Thomas ; Smant, Geert ; Weissenbach, Jean ; Wincker, Patrick
    Plant-parasitic nematodes are major agricultural pests worldwide and novel approaches to control them are sorely needed. We report the draft genome sequence of the root-knot nematode Meloidogyne incognita, a biotrophic parasite of many crops, including tomato, cotton and coffee. Most of the assembled sequence of this asexually reproducing nematode, totaling 86 Mb, exists in pairs of homologous but divergent segments. This suggests that ancient allelic regions in M. incognita are evolving toward effective haploidy, permitting new mechanisms of adaptation. The number and diversity of plant cell wall–degrading enzymes in M. incognita is unprecedented in any animal for which a genome sequence is available, and may derive from multiple horizontal gene transfers from bacterial sources. Our results provide insights into the adaptations required by metazoans to successfully parasitize immunocompetent plants, and open the way for discovering new antiparasitic strategies.
  • Article
    Concerning P450 evolution: structural analyses support bacterial origin of sterol 14α-demethylases
    (Oxford University Press, 2020-10-08) Lamb, David C. ; Hargrove, Tatiana Y. ; Zhao, Bin ; Wawrzak, Zdzislaw ; Goldstone, Jared V. ; Nes, William David ; Kelly, Steven L. ; Waterman, Michael R. ; Stegeman, John J. ; Lepesheva, Galina I.
    Sterol biosynthesis, primarily associated with eukaryotic kingdoms of life, occurs as an abbreviated pathway in the bacterium Methylococcus capsulatus. Sterol 14α-demethylation is an essential step in this pathway and is catalyzed by cytochrome P450 51 (CYP51). In M. capsulatus, the enzyme consists of the P450 domain naturally fused to a ferredoxin domain at the C-terminus (CYP51fx). The structure of M. capsulatus CYP51fx was solved to 2.7 Å resolution and is the first structure of a bacterial sterol biosynthetic enzyme. The structure contained one P450 molecule per asymmetric unit with no electron density seen for ferredoxin. We connect this with the requirement of P450 substrate binding in order to activate productive ferredoxin binding. Further, the structure of the P450 domain with bound detergent (which replaced the substrate upon crystallization) was solved to 2.4 Å resolution. Comparison of these two structures to the CYP51s from human, fungi, and protozoa reveals strict conservation of the overall protein architecture. However, the structure of an “orphan” P450 from nonsterol-producing Mycobacterium tuberculosis that also has CYP51 activity reveals marked differences, suggesting that loss of function in vivo might have led to alterations in the structural constraints. Our results are consistent with the idea that eukaryotic and bacterial CYP51s evolved from a common cenancestor and that early eukaryotes may have recruited CYP51 from a bacterial source. The idea is supported by bioinformatic analysis, revealing the presence of CYP51 genes in >1,000 bacteria from nine different phyla, >50 of them being natural CYP51fx fusion proteins.
  • Article
    Metabolic arsenal of giant viruses: host hijack or self-use?
    (eLife Sciences Publications, 2022-07-08) Brahim Belhaouari, Djamal ; Pires De Souza, Gabriel Augusto ; Lamb, David C. ; Kelly, Steven L. ; Goldstone, Jared V. ; Stegeman, John J. ; Colson, Philippe ; La Scola, Bernard ; Aherfi, Sarah
    Viruses generally are defined as lacking the fundamental properties of living organisms in that they do not harbor an energy metabolism system or protein synthesis machinery. However, the discovery of giant viruses of amoeba has fundamentally challenged this view because of their exceptional genome properties, particle sizes and encoding of the enzyme machinery for some steps of protein synthesis. Although giant viruses are not able to replicate autonomously and still require a host for their multiplication, numerous metabolic genes involved in energy production have been recently detected in giant virus genomes from many environments. These findings have further blurred the boundaries that separate viruses and living organisms. Herein, we summarize information concerning genes and proteins involved in cellular metabolic pathways and their orthologues that have, surprisingly, been discovered in giant viruses. The remarkable diversity of metabolic genes described in giant viruses include genes encoding enzymes involved in glycolysis, gluconeogenesis, tricarboxylic acid cycle, photosynthesis, and β-oxidation. These viral genes are thought to have been acquired from diverse biological sources through lateral gene transfer early in the evolution of Nucleo-Cytoplasmic Large DNA Viruses, or in some cases more recently. It was assumed that viruses are capable of hijacking host metabolic networks. But the giant virus auxiliary metabolic genes also may represent another form of host metabolism manipulation, by expanding the catalytic capabilities of the host cells especially in harsh environments, providing the infected host cells with a selective evolutionary advantage compared to non-infected cells and hence favoring the viral replication. However, the mechanism of these genes' functionality remains unclear to date.
  • Preprint
    Caenorhabditis elegans generates biologically relevant levels of genotoxic metabolites from aflatoxin B1 but not benzo[a]pyrene in vivo
    ( 2010-08-25) Leung, Maxwell C. K. ; Goldstone, Jared V. ; Boyd, Windy A. ; Freedman, Jonathan H. ; Meyer, Joel N.
    There is relatively little information regarding the critical xenobiotic-metabolizing cytochrome P450 (CYP) enzymes in Caenorhabditis elegans, despite this organism’s increasing use as a model in toxicology and pharmacology. We carried out experiments to elucidate the capacity of C. elegans to metabolically activate important promutagens via CYPs. Phylogenetic comparisons confirmed an earlier report indicating a lack of CYP1 family enzymes in C. elegans. Exposure to aflatoxin B1 (AFB1), which is metabolized in mammals by CYP1, CYP2, and CYP3 family enzymes, resulted in significant DNA damage in C. elegans. However, exposure to benzo[a]pyrene (BaP), which is metabolized in mammals by CYP1 family enzymes only, produced no detectable damage. To further test whether BaP exposure caused DNA damage, the toxicities of AFB1 and BaP were compared in nucleotide excision repair-deficient (xpa-1) and - proficient (N2) strains of C. elegans. Exposure to AFB1 inhibited growth more in xpa-1 than N2 nematodes, but the growth-inhibitory effects of BaP were indistinguishable in the two strains. Finally, a CYP-NADPH reductase- deficient strain (emb-8) of C. elegans was found to be more resistant to the growth inhibitory effect of AFB1 exposure than N2, confirming that the AFB1- mediated growth inhibition resulted from CYP-mediated metabolism. Together, these results indicate that C. elegans lacks biologically significant CYP1 family-mediated enzymatic metabolism of xenobiotics. Interestingly, we also found that xpa-1 nematodes were slightly more sensitive to chlorpyrifos than were wild-type. Our results highlight the importance of considering differences between xenobiotic metabolism in C. elegans and mammals when using this alternative model in pharmaceutical and toxicological research.
  • Article
    Cytochrome P450 diversity and induction by gorgonian allelochemicals in the marine gastropod Cyphoma gibbosum
    (BioMed Central, 2010-12-01) Whalen, Kristen E. ; Starczak, Victoria R. ; Nelson, David R. ; Goldstone, Jared V. ; Hahn, Mark E.
    Intense consumer pressure strongly affects the structural organization and function of marine ecosystems, while also having a profound effect on the phenotype of both predator and prey. Allelochemicals produced by prey often render their tissues unpalatable or toxic to a majority of potential consumers, yet some marine consumers have evolved resistance to host chemical defenses. A key challenge facing marine ecologists seeking to explain the vast differences in consumer tolerance of dietary allelochemicals is understanding the biochemical and molecular mechanisms underlying diet choice. The ability of marine consumers to tolerate toxin-laden prey may involve the cooperative action of biotransformation enzymes, including the inducible cytochrome P450s (CYPs), which have received little attention in marine invertebrates despite the importance of allelochemicals in their evolution. Here, we investigated the diversity, transcriptional response, and enzymatic activity of CYPs possibly involved in allelochemical detoxification in the generalist gastropod Cyphoma gibbosum, which feeds exclusively on chemically defended gorgonians. Twelve new genes in CYP family 4 were identified from the digestive gland of C. gibbosum. Laboratory-based feeding studies demonstrated a 2.7- to 5.1-fold induction of Cyphoma CYP4BK and CYP4BL transcripts following dietary exposure to the gorgonian Plexaura homomalla, which contains high concentrations of anti-predatory prostaglandins. Phylogenetic analysis revealed that C. gibbosum CYP4BK and CYP4BL were most closely related to vertebrate CYP4A and CYP4F, which metabolize pathophysiologically important fatty acids, including prostaglandins. Experiments involving heterologous expression of selected allelochemically-responsive C. gibbosum CYP4s indicated a possible role of one or more CYP4BL forms in eicosanoid metabolism. Sequence analysis further demonstrated that Cyphoma CYP4BK/4BL and vertebrate CYP4A/4F forms share identical amino acid residues at key positions within fatty acid substrate recognition sites. These results demonstrate differential regulation of CYP transcripts in a marine consumer feeding on an allelochemical-rich diet, and significantly advance our understanding of both the adaptive molecular mechanisms that marine consumers use to cope with environmental chemical pressures and the evolutionary history of allelochemical-metabolizing enzymes in the CYP superfamily.
  • Article
    Characterization of a virally encoded flavodoxin that can drive bacterial cytochrome P450 monooxygenase activity
    (MDPI, 2022-08-11) Lamb, David C. ; Goldstone, Jared V. ; Zhao, Bin ; Lei, Li ; Mullins, Jonathan G. L. ; Allen, Michael J. ; Kelly, Steven L. ; Stegeman, John J.
    Flavodoxins are small electron transport proteins that are involved in a myriad of photosynthetic and non-photosynthetic metabolic pathways in Bacteria (including cyanobacteria), Archaea and some algae. The sequenced genome of 0305φ8-36, a large bacteriophage that infects the soil bacterium Bacillus thuringiensis, was predicted to encode a putative flavodoxin redox protein. Here we confirm that 0305φ8-36 phage encodes a FMN-containing flavodoxin polypeptide and we report the expression, purification and enzymatic characterization of the recombinant protein. Purified 0305φ8-36 flavodoxin has near-identical spectral properties to control, purified Escherichia coli flavodoxin. Using in vitro assays we show that 0305φ8-36 flavodoxin can be reconstituted with E. coli flavodoxin reductase and support regio- and stereospecific cytochrome P450 CYP170A1 allyl-oxidation of epi-isozizaene to the sesquiterpene antibiotic product albaflavenone, found in the soil bacterium Streptomyces coelicolor. In vivo, 0305φ8-36 flavodoxin is predicted to mediate the 2-electron reduction of the β subunit of phage-encoded ribonucleotide reductase to catalyse the conversion of ribonucleotides to deoxyribonucleotides during viral replication. Our results demonstrate that this phage flavodoxin has the potential to manipulate and drive bacterial P450 cellular metabolism, which may affect both the host biological fitness and the communal microbiome. Such a scenario may also be applicable in other viral-host symbiotic/parasitic relationships.
  • Article
    Polycyclic aromatic hydrocarbons modulate the activity of Atlantic cod (Gadus morhua) vitamin D receptor paralogs in vitro
    (Elsevier, 2021-07-16) Goksøyr, Siri Ofsthus ; Goldstone, Jared V. ; Lille-Langoy, Roger ; Lock, Erik-Jan ; Olsvik, Pål A. ; Goksøyr, Anders ; Karlsen, Odd André
    Vitamin D receptor (VDR) mediates the biological function of the steroid hormone calcitriol, which is the metabolically active version of vitamin D. Calcitriol is important for a wide array of physiological functions, including calcium and phosphate homeostasis. In contrast to mammals, which harbor one VDR encoding gene, teleosts possess two orthologous vdr genes encoding Vdr alpha (Vdra) and Vdr beta (Vdrb). Genome mining identified the vdra and vdrb paralogs in the Atlantic cod (Gadus morhua) genome, which were further characterized regarding their phylogeny, tissue-specific expression, and transactivational properties induced by calcitriol. In addition, a selected set of polycyclic aromatic hydrocarbons (PAHs), including naphthalene, phenanthrene, fluorene, pyrene, chrysene, benzo[a]pyrene (BaP), and 7-methylbenzo[a]pyrene, were assessed for their ability to modulate the transcriptional activity of gmVdra and gmVdrb in vitro. Both gmVdra and gmVdrb were activated by calcitriol with similar potencies, but gmVdra produced significantly higher maximal fold activation. Notably, none of the tested PAHs showed agonistic properties towards the Atlantic cod Vdrs. However, binary exposures of calcitriol together with phenanthrene, fluorene, or pyrene, antagonized the activation of gmVdra, while chrysene and BaP significantly potentiated the calcitriol-mediated activity of both receptors. Homology modeling, solvent mapping, and docking analyses complemented the experimental data, and revealed a putative secondary binding site in addition to the canonical ligand-binding pocket (LBP). Calcitriol was predicted to interact with both binding sites, whereas PAHs docked primarily to the LBP. Importantly, our in vitro data suggest that PAHs can interact with the paralogous gmVdrs and interfere with their transcriptional activities, and thus potentially modulate the vitamin D signaling pathway and contribute to adverse effects of crude oil and PAH exposures on cardiac development and bone deformities in fish.
  • Article
    Identification and developmental expression of the full complement of Cytochrome P450 genes in Zebrafish
    (BioMed Central, 2010-11-18) Goldstone, Jared V. ; McArthur, Andrew G. ; Kubota, Akira ; Zanette, Juliano ; Parente, Thiago ; Jonsson, Maria E. ; Nelson, David R. ; Stegeman, John J.
    Increasing use of zebrafish in drug discovery and mechanistic toxicology demands knowledge of cytochrome P450 (CYP) gene regulation and function. CYP enzymes catalyze oxidative transformation leading to activation or inactivation of many endogenous and exogenous chemicals, with consequences for normal physiology and disease processes. Many CYPs potentially have roles in developmental specification, and many chemicals that cause developmental abnormalities are substrates for CYPs. Here we identify and annotate the full suite of CYP genes in zebrafish, compare these to the human CYP gene complement, and determine the expression of CYP genes during normal development. Zebrafish have a total of 94 CYP genes, distributed among 18 gene families found also in mammals. There are 32 genes in CYP families 5 to 51, most of which are direct orthologs of human CYPs that are involved in endogenous functions including synthesis or inactivation of regulatory molecules. The high degree of sequence similarity suggests conservation of enzyme activities for these CYPs, confirmed in reports for some steroidogenic enzymes (e.g. CYP19, aromatase; CYP11A, P450scc; CYP17, steroid 17a-hydroxylase), and the CYP26 retinoic acid hydroxylases. Complexity is much greater in gene families 1, 2, and 3, which include CYPs prominent in metabolism of drugs and pollutants, as well as of endogenous substrates. There are orthologous relationships for some CYP1 s and some CYP3 s between zebrafish and human. In contrast, zebrafish have 47 CYP2 genes, compared to 16 in human, with only two (CYP2R1 and CYP2U1) recognized as orthologous based on sequence. Analysis of shared synteny identified CYP2 gene clusters evolutionarily related to mammalian CYP2 s, as well as unique clusters. Transcript profiling by microarray and quantitative PCR revealed that the majority of zebrafish CYP genes are expressed in embryos, with waves of expression of different sets of genes over the course of development. Transcripts of some CYP occur also in oocytes. The results provide a foundation for the use of zebrafish as a model in toxicological, pharmacological and chemical disease research.
  • Article
    Developmental expression of the Nfe2-related factor (Nrf) transcription factor family in the zebrafish, Danio rerio
    (Public Library of Science, 2013-10-24) Williams, Larissa M. ; Timme-Laragy, Alicia R. ; Goldstone, Jared V. ; McArthur, Andrew G. ; Stegeman, John J. ; Smolowitz, Roxanna M. ; Hahn, Mark E.
    Transcription factors in the CNC-bZIP family (NFE2, NRF1, NRF2 and NRF3) regulate genes with a wide range of functions in response to both physiological and exogenous signals, including those indicating changes in cellular redox status. Given their role in helping to maintain cellular homeostasis, it is imperative to understand the expression, regulation, and function of CNC-bZIP genes during embryonic development. We explored the expression and function of six nrf genes (nfe2, nrf1a, nrf1b, nrf2a, nrf2b, and nrf3) using zebrafish embryos as a model system. Analysis by microarray and quantitative RT-PCR showed that genes in the nrf family were expressed throughout development from oocytes to larvae. The spatial expression of nrf3 suggested a role in regulating the development of the brain, brachia and pectoral fins. Knock-down by morpholino anti-sense oligonucleotides suggested that none of the genes were necessary for embryonic viability, but nfe2 was required for proper cellular organization in the pneumatic duct and subsequent swim bladder function, as well as for proper formation of the otic vesicles. nrf genes were induced by the oxidant tert-butylhydroperoxide, and some of this response was regulated through family members Nrf2a and Nrf2b. Our results provide a foundation for understanding the role of nrf genes in normal development and in regulating the response to oxidative stress in vertebrate embryos.
  • Article
    The chemical defensome of five model teleost fish
    (Nature Research, 2021-05-18) Eide, Marta ; Zhang, Xiaokang ; Karlsen, Odd André ; Goldstone, Jared V. ; Stegeman, John J. ; Jonassen, Inge ; Goksøyr, Anders
    How an organism copes with chemicals is largely determined by the genes and proteins that collectively function to defend against, detoxify and eliminate chemical stressors. This integrative network includes receptors and transcription factors, biotransformation enzymes, transporters, antioxidants, and metal- and heat-responsive genes, and is collectively known as the chemical defensome. Teleost fish is the largest group of vertebrate species and can provide valuable insights into the evolution and functional diversity of defensome genes. We have previously shown that the xenosensing pregnane x receptor (pxr, nr1i2) is lost in many teleost species, including Atlantic cod (Gadus morhua) and three-spined stickleback (Gasterosteus aculeatus), but it is not known if compensatory mechanisms or signaling pathways have evolved in its absence. In this study, we compared the genes comprising the chemical defensome of five fish species that span the teleosteii evolutionary branch often used as model species in toxicological studies and environmental monitoring programs: zebrafish (Danio rerio), medaka (Oryzias latipes), Atlantic killifish (Fundulus heteroclitus), Atlantic cod, and three-spined stickleback. Genome mining revealed evolved differences in the number and composition of defensome genes that can have implication for how these species sense and respond to environmental pollutants, but we did not observe any candidates of compensatory mechanisms or pathways in cod and stickleback in the absence of pxr. The results indicate that knowledge regarding the diversity and function of the defensome will be important for toxicological testing and risk assessment studies.
  • Article
    On the occurrence of cytochrome P450 in viruses
    (National Academy of Sciences, 2019-06-05) Lamb, David C. ; Follmer, Alec H. ; Goldstone, Jared V. ; Nelson, David R. ; Warrilow, Andrew G. ; Price, Claire L. ; True, Marie Y. ; Kelly, Steven L. ; Poulos, Thomas L. ; Stegeman, John J.
    Genes encoding cytochrome P450 (CYP; P450) enzymes occur widely in the Archaea, Bacteria, and Eukarya, where they play important roles in metabolism of endogenous regulatory molecules and exogenous chemicals. We now report that genes for multiple and unique P450s occur commonly in giant viruses in the Mimiviridae, Pandoraviridae, and other families in the proposed order Megavirales. P450 genes were also identified in a herpesvirus (Ranid herpesvirus 3) and a phage (Mycobacterium phage Adler). The Adler phage P450 was classified as CYP102L1, and the crystal structure of the open form was solved at 2.5 Å. Genes encoding known redox partners for P450s (cytochrome P450 reductase, ferredoxin and ferredoxin reductase, and flavodoxin and flavodoxin reductase) were not found in any viral genome so far described, implying that host redox partners may drive viral P450 activities. Giant virus P450 proteins share no more than 25% identity with the P450 gene products we identified in Acanthamoeba castellanii, an amoeba host for many giant viruses. Thus, the origin of the unique P450 genes in giant viruses remains unknown. If giant virus P450 genes were acquired from a host, we suggest it could have been from an as yet unknown and possibly ancient host. These studies expand the horizon in the evolution and diversity of the enormously important P450 superfamily. Determining the origin and function of P450s in giant viruses may help to discern the origin of the giant viruses themselves.
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    Glutathione redox dynamics and expression of glutathione-related genes in the developing embryo
    ( 2013-06) Timme-Laragy, Alicia R. ; Goldstone, Jared V. ; Imhoff, Barry R. ; Stegeman, John J. ; Hahn, Mark E. ; Hansen, Jason M.
    Embryonic development involves dramatic changes in cell proliferation and differentiation that must be highly coordinated and tightly regulated. Cellular redox balance is critical for cell fate decisions, but it is susceptible to disruption by endogenous and exogenous sources of oxidative stress. The most abundant endogenous non-protein antioxidant defense molecule is the tri-peptide glutathione (ϒ-glutamylcysteinylglycine, GSH), but the ontogeny of GSH concentration and redox state during early life stages is poorly understood. Here, we describe the GSH redox dynamics during embryonic and early larval development (0-5 days post-fertilization) in the zebrafish (Danio rerio), a model vertebrate embryo. We measured reduced and oxidized glutathione (GSH, GSSG) using HPLC, and calculated the whole embryo total glutathione (GSHT) concentrations and redox potentials (Eh) over 0-120 hours of zebrafish development (including mature oocytes, fertilization, mid-blastula transition, gastrulation, somitogenesis, pharyngula, pre-hatch embryos, and hatched eleutheroembryos). GSHT concentration doubled between 12 hours post fertilization (hpf) and hatching. The GSH Eh increased, becoming more oxidizing during the first 12 h, and then oscillated around -190 mV through organogenesis, followed by a rapid change, associated with hatching, to a more negative (more reducing) Eh (-220 mV). After hatching, Eh stabilized and remained steady through 120 hpf. The dynamic changes in GSH redox status and concentration defined discrete windows of development: primary organogenesis, organ differentiation, and larval growth. We identified the set of zebrafish genes involved in the synthesis, utilization, and recycling of GSH, including several novel paralogs, and measured how expression of these genes changes during development. Ontogenic changes in the expression of GSH-related genes support the hypothesis that GSH redox state is tightly regulated early in development. This study provides a foundation for understanding the redox regulation of developmental signaling and investigating the effects of oxidative stress during embryogenesis.