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Solano YJ, Everett MP, Dang KS, Abueg J, Kiser PD. Carotenoid cleavage enzymes evolved convergently to generate the visual chromophore. Nat Chem Biol 2024; 20:779-788. [PMID: 38355721 PMCID: PMC11142922 DOI: 10.1038/s41589-024-01554-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 01/12/2024] [Indexed: 02/16/2024]
Abstract
The retinal light response in animals originates from the photoisomerization of an opsin-coupled 11-cis-retinaldehyde chromophore. This visual chromophore is enzymatically produced through the action of carotenoid cleavage dioxygenases. Vertebrates require two carotenoid cleavage dioxygenases, β-carotene oxygenase 1 and retinal pigment epithelium 65 (RPE65), to form 11-cis-retinaldehyde from carotenoid substrates, whereas invertebrates such as insects use a single enzyme known as Neither Inactivation Nor Afterpotential B (NinaB). RPE65 and NinaB couple trans-cis isomerization with hydrolysis and oxygenation, respectively, but the mechanistic relationship of their isomerase activities remains unknown. Here we report the structure of NinaB, revealing details of its active site architecture and mode of membrane binding. Structure-guided mutagenesis studies identify a residue cluster deep within the NinaB substrate-binding cleft that controls its isomerization activity. Our data demonstrate that isomerization activity is mediated by distinct active site regions in NinaB and RPE65-an evolutionary convergence that deepens our understanding of visual system diversity.
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Affiliation(s)
- Yasmeen J Solano
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, CA, USA
| | - Michael P Everett
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, CA, USA
- Research Service, VA Long Beach Healthcare System, Long Beach, CA, USA
| | - Kelly S Dang
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, CA, USA
| | - Jude Abueg
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, CA, USA
| | - Philip D Kiser
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, CA, USA.
- Research Service, VA Long Beach Healthcare System, Long Beach, CA, USA.
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine School of Medicine, Irvine, CA, USA.
- Department of Clinical Pharmacy Practice, University of California Irvine School of Pharmacy and Pharmaceutical Sciences, Irvine, CA, USA.
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2
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Poli G, Demontis GC, Sodi A, Saba A, Rizzo S, Macchia M, Tuccinardi T. An in silico toolbox for the prediction of the potential pathogenic effects of missense mutations in the dimeric region of hRPE65. J Enzyme Inhib Med Chem 2023; 38:2162047. [PMID: 36629452 PMCID: PMC9848331 DOI: 10.1080/14756366.2022.2162047] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
hRPE65 is a fundamental enzyme of the retinoid visual cycle, and many missense mutations affecting its expression or function are associated with a wide range of diseases. Many hRPE65 missense mutations lack a clear pathogenicity classification or are labelled as VUS. In this context, we recently developed a protocol based on µs-long molecular dynamics simulations to study the potential pathogenic effect of hRPE65 missense mutations. In the present work, the structure-based protocol was integrated with a hRPE65-tailored consensus bioinformatics strategy, named ConPath, that showed high performance in predicting known pathogenic/benign hRPE65 missense mutations. The combined strategy was used to perform a multi-level evaluation of the potential pathogenicity of 13 different hRPE65 VUS, which were classified based on their likelihood of pathogenic effect. The obtained results provide information that may support the reclassification of these VUS and help clinicians evaluate the eligibility for gene therapy of patients diagnosed with such variants.
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Affiliation(s)
- Giulio Poli
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | | | - Andrea Sodi
- Department of Neurosciences, Psychology, Drug Research and Child Health Eye Clinic, University of Florence, AOU Careggi, Florence, Italy
| | - Alessandro Saba
- Department of Surgical Pathology, Molecular Medicine and of the Critical Area, University of Pisa, Pisa, Italy
| | - Stanislao Rizzo
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy,Catholic University Sacro Cuore, Rome, Italy,Consiglio Nazionale delle Ricerche, Istituto di Neuroscienze, Pisa, Italy
| | - Marco Macchia
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | - Tiziano Tuccinardi
- Department of Pharmacy, University of Pisa, Pisa, Italy,CONTACT Tiziano Tuccinardi Department of Pharmacy, University of Pisa, Via Bonanno 6, Pisa, 56126, Italy
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3
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Wu J, Sun Z, Zhang DW, Liu HL, Li T, Zhang S, Wu J. Development of a novel prediction model based on protein structure for identifying RPE65-associated inherited retinal disease (IRDs) of missense variants. PeerJ 2023; 11:e15702. [PMID: 37547722 PMCID: PMC10404030 DOI: 10.7717/peerj.15702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 06/14/2023] [Indexed: 08/08/2023] Open
Abstract
Purpose This study aimed to develop a prediction model to classify RPE65-mediated inherited retinal disease (IRDs) based on protein secondary structure and to analyze phenotype-protein structure correlations of RPE65 missense variants in a Chinese cohort. Methods Pathogenic or likely pathogenic missense variants of RPE65 were obtained from UniProt, ClinVar, and HGMD databases. The three-dimensional structure of RPE65 was retrieved from the Protein Data Bank (PDB) and modified with Pymol software. A novel prediction model was developed using LASSO regression and multivariate logistic regression to identify RPE65-associated IRDs. A total of 21 Chinese probands with RPE65 variants were collected to analyze phenotype-protein structure correlations of RPE65 missense variants. Results The study found that both pathogenic and population missense variants were associated with structural features of RPE65. Pathogenic variants were linked to sheet, β-sheet, strands, β-hairpins, Fe2+ (iron center), and active site cavity, while population variants were related to helix, loop, helices, and helix-helix interactions. The novel prediction model showed accuracy and confidence in predicting the disease type of RPE65 variants (AUC = 0.7531). The study identified 25 missense variants in Chinese patients, accounting for 72.4% of total mutations. A significant correlation was observed between clinical characteristics of RPE65-associated IRDs and changes in amino acid type, specifically for missense variants of F8 (H68Y, P419S). Conclusion The study developed a novel prediction model based on the protein structure of RPE65 and investigated phenotype-protein structure correlations of RPE65 missense variants in a Chinese cohort. The findings provide insights into the precise diagnosis of RPE65-mutated IRDs.
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Affiliation(s)
- Jiawen Wu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
| | - Zhongmou Sun
- University of Rochester School of Medicine and Dentistry, New York, United States of America
| | - Dao wei Zhang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
| | - Hong-Li Liu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
| | - Ting Li
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
| | - Shenghai Zhang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai, China
- Key Laboratory of Myopia, Ministry of Health, Shanghai, China
| | - Jihong Wu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai, China
- Key Laboratory of Myopia, Ministry of Health, Shanghai, China
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4
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Uppal S, Poliakov E, Gentleman S, Redmond TM. The Amphipathic Helix in Visual Cycle Proteins: A Review. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:533-537. [PMID: 37440083 PMCID: PMC11299856 DOI: 10.1007/978-3-031-27681-1_78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
The visual cycle is a complex biological process that involves the sequential action of proteins in the retinal pigment epithelial (RPE) cells and photoreceptors to modify and shuttle visual retinoids. A majority of the visual cycle proteins are membrane proteins, either integral or peripheral membrane proteins. Despite significant progress in understanding their physiological function, very limited structural information is available for the visual cycle proteins. Moreover, the mechanism of membrane interaction is not yet clear in all cases. Here, we demonstrate the presence of an amphipathic helix in selected RPE visual cycle proteins, using in silico tools, and highlight their role in membrane association and function.
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Affiliation(s)
- Sheetal Uppal
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Eugenia Poliakov
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Susan Gentleman
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
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5
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Stingl K, Kempf M, Jung R, Kortüm F, Righetti G, Reith M, Dimopoulos S, Ott S, Kohl S, Stingl K. Therapy with voretigene neparvovec. How to measure success? Prog Retin Eye Res 2023; 92:101115. [PMID: 36096933 DOI: 10.1016/j.preteyeres.2022.101115] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 02/01/2023]
Abstract
Retinal gene supplementation therapy such as the first approved one, voretigene neparvovec, delivers a functioning copy of the missing gene enabling the protein transcription in retinal cells and restore visual functions. After gene supplementation for the genetic defect, a complex network of functional regeneration is the consequence, whereas the extent is very individualized. Diagnostic and functional testings that have been used routinely by ophthalmologists so far to define the correct diagnosis, cannot be applied in the new context of defining small, sometimes subtle changes in visual functions. New view on retinal diagnostics is needed to understand this processes that define safety and efficacy of the treatment. Not only does vision have many aspects that must be addressed by specific evaluations and imaging techniques, but objective readouts of local retinal function for rods and cones separately have been an unmet need until recently. A reliable test-retest variability is necessary in rare diseases such as inherited retinal dystrophies, because statistics are often not applicable due to a low number of participants. Methods for a reliable individual evaluation of the therapy success are needed. In this manuscript we present an elaboration on retinal diagnostics combining psychophysics (eg. full-field stimulus threshold or dark adapted perimetry) as well as objective measures for local retinal function (eg. photopic and scotopic chromatic pupil campimetry) and retinal imaging for a meaningful workflow to apply in evaluation of the individual success in patients receiving gene therapy for photoreceptor diseases.
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Affiliation(s)
- Krunoslav Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany; Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany.
| | - Melanie Kempf
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany; Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany.
| | - Ronja Jung
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Friederike Kortüm
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Giulia Righetti
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Milda Reith
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Spyridon Dimopoulos
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Saskia Ott
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.
| | - Katarina Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany; Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany.
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6
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The First Homozygote Mutation c.499G>T (Asp167Tyr) in the RPE65 Gene Encoding Retinoid Isomerohydrolase Causing Retinal Dystrophy. Curr Issues Mol Biol 2022; 44:6397-6403. [PMID: 36547097 PMCID: PMC9777422 DOI: 10.3390/cimb44120436] [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: 11/23/2022] [Revised: 12/08/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
RPE65, an abundant membrane-associated protein present in the retinal pigment epithelium (RPE), is a vital retinoid isomerase necessary for regenerating 11-cis-retinaldehyde from all-trans retinol in the visual cycle. In patients with inherited retinal dystrophy (IRD), precise genetic diagnosis is an indispensable approach as it is required to establish eligibility for the genetic treatment of RPE65-associated IRDs. This case report aims to report the specific phenotype−genotype correlation of the first patient with a homozygous missense variant RPE65 c.499G>T, p. (Asp167Tyr). We report a case of a 66-year-old male who demonstrated a unique phenotype manifesting less severe functional vision deterioration in childhood and adolescence, and extensive nummular pigment clusters. The underlying causes of the differences in the typical bone spicule and atypical nummular pigment clumping are unknown, but suggest that the variant itself influenced the rate of photoreceptor death. Functional studies are needed to define whether the substitution of aspartate impairs the folding of the tertiary RPE65 structure only and does not lead to the complete abolishment of chromophore production, thus explaining the less severe phenotype in adolescence.
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7
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Poli G, Barravecchia I, Demontis GC, Sodi A, Saba A, Rizzo S, Macchia M, Tuccinardi T. Predicting potentially pathogenic effects of hRPE65 missense mutations: a computational strategy based on molecular dynamics simulations. J Enzyme Inhib Med Chem 2022; 37:1765-1772. [PMID: 35726567 PMCID: PMC9225791 DOI: 10.1080/14756366.2022.2090547] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The human retinal pigment epithelium-specific 65-kDa protein (hRPE65) plays a crucial role within the retinoid visual cycle and several mutations affecting either its expression level or its enzymatic function are associated with inherited retinal diseases such as Retinitis Pigmentosa. The gene therapy product voretigene neparvovec (Luxturna) has been recently approved for treating hereditary retinal dystrophies; however, the treatment is currently accessible only to patients presenting confirmed biallelic mutations that severely impair hRPE65 function, and many reported hRPE65 missense mutations lack sufficient evidences for proving their pathogenicity. In this context, we developed a computational approach aimed at evaluating the potential pathogenic effect of hRPE65 missense variants located on the dimerisation domain of the protein. The protocol evaluates how mutations may affect folding and conformation stability of this protein region, potentially helping clinicians to evaluate the eligibility for gene therapy of patients diagnosed with this type of hRPE65 variant of uncertain significance.
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Affiliation(s)
- Giulio Poli
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | - Ivana Barravecchia
- Department of Pharmacy, University of Pisa, Pisa, Italy.,Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | - Andrea Sodi
- Department of Neurosciences, Psychology, Drug Research and Child Health Eye Clinic, University of Florence, AOU Careggi, Florence, Italy
| | - Alessandro Saba
- Department of Surgical Pathology, Molecular Medicine and of the Critical Area, University of Pisa, Pisa, Italy
| | - Stanislao Rizzo
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Catholic University Sacro Cuore, Rome, Italy.,Consiglio Nazionale delle Ricerche, Istituto di Neuroscienze, Pisa, Italy
| | - Marco Macchia
- Department of Pharmacy, University of Pisa, Pisa, Italy
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8
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Bandara S, von Lintig J. Aster la vista: Unraveling the biochemical basis of carotenoid homeostasis in the human retina. Bioessays 2022; 44:e2200133. [PMID: 36127289 PMCID: PMC10044510 DOI: 10.1002/bies.202200133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/10/2022]
Abstract
Carotenoids play pivotal roles in vision as light filters and precursor of chromophore. Many vertebrates also display the colorful pigments as ornaments in bare skin parts and feathers. Proteins involved in the transport and metabolism of these lipids have been identified including class B scavenger receptors and carotenoid cleavage dioxygenases. Recent research implicates members of the Aster protein family, also known as GRAM domain-containing (GRAMD), in carotenoid metabolism. These multi-domain proteins facilitate the intracellular movement of carotenoids from their site of cellular uptake by scavenger receptors to the site of their metabolic processing by carotenoid cleavage dioxygenases. We provide a model how the coordinated interplay of these proteins and their differential expression establishes carotenoid distribution patterns and function in tissues, with particular emphasis on the human retina.
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Affiliation(s)
- Sepalika Bandara
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Johannes von Lintig
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
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9
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Uppal S, Liu T, Galvan E, Gomez F, Tittley T, Poliakov E, Gentleman S, Redmond TM. An inducible amphipathic α-helix mediates subcellular targeting and membrane binding of RPE65. Life Sci Alliance 2022; 6:6/1/e202201546. [PMID: 36265895 PMCID: PMC9585964 DOI: 10.26508/lsa.202201546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/24/2022] Open
Abstract
RPE65 retinol isomerase is an indispensable player in the visual cycle between the vertebrate retina and RPE. Although membrane association is critical for RPE65 function, its mechanism is not clear. Residues 107-125 are believed to interact with membranes but are unresolved in all RPE65 crystal structures, whereas palmitoylation at C112 also plays a role. We report the mechanism of membrane recognition and binding by RPE65. Binding of aa107-125 synthetic peptide with membrane-mimicking micellar surfaces induces transition from unstructured loop to amphipathic α-helical (AH) structure but this transition is automatic in the C112-palmitoylated peptide. We demonstrate that the AH significantly affects palmitoylation level, membrane association, and isomerization activity of RPE65. Furthermore, aa107-125 functions as a membrane sensor and the AH as a membrane-targeting motif. Molecular dynamic simulations clearly show AH-membrane insertion, supporting our experimental findings. Collectively, these studies allow us to propose a working model for RPE65-membrane binding, and to provide a novel role for cysteine palmitoylation.
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Affiliation(s)
| | | | | | | | | | | | | | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
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10
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Song YS, Annalora AJ, Marcus CB, Jefcoate CR, Sorenson CM, Sheibani N. Cytochrome P450 1B1: A Key Regulator of Ocular Iron Homeostasis and Oxidative Stress. Cells 2022; 11:2930. [PMID: 36230892 PMCID: PMC9563809 DOI: 10.3390/cells11192930] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/12/2022] [Accepted: 09/18/2022] [Indexed: 11/22/2022] Open
Abstract
Cytochrome P450 (CYP) 1B1 belongs to the superfamily of heme-containing monooxygenases. Unlike other CYP enzymes, which are highly expressed in the liver, CYP1B1 is predominantly found in extrahepatic tissues, such as the brain, and ocular tissues including retina and trabecular meshwork. CYP1B1 metabolizes exogenous chemicals such as polycyclic aromatic hydrocarbons. CYP1B1 also metabolizes endogenous bioactive compounds including estradiol and arachidonic acid. These metabolites impact various cellular and physiological processes during development and pathological processes. We previously showed that CYP1B1 deficiency mitigates ischemia-mediated retinal neovascularization and drives the trabecular meshwork dysgenesis through increased levels of oxidative stress. However, the underlying mechanisms responsible for CYP1B1-deficiency-mediated increased oxidative stress remain largely unresolved. Iron is an essential element and utilized as a cofactor in a variety of enzymes. However, excess iron promotes the production of hydroxyl radicals, lipid peroxidation, increased oxidative stress, and cell damage. The retinal endothelium is recognized as a major component of the blood-retinal barrier, which controls ocular iron levels through the modulation of proteins involved in iron regulation present in retinal endothelial cells, as well as other ocular cell types including trabecular meshwork cells. We previously showed increased levels of reactive oxygen species and lipid peroxidation in the absence of CYP1B1, and in the retinal vasculature and trabecular meshwork, which was reversed by administration of antioxidant N-acetylcysteine. Here, we review the important role CYP1B1 expression and activity play in maintaining retinal redox homeostasis through the modulation of iron levels by retinal endothelial cells. The relationship between CYP1B1 expression and activity and iron levels has not been previously delineated. We review the potential significance of CYP1B1 expression, estrogen metabolism, and hepcidin-ferroportin regulatory axis in the local regulation of ocular iron levels.
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Affiliation(s)
- Yong-Seok Song
- Departments of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Andrew J. Annalora
- Department of Environmental and Molecular Toxicology, Organ State University, Corvallis, OR 97331, USA
| | - Craig B. Marcus
- Department of Environmental and Molecular Toxicology, Organ State University, Corvallis, OR 97331, USA
| | - Colin R. Jefcoate
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Christine M. Sorenson
- Department of Pediatrics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Nader Sheibani
- Departments of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53705, USA
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11
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He L, Cheng L, Wang J, Liu J, Cheng J, Yang Z, Cao R, Han Y, Li H, Zhang B. Carotenoid Cleavage Dioxygenase 1 Catalyzes Lutein Degradation To Influence Carotenoid Accumulation and Color Development in Foxtail Millet Grains. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:9283-9294. [PMID: 35876162 DOI: 10.1021/acs.jafc.2c01951] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Foxtail millet is a minor but economically important crop in certain regions of the world. Millet color is often used to judge grain quality, yet the molecular determinants of millet coloration remain unclear. Here, we explored the relationship between SiCCD1 and millet coloration in yellow and white millet varieties. Carotenoid levels declined with grain maturation and were negatively correlated with SiCCD1 expression, which was significantly higher in white millet as compared to yellow millet during the color development stage. Cloning of the SiCCD1 promoter and CDS sequences from these different millet varieties revealed the presence of two additional cis-regulatory elements within the SiCCD1 promoter in white millet varieties, including an enhancer-like GC motif element associated with anoxic specific inducibility and a GCN4-motif element associated with endosperm expression. Dual-luciferase reporter assays confirmed that SiCCD1 promoter fragments containing these additional cis-acting elements derived from white millet varieties were significantly more active than those from yellow millet varieties, consistent with the observed SiCCD1 expression patterns. Further in vitro enzyme detection assays confirmed that SiCCD1 primarily targets and degrades lutein. Together, these data suggest that SiCCD1 promoter variation was a key factor associated with the observed differences in SiCCD1 expression, which in turn led to the difference in millet coloration.
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Affiliation(s)
- Lu He
- College of Agriculture, Shanxi Agricultural University, Taigu 030801, China
- Maize Research Institute, Shanxi Agricultural University, Xinzhou 034000, China
| | - Lu Cheng
- College of Agriculture, Shanxi Agricultural University, Taigu 030801, China
| | - Junjie Wang
- College of Agriculture, Shanxi Agricultural University, Taigu 030801, China
| | - Jing Liu
- College of Agriculture, Shanxi Agricultural University, Taigu 030801, China
| | - Jinjin Cheng
- College of Agriculture, Shanxi Agricultural University, Taigu 030801, China
| | - Zhirong Yang
- Department of Foundation, Shanxi Agricultural University, Taigu 030801, China
| | - Rui Cao
- Shanxi Biological Research Institute Co., Ltd, Taiyuan 030000, China
| | - Yuanhuai Han
- College of Agriculture, Shanxi Agricultural University, Taigu 030801, China
- Institute of Agricultural Bioengineering, Shanxi Agricultural University, Taigu 030801, China
- Ministerial and Provincial Co-Innovation Centre for Endemic Crops Production with High-quality and Efficiency in Loess Plateau, Shanxi Agricultural University, Taigu 030801, China
| | - Hongying Li
- College of Agriculture, Shanxi Agricultural University, Taigu 030801, China
- Institute of Agricultural Bioengineering, Shanxi Agricultural University, Taigu 030801, China
| | - Bin Zhang
- College of Agriculture, Shanxi Agricultural University, Taigu 030801, China
- Institute of Agricultural Bioengineering, Shanxi Agricultural University, Taigu 030801, China
- Ministerial and Provincial Co-Innovation Centre for Endemic Crops Production with High-quality and Efficiency in Loess Plateau, Shanxi Agricultural University, Taigu 030801, China
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12
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Wu W, Takahashi Y, Shin HY, Ma X, Moiseyev G, Ma JX. The interplay of environmental luminance and genetics in the retinal dystrophy induced by the dominant RPE65 mutation. Proc Natl Acad Sci U S A 2022; 119:e2115202119. [PMID: 35271391 PMCID: PMC8931212 DOI: 10.1073/pnas.2115202119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 01/11/2022] [Indexed: 01/09/2023] Open
Abstract
SignificanceIn humans, genetic mutations in the retinal pigment epithelium (RPE) 65 are associated with blinding diseases, for which there is no effective therapy alleviating progressive retinal degeneration in affected patients. Our findings uncovered that the increased free opsin caused by enhancing the ambient light intensity increased retinal activation, and when compounded with the RPE visual cycle dysfunction caused by the heterozygous D477G mutation and aggregation, led to the onset of retinal degeneration.
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Affiliation(s)
- Wenjing Wu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Yusuke Takahashi
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Henry Younghwa Shin
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Xiang Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Gennadiy Moiseyev
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
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13
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Pan W, Zhou YL, Wang J, Dai HE, Wang X, Liu L. Structural and Functional Analysis of Nonheme Iron Enzymes BCMO-1 and BCMO-2 from Caenorhabditis elegans. Front Mol Biosci 2022; 9:844453. [PMID: 35223999 PMCID: PMC8866865 DOI: 10.3389/fmolb.2022.844453] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 01/17/2022] [Indexed: 12/27/2022] Open
Abstract
Carotenoid metabolism is critical for diverse physiological processes. The nematode Caenorhabditis elegans has two genes that are annotated as β-carotene 15,15′-monooxygenase (BCMO) and are 17 centimorgan apart on chromosome II, but the function of BCMO-1 and BCMO-2 remains uncharacterized. Sequence homology indicates that the two enzymes belong to the carotenoid cleavage dioxygenase family that share a seven-bladed β-propeller fold with a nonheme iron center. Here we determined crystal structures of BCMO-1 and BCMO-2 at resolutions of 1.8 and 1.9 Å, respectively. Structural analysis reveals that BCMO-1 and BCMO-2 are strikingly similar to each other. We also characterized their β-carotene cleavage activity, but the results suggest that they may not act as β-carotene 15,15′-oxygenases.
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Affiliation(s)
- Weimin Pan
- School of Life Sciences, Anhui University, Hefei, China
| | | | - Jian Wang
- School of Life Sciences, Anhui University, Hefei, China
| | - Huai-En Dai
- School of Life Sciences, Anhui University, Hefei, China
| | - Xiao Wang
- School of Life Sciences, Anhui University, Hefei, China
- Anhui Key Laboratory of Modern Biomanufacturing, Anhui University, Hefei, China
| | - Lin Liu
- School of Life Sciences, Anhui University, Hefei, China
- Anhui Key Laboratory of Modern Biomanufacturing, Anhui University, Hefei, China
- *Correspondence: Lin Liu,
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14
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Abstract
Carotenoids constitute an essential dietary component of animals and other non-carotenogenic species which use these pigments in both their modified and unmodified forms. Animals utilize uncleaved carotenoids to mitigate light damage and oxidative stress and to signal fitness and health. Carotenoids also serve as precursors of apocarotenoids including retinol, and its retinoid metabolites, which carry out essential functions in animals by forming the visual chromophore 11-cis-retinaldehyde. Retinoids, such as all-trans-retinoic acid, can also act as ligands of nuclear hormone receptors. The fact that enzymes and biochemical pathways responsible for the metabolism of carotenoids in animals bear resemblance to the ones in plants and other carotenogenic species suggests an evolutionary relationship. We will explore some of the modes of transmission of carotenoid genes from carotenogenic species to metazoans. This apparent relationship has been successfully exploited in the past to identify and characterize new carotenoid and retinoid modifying enzymes. We will review approaches used to identify putative animal carotenoid enzymes, and we will describe methods used to functionally validate and analyze the biochemistry of carotenoid modifying enzymes encoded by animals.
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Affiliation(s)
- Alexander R Moise
- Northern Ontario School of Medicine, Sudbury, ON, Canada; Department of Chemistry and Biochemistry, Biology and Biomolecular Sciences Program, Laurentian University, Sudbury, ON, Canada.
| | - Sepalika Bandara
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Johannes von Lintig
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
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15
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Abstract
Carotenoid cleavage dioxygenases (CCDs) constitute a superfamily of enzymes that are found in all domains of life where they play key roles in the metabolism of carotenoids and apocarotenoids as well as certain phenylpropanoids such as resveratrol. Interest in these enzymes stems not only from their biological importance but also from their remarkable catalytic properties including their regioselectivity, their ability to accommodate diverse substrates, and the additional activities (e.g., isomerase) that some of these enzyme possess. X-ray crystallography is a key experimental approach that has allowed detailed investigation into the structural basis behind the interesting biochemical features of these enzymes. Here, we describe approaches used by our lab that have proven successful in generating single crystals of these enzymes in resting or ligand-bound states for high-resolution X-ray diffraction analysis.
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Affiliation(s)
- Anahita Daruwalla
- Department of Physiology & Biophysics, University of California, Irvine School of Medicine, Irvine, CA, United States
| | - Xuewu Sui
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, United States; Department of Cell Biology, Harvard Medical School, Boston, MA, United States
| | - Philip D Kiser
- Department of Physiology & Biophysics, University of California, Irvine School of Medicine, Irvine, CA, United States; Department of Ophthalmology, Center for Translational Vision Research, University of California, Irvine School of Medicine, Irvine, CA, United States; Research Service, VA Long Beach Healthcare System, Long Beach, CA, United States.
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16
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Martin Ask N, Leung M, Radhakrishnan R, Lobo GP. Vitamin A Transporters in Visual Function: A Mini Review on Membrane Receptors for Dietary Vitamin A Uptake, Storage, and Transport to the Eye. Nutrients 2021; 13:nu13113987. [PMID: 34836244 PMCID: PMC8620617 DOI: 10.3390/nu13113987] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/04/2021] [Accepted: 11/07/2021] [Indexed: 11/23/2022] Open
Abstract
Vitamins are essential compounds obtained through diet that are necessary for normal development and function in an organism. One of the most important vitamins for human physiology is vitamin A, a group of retinoid compounds and carotenoids, which generally function as a mediator for cell growth, differentiation, immunity, and embryonic development, as well as serving as a key component in the phototransduction cycle in the vertebrate retina. For humans, vitamin A is obtained through the diet, where provitamin A carotenoids such as β-carotene from plants or preformed vitamin A such as retinyl esters from animal sources are absorbed into the body via the small intestine and converted into all-trans retinol within the intestinal enterocytes. Specifically, once absorbed, carotenoids are cleaved by carotenoid cleavage oxygenases (CCOs), such as Beta-carotene 15,15’-monooxygenase (BCO1), to produce all-trans retinal that subsequently gets converted into all-trans retinol. CRBP2 bound retinol is then converted into retinyl esters (REs) by the enzyme lecithin retinol acyltransferase (LRAT) in the endoplasmic reticulum, which is then packaged into chylomicrons and sent into the bloodstream for storage in hepatic stellate cells in the liver or for functional use in peripheral tissues such as the retina. All-trans retinol also travels through the bloodstream bound to retinol binding protein 4 (RBP4), where it enters cells with the assistance of the transmembrane transporters, stimulated by retinoic acid 6 (STRA6) in peripheral tissues or retinol binding protein 4 receptor 2 (RBPR2) in systemic tissues (e.g., in the retina and the liver, respectively). Much is known about the intake, metabolism, storage, and function of vitamin A compounds, especially with regard to its impact on eye development and visual function in the retinoid cycle. However, there is much to learn about the role of vitamin A as a transcription factor in development and cell growth, as well as how peripheral cells signal hepatocytes to secrete all-trans retinol into the blood for peripheral cell use. This article aims to review literature regarding the major known pathways of vitamin A intake from dietary sources into hepatocytes, vitamin A excretion by hepatocytes, as well as vitamin A usage within the retinoid cycle in the RPE and retina to provide insight on future directions of novel membrane transporters for vitamin A in retinal cell physiology and visual function.
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17
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Kiser PD. Retinal pigment epithelium 65 kDa protein (RPE65): An update. Prog Retin Eye Res 2021; 88:101013. [PMID: 34607013 PMCID: PMC8975950 DOI: 10.1016/j.preteyeres.2021.101013] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/21/2021] [Accepted: 09/24/2021] [Indexed: 12/21/2022]
Abstract
Vertebrate vision critically depends on an 11-cis-retinoid renewal system known as the visual cycle. At the heart of this metabolic pathway is an enzyme known as retinal pigment epithelium 65 kDa protein (RPE65), which catalyzes an unusual, possibly biochemically unique, reaction consisting of a coupled all-trans-retinyl ester hydrolysis and alkene geometric isomerization to produce 11-cis-retinol. Early work on this isomerohydrolase demonstrated its membership to the carotenoid cleavage dioxygenase superfamily and its essentiality for 11-cis-retinal production in the vertebrate retina. Three independent studies published in 2005 established RPE65 as the actual isomerohydrolase instead of a retinoid-binding protein as previously believed. Since the last devoted review of RPE65 enzymology appeared in this journal, major advances have been made in a number of areas including our understanding of the mechanistic details of RPE65 isomerohydrolase activity, its phylogenetic origins, the relationship of its membrane binding affinity to its catalytic activity, its role in visual chromophore production for rods and cones, its modulation by macromolecules and small molecules, and the involvement of RPE65 mutations in the development of retinal diseases. In this article, I will review these areas of progress with the goal of integrating results from the varied experimental approaches to provide a comprehensive picture of RPE65 biochemistry. Key outstanding questions that may prove to be fruitful future research pursuits will also be highlighted.
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Affiliation(s)
- Philip D Kiser
- Research Service, VA Long Beach Healthcare System, Long Beach, CA, 90822, USA; Department of Physiology & Biophysics, University of California, Irvine School of Medicine, Irvine, CA, 92697, USA; Department of Ophthalmology and Center for Translational Vision Research, Gavin Herbert Eye Institute, University of California, Irvine School of Medicine, Irvine, CA, 92697, USA.
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18
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Lopez-Rodriguez R, Lantero E, Blanco-Kelly F, Avila-Fernandez A, Martin Merida I, Del Pozo-Valero M, Perea-Romero I, Zurita O, Jiménez-Rolando B, Swafiri ST, Riveiro-Alvarez R, Trujillo-Tiebas MJ, Carreño Salas E, García-Sandoval B, Corton M, Ayuso C. RPE65-related retinal dystrophy: Mutational and phenotypic spectrum in 45 affected patients. Exp Eye Res 2021; 212:108761. [PMID: 34492281 DOI: 10.1016/j.exer.2021.108761] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 08/27/2021] [Accepted: 09/01/2021] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Biallelic pathogenic RPE65 variants are related to a spectrum of clinically overlapping inherited retinal dystrophies (IRD). Most affected individuals progress to severe disease, with 50% of patients becoming legally blind by 20 years of age. Deeper knowledge of the mutational spectrum and the phenotype-genotype correlation in RPE65-related IRD is needed. PATIENTS AND METHODS Forty-five affected subjects from 27 unrelated families with a clinical diagnosis of RPE65-related IRD were included. Clinical evaluation consisted of self-reported ophthalmological history and objective ophthalmological examination. Patients' genotype was classified according to variant class (truncating or missense) or to variant location at different protein domains. The main phenotypic outcome measure was age at onset (AAO) of symptomatic disease and a Kaplan-Meier analysis of disease symptom event-free survival was performed. RESULTS Twenty-nine different RPE65 variants were identified in our cohort, 7 of them novel. Patients carrying two missense alleles showed a later disease onset than those with 1 or 2 truncating variants (log-rank test p <0.05). While 60% of patients carrying a missense/missense genotype presented symptoms before or during the first year of life, almost all patients with at least 1 truncating allele (91%) had an AAO ≤1 year (p <0.05). CONCLUSION Our findings suggest an association between the type of RPE65 variant carried and AAO. These findings provide useful data on RPE65-associated IRD phenotypes and may help improve clinical and therapeutic management of these patients.
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Affiliation(s)
- Rosario Lopez-Rodriguez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Esther Lantero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Fiona Blanco-Kelly
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Almudena Avila-Fernandez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Inmaculada Martin Merida
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Marta Del Pozo-Valero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Irene Perea-Romero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Olga Zurita
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Belén Jiménez-Rolando
- Department of Ophthalmology, Fundación Jiménez Díaz University Hospital (FJD), Madrid, Spain
| | - Saoud Tahsin Swafiri
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Rosa Riveiro-Alvarez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - María José Trujillo-Tiebas
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Ester Carreño Salas
- Department of Ophthalmology, Fundación Jiménez Díaz University Hospital (FJD), Madrid, Spain
| | - Blanca García-Sandoval
- Department of Ophthalmology, Fundación Jiménez Díaz University Hospital (FJD), Madrid, Spain
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain.
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19
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Yang U, Gentleman S, Gai X, Gorin MB, Borchert MS, Lee TC, Villanueva A, Koenekoop R, Maguire AM, Bennett J, Redmond TM, Nagiel A. Utility of In Vitro Mutagenesis of RPE65 Protein for Verification of Mutational Pathogenicity Before Gene Therapy. JAMA Ophthalmol 2021; 137:1381-1388. [PMID: 31580392 DOI: 10.1001/jamaophthalmol.2019.3914] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Importance Next-generation sequencing can detect variants of uncertain significance (VUSs), for some of which gene therapy would not be advantageous. Therefore, the pathogenicity of compound heterozygous or homozygous variants should be confirmed before bilateral vitrectomy and administration of voretigene neparvovec-rzyl. Objective To describe an in vitro mutagenesis assay for assessing the pathogenicity of variants in the RPE65 gene. Design, Setting, and Participants This case series was conducted at 2 tertiary referral centers. Clinical history, imaging, and electrophysiologic testing results were reviewed from September 5, 2008, to December 31, 2019. Participants were 4 pediatric patients with Leber congenital amaurosis who were evaluated for or met the inclusion criteria for phase 1 to 3 clinical trials or were referred for voretigene neparvovec-rzyl treatment. Main Outcomes and Measures A functional assay was used to confirm the pathogenicity of novel RPE65 VUSs in 4 patients with Leber congenital amaurosis. Results Four patients with Leber congenital amaurosis had VUSs in RPE65. Patients 1 and 2 were siblings with the homozygous VUS c.311G>T p.(G104V). Patient 3 was a compound heterozygote with 1 known pathogenic allele, c.1202_1203insCTGG p.(Glu404AlafsTer4), and 1 VUS, c.311G>T p.(G104V), which segregated to separate alleles. Patient 4 was also a compound heterozygote with 1 pathogenic variant, c.11 + 5G>A, and 1 variant in trans, c.1399C>T p.(P467S). In vitro mutagenesis revealed that the G104V and P467S RPE65 proteins were catalytically inactive (0% isomerase activity). Patients 1 and 2 were excluded from participation in a phase 1 trial owing to high Adeno-associated virus 2 capsid-neutralizing antibodies. Patients 3 (G104V) and 4 (P467S) underwent successful surgical gene therapy with voretigene neparvovec-rzyl, and their response to lower white light intensity and visual field increased in fewer than 30 days after gene therapy intervention. Conclusions and Relevance Findings from this study suggest that, in patients with missense mutations in RPE65, functional assays of protein function can be performed to assess the pathogenicity of variants in both compound heterozygous and homozygous cases. Given the potential risks of gene therapy operations, in vitro RPE65 activity testing should be considered to avoid the possibility of treating a false genotype.
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Affiliation(s)
- Unikora Yang
- Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, California
| | - Susan Gentleman
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, Bethesda, Maryland
| | - Xiaowu Gai
- Center for Personalized Medicine, Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, California
| | - Michael B Gorin
- Division of Retinal Disorders and Ophthalmic Genetics, Stein Eye Institute, David Geffen School of Medicine, UCLA (University of California, Los Angeles)
| | - Mark S Borchert
- The Vision Center, Department of Surgery, Children's Hospital Los Angeles, Los Angeles, California.,USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles
| | - Thomas C Lee
- The Vision Center, Department of Surgery, Children's Hospital Los Angeles, Los Angeles, California.,USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles
| | - Adda Villanueva
- Retina Department Genomics Institute, Mejora Vision MD/Virtual Eye Care MD, Mérida, Yucatán, México.,Laboratoire de Diagnostic Moleculaire, Hôpital Maisonneuve Rosemont, Montreal, Quebec, Canada
| | - Robert Koenekoop
- Department of Paediatric Surgery, Montreal Children's Hospital, McGill University and McGill University Health Centre Research Institute, Montreal, Quebec, Canada.,Department of Human Genetics and Ophthalmology, Montreal Children's Hospital, McGill University and McGill University Health Centre Research Institute, Montreal, Quebec, Canada
| | - Albert M Maguire
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia.,F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia
| | - Jean Bennett
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia.,F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia
| | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, Bethesda, Maryland
| | - Aaron Nagiel
- The Vision Center, Department of Surgery, Children's Hospital Los Angeles, Los Angeles, California.,USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles
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20
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Gazda MA, Toomey MB, Araújo PM, Lopes RJ, Afonso S, Myers CA, Serres K, Kiser PD, Hill GE, Corbo JC, Carneiro M. Genetic Basis of De Novo Appearance of Carotenoid Ornamentation in Bare Parts of Canaries. Mol Biol Evol 2021; 37:1317-1328. [PMID: 31930402 DOI: 10.1093/molbev/msaa006] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Unlike wild and domestic canaries (Serinus canaria), or any of the three dozen species of finches in genus Serinus, the domestic urucum breed of canaries exhibits bright red bills and legs. This novel trait offers a unique opportunity to understand the mechanisms of bare-part coloration in birds. To identify the mutation producing the colorful phenotype, we resequenced the genome of urucum canaries and performed a range of analyses to search for genotype-to-phenotype associations across the genome. We identified a nonsynonymous mutation in the gene BCO2 (beta-carotene oxygenase 2, also known as BCDO2), an enzyme involved in the cleavage and breakdown of full-length carotenoids into short apocarotenoids. Protein structural models and in vitro functional assays indicate that the urucum mutation abrogates the carotenoid-cleavage activity of BCO2. Consistent with the predicted loss of carotenoid-cleavage activity, urucum canaries tended to have increased levels of full-length carotenoid pigments in bill tissue and reduced levels of carotenoid-cleavage products (apocarotenoids) in retinal tissue compared with other breeds of canaries. We hypothesize that carotenoid-based bare-part coloration might be readily gained, modified, or lost through simple switches in the enzymatic activity or regulation of BCO2 and this gene may be an important mediator in the evolution of bare-part coloration among bird species.
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Affiliation(s)
- Małgorzata Anna Gazda
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vairão, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - Matthew B Toomey
- Department of Biological Science, University of Tulsa, Tulsa, OK
| | - Pedro M Araújo
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vairão, Portugal.,MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Ricardo J Lopes
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vairão, Portugal
| | - Sandra Afonso
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vairão, Portugal
| | - Connie A Myers
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - Kyla Serres
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - Philip D Kiser
- Department of Physiology & Biophysics, School of Medicine, Gillespie Neuroscience Research Facility, University of California, Irvine, Irvine, CA
| | - Geoffrey E Hill
- Department of Biological Sciences, Auburn University, Auburn, AL
| | - Joseph C Corbo
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - Miguel Carneiro
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vairão, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
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21
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Choi EH, Daruwalla A, Suh S, Leinonen H, Palczewski K. Retinoids in the visual cycle: role of the retinal G protein-coupled receptor. J Lipid Res 2021; 62:100040. [PMID: 32493732 PMCID: PMC7910522 DOI: 10.1194/jlr.tr120000850] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/20/2020] [Indexed: 12/13/2022] Open
Abstract
Driven by the energy of a photon, the visual pigments in rod and cone photoreceptor cells isomerize 11-cis-retinal to the all-trans configuration. This photochemical reaction initiates the signal transduction pathway that eventually leads to the transmission of a visual signal to the brain and leaves the opsins insensitive to further light stimulation. For the eye to restore light sensitivity, opsins require recharging with 11-cis-retinal. This trans-cis back conversion is achieved through a series of enzymatic reactions composing the retinoid (visual) cycle. Although it is evident that the classical retinoid cycle is critical for vision, the existence of an adjunct pathway for 11-cis-retinal regeneration has been debated for many years. Retinal pigment epithelium (RPE)-retinal G protein-coupled receptor (RGR) has been identified previously as a mammalian retinaldehyde photoisomerase homologous to retinochrome found in invertebrates. Using pharmacological, genetic, and biochemical approaches, researchers have now established the physiological relevance of the RGR in 11-cis-retinal regeneration. The photoisomerase activity of RGR in the RPE and Müller glia explains how the eye can remain responsive in daylight. In this review, we will focus on retinoid metabolism in the eye and visual chromophore regeneration mediated by RGR.
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Affiliation(s)
- Elliot H Choi
- Department of Ophthalmology, Gavin Herbert Eye Institute, Center for Translational Vision Research, University of California, Irvine, CA, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA.
| | - Anahita Daruwalla
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA; Departments of Physiology and Biophysics, and Chemistry, University of California, Irvine, CA, USA
| | - Susie Suh
- Department of Ophthalmology, Gavin Herbert Eye Institute, Center for Translational Vision Research, University of California, Irvine, CA, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Henri Leinonen
- Department of Ophthalmology, Gavin Herbert Eye Institute, Center for Translational Vision Research, University of California, Irvine, CA, USA
| | - Krzysztof Palczewski
- Department of Ophthalmology, Gavin Herbert Eye Institute, Center for Translational Vision Research, University of California, Irvine, CA, USA; Departments of Physiology and Biophysics, and Chemistry, University of California, Irvine, CA, USA.
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22
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Kiser PD, Palczewski K. Pathways and disease-causing alterations in visual chromophore production for vertebrate vision. J Biol Chem 2021; 296:100072. [PMID: 33187985 PMCID: PMC7948990 DOI: 10.1074/jbc.rev120.014405] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 12/14/2022] Open
Abstract
All that we view of the world begins with an ultrafast cis to trans photoisomerization of the retinylidene chromophore associated with the visual pigments of rod and cone photoreceptors. The continual responsiveness of these photoreceptors is then sustained by regeneration processes that convert the trans-retinoid back to an 11-cis configuration. Recent biochemical and electrophysiological analyses of the retinal G-protein-coupled receptor (RGR) suggest that it could sustain the responsiveness of photoreceptor cells, particularly cones, even under bright light conditions. Thus, two mechanisms have evolved to accomplish the reisomerization: one involving the well-studied retinoid isomerase (RPE65) and a second photoisomerase reaction mediated by the RGR. Impairments to the pathways that transform all-trans-retinal back to 11-cis-retinal are associated with mild to severe forms of retinal dystrophy. Moreover, with age there also is a decline in the rate of chromophore regeneration. Both pharmacological and genetic approaches are being used to bypass visual cycle defects and consequently mitigate blinding diseases. Rapid progress in the use of genome editing also is paving the way for the treatment of disparate retinal diseases. In this review, we provide an update on visual cycle biochemistry and then discuss visual-cycle-related diseases and emerging therapeutics for these disorders. There is hope that these advances will be helpful in treating more complex diseases of the eye, including age-related macular degeneration (AMD).
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Affiliation(s)
- Philip D Kiser
- The Department of Physiology & Biophysics, University of California, Irvine, California, USA; Research Service, The VA Long Beach Health Care System, Long Beach, California, USA; The Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California, USA.
| | - Krzysztof Palczewski
- The Department of Physiology & Biophysics, University of California, Irvine, California, USA; The Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California, USA; The Department of Chemistry, University of California, Irvine, California, USA.
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23
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Inverse correlation between fatty acid transport protein 4 and vision in Leber congenital amaurosis associated with RPE65 mutation. Proc Natl Acad Sci U S A 2020; 117:32114-32123. [PMID: 33257550 DOI: 10.1073/pnas.2012623117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Fatty acid transport protein 4 (FATP4), a transmembrane protein in the endoplasmic reticulum (ER), is a recently identified negative regulator of the ER-associated retinal pigment epithelium (RPE)65 isomerase necessary for recycling 11-cis-retinal, the light-sensitive chromophore of both rod and cone opsin visual pigments. The role of FATP4 in the disease progression of retinal dystrophies associated with RPE65 mutations is completely unknown. Here we show that FATP4-deficiency in the RPE results in 2.8-fold and 1.7-fold increase of 11-cis- and 9-cis-retinals, respectively, improving dark-adaptation rates as well as survival and function of rods in the Rpe65 R91W knockin (KI) mouse model of Leber congenital amaurosis (LCA). Degradation of S-opsin in the proteasomes, but not in the lysosomes, was remarkably reduced in the KI mouse retinas lacking FATP4. FATP4-deficiency also significantly rescued S-opsin trafficking and M-opsin solubility in the KI retinas. The number of S-cones in the inferior retinas of 4- or 6-mo-old KI;Fatp4 -/- mice was 7.6- or 13.5-fold greater than those in age-matched KI mice. Degeneration rates of S- and M-cones are negatively correlated with expression levels of FATP4 in the RPE of the KI, KI;Fatp4 +/- , and KI;Fatp4 -/- mice. Moreover, the visual function of S- and M-cones is markedly preserved in the KI;Fatp4 -/- mice, displaying an inverse correlation with the FATP4 expression levels in the RPE of the three mutant lines. These findings establish FATP4 as a promising therapeutic target to improve the visual cycle, as well as survival and function of cones and rods in patients with RPE65 mutations.
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Properties and Therapeutic Implications of an Enigmatic D477G RPE65 Variant Associated with Autosomal Dominant Retinitis Pigmentosa. Genes (Basel) 2020; 11:genes11121420. [PMID: 33261050 PMCID: PMC7760593 DOI: 10.3390/genes11121420] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 12/22/2022] Open
Abstract
RPE65 isomerase, expressed in the retinal pigmented epithelium (RPE), is an enzymatic component of the retinoid cycle, converting all-trans retinyl ester into 11-cis retinol, and it is essential for vision, because it replenishes the photon capturing 11-cis retinal. To date, almost 200 loss-of-function mutations have been identified within the RPE65 gene causing inherited retinal dystrophies, most notably Leber congenital amaurosis (LCA) and autosomal recessive retinitis pigmentosa (arRP), which are both severe and early onset disease entities. We previously reported a mutation, D477G, co-segregating with the disease in a late-onset form of autosomal dominant RP (adRP) with choroidal involvement; uniquely, it is the only RPE65 variant to be described with a dominant component. Families or individuals with this variant have been encountered in five countries, and a number of subsequent studies have been reported in which the molecular biological and physiological properties of the variant have been studied in further detail, including observations of possible novel functions in addition to reduced RPE65 enzymatic activity. With regard to the latter, a human phase 1b proof-of-concept study has recently been reported in which aspects of remaining vision were improved for up to one year in four of five patients with advanced disease receiving a single one-week oral dose of 9-cis retinaldehyde, which is the first report showing efficacy and safety of an oral therapy for a dominant form of RP. Here, we review data accrued from published studies investigating molecular mechanisms of this unique variant and include hitherto unpublished material on the clinical spectrum of disease encountered in patients with the D477G variant, which, in many cases bears striking similarities to choroideremia.
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25
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Widjaja-Adhi MAK, Golczak M. The molecular aspects of absorption and metabolism of carotenoids and retinoids in vertebrates. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158571. [PMID: 31770587 PMCID: PMC7244374 DOI: 10.1016/j.bbalip.2019.158571] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/04/2019] [Accepted: 11/07/2019] [Indexed: 02/08/2023]
Abstract
Vitamin A is an essential nutrient necessary for numerous basic physiological functions, including reproduction and development, immune cell differentiation and communication, as well as the perception of light. To evade the dire consequences of vitamin A deficiency, vertebrates have evolved specialized metabolic pathways that enable the absorption, transport, and storage of vitamin A acquired from dietary sources as preformed retinoids or provitamin A carotenoids. This evolutionary advantage requires a complex interplay between numerous specialized retinoid-transport proteins, receptors, and enzymes. Recent advances in molecular and structural biology resulted in a rapid expansion of our understanding of these processes at the molecular level. This progress opened new avenues for the therapeutic manipulation of retinoid homeostasis. In this review, we summarize current research related to the biochemistry of carotenoid and retinoid-processing proteins with special emphasis on the structural aspects of their physiological actions. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.
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Affiliation(s)
- Made Airanthi K Widjaja-Adhi
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States of America
| | - Marcin Golczak
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States of America; Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States of America.
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26
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Poliakov E, Uppal S, Rogozin IB, Gentleman S, Redmond TM. Evolutionary aspects and enzymology of metazoan carotenoid cleavage oxygenases. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158665. [PMID: 32061750 PMCID: PMC7423639 DOI: 10.1016/j.bbalip.2020.158665] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/25/2020] [Accepted: 02/05/2020] [Indexed: 12/18/2022]
Abstract
The carotenoids are terpenoid fat-soluble pigments produced by plants, algae, and several bacteria and fungi. They are ubiquitous components of animal diets. Carotenoid cleavage oxygenase (CCO) superfamily members are involved in carotenoid metabolism and are present in all kingdoms of life. Throughout the animal kingdom, carotenoid oxygenases are widely distributed and they are completely absent only in two unicellular organisms, Monosiga and Leishmania. Mammals have three paralogs 15,15'-β-carotene oxygenase (BCO1), 9',10'-β-carotene oxygenase (BCO2) and RPE65. The first two enzymes are classical carotenoid oxygenases: they cleave carbon‑carbon double bonds and incorporate two atoms of oxygen in the substrate at the site of cleavage. The third, RPE65, is an unusual family member, it is the retinoid isomerohydrolase in the visual cycle that converts all-trans-retinyl ester into 11-cis-retinol. Here we discuss evolutionary aspects of the carotenoid cleavage oxygenase superfamily and their enzymology to deduce what insight we can obtain from their evolutionary conservation.
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Affiliation(s)
- Eugenia Poliakov
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Sheetal Uppal
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Igor B Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Susan Gentleman
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - T Michael Redmond
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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27
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Abstract
The visual phototransduction cascade begins with a cis-trans photoisomerization of a retinylidene chromophore associated with the visual pigments of rod and cone photoreceptors. Visual opsins release their all-trans-retinal chromophore following photoactivation, which necessitates the existence of pathways that produce 11-cis-retinal for continued formation of visual pigments and sustained vision. Proteins in the retinal pigment epithelium (RPE), a cell layer adjacent to the photoreceptor outer segments, form the well-established "dark" regeneration pathway known as the classical visual cycle. This pathway is sufficient to maintain continuous rod function and support cone photoreceptors as well although its throughput has to be augmented by additional mechanism(s) to maintain pigment levels in the face of high rates of photon capture. Recent studies indicate that the classical visual cycle works together with light-dependent processes in both the RPE and neural retina to ensure adequate 11-cis-retinal production under natural illuminances that can span ten orders of magnitude. Further elucidation of the interplay between these complementary systems is fundamental to understanding how cone-mediated vision is sustained in vivo. Here, we describe recent advances in understanding how 11-cis-retinal is synthesized via light-dependent mechanisms.
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Structural basis for carotenoid cleavage by an archaeal carotenoid dioxygenase. Proc Natl Acad Sci U S A 2020; 117:19914-19925. [PMID: 32747548 DOI: 10.1073/pnas.2004116117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Apocarotenoids are important signaling molecules generated from carotenoids through the action of carotenoid cleavage dioxygenases (CCDs). These enzymes have a remarkable ability to cleave carotenoids at specific alkene bonds while leaving chemically similar sites within the polyene intact. Although several bacterial and eukaryotic CCDs have been characterized, the long-standing goal of experimentally visualizing a CCD-carotenoid complex at high resolution to explain this exquisite regioselectivity remains unfulfilled. CCD genes are also present in some archaeal genomes, but the encoded enzymes remain uninvestigated. Here, we address this knowledge gap through analysis of a metazoan-like archaeal CCD from Candidatus Nitrosotalea devanaterra (NdCCD). NdCCD was active toward β-apocarotenoids but did not cleave bicyclic carotenoids. It exhibited an unusual regiospecificity, cleaving apocarotenoids solely at the C14'-C13' alkene bond to produce β-apo-14'-carotenals. The structure of NdCCD revealed a tapered active site cavity markedly different from the broad active site observed for the retinal-forming Synechocystis apocarotenoid oxygenase (SynACO) but similar to the vertebrate retinoid isomerase RPE65. The structure of NdCCD in complex with its apocarotenoid product demonstrated that the site of cleavage is defined by interactions along the substrate binding cleft as well as selective stabilization of reaction intermediates at the scissile alkene. These data on the molecular basis of CCD catalysis shed light on the origins of the varied catalytic activities found in metazoan CCDs, opening the possibility of modifying their activity through rational chemical or genetic approaches.
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29
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Structural dynamics in the C terminal domain homolog of orange carotenoid Protein reveals residues critical for carotenoid uptake. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148214. [DOI: 10.1016/j.bbabio.2020.148214] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 03/19/2020] [Accepted: 04/27/2020] [Indexed: 01/01/2023]
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30
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von Lintig J, Moon J, Babino D. Molecular components affecting ocular carotenoid and retinoid homeostasis. Prog Retin Eye Res 2020; 80:100864. [PMID: 32339666 DOI: 10.1016/j.preteyeres.2020.100864] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/13/2020] [Accepted: 04/17/2020] [Indexed: 12/15/2022]
Abstract
The photochemistry of vision employs opsins and geometric isomerization of their covalently bound retinylidine chromophores. In different animal classes, these light receptors associate with distinct G proteins that either hyperpolarize or depolarize photoreceptor membranes. Vertebrates also use the acidic form of chromophore, retinoic acid, as the ligand of nuclear hormone receptors that orchestrate eye development. To establish and sustain these processes, animals must acquire carotenoids from the diet, transport them, and metabolize them to chromophore and retinoic acid. The understanding of carotenoid metabolism, however, lagged behind our knowledge about the biology of their receptor molecules. In the past decades, much progress has been made in identifying the genes encoding proteins that mediate the transport and enzymatic transformations of carotenoids and their retinoid metabolites. Comparative analysis in different animal classes revealed how evolutionary tinkering with a limited number of genes evolved different biochemical strategies to supply photoreceptors with chromophore. Mutations in these genes impair carotenoid metabolism and induce various ocular pathologies. This review summarizes this advancement and introduces the involved proteins, including the homeostatic regulation of their activities.
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Affiliation(s)
- Johannes von Lintig
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
| | - Jean Moon
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Darwin Babino
- Department of Ophthalmology, School of Medicine, University of Washington, Seattle, WA, USA
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31
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Uppal S, Rogozin IB, Redmond T, Poliakov E. Palmitoylation of Metazoan Carotenoid Oxygenases. Molecules 2020; 25:E1942. [PMID: 32331396 PMCID: PMC7221588 DOI: 10.3390/molecules25081942] [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: 03/18/2020] [Revised: 04/10/2020] [Accepted: 04/13/2020] [Indexed: 11/16/2022] Open
Abstract
Abundant in nature, carotenoids are a class of fat-soluble pigments with a polyene tetraterpenoid structure. They possess antioxidant properties and their consumption leads to certain health benefits in humans. Carotenoid cleavage oxygenases (CCOs) are a superfamily of enzymes which oxidatively cleave carotenoids and they are present in all kingdoms of life. Complexity of CCO evolution is high. For example, in this study we serendipitously found a new family of eukaryotic CCOs, the apocarotenoid oxygenase-like (ACOL) family. This family has several members in animal genomes and lacks the animal-specific amino acid motif PDPCK. This motif is likely to be associated with palmitoylation of some animal CCOs. We recently demonstrated that two mammalian members of the carotenoid oxygenase family retinal pigment epithelial-specific 65 kDa protein (RPE65) and beta-carotene oxygenase 2 (BCO2) are palmitoylated proteins. Here we used the acyl-resin-assisted capture (acyl-RAC) method to demonstrate protein palmitoylation and immunochemistry to localize mouse BCO2 (mBCO2) in COS7 cell line in the absence and presence of its substrate β-carotene. We demonstrate that mBCO2 palmitoylation depends on the evolutionarily conserved motif PDPCK and that metazoan family members lacking the motif (Lancelet beta-carotene oxygenase-like protein (BCOL) and Acropora ACOL) are not palmitoylated. Additionally, we observed that the palmitoylation status of mBCO2 and its membrane association depend on the presence of its substrate β-carotene. Based on our results we conclude that most metazoan carotenoid oxygenases retain the evolutionarily conserved palmitoylation PDPCK motif to target proteins to internal membranes depending on substrate status. Exceptions are in the secreted BCOL subfamily and the strictly cytosolic ancient ACOL subfamily of carotenoid oxygenases.
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Affiliation(s)
- Sheetal Uppal
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.U.); (T.M.R.)
| | - Igor B. Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA;
| | - T.Michael Redmond
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.U.); (T.M.R.)
| | - Eugenia Poliakov
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.U.); (T.M.R.)
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32
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Helgeland H, Sodeland M, Zoric N, Torgersen JS, Grammes F, von Lintig J, Moen T, Kjøglum S, Lien S, Våge DI. Genomic and functional gene studies suggest a key role of beta-carotene oxygenase 1 like (bco1l) gene in salmon flesh color. Sci Rep 2019; 9:20061. [PMID: 31882713 PMCID: PMC6934663 DOI: 10.1038/s41598-019-56438-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 12/12/2019] [Indexed: 12/19/2022] Open
Abstract
Red coloration of muscle tissue (flesh) is a unique trait in several salmonid genera, including Atlantic salmon. The color results from dietary carotenoids deposited in the flesh, whereas the color intensity is affected both by diet and genetic components. Herein we report on a genome-wide association study (GWAS) to identify genetic variation underlying this trait. Two SNPs on ssa26 showed strong associations to the flesh color in salmon. Two genes known to be involved in carotenoid metabolism were located in this QTL- region: beta-carotene oxygenase 1 (bco1) and beta-carotene oxygenase 1 like (bco1l). To determine whether flesh color variation is caused by one, or both, of these genes, functional studies were carried out including mRNA and protein expression in fish with red and pale flesh color. The catalytic abilities of these two genes were also tested with different carotenoids. Our results suggest bco1l to be the most likely gene to explain the flesh color variation observed in this population.
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Affiliation(s)
- Hanna Helgeland
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, NO-1432, Ås, Norway.,Oslo University Hospital, Department of Radiation Biology, Institute for Cancer Research, N-0310, Oslo, Norway
| | - Marte Sodeland
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, NO-1432, Ås, Norway.,Institute of Marine research, N-4817, His, Norway.,University of Agder, Department of Natural Sciences, Faculty of Engineering and Science, N-4604, Kristiansand, Norway
| | - Nina Zoric
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, NO-1432, Ås, Norway
| | | | - Fabian Grammes
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, NO-1432, Ås, Norway
| | - Johannes von Lintig
- Case Western Reserve University, Department of Pharmacology, 2109 Adelbert Rd. Wood Bldg. 341, Cleveland, OH, 44106, USA
| | | | | | - Sigbjørn Lien
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, NO-1432, Ås, Norway
| | - Dag Inge Våge
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, NO-1432, Ås, Norway.
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33
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Daruwalla A, Kiser PD. Structural and mechanistic aspects of carotenoid cleavage dioxygenases (CCDs). Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158590. [PMID: 31874225 DOI: 10.1016/j.bbalip.2019.158590] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 02/03/2023]
Abstract
Carotenoid cleavage dioxygenases (CCDs) comprise a superfamily of mononuclear non-heme iron proteins that catalyze the oxygenolytic fission of alkene bonds in carotenoids to generate apocarotenoid products. Some of these enzymes exhibit additional activities such as carbon skeleton rearrangement and trans-cis isomerization. The group also includes a subfamily of enzymes that split the interphenyl alkene bond in molecules such as resveratrol and lignostilbene. CCDs are involved in numerous biological processes ranging from production of light-sensing chromophores to degradation of lignin derivatives in pulping waste sludge. These enzymes exhibit unique features that distinguish them from other families of non-heme iron enzymes. The distinctive properties and biological importance of CCDs have stimulated interest in their modes of catalysis. Recent structural, spectroscopic, and computational studies have helped clarify mechanistic aspects of CCD catalysis. Here, we review these findings emphasizing common and unique properties of CCDs that enable their variable substrate specificity and regioselectivity. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.
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Affiliation(s)
- Anahita Daruwalla
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, United States of America; Department of Physiology & Biophysics, University of California, Irvine, CA 92697, United States of America
| | - Philip D Kiser
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697, United States of America; Research Service, VA Long Beach Healthcare System, Long Beach, CA 90822, United States of America.
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34
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Li S, Green JF, Jin M. Impacts of deletion and ichthyosis prematurity syndrome-associated mutations in fatty acid transport protein 4 on the function of RPE65. FEBS Lett 2019; 594:540-552. [PMID: 31595490 DOI: 10.1002/1873-3468.13633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/16/2019] [Accepted: 09/16/2019] [Indexed: 12/23/2022]
Abstract
The retinal pigment epithelium-specific 65 kDa (RPE65) isomerase plays a pivotal role in photoreceptor survival and function. RPE65-catalyzed synthesis of 11-cis-retinol from all-trans-retinyl esters in the visual cycle is negatively regulated, through a heretofore unknown mechanism, by the fatty acid transport protein FATP4, mutations in which are associated with ichthyosis prematurity syndrome (IPS). Here, we analyzed the interaction between deletion mutants of FATP4 and RPE65 and the impacts of IPS-associated FATP4 mutations on RPE65 expression, 11-cis-retinol synthesis, and all-trans-retinyl ester synthesis. Our results suggest that the interaction between FATP4 and RPE65 contributes to the inhibition of RPE65 function and that IPS-associated nonsense and missense mutations in FATP4 have different effects on the visual cycle.
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Affiliation(s)
- Songhua Li
- Neuroscience Center of Excellence, Louisiana State University School of Medicine, New Orleans, LA, USA
| | - John F Green
- Neuroscience Center of Excellence, Louisiana State University School of Medicine, New Orleans, LA, USA
| | - Minghao Jin
- Neuroscience Center of Excellence, Louisiana State University School of Medicine, New Orleans, LA, USA.,Department of Ophthalmology, Louisiana State University School of Medicine, New Orleans, LA, USA
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35
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Uppal S, Liu T, Poliakov E, Gentleman S, Redmond TM. The dual roles of RPE65 S-palmitoylation in membrane association and visual cycle function. Sci Rep 2019; 9:5218. [PMID: 30914787 PMCID: PMC6435699 DOI: 10.1038/s41598-019-41501-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 03/07/2019] [Indexed: 12/31/2022] Open
Abstract
Association with the endoplasmic reticulum (ER) membrane is a critical requirement for the catalytic function of RPE65. Several studies have investigated the nature of the RPE65-membrane interaction; however, complete understanding of its mode of membrane binding is still lacking. Previous biochemical studies suggest the membrane interaction can be partly attributed to S-palmitoylation, but the existence of RPE65 palmitoylation remains a matter of debate. Here, we re-examined RPE65 palmitoylation, and its functional consequence in the visual cycle. We clearly demonstrate that RPE65 is post-translationally modified by a palmitoyl moiety, but this is not universal (about 25% of RPE65). By extensive mutational studies we mapped the S-palmitoylation sites to residues C112 and C146. Inhibition of palmitoylation using 2-bromopalmitate and 2-fluoropalmitate completely abolish its membrane association. Furthermore, palmitoylation-deficient C112 mutants are significantly impeded in membrane association. Finally, we show that RPE65 palmitoylation level is highly regulated by lecithin:retinol acyltransferase (LRAT) enzyme. In the presence of all-trans retinol, LRAT substrate, there is a significant decrease in the level of palmitoylation of RPE65. In conclusion, our findings suggest that RPE65 is indeed a dynamically-regulated palmitoylated protein and that palmitoylation is necessary for regulating its membrane binding, and to perform its normal visual cycle function.
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Affiliation(s)
- Sheetal Uppal
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Tingting Liu
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States.,Department of Transfusion, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, P.R. China
| | - Eugenia Poliakov
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Susan Gentleman
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States.
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36
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Choi EH, Suh S, Sander CL, Hernandez CJO, Bulman ER, Khadka N, Dong Z, Shi W, Palczewski K, Kiser PD. Insights into the pathogenesis of dominant retinitis pigmentosa associated with a D477G mutation in RPE65. Hum Mol Genet 2019; 27:2225-2243. [PMID: 29659842 DOI: 10.1093/hmg/ddy128] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/06/2018] [Indexed: 12/31/2022] Open
Abstract
RPE65 is the essential trans-cis isomerase of the classical retinoid (visual) cycle. Mutations in RPE65 give rise to severe retinal dystrophies, most of which are associated with loss of protein function and recessive inheritance. The only known exception is a c.1430G>A (D477G) mutation that gives rise to dominant retinitis pigmentosa with delayed onset and choroidal and macular involvement. Position 477 is distant from functionally critical regions of RPE65. Hence, the mechanism of D477G pathogenicity remains unclear, although protein misfolding and aggregation mechanisms have been suggested. We characterized a D477G knock-in mouse model which exhibited mild age-dependent changes in retinal structure and function. Immunoblot analysis of protein extracts from the eyes of these knock-in mice demonstrated the presence of ubiquitinated RPE65 and reduced RPE65 expression. We observed an accumulation of retinyl esters in the knock-in mice as well as a delay in rhodopsin regeneration kinetics and diminished electroretinography responses, indicative of RPE65 functional impairment induced by the D477G mutation in vivo. However, a cell line expressing D477G RPE65 revealed protein expression levels, cellular localization and retinoid isomerase activity comparable to cells expressing wild-type protein. Structural analysis of an RPE65 chimera suggested that the D477G mutation does not perturb protein folding or tertiary structure. Instead, the mutation generates an aggregation-prone surface that could induce cellular toxicity through abnormal complex formation as suggested by crystal packing analysis. These results indicate that a toxic gain-of-function induced by the D477G RPE65 substitution may play a role in the pathogenesis of this form of dominant retinitis pigmentosa.
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Affiliation(s)
- Elliot H Choi
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Susie Suh
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Christopher L Sander
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Christian J Ortiz Hernandez
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.,University of Puerto Rico at Humacao, Humacao, PR, USA
| | - Elizabeth R Bulman
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.,Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH 44106, USA
| | - Nimesh Khadka
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Zhiqian Dong
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.,Polgenix Inc., Cleveland, OH 44106, USA
| | - Wuxian Shi
- National Synchrotron Light Source-II, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.,Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Philip D Kiser
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.,Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH 44106, USA.,Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, OH 44106, USA
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Structural biology of 11- cis-retinaldehyde production in the classical visual cycle. Biochem J 2018; 475:3171-3188. [PMID: 30352831 DOI: 10.1042/bcj20180193] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 09/20/2018] [Accepted: 09/26/2018] [Indexed: 12/21/2022]
Abstract
The vitamin A derivative 11-cis-retinaldehyde plays a pivotal role in vertebrate vision by serving as the chromophore of rod and cone visual pigments. In the initial step of vision, a photon is absorbed by this chromophore resulting in its isomerization to an all-trans state and consequent activation of the visual pigment and phototransduction cascade. Spent chromophore is released from the pigments through hydrolysis. Subsequent photon detection requires the delivery of regenerated 11-cis-retinaldehyde to the visual pigment. This trans-cis conversion is achieved through a process known as the visual cycle. In this review, we will discuss the enzymes, binding proteins and transporters that enable the visual pigment renewal process with a focus on advances made during the past decade in our understanding of their structural biology.
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Examining the Role of Cone-expressed RPE65 in Mouse Cone Function. Sci Rep 2018; 8:14201. [PMID: 30242264 PMCID: PMC6155087 DOI: 10.1038/s41598-018-32667-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 09/13/2018] [Indexed: 11/08/2022] Open
Abstract
Efficient chromophore supply is paramount for the continuous function of vertebrate cone photoreceptors. It is well established that isomerization of all-trans- to 11-cis- retinoid in the retinal pigmented epithelium by RPE65 is a key reaction in this process. Mutations in RPE65 result in a disrupted chromophore supply, retinal degeneration, and blindness. Interestingly, RPE65 has recently been found to also be expressed in cone photoreceptors in several species, including mouse and human. However, the functional role of cone-expressed RPE65 has remained unknown. Here, we used loss and gain of function approaches to investigate this issue. First, we compared the function of cones from control and RPE65-deficient mice. Although we found that deletion of RPE65 partially suppressed cone dark adaptation, the interpretation of this result was complicated by the abnormal cone structure and function caused by the chromophore deficiency in the absence of RPE65 in the pigmented epithelium. As an alternative approach, we generated transgenic mice to express human RPE65 in the cones of mice where RPE65 expression is normally restricted to the pigmented epithelium. Comparison of control (RPE65-deficient) and transgenic (RPE65-expressing) cones revealed no morphological or functional changes, with only a slight delay in dark adaptation, possibly caused by the buffering of retinoids by RPE65. Together, our results do not provide any evidence for a functional role of RPE65 in mouse cones. Future studies will have to determine whether cone-expressed RPE65 plays a role in maintaining the long-term homeostasis of retinoids in cones and their function and survival, particularly in humans.
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Kelly ME, Ramkumar S, Sun W, Colon Ortiz C, Kiser PD, Golczak M, von Lintig J. The Biochemical Basis of Vitamin A Production from the Asymmetric Carotenoid β-Cryptoxanthin. ACS Chem Biol 2018; 13:2121-2129. [PMID: 29883100 PMCID: PMC6158786 DOI: 10.1021/acschembio.8b00290] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Vitamin A serves essential functions in mammalian biology as a signaling molecule and chromophore. This lipid can be synthesized from more than 50 putative dietary provitamin A precursor molecules which contain at least one unsubstituted β-ionone ring. We here scrutinized the enzymatic properties and substrate specificities of the two structurally related carotenoid cleavage dioxygenases (CCDs) which catalyze this synthesis. Recombinant BCO1 split substrates across the C15,C15' double bond adjacent to a canonical β-ionone ring site to vitamin A aldehyde. Substitution of the ring with a hydroxyl group prevented this conversion. The removal of methyl groups from the polyene carbon backbone of the substrate did not impede enzyme activity. Homology modeling and site-directed mutagenesis identified amino acid residues at the entrance of the substrate tunnel, which determined BCO1's specificity for the canonical β-ionone ring site. In contrast, BCO2 split substrates across the C9,C10 double bond adjacent to assorted ionone ring sites. Kinetic analysis revealed a higher catalytic efficiency of BCO2 with substrates bearing 3-hydroxy-β-ionone rings. In the mouse intestine, the asymmetric carotenoid β-cryptoxanthin with one canonical and one 3-hydroxy-β-ionone ring site was meticulously converted to vitamin A. The tailoring of this asymmetric substrate occurred by a stepwise processing of the carotenoid substrate by both CCDs and involved a β-apo-10'-carotenal intermediate. Thus, opposite selectivity for ionone ring sites of the two mammalian CCDs complement each other in the metabolic challenge of vitamin A production from a chemically diverse set of precursor molecules.
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Affiliation(s)
- Mary E. Kelly
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Srinivasagan Ramkumar
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Weizhong Sun
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Crystal Colon Ortiz
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Philip D. Kiser
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Marcin Golczak
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Johannes von Lintig
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106
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Loewen PC, Switala J, Wells JP, Huang F, Zara AT, Allingham JS, Loewen MC. Structure and function of a lignostilbene-α,β-dioxygenase orthologue from Pseudomonas brassicacearum. BMC BIOCHEMISTRY 2018; 19:8. [PMID: 30115012 PMCID: PMC6097328 DOI: 10.1186/s12858-018-0098-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 08/02/2018] [Indexed: 01/28/2023]
Abstract
BACKGROUND Stilbene cleaving oxygenases (SCOs), also known as lignostilbene-α,β-dioxygenases (LSDs) mediate the oxidative cleavage of the olefinic double bonds of lignin-derived intermediate phenolic stilbenes, yielding small modified benzaldehyde compounds. SCOs represent one branch of the larger carotenoid cleavage oxygenases family. Here, we describe the structural and functional characterization of an SCO-like enzyme from the soil-born, bio-control agent Pseudomonas brassicacearum. METHODS In vitro and in vivo assays relying on visual inspection, spectrophotometric quantification, as well as liquid-chormatographic and mass spectrometric characterization were applied for functional evaluation of the enzyme. X-ray crystallographic analyses and in silico modeling were applied for structural investigations. RESULTS In vitro assays demonstrated preferential cleavage of resveratrol, while in vivo analyses detected putative cleavage of the straight chain carotenoid, lycopene. A high-resolution structure containing the seven-bladed β-propeller fold and conserved 4-His-Fe unit at the catalytic site, was obtained. Comparative structural alignments, as well as in silico modelling and docking, highlight potential molecular factors contributing to both the primary in vitro activity against resveratrol, as well as the putative subsidiary activities against carotenoids in vivo, for future validation. CONCLUSIONS The findings reported here provide validation of the SCO structure, and highlight enigmatic points with respect to the potential effect of the enzyme's molecular environment on substrate specificities for future investigation.
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Affiliation(s)
- Peter C Loewen
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Jacek Switala
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - James P Wells
- National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada
| | - Fang Huang
- National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada
| | - Anthony T Zara
- Department of BioMedical and Molecular Sciences, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - John S Allingham
- Department of BioMedical and Molecular Sciences, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Michele C Loewen
- National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada.
- Department of BioMedical and Molecular Sciences, Queen's University, Kingston, ON, K7L 3N6, Canada.
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41
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Jia KP, Baz L, Al-Babili S. From carotenoids to strigolactones. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:2189-2204. [PMID: 29253188 DOI: 10.1093/jxb/erx476] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/07/2017] [Indexed: 05/18/2023]
Abstract
Strigolactones are phytohormones that regulate various plant developmental and adaptation processes. When released into soil, strigolactones act as chemical signals, attracting symbiotic arbuscular mycorrhizal fungi and inducing seed germination in root-parasitic weeds. Strigolactones are carotenoid derivatives, characterized by the presence of a butenolide ring that is connected by an enol ether bridge to a less conserved second moiety. Carotenoids are isopenoid pigments that differ in structure, number of conjugated double bonds, and stereoconfiguration. Genetic analysis and enzymatic studies have demonstrated that strigolactones originate from all-trans-β-carotene in a pathway that involves the all-trans-/9-cis-β-carotene isomerase DWARF27 and carotenoid cleavage dioxygenase 7 and 8 (CCD7, 8). The CCD7-mediated, regiospecific and stereospecific double-bond cleavage of 9-cis-β-carotene leads to a 9-cis-configured intermediate that is converted by CCD8 via a combination of reactions into the central metabolite carlactone. By catalyzing repeated oxygenation reactions that can be coupled to ring closure, CYP711 enzymes convert carlactone into tricyclic-ring-containing canonical and non-canonical strigolactones. Modifying enzymes, which are mostly unknown, further increase the diversity of strigolactones. This review explores carotenogenesis, provides an update on strigolactone biosynthesis, with emphasis on the substrate specificity and reactions catalyzed by the different enzymes, and describes the regulation of the biosynthetic pathway.
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Affiliation(s)
- Kun-Peng Jia
- King Abdullah University of Science and Technology, Biological and Environmental Sciences and Engineering Division, The Bioactives Lab, Thuwal, Kingdom of Saudi Arabia
| | - Lina Baz
- King Abdullah University of Science and Technology, Biological and Environmental Sciences and Engineering Division, The Bioactives Lab, Thuwal, Kingdom of Saudi Arabia
| | - Salim Al-Babili
- King Abdullah University of Science and Technology, Biological and Environmental Sciences and Engineering Division, The Bioactives Lab, Thuwal, Kingdom of Saudi Arabia
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42
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Phylogenetic analysis of the metazoan carotenoid oxygenase superfamily: a new ancestral gene assemblage of BCO-like (BCOL) proteins. Sci Rep 2017; 7:13192. [PMID: 29038443 PMCID: PMC5643517 DOI: 10.1038/s41598-017-13521-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 09/25/2017] [Indexed: 11/08/2022] Open
Abstract
Here we describe a new family of carotenoid cleavage oxygenases (CCOs) in metazoans, the BCO2-like (BCOL) clade, which contains lancelet, nematode, and molluscan carotenoid oxygenase sequences. Phylogenetic analysis of CCOs in all kingdoms of life confirmed that the BCOL enzymes are an independent clade of ancient origin. One of the predicted lancelet BCOL proteins, cloned and analyzed for carotenoid cleavage activity in a bacterial carotenoid expression system, had activity similar to lancelet BCO2 proteins, although with a preference for cis isomers. Our docking predictions correlated well with the cis-favored activity. The extensive expansions of the new animal BCOL family in some species (e.g., lancelet) suggests that the carotenoid cleavage oxygenase superfamily has evolved in the “extremely high turnover” fashion: numerous losses and duplications of this family are likely to reflect complex regulation processes during development, and interactions with the environment. These findings also serve to provide a rationale for the evolution of the BCO-related outlier RPE65 retinol isomerase, an enzyme that does not utilize carotenoids as substrate or perform double-bond cleavage.
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44
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Sears AE, Bernstein PS, Cideciyan AV, Hoyng C, Charbel Issa P, Palczewski K, Rosenfeld PJ, Sadda S, Schraermeyer U, Sparrow JR, Washington I, Scholl HPN. Towards Treatment of Stargardt Disease: Workshop Organized and Sponsored by the Foundation Fighting Blindness. Transl Vis Sci Technol 2017; 6:6. [PMID: 28920007 PMCID: PMC5599228 DOI: 10.1167/tvst.6.5.6] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 07/11/2017] [Indexed: 01/13/2023] Open
Abstract
Accumulation of fluorescent metabolic byproducts of the visual (retinoid) cycle is associated with photoreceptor and retinal pigment epithelial cell death in both Stargardt disease and atrophic (nonneovascular) age-related macular degeneration (AMD). As a consequence of this observation, small molecular inhibitors of enzymes in the visual cycle were recently tested in clinical trials as a strategy to protect the retina and retinal pigment epithelium in patients with atrophic AMD. To address the clinical translational needs for therapies aimed at both diseases, a workshop organized by the Foundation Fighting Blindness was hosted by the Department of Pharmacology at Case Western Reserve University on February 17, 2017, at the Tinkham Veale University Center, Cleveland, OH, USA. Invited speakers highlighted recent advances in the understanding of the pathophysiology of Stargardt disease, in terms of its clinical characterization and the development of endpoints for clinical trials, and discussed the comparability of therapeutic strategies between atrophic age-related macular degeneration (AMD) and Stargardt disease. Investigators speculated that reducing the concentrations of visual cycle precursor substances and/or their byproducts may provide valid therapeutic options for the treatment of Stargardt disease. Here we review the workshop's presentations in the context of published literature to help shape the aims of ongoing research endeavors and aid the development of therapies for Stargardt disease.
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Affiliation(s)
- Avery E Sears
- Department of Pharmacology, School of Medicine, Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, OH, USA
| | | | - Artur V Cideciyan
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Carel Hoyng
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Peter Charbel Issa
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, and the Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, OH, USA
| | - Philip J Rosenfeld
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - SriniVas Sadda
- Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, CA, USA
| | - Ulrich Schraermeyer
- Institute of Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Janet R Sparrow
- Edward S. Harkness Eye Institute, Columbia University Medical Center, New York, NY, USA
| | - Ilyas Washington
- Edward S. Harkness Eye Institute, Columbia University Medical Center, New York, NY, USA
| | - Hendrik P N Scholl
- Department of Ophthalmology, University of Basel, Basel, Switzerland.,Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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RPE65 has an additional function as the lutein to meso-zeaxanthin isomerase in the vertebrate eye. Proc Natl Acad Sci U S A 2017; 114:10882-10887. [PMID: 28874556 DOI: 10.1073/pnas.1706332114] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Carotenoids are plant-derived pigment molecules that vertebrates cannot synthesize de novo that protect the fovea of the primate retina from oxidative stress and light damage. meso-Zeaxanthin is an ocular-specific carotenoid for which there are no common dietary sources. It is one of the three major carotenoids present at the foveal center, but the mechanism by which it is produced in the eye is unknown. An isomerase enzyme is thought to be responsible for the transformation of lutein to meso-zeaxanthin by a double-bond shift mechanism, but its identity has been elusive. We previously found that meso-zeaxanthin is produced in a developmentally regulated manner in chicken embryonic retinal pigment epithelium (RPE)/choroid in the absence of light. In the present study, we show that RPE65, the isomerohydrolase enzyme of the vertebrate visual cycle that catalyzes the isomerization of all-trans-retinyl esters to 11-cis-retinol, is also the isomerase enzyme responsible for the production of meso-zeaxanthin in vertebrates. Its RNA is up-regulated 23-fold at the time of meso-zeaxanthin production during chicken eye development, and we present evidence that overexpression of either chicken or human RPE65 in cell culture leads to the production of meso-zeaxanthin from lutein. Pharmacologic inhibition of RPE65 function resulted in significant inhibition of meso-zeaxanthin biosynthesis during chicken eye development. Structural docking experiments revealed that the epsilon ring of lutein fits into the active site of RPE65 close to the nonheme iron center. This report describes a previously unrecognized additional activity of RPE65 in ocular carotenoid metabolism.
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Brausemann A, Gemmecker S, Koschmieder J, Ghisla S, Beyer P, Einsle O. Structure of Phytoene Desaturase Provides Insights into Herbicide Binding and Reaction Mechanisms Involved in Carotene Desaturation. Structure 2017; 25:1222-1232.e3. [PMID: 28669634 DOI: 10.1016/j.str.2017.06.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 05/10/2017] [Accepted: 06/01/2017] [Indexed: 11/16/2022]
Abstract
Cyanobacteria and plants synthesize carotenoids via a poly-cis pathway starting with phytoene, a membrane-bound C40 hydrocarbon. Phytoene desaturase (PDS) introduces two double bonds and concomitantly isomerizes two neighboring double bonds from trans to cis. PDS assembles into homo-tetramers that interact monotopically with membranes. A long hydrophobic tunnel is proposed to function in the sequential binding of phytoene and the electron acceptor plastoquinone. The herbicidal inhibitor norflurazon binds at a plastoquinone site thereby blocking reoxidation of FADred. Comparison with the sequence-dissimilar bacterial carotene desaturase CRTI reveals substantial similarities in the overall protein fold, defining both as members of the GR2 family of flavoproteins. However, the PDS active center architecture is unprecedented: no functional groups are found in the immediate flavin vicinity that might participate in dehydrogenation and isomerization. This suggests that the isoalloxazine moiety is sufficient for catalysis. Despite mechanistic differences, an ancient evolutionary relation of PDS and CRTI is apparent.
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Affiliation(s)
- Anton Brausemann
- Institute for Biochemistry, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Sandra Gemmecker
- Faculty of Biology, Albert-Ludwigs Universität Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Julian Koschmieder
- Faculty of Biology, Albert-Ludwigs Universität Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Sandro Ghisla
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Peter Beyer
- Faculty of Biology, Albert-Ludwigs Universität Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany; BIOSS Centre for Biological Signaling Studies, Schänzlestrasse 1, 79104 Freiburg, Germany.
| | - Oliver Einsle
- Institute for Biochemistry, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany; BIOSS Centre for Biological Signaling Studies, Schänzlestrasse 1, 79104 Freiburg, Germany.
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Sui X, Weitz AC, Farquhar ER, Badiee M, Banerjee S, von Lintig J, Tochtrop GP, Palczewski K, Hendrich MP, Kiser PD. Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center. Biochemistry 2017; 56:2836-2852. [PMID: 28493664 DOI: 10.1021/acs.biochem.7b00251] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Carotenoid cleavage oxygenases (CCOs) are non-heme iron enzymes that catalyze scission of alkene groups in carotenoids and stilbenoids to form biologically important products. CCOs possess a rare four-His iron center whose resting-state structure and interaction with substrates are incompletely understood. Here, we address this knowledge gap through a comprehensive structural and spectroscopic study of three phyletically diverse CCOs. The crystal structure of a fungal stilbenoid-cleaving CCO, CAO1, reveals strong similarity between its iron center and those of carotenoid-cleaving CCOs, but with a markedly different substrate-binding cleft. These enzymes all possess a five-coordinate high-spin Fe(II) center with resting-state Fe-His bond lengths of ∼2.15 Å. This ligand set generates an iron environment more electropositive than those of other non-heme iron dioxygenases as observed by Mössbauer isomer shifts. Dioxygen (O2) does not coordinate iron in the absence of substrate. Substrates bind away (∼4.7 Å) from the iron and have little impact on its electronic structure, thus excluding coordination-triggered O2 binding. However, substrate binding does perturb the spectral properties of CCO Fe-NO derivatives, indicating proximate organic substrate and O2-binding sites, which might influence Fe-O2 interactions. Together, these data provide a robust description of the CCO iron center and its interactions with substrates and substrate mimetics that illuminates commonalities as well as subtle and profound structural differences within the CCO family.
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Affiliation(s)
- Xuewu Sui
- Department of Pharmacology, School of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Andrew C Weitz
- Department of Chemistry, Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Erik R Farquhar
- National Synchrotron Light Source-II, Brookhaven National Laboratory , Upton, New York 11973, United States.,Center for Proteomics and Bioinformatics, Center for Synchrotron Biosciences, School of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106-4988, United States
| | - Mohsen Badiee
- Department of Chemistry, Case Western Reserve University , 2080 Adelbert Road, Cleveland, Ohio 44106, United States
| | - Surajit Banerjee
- Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14850, United States.,Northeastern Collaborative Access Team, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Johannes von Lintig
- Department of Pharmacology, School of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Gregory P Tochtrop
- Department of Chemistry, Case Western Reserve University , 2080 Adelbert Road, Cleveland, Ohio 44106, United States
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.,Cleveland Center for Membrane and Structural Biology, Case Western Reserve University , 1819 East 101st Street, Cleveland, Ohio 44106, United States
| | - Michael P Hendrich
- Department of Chemistry, Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Philip D Kiser
- Department of Pharmacology, School of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.,Research Service, Louis Stokes Cleveland VA Medical Center , 10701 East Boulevard, Cleveland, Ohio 44106, United States
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48
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Kiser PD, Zhang J, Badiee M, Kinoshita J, Peachey NS, Tochtrop GP, Palczewski K. Rational Tuning of Visual Cycle Modulator Pharmacodynamics. J Pharmacol Exp Ther 2017; 362:131-145. [PMID: 28476927 DOI: 10.1124/jpet.117.240721] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 05/01/2017] [Indexed: 11/22/2022] Open
Abstract
Modulators of the visual cycle have been developed for treatment of various retinal disorders. These agents were designed to inhibit retinoid isomerase [retinal pigment epithelium-specific 65 kDa protein (RPE65)], the rate-limiting enzyme of the visual cycle, based on the idea that attenuation of visual pigment regeneration could reduce formation of toxic retinal conjugates. Of these agents, certain ones that contain primary amine groups can also reversibly form retinaldehyde Schiff base adducts, which contributes to their retinal protective activity. Direct inhibition of RPE65 as a therapeutic strategy is complicated by adverse effects resulting from slowed chromophore regeneration, whereas effective retinal sequestration can require high drug doses with potential off-target effects. We hypothesized that the RPE65-emixustat crystal structure could help guide the design of retinaldehyde-sequestering agents with varying degrees of RPE65 inhibitory activity. We found that addition of an isopropyl group to the central phenyl ring of emixustat and related compounds resulted in agents effectively lacking in vitro retinoid isomerase inhibitory activity, whereas substitution of the terminal 6-membered ring with branched moieties capable of stronger RPE65 interaction potentiated inhibition. The isopropyl derivative series produced discernible visual cycle suppression in vivo, albeit much less potently than compounds with a high affinity for the RPE65 active site. These agents were distributed into the retina and formed Schiff base adducts with retinaldehyde. Except for one compound [3-amino-1-(3-isopropyl-5-((2,6,6-trimethylcyclohex-1-en-1-yl)methoxy)phenyl)propan-1-ol (MB-007)], these agents conferred protection against retinal phototoxicity, suggesting that both direct RPE65 inhibition and retinal sequestration are mechanisms of potential therapeutic relevance.
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Affiliation(s)
- Philip D Kiser
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Jianye Zhang
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Mohsen Badiee
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Junzo Kinoshita
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Neal S Peachey
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Gregory P Tochtrop
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
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49
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Priya R, Sneha P, Rivera Madrid R, Doss CP, Singh P, Siva R. Molecular Modeling and Dynamic Simulation of Arabidopsis Thaliana
Carotenoid Cleavage Dioxygenase Gene: A Comparison with Bixa orellana
and Crocus Sativus. J Cell Biochem 2017; 118:2712-2721. [DOI: 10.1002/jcb.25919] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 01/30/2017] [Indexed: 01/18/2023]
Affiliation(s)
- R. Priya
- School of Bio Sciences and Technology; VIT University; Vellore 632014 Tamil Nadu India
| | - P. Sneha
- School of Bio Sciences and Technology; VIT University; Vellore 632014 Tamil Nadu India
| | - Renata Rivera Madrid
- Cenro de Investigacion Cientifica de Yucatan A.C. Calle 43 No. 130; Col. Chuburnade Hidalgo; Merida 97200 Yucatan Mexico
| | - C.George Priya Doss
- School of Bio Sciences and Technology; VIT University; Vellore 632014 Tamil Nadu India
| | - Pooja Singh
- Centre for Research in Biotechnology for Agriculture; University of Malaya; Kuala Lumpur 50603 Malaysia
| | - Ramamoorthy Siva
- School of Bio Sciences and Technology; VIT University; Vellore 632014 Tamil Nadu India
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50
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McAndrew RP, Sathitsuksanoh N, Mbughuni MM, Heins RA, Pereira JH, George A, Sale KL, Fox BG, Simmons BA, Adams PD. Structure and mechanism of NOV1, a resveratrol-cleaving dioxygenase. Proc Natl Acad Sci U S A 2016; 113:14324-14329. [PMID: 27911781 PMCID: PMC5167157 DOI: 10.1073/pnas.1608917113] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Stilbenes are diphenyl ethene compounds produced naturally in a wide variety of plant species and some bacteria. Stilbenes are also derived from lignin during kraft pulping. Stilbene cleavage oxygenases (SCOs) cleave the central double bond of stilbenes, forming two phenolic aldehydes. Here, we report the structure of an SCO. The X-ray structure of NOV1 from Novosphingobium aromaticivorans was determined in complex with its substrate resveratrol (1.89 Å), its product vanillin (1.75 Å), and without any bound ligand (1.61 Å). The enzyme is a seven-bladed β-propeller with an iron cofactor coordinated by four histidines. In all three structures, dioxygen is observed bound to the iron in a side-on fashion. These structures, along with EPR analysis, allow us to propose a mechanism in which a ferric-superoxide reacts with substrate activated by deprotonation of a phenol group at position 4 of the substrate, which allows movement of electron density toward the central double bond and thus facilitates reaction with the ferric superoxide electrophile. Correspondingly, NOV1 cleaves a wide range of other stilbene-like compounds with a 4'-OH group, offering potential in processing some solubilized fragments of lignin into monomer aromatic compounds.
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Affiliation(s)
- Ryan P McAndrew
- Joint BioEnergy Institute, Emeryville, CA 94608;
- Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Noppadon Sathitsuksanoh
- Joint BioEnergy Institute, Emeryville, CA 94608
- Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Department of Chemical Engineering, University of Louisville, Louisville, KY 40292
- Conn Center for Renewable Energy Research, University of Louisville, Louisville, KY 40292
| | - Michael M Mbughuni
- Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison, WI 53706
- Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI 53706
| | - Richard A Heins
- Joint BioEnergy Institute, Emeryville, CA 94608
- Biological and Engineering Sciences Center, Sandia National Laboratories, Livermore, CA 94551
| | - Jose H Pereira
- Joint BioEnergy Institute, Emeryville, CA 94608
- Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Anthe George
- Joint BioEnergy Institute, Emeryville, CA 94608
- Biological and Engineering Sciences Center, Sandia National Laboratories, Livermore, CA 94551
| | - Kenneth L Sale
- Joint BioEnergy Institute, Emeryville, CA 94608
- Biological and Engineering Sciences Center, Sandia National Laboratories, Livermore, CA 94551
| | - Brian G Fox
- Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison, WI 53706
- Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI 53706
| | - Blake A Simmons
- Joint BioEnergy Institute, Emeryville, CA 94608
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Paul D Adams
- Joint BioEnergy Institute, Emeryville, CA 94608;
- Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Department of Bioengineering, University of California, Berkeley, CA 94720
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