1
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Williams D. Eagle eyed or bird brained? Eye (Lond) 2023; 37:2426-2430. [PMID: 37353509 PMCID: PMC10397276 DOI: 10.1038/s41433-023-02568-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 06/25/2023] Open
Abstract
The importance of the visual system to birds for behaviours from feeding, mate choice, flying, navigation and determination of seasons, together with the presence of photoreceptors in the retina, the pineal and the brain, render the avian visual system a particularly fruitful model for understanding of eye-brain interactions. In this review we will particularly focus on the pigeon, since here we have a brain stereotactically mapped and a genome fully sequenced, together with a particular bird, the homing pigeon, with remarkable ability to navigate over hundreds of miles and return to exactly the same roosting site with exceptional precision. We might denigrate the avian species by the term bird brained, but here are animals with phenomenal abilities to use their exceptional vision, their eagle eyedness, to best advantage.
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2
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Drepanos L, Gans IM, Grendler J, Guitar S, Fuqua JH, Maki NJ, Tilden AR, Graber JH, Coffman JA. Loss of Krüppel-like factor 9 deregulates both physiological gene expression and development. Sci Rep 2023; 13:12239. [PMID: 37507475 PMCID: PMC10382561 DOI: 10.1038/s41598-023-39453-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 07/25/2023] [Indexed: 07/30/2023] Open
Abstract
Krüppel-like factor 9 (Klf9) is a ubiquitously expressed transcription factor that is a feedforward regulator of multiple stress-responsive and endocrine signaling pathways. We previously described how loss of Klf9 function affects the transcriptome of zebrafish larvae sampled at a single time point 5 days post-fertilization (dpf). However, klf9 expression oscillates diurnally, and the sampled time point corresponded to its expression nadir. To determine if the transcriptomic effects of the klf9-/- mutation vary with time of day, we performed bulk RNA-seq on 5 dpf zebrafish embryos sampled at three timepoints encompassing the predawn peak and midmorning nadir of klf9 expression. We found that while the major effects of the klf9-/- mutation that we reported previously are robust to time of day, the mutation has additional effects that manifest only at the predawn time point. We used a published single-cell atlas of zebrafish development to associate the effects of the klf9-/- mutation with different cell types and found that the mutation increased mRNA associated with digestive organs (liver, pancreas, and intestine) and decreased mRNA associated with differentiating neurons and blood. Measurements from confocally-imaged larvae suggest that overrepresentation of liver mRNA in klf9-/- mutants is due to development of enlarged livers.
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Affiliation(s)
| | - Ian M Gans
- MDI Biological Laboratory, Salisbury Cove, ME, USA
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA
| | | | | | | | | | | | | | - James A Coffman
- MDI Biological Laboratory, Salisbury Cove, ME, USA.
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA.
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3
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Bhoi JD, Goel M, Ribelayga CP, Mangel SC. Circadian clock organization in the retina: From clock components to rod and cone pathways and visual function. Prog Retin Eye Res 2023; 94:101119. [PMID: 36503722 PMCID: PMC10164718 DOI: 10.1016/j.preteyeres.2022.101119] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 08/22/2022] [Accepted: 08/25/2022] [Indexed: 12/13/2022]
Abstract
Circadian (24-h) clocks are cell-autonomous biological oscillators that orchestrate many aspects of our physiology on a daily basis. Numerous circadian rhythms in mammalian and non-mammalian retinas have been observed and the presence of an endogenous circadian clock has been demonstrated. However, how the clock and associated rhythms assemble into pathways that support and control retina function remains largely unknown. Our goal here is to review the current status of our knowledge and evaluate recent advances. We describe many previously-observed retinal rhythms, including circadian rhythms of morphology, biochemistry, physiology, and gene expression. We evaluate evidence concerning the location and molecular machinery of the retinal circadian clock, as well as consider findings that suggest the presence of multiple clocks. Our primary focus though is to describe in depth circadian rhythms in the light responses of retinal neurons with an emphasis on clock control of rod and cone pathways. We examine evidence that specific biochemical mechanisms produce these daily light response changes. We also discuss evidence for the presence of multiple circadian retinal pathways involving rhythms in neurotransmitter activity, transmitter receptors, metabolism, and pH. We focus on distinct actions of two dopamine receptor systems in the outer retina, a dopamine D4 receptor system that mediates circadian control of rod/cone gap junction coupling and a dopamine D1 receptor system that mediates non-circadian, light/dark adaptive regulation of gap junction coupling between horizontal cells. Finally, we evaluate the role of circadian rhythmicity in retinal degeneration and suggest future directions for the field of retinal circadian biology.
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Affiliation(s)
- Jacob D Bhoi
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA; Neuroscience Honors Research Program, William Marsh Rice University, Houston, TX, USA
| | - Manvi Goel
- Department of Neuroscience, Wexner Medical Center, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Christophe P Ribelayga
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA; Neuroscience Honors Research Program, William Marsh Rice University, Houston, TX, USA.
| | - Stuart C Mangel
- Department of Neuroscience, Wexner Medical Center, College of Medicine, The Ohio State University, Columbus, OH, USA.
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4
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Deppisch P, Helfrich-Förster C, Senthilan PR. The Gain and Loss of Cryptochrome/Photolyase Family Members during Evolution. Genes (Basel) 2022; 13:genes13091613. [PMID: 36140781 PMCID: PMC9498864 DOI: 10.3390/genes13091613] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/02/2022] [Accepted: 09/05/2022] [Indexed: 11/20/2022] Open
Abstract
The cryptochrome/photolyase (CRY/PL) family represents an ancient group of proteins fulfilling two fundamental functions. While photolyases repair UV-induced DNA damages, cryptochromes mainly influence the circadian clock. In this study, we took advantage of the large number of already sequenced and annotated genes available in databases and systematically searched for the protein sequences of CRY/PL family members in all taxonomic groups primarily focusing on metazoans and limiting the number of species per taxonomic order to five. Using BLASTP searches and subsequent phylogenetic tree and motif analyses, we identified five distinct photolyases (CPDI, CPDII, CPDIII, 6-4 photolyase, and the plant photolyase PPL) and six cryptochrome subfamilies (DASH-CRY, mammalian-type MCRY, Drosophila-type DCRY, cnidarian-specific ACRY, plant-specific PCRY, and the putative magnetoreceptor CRY4. Manually assigning the CRY/PL subfamilies to the species studied, we have noted that over evolutionary history, an initial increase of various CRY/PL subfamilies was followed by a decrease and specialization. Thus, in more primitive organisms (e.g., bacteria, archaea, simple eukaryotes, and in basal metazoans), we find relatively few CRY/PL members. As species become more evolved (e.g., cnidarians, mollusks, echinoderms, etc.), the CRY/PL repertoire also increases, whereas it appears to decrease again in more recent organisms (humans, fruit flies, etc.). Moreover, our study indicates that all cryptochromes, although largely active in the circadian clock, arose independently from different photolyases, explaining their different modes of action.
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5
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Einwich A, Seth PK, Bartölke R, Bolte P, Feederle R, Dedek K, Mouritsen H. Localisation of cryptochrome 2 in the avian retina. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2021; 208:69-81. [PMID: 34677638 PMCID: PMC8918457 DOI: 10.1007/s00359-021-01506-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 12/12/2022]
Abstract
Cryptochromes are photolyase-related blue-light receptors acting as core components of the mammalian circadian clock in the cell nuclei. One or more members of the cryptochrome protein family are also assumed to play a role in avian magnetoreception, but the primary sensory molecule in the retina of migratory birds that mediates light-dependent magnetic compass orientation has still not been identified. The mRNA of cryptochrome 2 (Cry2) has been reported to be located in the cell nuclei of the retina, but Cry2 localisation has not yet been demonstrated at the protein level. Here, we provide evidence that Cry2 protein is located in the photoreceptor inner segments, the outer nuclear layer, the inner nuclear layer and the ganglion cell layer in the retina of night-migratory European robins, homing pigeons and domestic chickens. At the subcellular level, we find Cry2 both in the cytoplasm and the nucleus of cells residing in these layers. This broad nucleic expression rather points to a role for avian Cry2 in the circadian clock and is consistent with a function as a transcription factor, analogous to mammalian Cry2, and speaks against an involvement in magnetoreception.
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Affiliation(s)
- Angelika Einwich
- Institute for Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Pranav Kumar Seth
- Institute for Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Rabea Bartölke
- Institute for Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Petra Bolte
- Institute for Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Regina Feederle
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility, Neuherberg, Germany
| | - Karin Dedek
- Institute for Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.,Research Centre for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Henrik Mouritsen
- Institute for Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany. .,Research Centre for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.
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6
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Balay SD, Hochstoeger T, Vilceanu A, Malkemper EP, Snider W, Dürnberger G, Mechtler K, Schuechner S, Ogris E, Nordmann GC, Ushakova L, Nimpf S, Keays DA. The expression, localisation and interactome of pigeon CRY2. Sci Rep 2021; 11:20293. [PMID: 34645873 PMCID: PMC8514597 DOI: 10.1038/s41598-021-99207-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/13/2021] [Indexed: 11/18/2022] Open
Abstract
Cryptochromes (CRY) are highly conserved signalling molecules that regulate circadian rhythms and are candidate radical pair based magnetoreceptors. Birds have at least four cryptochromes (CRY1a, CRY1b, CRY2, and CRY4), but few studies have interrogated their function. Here we investigate the expression, localisation and interactome of clCRY2 in the pigeon retina. We report that clCRY2 has two distinct transcript variants, clCRY2a, and a previously unreported splice isoform, clCRY2b which is larger in size. We show that clCRY2a mRNA is expressed in all retinal layers and clCRY2b is enriched in the inner and outer nuclear layer. To define the localisation and interaction network of clCRY2 we generated and validated a monoclonal antibody that detects both clCRY2 isoforms. Immunohistochemical studies revealed that clCRY2a/b is present in all retinal layers and is enriched in the outer limiting membrane and outer plexiform layer. Proteomic analysis showed clCRY2a/b interacts with typical circadian molecules (PER2, CLOCK, ARTNL), cell junction proteins (CTNNA1, CTNNA2) and components associated with the microtubule motor dynein (DYNC1LI2, DCTN1, DCTN2, DCTN3) within the retina. Collectively these data show that clCRY2 is a component of the avian circadian clock and unexpectedly associates with the microtubule cytoskeleton.
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Affiliation(s)
- Spencer D Balay
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus Vienna Biocenter 1, 1030, Vienna, Austria.,Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, 1030, Vienna, Austria
| | - Tobias Hochstoeger
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus Vienna Biocenter 1, 1030, Vienna, Austria
| | - Alexandra Vilceanu
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus Vienna Biocenter 1, 1030, Vienna, Austria
| | - E Pascal Malkemper
- Max Planck Research Group Neurobiology of Magnetoreception, Center of Advanced European Studies and Research (Caesar), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - William Snider
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Gerhard Dürnberger
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus Vienna Biocenter 1, 1030, Vienna, Austria.,Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030, Vienna, Austria
| | - Karl Mechtler
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus Vienna Biocenter 1, 1030, Vienna, Austria.,Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030, Vienna, Austria
| | - Stefan Schuechner
- Monoclonal Antibody Facility, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9, 1030, Vienna, Austria
| | - Egon Ogris
- Monoclonal Antibody Facility, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9, 1030, Vienna, Austria
| | - Gregory C Nordmann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus Vienna Biocenter 1, 1030, Vienna, Austria.,Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, 1030, Vienna, Austria
| | - Lyubov Ushakova
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus Vienna Biocenter 1, 1030, Vienna, Austria
| | - Simon Nimpf
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus Vienna Biocenter 1, 1030, Vienna, Austria
| | - David A Keays
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus Vienna Biocenter 1, 1030, Vienna, Austria. .,Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia. .,Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University Munich, Planegg-Martinsried, 82152, Munich, Germany.
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7
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Pinzon-Rodriguez A, Muheim R. Cryptochrome expression in avian UV cones: revisiting the role of CRY1 as magnetoreceptor. Sci Rep 2021; 11:12683. [PMID: 34135416 PMCID: PMC8209128 DOI: 10.1038/s41598-021-92056-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 06/03/2021] [Indexed: 02/05/2023] Open
Abstract
Cryptochromes (CRY) have been proposed as putative magnetoreceptors in vertebrates. Localisation of CRY1 in the UV cones in the retinas of birds suggested that it could be the candidate magnetoreceptor. However, recent findings argue against this possibility. CRY1 is a type II cryptochrome, a subtype of cryptochromes that may not be inherently photosensitive, and it exhibits a clear circadian expression in the retinas of birds. Here, we reassessed the localisation and distribution of CRY1 in the retina of the zebra finch. Zebra finches have a light-dependent magnetic compass based on a radical-pair mechanism, similar to migratory birds. We found that CRY1 colocalised with the UV/V opsin (SWS1) in the outer segments of UV cones, but restricted to the tip of the segments. CRY1 was found in all UV cones across the entire retina, with the highest densities near the fovea. Pre-exposure of birds to different wavelengths of light did not result in any difference in CRY1 detection, suggesting that CRY1 did not undergo any detectable functional changes as result of light activation. Considering that CRY1 is likely not involved in magnetoreception, our findings open the possibility for an involvement in different, yet undetermined functions in the avian UV/V cones.
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Affiliation(s)
- Atticus Pinzon-Rodriguez
- grid.4514.40000 0001 0930 2361Department of Biology, Lund University, Biology Building B, 223 62 Lund, Sweden
| | - Rachel Muheim
- grid.4514.40000 0001 0930 2361Department of Biology, Lund University, Biology Building B, 223 62 Lund, Sweden
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8
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Abstract
Species throughout the animal kingdom use the Earth's magnetic field (MF) to navigate using either or both of two mechanisms. The first relies on magnetite crystals in tissue where their magnetic moments align with the MF to transduce a signal transmitted to the central nervous system. The second and the subject of this paper involves cryptochrome (CRY) proteins located in cone photoreceptors distributed across the retina, studied most extensively in birds. According to the "Radical Pair Mechanism" (RPM), blue/UV light excites CRY's flavin cofactor (FAD) to generate radical pairs whose singlet-to-triplet interconversion rate is modulated by an external MF. The signaling product of the RPM produces an impression of the field across the retinal surface. In birds, the resulting signal on the optic nerve is transmitted along the thalamofugal pathway to the primary visual cortex, which projects to brain regions concerned with image processing, memory, and executive function. The net result is a bird's orientation to the MF's inclination: its vector angle relative to the Earth's surface. The quality of ambient light (e.g., polarization) provides additional input to the compass. In birds, the Type IV CRY isoform appears pivotal to the compass, given its positioning within retinal cones; a cytosolic location therein indicating no role in the circadian clock; relatively steady diurnal levels (unlike Type II CRY's cycling); and a full complement of FAD (essential for photosensitivity). The evidence indicates that mammalian Type II CRY isoforms play a light-independent role in the cellular molecular clock without a photoreceptive function.
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Affiliation(s)
| | - Joseph Brain
- Environmental Physiology, Molecular, and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
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9
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Bolte P, Einwich A, Seth PK, Chetverikova R, Heyers D, Wojahn I, Janssen-Bienhold U, Feederle R, Hore P, Dedek K, Mouritsen H. Cryptochrome 1a localisation in light- and dark-adapted retinae of several migratory and non-migratory bird species: no signs of light-dependent activation. ETHOL ECOL EVOL 2021. [DOI: 10.1080/03949370.2020.1870571] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Petra Bolte
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Angelika Einwich
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Pranav K. Seth
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Raisa Chetverikova
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Dominik Heyers
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
- Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Irina Wojahn
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Ulrike Janssen-Bienhold
- Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
- Department of Neuroscience, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Regina Feederle
- Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Peter Hore
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Karin Dedek
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
- Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Henrik Mouritsen
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
- Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
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10
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Einwich A, Dedek K, Seth PK, Laubinger S, Mouritsen H. A novel isoform of cryptochrome 4 (Cry4b) is expressed in the retina of a night-migratory songbird. Sci Rep 2020; 10:15794. [PMID: 32978454 PMCID: PMC7519125 DOI: 10.1038/s41598-020-72579-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 07/28/2020] [Indexed: 01/22/2023] Open
Abstract
The primary sensory molecule underlying light-dependent magnetic compass orientation in migratory birds has still not been identified. The cryptochromes are the only known class of vertebrate proteins which could mediate this mechanism in the avian retina. Cryptochrome 4 of the night-migratory songbird the European robin (Erithacus rubecula; erCry4) has several of the properties needed to be the primary magnetoreceptor in the avian eye. Here, we report on the identification of a novel isoform of erCry4, which we named erCry4b. Cry4b includes an additional exon of 29 amino acids compared to the previously described form of Cry4, now called Cry4a. When comparing the retinal circadian mRNA expression pattern of the already known isoform erCry4a and the novel erCry4b isoform, we find that erCry4a is stably expressed throughout day and night, whereas erCry4b shows a diurnal mRNA oscillation. The differential characteristics of the two erCry4 isoforms regarding their 24-h rhythmicity in mRNA expression leads us to suggest that they might have different functions. Based on the 24-h expression pattern, erCry4a remains the more likely cryptochrome to be involved in radical-pair-based magnetoreception, but at the present time, an involvement of erCry4b cannot be excluded.
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Affiliation(s)
- Angelika Einwich
- Institute for Biology and Environmental Sciences, Neurosensorics/Animal Navigation, Carl-von-Ossietzky-Universität Oldenburg, Oldenburg, Germany.,Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-Universität Oldenburg, Oldenburg, Germany
| | - Karin Dedek
- Institute for Biology and Environmental Sciences, Neurosensorics/Animal Navigation, Carl-von-Ossietzky-Universität Oldenburg, Oldenburg, Germany.,Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-Universität Oldenburg, Oldenburg, Germany
| | - Pranav Kumar Seth
- Institute for Biology and Environmental Sciences, Neurosensorics/Animal Navigation, Carl-von-Ossietzky-Universität Oldenburg, Oldenburg, Germany.,Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-Universität Oldenburg, Oldenburg, Germany
| | - Sascha Laubinger
- Institute for Biology and Environmental Sciences, Evolutionäre Genetik der Pflanzen, Carl-von-Ossietzky-Universität Oldenburg, Oldenburg, Germany
| | - Henrik Mouritsen
- Institute for Biology and Environmental Sciences, Neurosensorics/Animal Navigation, Carl-von-Ossietzky-Universität Oldenburg, Oldenburg, Germany. .,Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-Universität Oldenburg, Oldenburg, Germany.
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11
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Otsuka H, Mitsui H, Miura K, Okano K, Imamoto Y, Okano T. Rapid Oxidation Following Photoreduction in the Avian Cryptochrome4 Photocycle. Biochemistry 2020; 59:3615-3625. [PMID: 32915550 DOI: 10.1021/acs.biochem.0c00495] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Avian magnetoreception is assumed to occur in the retina. Although its molecular mechanism is unclear, magnetic field-dependent formation and the stability of radical-containing photointermediate(s) are suggested to play key roles in a hypothesis called the radical pair mechanism. Chicken cryptochrome4 (cCRY4) has been identified as a candidate magnetoreceptive molecule due to its expression in the retina and its ability to form stable flavin neutral radicals (FADH●) upon blue light absorption. Herein, we used millisecond flash photolysis to investigate the cCRY4 photocycle, in both the presence and absence of dithiothreitol (DTT); detecting the anion radical form of FAD (FAD●-) under both conditions. Using spectral data obtained during flash photolysis and UV-visible photospectroscopy, we estimated the absolute absorbance spectra of the photointermediates, thus allowing us to decompose each spectrum into its individual components. Notably, in the absence of DTT, approximately 37% and 63% of FAD●- was oxidized to FADOX and protonated to form FADH●, respectively. Singular value decomposition analysis suggested the presence of two FAD●- molecular species, each of which was destined to be oxidized to FADOX or protonated to FADH●. A tyrosine neutral radical was also detected; however, it likely decayed concomitantly with the oxidation of FAD●-. On the basis of these results, we considered the occurrence of bifurcation prior to FAD●- generation, or during FAD●- oxidization, and discussed the potential role played by the tyrosine radical in the radical pair mechanism.
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Affiliation(s)
- Hiroaki Otsuka
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, Waseda University, TWIns, Wakamatsucho 2-2, Shinjuku-Ku, Tokyo 162-8480, Japan
| | - Hiromasa Mitsui
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, Waseda University, TWIns, Wakamatsucho 2-2, Shinjuku-Ku, Tokyo 162-8480, Japan
| | - Kota Miura
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, Waseda University, TWIns, Wakamatsucho 2-2, Shinjuku-Ku, Tokyo 162-8480, Japan
| | - Keiko Okano
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, Waseda University, TWIns, Wakamatsucho 2-2, Shinjuku-Ku, Tokyo 162-8480, Japan
| | - Yasushi Imamoto
- Department of Biophysics, Division of Biological Sciences, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Toshiyuki Okano
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, Waseda University, TWIns, Wakamatsucho 2-2, Shinjuku-Ku, Tokyo 162-8480, Japan
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12
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Hochstoeger T, Al Said T, Maestre D, Walter F, Vilceanu A, Pedron M, Cushion TD, Snider W, Nimpf S, Nordmann GC, Landler L, Edelman N, Kruppa L, Dürnberger G, Mechtler K, Schuechner S, Ogris E, Malkemper EP, Weber S, Schleicher E, Keays DA. The biophysical, molecular, and anatomical landscape of pigeon CRY4: A candidate light-based quantal magnetosensor. SCIENCE ADVANCES 2020; 6:eabb9110. [PMID: 32851187 PMCID: PMC7423367 DOI: 10.1126/sciadv.abb9110] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 06/26/2020] [Indexed: 06/11/2023]
Abstract
The biophysical and molecular mechanisms that enable animals to detect magnetic fields are unknown. It has been proposed that birds have a light-dependent magnetic compass that relies on the formation of radical pairs within cryptochrome molecules. Using spectroscopic methods, we show that pigeon cryptochrome clCRY4 is photoreduced efficiently and forms long-lived spin-correlated radical pairs via a tetrad of tryptophan residues. We report that clCRY4 is broadly and stably expressed within the retina but enriched at synapses in the outer plexiform layer in a repetitive manner. A proteomic survey for retinal-specific clCRY4 interactors identified molecules that are involved in receptor signaling, including glutamate receptor-interacting protein 2, which colocalizes with clCRY4. Our data support a model whereby clCRY4 acts as an ultraviolet-blue photoreceptor and/or a light-dependent magnetosensor by modulating glutamatergic synapses between horizontal cells and cones.
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Affiliation(s)
- Tobias Hochstoeger
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Tarek Al Said
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, Freiburg 79104, Germany
| | - Dante Maestre
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Florian Walter
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Alexandra Vilceanu
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Miriam Pedron
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Thomas D. Cushion
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - William Snider
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Simon Nimpf
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Gregory Charles Nordmann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Lukas Landler
- Institute of Zoology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Nathaniel Edelman
- Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA
| | - Lennard Kruppa
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, Freiburg 79104, Germany
| | - Gerhard Dürnberger
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), VBC, Dr. Bohr-Gasse 3, Vienna 1030, Austria
| | - Karl Mechtler
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), VBC, Dr. Bohr-Gasse 3, Vienna 1030, Austria
| | - Stefan Schuechner
- Monoclonal Antibody Facility, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9, Vienna 1030, Austria
| | - Egon Ogris
- Monoclonal Antibody Facility, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9, Vienna 1030, Austria
| | - E. Pascal Malkemper
- Monoclonal Antibody Facility, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9, Vienna 1030, Austria
- Max Planck Research Group Neurobiology of Magnetoreception, Center of Advanced European Studies and Research (CAESAR), Ludwig-Erhard-Allee 2, Bonn 53175, Germany
| | - Stefan Weber
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, Freiburg 79104, Germany
| | - Erik Schleicher
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, Freiburg 79104, Germany
| | - David A. Keays
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University Munich, Planegg-Martinsried 82152, Germany
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A photoperiodic time measurement served by the biphasic expression of Cryptochrome1ab in the zebrafish eye. Sci Rep 2020; 10:5056. [PMID: 32193419 PMCID: PMC7081220 DOI: 10.1038/s41598-020-61877-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 02/28/2020] [Indexed: 11/08/2022] Open
Abstract
The zebrafish (Danio rerio) is a model species that is used to study the circadian clock. It possesses light-entrainable circadian clocks in both central and peripheral tissues, and its core circadian factor cryptochromes (CRYs) have diverged significantly during evolution. In order to elucidate the functional diversity and involvement of CRYs in photoperiodic mechanisms, we investigated the daily expression profiles of six Cry transcripts in central (brain and eye) and peripheral (fin, skin and muscle) tissues. The zCry genes exhibited gene-specific diurnal conserved variations, and were divided into morning and evening groups. Notably, zCry1ab exhibited biphasic expression profiles in the eye, with peaks in the morning and evening. Comparing ocular zCry1ab expression in different photoperiods (18L:6D, 14L:10D, 10L:14D and 6L:18D) revealed that zCry1ab expression duration changed depending on the photoperiod: it increased at midnight and peaked before lights off. zCry1ab expression in constant light or dark after entrainment under long- or short-day conditions suggested that the evening clock and photic input pathway are involved in photoperiod-dependent zCry1ab expression. Laser microdissection followed by qRT-PCR analysis showed that the evening peak of zCry1ab was likely ascribed to visual photoreceptors. These results suggest the presence of an eye-specific photoperiodic time measurement served by zCry1ab.
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Margiotta JF, Howard MJ. Cryptochromes Mediate Intrinsic Photomechanical Transduction in Avian Iris and Somatic Striated Muscle. Front Physiol 2020; 11:128. [PMID: 32153427 PMCID: PMC7047837 DOI: 10.3389/fphys.2020.00128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 02/06/2020] [Indexed: 01/12/2023] Open
Abstract
Irises isolated from the eyes of diverse species constrict when exposed to light. Depending on species this intrinsic photomechanical transduction response (PMTR) requires either melanopsin or cryptochrome (CRY) photopigment proteins, generated by their respective association with retinoid or flavin adenine dinucleotide (FAD) chromophores. Although developmentally relevant circadian rhythms are also synchronized and reset by these same proteins, the cell type, mechanism, and specificity of photomechanical transduction (PMT) and its relationship to circadian processes remain poorly understood. Here we show that PMTRs consistent with CRY activation by 430 nm blue light occur in developing chicken iris striated muscle, identify relevant mechanisms, and demonstrate that similar PMTRs occur in striated iris and pectoral muscle fibers, prevented in both cases by knocking down CRY gene transcript levels. Supporting CRY activation, iris PMTRs were reduced by inhibiting flavin reductase, but unaffected by melanopsin antagonism. The largest iris PMTRs paralleled the developmental predominance of striated over smooth muscle fibers, and shared their requirement for extracellular Ca2+ influx and release of intracellular Ca2+. Photo-stimulation of identified striated myotubes maintained in dissociated culture revealed the cellular and molecular bases of PMT. Myotubes in iris cell cultures responded to 435 nm light with increased intracellular Ca2+ and contractions, mimicking iris PMTRs and their spectral sensitivity. Interestingly PMTRs featuring contractions and requiring extracellular Ca2+ influx and release of intracellular Ca2+ were also displayed by striated myotubes derived from pectoral muscle. Consistent with these findings, cytosolic CRY1 and CRY2 proteins were detected in both iris and pectoral myotubes, and knocking down myotube CRY1/CRY2 gene transcript levels specifically blocked PMTRs in both cases. Thus CRY-mediated PMT is not unique to iris, but instead reflects a more general feature of developing striated muscle fibers. Because CRYs are core timing components of circadian clocks and CRY2 is critical for circadian regulation of myogenic differentiation CRY-mediated PMT may interact with cell autonomous clocks to influence the progression of striated muscle development.
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Affiliation(s)
- Joseph F Margiotta
- Department of Neurosciences, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Marthe J Howard
- Department of Neurosciences, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
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15
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Hore PJ. Upper bound on the biological effects of 50/60 Hz magnetic fields mediated by radical pairs. eLife 2019; 8:44179. [PMID: 30801245 PMCID: PMC6417859 DOI: 10.7554/elife.44179] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 02/02/2019] [Indexed: 01/02/2023] Open
Abstract
Prolonged exposure to weak (~1 μT) extremely-low-frequency (ELF, 50/60 Hz) magnetic fields has been associated with an increased risk of childhood leukaemia. One of the few biophysical mechanisms that might account for this link involves short-lived chemical reaction intermediates known as radical pairs. In this report, we use spin dynamics simulations to derive an upper bound of 10 parts per million on the effect of a 1 μT ELF magnetic field on the yield of a radical pair reaction. By comparing this figure with the corresponding effects of changes in the strength of the Earth’s magnetic field, we conclude that if exposure to such weak 50/60 Hz magnetic fields has any effect on human biology, and results from a radical pair mechanism, then the risk should be no greater than travelling a few kilometres towards or away from the geomagnetic north or south pole.
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Affiliation(s)
- P J Hore
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford, United Kingdom
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16
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Wang X, Jing C, Selby CP, Chiou YY, Yang Y, Wu W, Sancar A, Wang J. Comparative properties and functions of type 2 and type 4 pigeon cryptochromes. Cell Mol Life Sci 2018; 75:4629-4641. [PMID: 30264181 PMCID: PMC6383368 DOI: 10.1007/s00018-018-2920-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/20/2018] [Accepted: 09/18/2018] [Indexed: 10/28/2022]
Abstract
Two types of vertebrate cryptochromes (Crys) are currently recognized. Type 2 Crys function in the molecular circadian clock as light-independent transcriptional repressors. Type 4 Crys are a newly discovered group with unknown function, although they are flavoproteins, and therefore, may function as photoreceptors. It has been postulated that Crys function in light-dependent magnetoreception, which is thought to contribute towards homing and migratory behaviors. Here we have cloned and annotated the full-length pigeon ClCry1, ClCry2, and ClCry4 genes, and characterized the full-length proteins and several site-directed mutants to investigate the roles of these proteins. ClCry1 and ClCry2 are phylogenetically grouped as Type 2 Crys and thus are expected to be core components of the pigeon circadian clock. Interestingly, we find that ClCry4 is properly annotated as a Type 4 Cry. It appears that many birds possess a Type 4 Cry which, as in pigeon, is misannotated. Like the Type 2 Crys, ClCry4 is widespread in pigeon tissues. However, unlike the Type 2 Crys, ClCry4 is cytosolic, and purified ClCry4 possesses FAD cofactor, which confers characteristic UV-Vis spectra as well as two photochemical activities. We find that ClCry4 undergoes light-dependent conformational change, which is a property of insect Type 1 Crys involved in the insect-specific pathway of photoentrainment of the biological clock. ClCry4 can also be photochemically reduced by a mechanism common to all FAD-containing Cry family members, and this mechanism is postulated to be influenced by the geomagnetic field. Thus pigeon Crys control circadian behavior and may also have photosensory function.
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Affiliation(s)
- Xuefeng Wang
- College of Science, National University of Defense Technology, Changsha, 410073, Hunan, People's Republic of China
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Chengyu Jing
- College of Science, National University of Defense Technology, Changsha, 410073, Hunan, People's Republic of China
| | - Christopher P Selby
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Yi-Ying Chiou
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
- Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan
| | - Yanyan Yang
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Wenjian Wu
- College of Science, National University of Defense Technology, Changsha, 410073, Hunan, People's Republic of China
| | - Aziz Sancar
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.
| | - Jing Wang
- College of Science, National University of Defense Technology, Changsha, 410073, Hunan, People's Republic of China.
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17
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Pinzon-Rodriguez A, Bensch S, Muheim R. Expression patterns of cryptochrome genes in avian retina suggest involvement of Cry4 in light-dependent magnetoreception. J R Soc Interface 2018; 15:20180058. [PMID: 29593090 PMCID: PMC5908540 DOI: 10.1098/rsif.2018.0058] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 03/05/2018] [Indexed: 12/23/2022] Open
Abstract
The light-dependent magnetic compass of birds provides orientation information about the spatial alignment of the geomagnetic field. It is proposed to be located in the avian retina, and be mediated by a light-induced, biochemical radical-pair mechanism involving cryptochromes as putative receptor molecules. At the same time, cryptochromes are known for their role in the negative feedback loop in the circadian clock. We measured gene expression of Cry1, Cry2 and Cry4 in the retina, muscle and brain of zebra finches over the circadian day to assess whether they showed any circadian rhythmicity. We hypothesized that retinal cryptochromes involved in magnetoreception should be expressed at a constant level over the circadian day, because birds use a light-dependent magnetic compass for orientation not only during migration, but also for spatial orientation tasks in their daily life. Cryptochromes serving in circadian tasks, on the other hand, are expected to be expressed in a rhythmic (circadian) pattern. Cry1 and Cry2 displayed a daily variation in the retina as expected for circadian clock genes, while Cry4 expressed at constant levels over time. We conclude that Cry4 is the most likely candidate magnetoreceptor of the light-dependent magnetic compass in birds.
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Affiliation(s)
| | - Staffan Bensch
- Department of Biology, Lund University, Ecology Building, Lund 223 62, Sweden
| | - Rachel Muheim
- Department of Biology, Lund University, Biology Building B, Lund 223 62, Sweden
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18
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Günther A, Einwich A, Sjulstok E, Feederle R, Bolte P, Koch KW, Solov’yov IA, Mouritsen H. Double-Cone Localization and Seasonal Expression Pattern Suggest a Role in Magnetoreception for European Robin Cryptochrome 4. Curr Biol 2018; 28:211-223.e4. [DOI: 10.1016/j.cub.2017.12.003] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 11/24/2017] [Accepted: 12/02/2017] [Indexed: 01/07/2023]
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19
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Mitsui H, Maeda T, Yamaguchi C, Tsuji Y, Watari R, Kubo Y, Okano K, Okano T. Overexpression in yeast, photocycle, and in vitro structural change of an avian putative magnetoreceptor cryptochrome4. Biochemistry 2015; 54:1908-17. [PMID: 25689419 DOI: 10.1021/bi501441u] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cryptochromes (CRYs) have been found in a wide variety of living organisms and can function as blue light photoreceptors, circadian clock molecules, or magnetoreceptors. Non-mammalian vertebrates have CRY4 in addition to the CRY1 and CRY2 circadian clock components. Though the function of CRY4 is not well understood, chicken CRY4 (cCRY4) may be a magnetoreceptor because of its high level of expression in the retina and light-dependent structural changes in retinal homogenates. To further characterize the photosensitive nature of cCRY4, we developed an expression system using budding yeast and purified cCRY4 at yields of submilligrams of protein per liter with binding of the flavin adenine dinucleotide (FAD) chromophore. Recombinant cCRY4 dissociated from anti-cCRY4 C1 mAb, which recognizes the C-terminal region of cCRY4, in a light-dependent manner and showed a light-dependent change in its trypsin digestion pattern, suggesting that cCRY4 changes its conformation with light irradiation in the absence of other retinal factors. Combinatorial analyses with UV-visible spectroscopy and immunoprecipitation revealed that there is chromophore reduction in the cCRY4 photocycle and formation of a flavosemiquinone radical intermediate that is likely accompanied by a conformational change in the carboxyl-terminal region. Thus, cCRY4 seems to be an intrinsically photosensitive and photoswitchable molecule and may exemplify a vertebrate model of cryptochrome with possible function as a photosensor and/or magnetoreceptor.
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Affiliation(s)
- Hiromasa Mitsui
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Toshinori Maeda
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Chiaki Yamaguchi
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Yusuke Tsuji
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Ryuji Watari
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Yoko Kubo
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Keiko Okano
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Toshiyuki Okano
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku, Tokyo 162-8480, Japan
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20
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Haug MF, Gesemann M, Lazović V, Neuhauss SCF. Eumetazoan cryptochrome phylogeny and evolution. Genome Biol Evol 2015; 7:601-19. [PMID: 25601102 PMCID: PMC4350181 DOI: 10.1093/gbe/evv010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cryptochromes (Crys) are light sensing receptors that are present in all eukaryotes. They mainly absorb light in the UV/blue spectrum. The extant Crys consist of two subfamilies, which are descendants of photolyases but are now involved in the regulation of circadian rhythms. So far, knowledge about the evolution, phylogeny, and expression of cry genes is still scarce. The inclusion of cry sequences from a wide range of bilaterian species allowed us to analyze their phylogeny in detail, identifying six major Cry subgroups. Selective gene inactivations and stabilizations in multiple chordate as well as arthropod lineages suggest several sub- and/or neofunctionalization events. An expression study performed in zebrafish, the model organism harboring the largest amount of crys, showed indeed only partially overlapping expression of paralogous mRNA, supporting gene sub- and/or neofunctionalization. Moreover, the daily cry expression in the adult zebrafish retina indicated varying oscillation patterns in different cell types. Our extensive phylogenetic analysis provides for the first time an overview of cry evolutionary history. Although several, especially parasitic or blind species, have lost all cry genes, crustaceans have retained up to three crys, teleosts possess up to seven, and tetrapods up to four crys. The broad and cyclic expression pattern of all cry transcripts in zebrafish retinal layers implies an involvement in retinal circadian processes and supports the hypothesis of several autonomous circadian clocks present in the vertebrate retina.
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Affiliation(s)
- Marion F Haug
- Institute of Molecular Life Sciences, Neuroscience Center Zurich and Center for Integrative Human Physiology, University of Zurich, Switzerland
| | - Matthias Gesemann
- Institute of Molecular Life Sciences, Neuroscience Center Zurich and Center for Integrative Human Physiology, University of Zurich, Switzerland
| | - Viktor Lazović
- Institute of Molecular Life Sciences, Neuroscience Center Zurich and Center for Integrative Human Physiology, University of Zurich, Switzerland
| | - Stephan C F Neuhauss
- Institute of Molecular Life Sciences, Neuroscience Center Zurich and Center for Integrative Human Physiology, University of Zurich, Switzerland
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21
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Takeuchi T, Kubo Y, Okano K, Okano T. Identification and characterization of cryptochrome4 in the ovary of western clawed frog Xenopus tropicalis. Zoolog Sci 2014; 31:152-9. [PMID: 24601777 DOI: 10.2108/zsj.31.152] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
CRY proteins can be classified into several groups based on their phylogenetic relationships, and they function as a photoreceptor, a photolyase, and/or a transcriptional repressor of the circadian clock. In order to elucidate the expression profile and functional diversity of CRYs in vertebrates, we focused on XtCRY4, a member of the uncharacterized cryptochrome family CRY4 in Xenopus tropicalis. XtCRY4 cDNA was isolated by RT-PCR, and a phylogenetic analysis of deduced sequence of XtCRY4 suggested that the vertebrate Cry4 genes evolved at much higher evolutionary rates than mammalian-type Cry genes, such as the CRY1 and CRY2 circadian clock molecules. A transcriptional assay was performed to examine the transcriptional regulatory function as circadian repressor, and XtCRY4 had marginal effects on the transactivation of XtCLOCK/XtBMAL1 via E-box element. In situ hybridization and quantitative RT-PCR was performed to detect mRNA expression in native tissues. Quantitative RT-PCR revealed that XtCry4 mRNA was highly transcribed in the ovary. In situ hybridization showed the presence of XtCry4 transcripts in the oocytes, testis, renal tubules, the visual photoreceptors, and the retinal ganglion cells. A specific antiserum to XtCRY4 was developed to detect endogeneous expression of XtCRY4 protein in the ovary. The expression level was estimated by immunoblot analysis, and this is the first detection and estimation of endogenous expression of CRY protein in the ovary. These results suggest that X. tropicalis ovary may respond to blue-light by using XtCRY4.
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Affiliation(s)
- Takahiro Takeuchi
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University (TWIns), Tokyo, Japan
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22
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Watari R, Yamaguchi C, Zemba W, Kubo Y, Okano K, Okano T. Light-dependent structural change of chicken retinal Cryptochrome4. J Biol Chem 2012; 287:42634-41. [PMID: 23095750 DOI: 10.1074/jbc.m112.395731] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Animals have several classes of cryptochromes (CRYs), some of which function as core elements of circadian clockwork, circadian photoreceptors, and/or light-dependent magnetoreceptors. In addition to the circadian clock genes Cry1 and Cry2, nonmammalian vertebrates have the Cry4 gene, the molecular function of which remains unknown. Here we analyzed chicken CRY4 (cCRY4) expression in the retina with in situ hybridization and found that cCRY4 was likely transcribed in the visual pigment cells, cells in the inner nuclear layer, and retinal ganglion cells. We further developed several monoclonal antibodies to the carboxyl-terminal extension of cCRY4 and localized cCRY4 protein with immunohistochemistry. Consistent with the results of in situ hybridization, cCRY4 immunoreactivity was found in visual pigment cells and cells located at the inner nuclear layer and the retinal ganglion cell layer. Among the antibodies, one termed C1-mAb had its epitope within the carboxyl-terminal 14-amino acid sequence (QLTRDDADDPMEMK) and associated with cCRY4 in the retinal soluble fraction more strongly in the dark than under blue light conditions. Immunoprecipitation experiments under various light conditions indicated that cCRY4 from the immunocomplex formed in the dark dissociated from C1-mAb during blue light illumination as weak as 25 μW/cm(2) and that the release occurred with not only blue but also near UV light. These results suggest that cCRY4 reversibly changes its structure within the carboxyl-terminal region in a light-dependent manner and operates as a photoreceptor or magnetoreceptor with short wavelength sensitivity in the retina.
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Affiliation(s)
- Ryuji Watari
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku, Tokyo 162-8480, Japan
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23
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Wang G, Wingfield JC. Immunocytochemical study of rhodopsin-containing putative encephalic photoreceptors in house sparrow, Passer domesticus. Gen Comp Endocrinol 2011; 170:589-96. [PMID: 21118688 DOI: 10.1016/j.ygcen.2010.11.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2009] [Revised: 10/03/2010] [Accepted: 11/18/2010] [Indexed: 11/19/2022]
Abstract
In seasonally breeding birds, encephalic photoreceptors (EPs) play an important role in regulating photoperiodic gonadal responses. Multiple photopigments have been suggested as the putative EPs, including rhodopsin, melanopsin, VA opsin and the cryptochromes. As for rhodopsin, two potential brain sites, the lateral septum (SL) and the infundibulum (INF) have been reported to co-express rhodopsin immunoreactivity (rhodopsin-ir) with vasoactive intestinal polypeptide immunoreactivity (VIP-ir) in groups of cerebrospinal fluid-contacting (CSF) cells, hypothesized to be the EPs for gonadal responses. In order to confirm the presence of rhodopsin in seasonally breeding birds and examine whether these EPs show daily change as do the photopigments in the retina and pineal gland, the present study immunocytochemically investigated: (1) the presence of rhodopsin expression in the deep brain of the house sparrow, Passer domesticus maintained in short days, and (2) rhythmic expression of rhodopsin and VIP in both SL and INF at Zeitgeber time (ZT) 1 and ZT 17 in house sparrows. Rhodopsin-ir and VIP-ir were observed in both areas of sparrow brains as previously described in other avian species but with a novel rod-like rhodopsin-ir cell type in the INF and novel expression of rhodopsin-ir fiber close to the preoptic area. Daily changes of rhodopsin-ir and VIP-ir cell number were revealed in the INF, but not in the SL. More rhodopsin-ir and fewer VIP-ir cells were found at ZT 17 than at ZT 1. In the median eminence, rhodopsin-ir fibers were only observed at ZT 1, and the relative optic density (ROD) of VIP-ir fibers was higher at ZT 1 than ZT 17. The results indicate daily changes of EPs in the IN and ME, suggesting a role of EPs in the orchestration of photoperiodic gonadal recrudesence.
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Affiliation(s)
- Gang Wang
- Department of Biology, University of Washington, Seattle, WA 98195, USA.
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Ozturk N, Selby CP, Song SH, Ye R, Tan C, Kao YT, Zhong D, Sancar A. Comparative photochemistry of animal type 1 and type 4 cryptochromes. Biochemistry 2009; 48:8585-93. [PMID: 19663499 PMCID: PMC2739604 DOI: 10.1021/bi901043s] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cryptochromes (CRYs) are blue-light photoreceptors with known or presumed functions in light-dependent and light-independent gene regulation in plants and animals. Although the photochemistry of plant CRYs has been studied in some detail, the photochemical behavior of animal cryptochromes remains poorly defined in part because it has been difficult to purify animal CRYs with their flavin cofactors. Here we describe the purification of type 4 CRYs of zebrafish and chicken as recombinant proteins with full flavin complement and compare the spectroscopic properties of type 4 and type 1 CRYs. In addition, we analyzed photoinduced proteolytic degradation of both types of CRYs in vivo in heterologous systems. We find that even though both types of CRYs contain stoichiometric flavin, type 1 CRY is proteolytically degraded by a light-initiated reaction in Drosophila S2, zebrafish Z3, and human HEK293T cell lines, but zebrafish CRY4 (type 4) is not. In vivo degradation of type 1 CRYs does not require continuous illumination, and a single light flash of 1 ms duration leads to degradation of about 80% of Drosophila CRY in 60 min. Finally, we demonstrate that in contrast to animal type 2 CRYs and Arabidopsis CRY1 neither insect type 1 nor type 4 CRYs have autokinase activities.
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Affiliation(s)
- Nuri Ozturk
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA
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Valdez DJ, Nieto PS, Garbarino-Pico E, Avalle LB, Díaz-Fajreldines H, Schurrer C, Cheng KM, Guido ME. A nonmammalian vertebrate model of blindness reveals functional photoreceptors in the inner retina. FASEB J 2008; 23:1186-95. [DOI: 10.1096/fj.08-117085] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Diego J. Valdez
- CIQUIBIC-Departamento de Química BiológicaFacultad de Ciencias Químicas Universidad Nacional de Córdoba Córdoba Argentina
| | - Paula S. Nieto
- CIQUIBIC-Departamento de Química BiológicaFacultad de Ciencias Químicas Universidad Nacional de Córdoba Córdoba Argentina
| | - Eduardo Garbarino-Pico
- CIQUIBIC-Departamento de Química BiológicaFacultad de Ciencias Químicas Universidad Nacional de Córdoba Córdoba Argentina
| | - Lucia B. Avalle
- Facultad de MatemáticasAstronomía y Física Universidad Nacional de Córdoba Córdoba Argentina
| | | | - Clemar Schurrer
- Facultad de MatemáticasAstronomía y Física Universidad Nacional de Córdoba Córdoba Argentina
| | - Kimberly M. Cheng
- Avian Research CenterFaculty of Land and Food Systems University of British Columbia Vancouver British Columbia Canada
| | - Mario E. Guido
- CIQUIBIC-Departamento de Química BiológicaFacultad de Ciencias Químicas Universidad Nacional de Córdoba Córdoba Argentina
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