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Dai P, Chen C, Yu J, Ma C, Zhang X. New insights into sperm physiology regulation: Enlightenment from G-protein-coupled receptors. Andrology 2024. [PMID: 38225815 DOI: 10.1111/andr.13593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/26/2023] [Accepted: 12/29/2023] [Indexed: 01/17/2024]
Abstract
BACKGROUND G-protein-coupled receptors are critical in many physiological and pathological processes in various organs. Serving as the control panel for sensing extracellular stimuli, G-protein-coupled receptors recognise various ligands, including light, temperature, odours, pheromones, hormones, neurotransmitters, chemokines, etc. Most recently, G-protein-coupled receptors residing in spermatozoa have been found to be indispensable for sperm function. OBJECTIVE Here, we have summarised cutting-edge findings on the functional mechanisms of G-protein-coupled receptors that are known to be associated with sperm functions and the activation of their downstream effectors, providing new insights into the roles of G-protein-coupled receptors in sperm physiology. RESULTS Emerging studies hint that alterations in G-protein-coupled receptors could affect sperm function, implicating their role in fertility, but solid evidence needs to be continuing excavated with various means. Several members of the G-protein-coupled receptor superfamily, including olfactory receptors, opsins, orphan G-protein-coupled receptors, CXC chemokine receptor 4, CC chemokine receptor 5 and CC chemokine receptor 6 as well as their downstream effector β-arrestins, etc., were suggested to be essential for sperm motility, capacitation, thermotaxis, chemotaxis, Ca2+ influx through CatSper channel and fertilisation capacity. CONCLUSION The present review provides a comprehensive overview of studies describing G-protein-coupled receptors and their potential action in sperm function. We also present a critical discussion of these issues, and a possible framework for future investigations on the diverse ligands, biological functions and cell signalling of G-protein-coupled receptors in spermatozoa. Here, the G-protein-coupled receptors and their related G proteins that specifically were identified in spermatozoa were summarised, and provided references valuable for further illumination, despite the evidence that is not overwhelming in most cases.
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Affiliation(s)
- Pengyuan Dai
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, PR China
| | - Chen Chen
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, PR China
| | - Jingyan Yu
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, PR China
| | - Chaoye Ma
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, PR China
| | - Xiaoning Zhang
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, PR China
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2
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Pan D, Wang Z, Chen Y, Cao J. Melanopsin-mediated optical entrainment regulates circadian rhythms in vertebrates. Commun Biol 2023; 6:1054. [PMID: 37853054 PMCID: PMC10584931 DOI: 10.1038/s42003-023-05432-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 10/09/2023] [Indexed: 10/20/2023] Open
Abstract
Melanopsin (OPN4) is a light-sensitive protein that plays a vital role in the regulation of circadian rhythms and other nonvisual functions. Current research on OPN4 has focused on mammals; more evidence is needed from non-mammalian vertebrates to fully assess the significance of the non-visual photosensitization of OPN4 for circadian rhythm regulation. There are species differences in the regulatory mechanisms of OPN4 for vertebrate circadian rhythms, which may be due to the differences in the cutting variants, tissue localization, and photosensitive activation pathway of OPN4. We here summarize the distribution of OPN4 in mammals, birds, and teleost fish, and the classical excitation mode for the non-visual photosensitive function of OPN4 in mammals is discussed. In addition, the role of OPN4-expressing cells in regulating circadian rhythm in different vertebrates is highlighted, and the potential rhythmic regulatory effects of various neuropeptides or neurotransmitters expressed in mammalian OPN4-expressing ganglion cells are summarized among them.
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Affiliation(s)
- Deng Pan
- Laboratory of Anatomy of Domestic Animals, National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Haidian, 100193, Beijing, China
| | - Zixu Wang
- Laboratory of Anatomy of Domestic Animals, National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Haidian, 100193, Beijing, China
| | - Yaoxing Chen
- Laboratory of Anatomy of Domestic Animals, National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Haidian, 100193, Beijing, China
| | - Jing Cao
- Laboratory of Anatomy of Domestic Animals, National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Haidian, 100193, Beijing, China.
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3
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Moraes MM, Marques AL, Borges L, Hatanaka E, Heller D, Núñez-Espinosa C, Gonçalves DAP, Soares DD, Wanner SP, Mendes TT, Arantes RME. Sleep impairment and altered pattern of circadian biomarkers during a long-term Antarctic summer camp. Sci Rep 2023; 13:15959. [PMID: 37749123 PMCID: PMC10519969 DOI: 10.1038/s41598-023-42910-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 09/15/2023] [Indexed: 09/27/2023] Open
Abstract
Antarctic expeditions include isolation and exposure to cold and extreme photoperiods (with continuous natural light during summer) that may influence psychophysiological responses modulated by luminosity and sleep. We assessed changes in night sleep patterns by actigraphy, salivary biomarkers, and perceptual variables in seven participants in the following time points along a 50-day camping expedition in Antarctica (Nelson Island): Pre-Field (i.e., on the ship before camp), Field-1, Field-2, Field-3, Field-4 (from 1st to 10th, 11th to 20th, 21st to 35th and 36th to 50th days in camp, respectively), and Post-Field (on the ship after camp). We also characterized mood states, daytime sleepiness, and sleep quality by questionnaires. Staying in an Antarctic camp reduced sleep efficiency (5.2%) and increased the number of awakenings and wakefulness after sleep onset (51.8% and 67.1%, respectively). Furthermore, transient increases in time in bed (16.5%) and sleep onset latency (4.8 ± 4.0 min, from Pre- to Field-3) was observed. These changes were accompanied by an altered pattern of the emerging circadian marker β-Arrestin-1 and a trend to reduce nocturnal melatonin [57.1%; P = 0.066, with large effect size (ES) from Pre-Field to Field-2 (ES = 1.2) and Field-3 (ES = 1.2)]. All changes returned to Pre-Field values during the Post-Field. The volunteers reported sleep-related physical complaints (feeling of cold and pain, discomfort to breathe, and cough or loud snoring), excessive daytime sleepiness, and reduced vigor during the camp. Thus, a 50-day camp alters neuroendocrine regulation and induces physical discomfort, which may explain the impaired sleep pattern and the consequent daytime sleepiness and mood changes.
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Affiliation(s)
- Michele Macedo Moraes
- Department of Pathology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
- Center for Newborn Screening and Genetics Diagnosis, Faculty of Medicine, Universidade Federal de Minas Gerais (NUPAD-FM/UFMG), Belo Horizonte, MG, Brazil
| | - Alice Lamounier Marques
- Post-Graduation Program in Social Sciences in Development, Culture and Society, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brazil
| | - Leandro Borges
- Interdisciplinary Program in Health Sciences, Universidade Cruzeiro do Sul, São Paulo, SP, Brazil
| | - Elaine Hatanaka
- Interdisciplinary Program in Health Sciences, Universidade Cruzeiro do Sul, São Paulo, SP, Brazil
| | - Debora Heller
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil
- Post-Graduate Studies in Dentistry, Universidade Cruzeiro Do Sul, São Paulo, SP, Brazil
- Department of Periodontology, School of Dentistry, UT Health San Antonio, San Antonio, TX, USA
| | - Cristian Núñez-Espinosa
- Escuela de Medicina, Universidad de Magallanes, Punta Arenas, Chile
- Centro Asistencial Docente y de Investigación, Universidad de Magallanes, Punta Arenas, Chile
- Interuniversity Center for Healthy Aging, Chilecito, Chile
| | - Dawit Albieiro Pinheiro Gonçalves
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Danusa Dias Soares
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Samuel Penna Wanner
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Thiago Teixeira Mendes
- Department of Physical Education, Faculty of Education, Universidade Federal da Bahia, Salvador, BA, Brazil
| | - Rosa Maria Esteves Arantes
- Department of Pathology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
- Center for Newborn Screening and Genetics Diagnosis, Faculty of Medicine, Universidade Federal de Minas Gerais (NUPAD-FM/UFMG), Belo Horizonte, MG, Brazil.
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Abstract
Melanopsin is a light-activated G protein coupled receptor that is expressed widely across phylogeny. In mammals, melanopsin is found in intrinsically photosensitive retinal ganglion cells (ipRGCs), which are especially important for "non-image" visual functions that include the regulation of circadian rhythms, sleep, and mood. Photochemical and electrophysiological experiments have provided evidence that melanopsin has at least two stable conformations and is thus multistable, unlike the monostable photopigments of the classic rod and cone photoreceptors. Estimates of melanopsin's properties vary, challenging efforts to understand how the molecule influences vision. This article seeks to reconcile disparate views of melanopsin and offer a practical guide to melanopsin's complexities.
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Affiliation(s)
- Alan J. Emanuel
- F.M. Kirby Neurobiology Center and Department of Neurology, Boston Children’s Hospital and Harvard Medical School. Boston, MA, USA
- Present address: Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Michael Tri H. Do
- F.M. Kirby Neurobiology Center and Department of Neurology, Boston Children’s Hospital and Harvard Medical School. Boston, MA, USA
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Gilhooley MJ, Lindner M, Palumaa T, Hughes S, Peirson SN, Hankins MW. A systematic comparison of optogenetic approaches to visual restoration. Mol Ther Methods Clin Dev 2022; 25:111-123. [PMID: 35402632 PMCID: PMC8956963 DOI: 10.1016/j.omtm.2022.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 03/04/2022] [Indexed: 02/06/2023]
Abstract
During inherited retinal degenerations (IRDs), vision is lost due to photoreceptor cell death; however, a range of optogenetic tools have been shown to restore light responses in animal models. Restored response characteristics vary between tools and the neuronal cell population to which they are delivered: the interplay between these is complex, but targeting upstream neurons (such as retinal bipolar cells) may provide functional benefit by retaining intraretinal signal processing. In this study, our aim was to compare two optogenetic tools: mammalian melanopsin (hOPN4) and microbial red-shifted channelrhodopsin (ReaChR) expressed within two subpopulations of surviving cells in a degenerate retina. Intravitreal adeno-associated viral vectors and mouse models utilising the Cre/lox system restricted expression to populations dominated by bipolar cells or retinal ganglion cells and was compared with non-targeted delivery using the chicken beta actin (CBA) promoter. In summary, we found bipolar-targeted optogenetic tools produced faster kinetics and flatter intensity-response relationships compared with non-targeted or retinal-ganglion-cell-targeted hOPN4. Hence, optogenetic tools of both mammalian and microbial origins show advantages when targeted to bipolar cells. This demonstrates the advantage of bipolar-cell-targeted optogenetics for vision restoration in IRDs. We therefore developed a bipolar-cell-specific gene delivery system employing a compressed promoter with the potential for clinical translation.
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Affiliation(s)
- Michael J. Gilhooley
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- The Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK
- Moorfields Eye Hospital, 162, City Road, London EC1V 2PD, UK
| | - Moritz Lindner
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps University, Deutschhausstrasse 1-2, Marburg 35037, Germany
| | - Teele Palumaa
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- East Tallinn Central Hospital Eye Clinic, Ravi 18, 10138 Tallinn, Estonia
| | - Steven Hughes
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
| | - Stuart N. Peirson
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
| | - Mark W. Hankins
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Corresponding author Mark W. Hankins, Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK.
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Sheng Y, Chen L, Ren X, Jiang Z, Yau KW. Molecular determinants of response kinetics of mouse M1 intrinsically-photosensitive retinal ganglion cells. Sci Rep 2021; 11:23424. [PMID: 34873237 PMCID: PMC8648817 DOI: 10.1038/s41598-021-02832-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 11/19/2021] [Indexed: 11/28/2022] Open
Abstract
Intrinsically-photosensitive retinal ganglion cells (ipRGCs) are non-rod/non-cone retinal photoreceptors expressing the visual pigment, melanopsin, to detect ambient irradiance for various non-image-forming visual functions. The M1-subtype, amongst the best studied, mediates primarily circadian photoentrainment and pupillary light reflex. Their intrinsic light responses are more prolonged than those of rods and cones even at the single-photon level, in accordance with the typically slower time course of non-image-forming vision. The short (OPN4S) and long (OPN4L) alternatively-spliced forms of melanopsin proteins are both present in M1-ipRGCs, but their functional difference is unclear. We have examined this point by genetically removing the Opn4 gene (Opn4-/-) in mouse and re-expressing either OPN4S or OPN4L singly in Opn4-/- mice by using adeno-associated virus, but found no obvious difference in their intrinsic dim-flash responses. Previous studies have indicated that two dominant slow steps in M1-ipRGC phototransduction dictate these cells' intrinsic dim-flash-response kinetics, with time constants (τ1 and τ2) at room temperature of ~ 2 s and ~ 20 s, respectively. Here we found that melanopsin inactivation by phosphorylation or by β-arrestins may not be one of these two steps, because their genetic disruptions did not prolong the two time constants or affect the response waveform. Disruption of GAP (GTPase-Activating-Protein) activity on the effector enzyme, PLCβ4, in M1-ipRGC phototransduction to slow down G-protein deactivation also did not prolong the response decay, but caused its rising phase to become slightly sigmoidal by giving rise to a third time constant, τ3, of ~ 2 s (room temperature). This last observation suggests that GAP-mediated G-protein deactivation does partake in the flash-response termination, although normally with a time constant too short to be visible in the response waveform.
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Affiliation(s)
- Yanghui Sheng
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 North Wolfe St, Baltimore, MD, 21205, USA
- Graduate Neuroscience Program, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Lujing Chen
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 North Wolfe St, Baltimore, MD, 21205, USA
- Graduate Neuroscience Program, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Neurobiology, Harvard Medical School, 220 Longwood Ave, Boston, MA, 02115, USA
| | - Xiaozhi Ren
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 North Wolfe St, Baltimore, MD, 21205, USA
- Vedere Bio II, Inc., 700 Main St, Cambridge, MA, 02139, USA
| | - Zheng Jiang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 North Wolfe St, Baltimore, MD, 21205, USA
- Department of Ophthalmology, Baylor College of Medicine, 6565 Fannin St, Houston, TX, 77030, USA
| | - King-Wai Yau
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 North Wolfe St, Baltimore, MD, 21205, USA.
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7
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Abstract
Melanopsin is a visual pigment that is expressed in a small subset of intrinsically photosensitive retinal ganglion cells (ipRGCs). It is involved in regulating non-image forming visual behaviors, such as circadian photoentrainment and the pupillary light reflex, while also playing a role in many aspects of image-forming vision, such as contrast sensitivity. Melanopsin was initially discovered in the melanophores of the skin of the frog Xenopus, and subsequently found in a subset of ganglion cells in rat, mouse and primate retinas. ipRGCs were initially thought to be a single retinal ganglion cell population, and melanopsin was thought to activate a single, invertebrate-like Gq/transient receptor potential canonical (TRPC)-based phototransduction cascade within these cells. However, in the 20 years since the discovery of melanopsin, our knowledge of this visual pigment and ipRGCs has expanded dramatically. Six ipRGC subtypes have now been identified in the mouse, each with unique morphological, physiological and functional properties. Multiple subtypes have also been identified in other species, suggesting that this cell type diversity is a general feature of the ipRGC system. This diversity has led to a renewed interest in melanopsin phototransduction that may not follow the canonical Gq/TRPC cascade in the mouse or in the plethora of other organisms that express the melanopsin photopigment. In this Review, we discuss recent findings and discoveries that have challenged the prevailing view of melanopsin phototransduction as a single pathway that influences solely non-image forming functions.
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Affiliation(s)
- Ely Contreras
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA,Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL 60208, USA
| | - Alexis P. Nobleman
- University of Maryland Baltimore County, Department of Biological Sciences, Baltimore, MD 21250, USA,Section on Light and Circadian Rhythms (SLCR), National Institute of Mental Health, NIH, Bethesda, MD 20892, USA
| | - Phyllis R. Robinson
- University of Maryland Baltimore County, Department of Biological Sciences, Baltimore, MD 21250, USA,Authors for correspondence (; )
| | - Tiffany M. Schmidt
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA,Department of Ophthalmology, Feinberg School of Medicine, Chicago, IL 60611, USA,Authors for correspondence (; )
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Valdez-Lopez JC, Gebreegziabher M, Bailey RJ, Flores J, Awotunde O, Burnett T, Robinson PR. Protein Phosphatase 2A and Clathrin-Mediated Endocytosis Facilitate Robust Melanopsin Light Responses and Resensitization. Invest Ophthalmol Vis Sci 2020; 61:10. [PMID: 33049058 PMCID: PMC7571330 DOI: 10.1167/iovs.61.12.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Intrinsically photosensitive retinal ganglion cells (ipRGCs) that express the visual pigment melanopsin regulate non-image-forming visual tasks, such as circadian photoentrainment and pupil constriction, as well as contrast detection for image formation. Sustained ipRGC function throughout the day is, therefore, of great importance. Melanopsin is a bistable rhabdomeric-type (R-type) visual pigment, which is thought to use light to regenerate its chromophore from all-trans-retinal back to 11-cis-retinal and does not depend on constant chromophore supply to the extent required by visual pigment in rod and cone photoreceptors. Like the majority of photopigments and G-protein-coupled receptors (GPCRs), melanopsin deactivation requires C-terminal phosphorylation and subsequent β-arrestin binding. We hypothesize that melanopsin utilizes canonical GPCR resensitization mechanisms, including dephosphorylation and endocytosis, during the light, and together, they provide a mechanism for prolonged light responses. Methods Here, we examined expression of protein phosphatases from a variety of subfamilies by RT-PCR and immunohistochemical analyses of the mouse retina. The expression of protein phosphatase 2A (PP2A) in ipRGCs was assessed. We also examine the role of phosphatase and endocytic activity in sustaining melanopsin signaling using transiently-transfected HEK293 cells. Results Our analyses suggest that melanopsin-mediated light responses can be rapidly and extensively enhanced by PP2A activity. Light-activated melanopsin undergoes endocytosis in a clathrin-dependent manner. This endocytic activity enhances light responses upon repeated stimulation, implicating a role for endocytic activity in resensitization. Conclusions Thus, we propose that melanopsin phototransduction is maintained by utilizing canonical GPCR resensitization mechanisms rather than reliance on chromophore replenishment from supporting cells.
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Affiliation(s)
- Juan C Valdez-Lopez
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States
| | - Meheret Gebreegziabher
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States.,National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Robin J Bailey
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States
| | - Jair Flores
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States
| | - Olanike Awotunde
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States
| | - Thomas Burnett
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States.,Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Phyllis R Robinson
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States
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Valdez-Lopez JC, Petr ST, Donohue MP, Bailey RJ, Gebreeziabher M, Cameron EG, Wolf JB, Szalai VA, Robinson PR. The C-Terminus and Third Cytoplasmic Loop Cooperatively Activate Mouse Melanopsin Phototransduction. Biophys J 2020; 119:389-401. [PMID: 32621866 PMCID: PMC7376183 DOI: 10.1016/j.bpj.2020.06.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/28/2020] [Accepted: 06/10/2020] [Indexed: 11/30/2022] Open
Abstract
Melanopsin, an atypical vertebrate visual pigment, mediates non-image-forming light responses including circadian photoentrainment and pupillary light reflexes and contrast detection for image formation. Melanopsin-expressing intrinsically photosensitive retinal ganglion cells are characterized by sluggish activation and deactivation of their light responses. The molecular determinants of mouse melanopsin's deactivation have been characterized (i.e., C-terminal phosphorylation and β-arrestin binding), but a detailed analysis of melanopsin's activation is lacking. We propose that an extended third cytoplasmic loop is adjacent to the proximal C-terminal region of mouse melanopsin in the inactive conformation, which is stabilized by the ionic interaction of these two regions. This model is supported by site-directed spin labeling and electron paramagnetic resonance spectroscopy of melanopsin, the results of which suggests a high degree of steric freedom at the third cytoplasmic loop, which is increased upon C-terminus truncation, supporting the idea that these two regions are close in three-dimensional space in wild-type melanopsin. To test for a functionally critical C-terminal conformation, calcium imaging of melanopsin mutants including a proximal C-terminus truncation (at residue 365) and proline mutation of this proximal region (H377P, L380P, Y382P) delayed melanopsin's activation rate. Mutation of all potential phosphorylation sites, including a highly conserved tyrosine residue (Y382), into alanines also delayed the activation rate. A comparison of mouse melanopsin with armadillo melanopsin-which has substitutions of various potential phosphorylation sites and a substitution of the conserved tyrosine-indicates that substitution of these potential phosphorylation sites and the tyrosine residue result in dramatically slower activation kinetics, a finding that also supports the role of phosphorylation in signaling activation. We therefore propose that melanopsin's C-terminus is proximal to intracellular loop 3, and C-terminal phosphorylation permits the ionic interaction between these two regions, thus forming a stable structural conformation that is critical for initiating G-protein signaling.
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Affiliation(s)
- Juan C Valdez-Lopez
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Stephen T Petr
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Matthew P Donohue
- Center for Nanoscale and Technology, National Institutes of Standards and Technology, Gaithersburg, Maryland; Maryland NanoCenter, University of Maryland College Park, College Park, Maryland
| | - Robin J Bailey
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Meheret Gebreeziabher
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Evan G Cameron
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Julia B Wolf
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Veronika A Szalai
- Center for Nanoscale and Technology, National Institutes of Standards and Technology, Gaithersburg, Maryland
| | - Phyllis R Robinson
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland.
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10
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Do MTH. Melanopsin and the Intrinsically Photosensitive Retinal Ganglion Cells: Biophysics to Behavior. Neuron 2019; 104:205-26. [PMID: 31647894 DOI: 10.1016/j.neuron.2019.07.016] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 06/19/2019] [Accepted: 07/12/2019] [Indexed: 12/19/2022]
Abstract
The mammalian visual system encodes information over a remarkable breadth of spatiotemporal scales and light intensities. This performance originates with its complement of photoreceptors: the classic rods and cones, as well as the intrinsically photosensitive retinal ganglion cells (ipRGCs). IpRGCs capture light with a G-protein-coupled receptor called melanopsin, depolarize like photoreceptors of invertebrates such as Drosophila, discharge electrical spikes, and innervate dozens of brain areas to influence physiology, behavior, perception, and mood. Several visual responses rely on melanopsin to be sustained and maximal. Some require ipRGCs to occur at all. IpRGCs fulfill their roles using mechanisms that include an unusual conformation of the melanopsin protein, an extraordinarily slow phototransduction cascade, divisions of labor even among cells of a morphological type, and unorthodox configurations of circuitry. The study of ipRGCs has yielded insight into general topics that include photoreceptor evolution, cellular diversity, and the steps from biophysical mechanisms to behavior.
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11
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Valdez-Lopez JC, Gulati S, Ortiz EA, Palczewski K, Robinson PR. Melanopsin Carboxy-terminus phosphorylation plasticity and bulk negative charge, not strict site specificity, achieves phototransduction deactivation. PLoS One 2020; 15:e0228121. [PMID: 32236094 PMCID: PMC7112210 DOI: 10.1371/journal.pone.0228121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 03/06/2020] [Indexed: 11/19/2022] Open
Abstract
Melanopsin is a visual pigment expressed in a small subset of ganglion cells in the mammalian retina known as intrinsically photosensitive retinal ganglion cells (ipRGCs) and is implicated in regulating non-image forming functions such as circadian photoentrainment and pupil constriction and contrast sensitivity in image formation. Mouse melanopsin's Carboxy-terminus (C-terminus) possesses 38 serine and threonine residues, which can potentially serve as phosphorylation sites for a G-protein Receptor Kinase (GRK) and be involved in the deactivation of signal transduction. Previous studies suggest that S388, T389, S391, S392, S394, S395 on the proximal region of the C-terminus of mouse melanopsin are necessary for melanopsin deactivation. We expressed a series of mouse melanopsin C-terminal mutants in HEK293 cells and using calcium imaging, and we found that the necessary cluster of six serine and threonine residues, while being critical, are insufficient for proper melanopsin deactivation. Interestingly, the additional six serine and threonine residues adjacent to the required six sites, in either proximal or distal direction, are capable of restoring wild-type deactivation of melanopsin. These findings suggest an element of plasticity in the molecular basis of melanopsin phosphorylation and deactivation. In addition, C-terminal chimeric mutants and molecular modeling studies support the idea that the initial steps of deactivation and β-arrestin binding are centered around these critical phosphorylation sites (S388-S395). The degree of functional versatility described in this study, along with ipRGC biophysical heterogeneity and the possible use of multiple signal transduction cascades, might contribute to the diverse ipRGC light responses for use in non-image and image forming behaviors, even though all six sub types of ipRGCs express the same melanopsin gene OPN4.
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MESH Headings
- HEK293 Cells
- Humans
- Light Signal Transduction/physiology
- Models, Molecular
- Mutagenesis, Site-Directed
- Mutation
- Phosphorylation/physiology
- Protein Binding
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Rod Opsins/chemistry
- Rod Opsins/genetics
- Rod Opsins/metabolism
- Serine/genetics
- Serine/metabolism
- Threonine/genetics
- Threonine/metabolism
- beta-Arrestin 1/chemistry
- beta-Arrestin 1/metabolism
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Affiliation(s)
- Juan C. Valdez-Lopez
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States of America
| | - Sahil Gulati
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, California, United States of America
- Gatan Inc, Pleasanton, California, United States of America
| | - Elelbin A. Ortiz
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States of America
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Krzysztof Palczewski
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, California, United States of America
| | - Phyllis R. Robinson
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States of America
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12
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Mure LS, Hatori M, Ruda K, Benegiamo G, Demas J, Panda S. Sustained Melanopsin Photoresponse Is Supported by Specific Roles of β-Arrestin 1 and 2 in Deactivation and Regeneration of Photopigment. Cell Rep 2019; 25:2497-2509.e4. [PMID: 30485815 PMCID: PMC6396282 DOI: 10.1016/j.celrep.2018.11.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 09/04/2018] [Accepted: 10/31/2018] [Indexed: 12/14/2022] Open
Abstract
Melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) are indispensable for non-image-forming visual responses that sustain under prolonged illumination. For sustained signaling of ipRGCs, the melanopsin photopigment must continuously regenerate. The underlying mechanism is unknown. We discovered that a cluster of Ser/Thr sites within the C-terminal region of mammalian melanopsin is phosphorylated after a light pulse. This forms a binding site for β-arrestin 1 (βARR1) and β-arrestin 2. β-arrestin 2 primarily regulates the deactivation of melanopsin; accordingly, βαrr2–/–mice exhibit prolonged ipRGC responses after cessation of a light pulse. β-arrestin 1 primes melanopsin for regeneration. Therefore, βαrr1–/– ipRGCs become desensitized after repeated or prolonged photostimulation. The lack of either β-arrestin atten-uates ipRGC response under prolonged illumination, suggesting that β-arrestin 2-mediated deactivation and β-arrestin 1-dependent regeneration of melanopsin function in sequence. In conclusion, we discovered a molecular mechanism by which β-arrestins regulate different aspects of melanopsin photoresponses and allow ipRGC-sustained responses under prolonged illumination. The mechanism by which melanopsin-expressing retinal ganglion cells (mRGCs) tonically respond to continuous illumination is unknown. Mure et al. show that phosphorylation-dependent binding of β-arrestin 1 and 2 coordinately deactivate and regenerate melanopsin photopigment to enable sustained firing of mRGCs in response to prolonged illumination.
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Affiliation(s)
- Ludovic S Mure
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Megumi Hatori
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Keio University School of Medicine, Tokyo, Japan
| | - Kiersten Ruda
- St. Olaf College, 1520 St. Olaf Avenue, Northfield, MN 55057, USA
| | - Giorgia Benegiamo
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - James Demas
- St. Olaf College, 1520 St. Olaf Avenue, Northfield, MN 55057, USA
| | - Satchidananda Panda
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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13
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Tomita T, Mori T, Onishi Y. β-Arrestin 1 (ARRB1) serves as a molecular marker of the peripheral circadian rhythm. Int J Oral Sci 2019; 11:32. [PMID: 31685794 PMCID: PMC6828763 DOI: 10.1038/s41368-019-0065-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/25/2019] [Accepted: 08/25/2019] [Indexed: 01/14/2023] Open
Abstract
The control of the circadian rhythm is important for health because it regulates physiological functions and is associated with health hazards. We aimed to identify a circadian biomarker of health status in human saliva, since collecting saliva is non-invasive, straightforward, and cost-effective. Among 500 genes potentially controlled by the salivary clock identified using chromatin immunoprecipitation (ChIP) assays, 22 of them showed reasonable transcriptional responses according to a DNA array in a salivary model system. Among these 22 genes, ARRB1, which is expressed in human salivary glands, was also expressed in model HSG cells at the transcriptional and translational levels. The profile of ARRB1 expression in human saliva was circadian, suggesting that ARRB1 could serve as a candidate circadian biomarker in saliva. We compared ARRB1 with other biomarkers in salivary samples from jet-lagged individuals. The circadian profile of ARRB1 reflected the time lag more than the profile of melatonin, whereas the profiles of cortisol and α-amylase did not reflect the time lag. Overall, these findings suggest that salivary ARRB1 could serve as a candidate biomarker that could be used to monitor the internal body clock.
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Affiliation(s)
- Tatsunosuke Tomita
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), DBT-AIST International Laboratory for Advanced Biomedicine (DAILAB), Higashi 1-1-1, Tsukuba, Japan
| | - Taisuke Mori
- Molecular Pathology Division and Diagnostic Pathology Division, National Cancer Center Research Institute, Tsukiji 5-5-1, Chuo-ku, Tokyo, Japan
| | - Yoshiaki Onishi
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), DBT-AIST International Laboratory for Advanced Biomedicine (DAILAB), Higashi 1-1-1, Tsukuba, Japan.
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14
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Berg DJ, Kartheiser K, Leyrer M, Saali A, Berson DM. Transcriptomic Signatures of Postnatal and Adult Intrinsically Photosensitive Ganglion Cells. eNeuro 2019; 6:ENEURO. [PMID: 31387875 DOI: 10.1523/ENEURO.0022-19.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 11/21/2022] Open
Abstract
Intrinsically photosensitive retinal ganglion cells (ipRGCs) are rare mammalian photoreceptors essential for non-image-forming vision functions, such as circadian photoentrainment and the pupillary light reflex. They comprise multiple subtypes distinguishable by morphology, physiology, projections, and levels of expression of melanopsin (Opn4), their photopigment. The molecular programs that distinguish ipRGCs from other ganglion cells and ipRGC subtypes from one another remain elusive. Here, we present comprehensive gene expression profiles of early postnatal and adult mouse ipRGCs purified from two lines of reporter mice that mark different sets of ipRGC subtypes. We find dozens of novel genes highly enriched in ipRGCs. We reveal that Rasgrp1 and Tbx20 are selectively expressed in subsets of ipRGCs, though these molecularly defined groups imperfectly match established ipRGC subtypes. We demonstrate that the ipRGCs regulating circadian photoentrainment are diverse at the molecular level. Our findings reveal unexpected complexity in gene expression patterns across mammalian ipRGC subtypes.
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15
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Stachurska A, Sarna T. Regulation of Melanopsin Signaling: Key Interactions of the Nonvisual Photopigment. Photochem Photobiol 2018; 95:83-94. [DOI: 10.1111/php.12995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 07/26/2018] [Indexed: 02/06/2023]
Affiliation(s)
- Anna Stachurska
- Labolatory of Imaging and Force Spectroscopy; Malopolska Centre of Biotechnology; Jagiellonian University; Krakow Poland
| | - Tadeusz Sarna
- Department of Biophysics; Faculty of Biochemistry, Biophysics and Biotechnology; Jagiellonian University; Krakow Poland
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16
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Barreto Ortiz S, Hori D, Nomura Y, Yun X, Jiang H, Yong H, Chen J, Paek S, Pandey D, Sikka G, Bhatta A, Gillard A, Steppan J, Kim JH, Adachi H, Barodka VM, Romer L, An SS, Shimoda LA, Santhanam L, Berkowitz DE. Opsin 3 and 4 mediate light-induced pulmonary vasorelaxation that is potentiated by G protein-coupled receptor kinase 2 inhibition. Am J Physiol Lung Cell Mol Physiol 2017; 314:L93-L106. [PMID: 28882814 DOI: 10.1152/ajplung.00091.2017] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We recently demonstrated that blue light induces vasorelaxation in the systemic mouse circulation, a phenomenon mediated by the nonvisual G protein-coupled receptor melanopsin (Opsin 4; Opn4). Here we tested the hypothesis that nonvisual opsins mediate photorelaxation in the pulmonary circulation. We discovered Opsin 3 (Opn3), Opn4, and G protein-coupled receptor kinase 2 (GRK2) in rat pulmonary arteries (PAs) and in pulmonary arterial smooth muscle cells (PASMCs), where the opsins interact directly with GRK2, as demonstrated with a proximity ligation assay. Light elicited an intensity-dependent relaxation of PAs preconstricted with phenylephrine (PE), with a maximum response between 400 and 460 nm (blue light). Wavelength-specific photorelaxation was attenuated in PAs from Opn4-/- mice and further reduced following shRNA-mediated knockdown of Opn3. Inhibition of GRK2 amplified the response and prevented physiological desensitization to repeated light exposure. Blue light also prevented PE-induced constriction in isolated PAs, decreased basal tone, ablated PE-induced single-cell contraction of PASMCs, and reversed PE-induced depolarization in PASMCs when GRK2 was inhibited. The photorelaxation response was modulated by soluble guanylyl cyclase but not by protein kinase G or nitric oxide. Most importantly, blue light induced significant vasorelaxation of PAs from rats with chronic pulmonary hypertension and effectively lowered pulmonary arterial pressure in isolated intact perfused rat lungs subjected to acute hypoxia. These findings show that functional Opn3 and Opn4 in PAs represent an endogenous "optogenetic system" that mediates photorelaxation in the pulmonary vasculature. Phototherapy in conjunction with GRK2 inhibition could therefore provide an alternative treatment strategy for pulmonary vasoconstrictive disorders.
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Affiliation(s)
- Sebastian Barreto Ortiz
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Daijiro Hori
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland.,Division of Cardiac Surgery, Johns Hopkins University , Baltimore, Maryland
| | - Yohei Nomura
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland.,Division of Cardiac Surgery, Johns Hopkins University , Baltimore, Maryland
| | - Xin Yun
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins Asthma and Allergy Center, Johns Hopkins University , Baltimore, Maryland
| | - Haiyang Jiang
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins Asthma and Allergy Center, Johns Hopkins University , Baltimore, Maryland
| | - Hwanmee Yong
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health , Baltimore, Maryland
| | - James Chen
- Department of Biomedical Engineering, Johns Hopkins University , Baltimore, Maryland
| | - Sam Paek
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health , Baltimore, Maryland
| | - Deepesh Pandey
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Gautam Sikka
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Anil Bhatta
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Andrew Gillard
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Jochen Steppan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Jae Hyung Kim
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Hideo Adachi
- Department of Cardiovascular Surgery, Saitama Medical Center, Jichi Medical University, Shimotsuke, Japan
| | - Viachaslau M Barodka
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Lewis Romer
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland.,Department of Biomedical Engineering, Johns Hopkins University , Baltimore, Maryland.,Departments of Cell Biology, Pediatrics, and the Center for Cell Dynamics, Johns Hopkins University , Baltimore, Maryland
| | - Steven S An
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health , Baltimore, Maryland
| | - Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins Asthma and Allergy Center, Johns Hopkins University , Baltimore, Maryland
| | - Lakshmi Santhanam
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland.,Department of Biomedical Engineering, Johns Hopkins University , Baltimore, Maryland
| | - Dan E Berkowitz
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland.,Department of Biomedical Engineering, Johns Hopkins University , Baltimore, Maryland
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17
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Mure LS, Hatori M, Zhu Q, Demas J, Kim IM, Nayak SK, Panda S. Melanopsin-Encoded Response Properties of Intrinsically Photosensitive Retinal Ganglion Cells. Neuron 2016; 90:1016-27. [PMID: 27181062 DOI: 10.1016/j.neuron.2016.04.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/17/2016] [Accepted: 04/06/2016] [Indexed: 11/16/2022]
Abstract
Melanopsin photopigment expressed in intrinsically photosensitive retinal ganglion cells (ipRGCs) plays a crucial role in the adaptation of mammals to their ambient light environment through both image-forming and non-image-forming visual responses. The ipRGCs are structurally and functionally distinct from classical rod/cone photoreceptors and have unique properties, including single-photon response, long response latency, photon integration over time, and slow deactivation. We discovered that amino acid sequence features of melanopsin protein contribute to the functional properties of the ipRGCs. Phosphorylation of a cluster of Ser/Thr residues in the C-terminal cytoplasmic region of melanopsin contributes to deactivation, which in turn determines response latency and threshold sensitivity of the ipRGCs. The poorly conserved region distal to the phosphorylation cluster inhibits phosphorylation's functional role, thereby constituting a unique delayed deactivation mechanism. Concerted action of both regions sustains responses to dim light, allows for the integration of light over time, and results in precise signal duration.
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Affiliation(s)
- Ludovic S Mure
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Megumi Hatori
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Quansheng Zhu
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - James Demas
- St. Olaf College, 1520 St. Olaf Avenue, Northfield, MN 55057, USA
| | - Irene M Kim
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Surendra K Nayak
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Satchidananda Panda
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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18
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Shirzad-Wasei N, DeGrip WJ. Heterologous expression of melanopsin: Present, problems and prospects. Prog Retin Eye Res 2016; 52:1-21. [DOI: 10.1016/j.preteyeres.2016.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/25/2016] [Accepted: 02/01/2016] [Indexed: 12/12/2022]
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19
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Spoida K, Eickelbeck D, Karapinar R, Eckhardt T, Mark MD, Jancke D, Ehinger BV, König P, Dalkara D, Herlitze S, Masseck OA. Melanopsin Variants as Intrinsic Optogenetic On and Off Switches for Transient versus Sustained Activation of G Protein Pathways. Curr Biol 2016; 26:1206-12. [PMID: 27068418 DOI: 10.1016/j.cub.2016.03.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/09/2016] [Accepted: 03/01/2016] [Indexed: 10/22/2022]
Abstract
G-protein-coupled receptors (GPCRs) represent the major protein family for cellular modulation in mammals. Therefore, various strategies have been developed to analyze the function of GPCRs involving pharmaco- and optogenetic approaches [1, 2]. However, a tool that combines precise control of the activation and deactivation of GPCR pathways and/or neuronal firing with limited phototoxicity is still missing. We compared the biophysical properties and optogenetic application of a human and a mouse melanopsin variant (hOpn4L and mOpn4L) on the control of Gi/o and Gq pathways in heterologous expression systems and mouse brain. We found that GPCR pathways can be switched on/off by blue/yellow light. The proteins differ in their kinetics and wavelength dependence to activate and deactivate G protein pathways. Whereas mOpn4L is maximally activated by very short light pulses, leading to sustained G protein activation, G protein responses of hOpn4L need longer light pulses to be activated and decline in amplitude. Based on the different biophysical properties, brief light activation of mOpn4L is sufficient to induce sustained neuronal firing in cerebellar Purkinje cells (PC), whereas brief light activation of hOpn4L induces AP firing, which declines in frequency over time. Most importantly, mOpn4L-induced sustained firing can be switched off by yellow light. Based on the biophysical properties, hOpn4L and mOpn4L represent the first GPCR optogenetic tools, which can be used to switch GPCR pathways/neuronal firing on an off with temporal precision and limited phototoxicity. We suggest to name these tools moMo and huMo for future optogenetic applications.
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Affiliation(s)
- Katharina Spoida
- Department of General Zoology and Neurobiology, ND 7/31, Ruhr University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Dennis Eickelbeck
- Department of General Zoology and Neurobiology, ND 7/31, Ruhr University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Raziye Karapinar
- Department of General Zoology and Neurobiology, ND 7/31, Ruhr University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Tobias Eckhardt
- Department of General Zoology and Neurobiology, ND 7/31, Ruhr University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Melanie D Mark
- Department of General Zoology and Neurobiology, ND 7/31, Ruhr University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Dirk Jancke
- Optical Imaging Group, Institut für Neuroinformatik, NB 2/27, Ruhr University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Benedikt Valerian Ehinger
- Institute of Cognitive Science, University of Osnabrück, Albrechtstrasse 28, 49076 Osnabrück, Germany
| | - Peter König
- Institute of Cognitive Science, University of Osnabrück, Albrechtstrasse 28, 49076 Osnabrück, Germany; Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Deniz Dalkara
- Sorbonne Universités, UPMC University Paris 06, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France
| | - Stefan Herlitze
- Department of General Zoology and Neurobiology, ND 7/31, Ruhr University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
| | - Olivia A Masseck
- Department of General Zoology and Neurobiology, ND 7/31, Ruhr University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
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20
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Tsukamoto H, Kubo Y, Farrens DL, Koyanagi M, Terakita A, Furutani Y. Retinal Attachment Instability Is Diversified among Mammalian Melanopsins. J Biol Chem 2015; 290:27176-27187. [PMID: 26416885 DOI: 10.1074/jbc.m115.666305] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Indexed: 01/12/2023] Open
Abstract
Melanopsins play a key role in non-visual photoreception in mammals. Their close phylogenetic relationship to the photopigments in invertebrate visual cells suggests they have evolved to acquire molecular characteristics that are more suited for their non-visual functions. Here we set out to identify such characteristics by comparing the molecular properties of mammalian melanopsin to those of invertebrate melanopsin and visual pigment. Our data show that the Schiff base linking the chromophore retinal to the protein is more susceptive to spontaneous cleavage in mammalian melanopsins. We also find this stability is highly diversified between mammalian species, being particularly unstable for human melanopsin. Through mutagenesis analyses, we find that this diversified stability is mainly due to parallel amino acid substitutions in extracellular regions. We propose that the different stability of the retinal attachment in melanopsins may contribute to functional tuning of non-visual photoreception in mammals.
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Affiliation(s)
- Hisao Tsukamoto
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, Okazaki, 444-8585, Japan,; Department of Structural Molecular Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan,.
| | - Yoshihiro Kubo
- Division of Biophysics and Neurobiology, Department of Molecular Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan,; Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan
| | - David L Farrens
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239-3098
| | - Mitsumasa Koyanagi
- Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
| | - Akihisa Terakita
- Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
| | - Yuji Furutani
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, Okazaki, 444-8585, Japan,; Department of Structural Molecular Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan
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21
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Deming JD, Shin JA, Lim K, Lee EJ, Van Craenenbroeck K, Craft CM. Dopamine receptor D4 internalization requires a beta-arrestin and a visual arrestin. Cell Signal 2015; 27:2002-13. [PMID: 26169958 DOI: 10.1016/j.cellsig.2015.06.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 06/30/2015] [Indexed: 11/25/2022]
Abstract
PURPOSE The G-protein coupled receptor (GPCR) Dopamine Receptor D4 (DRD4) plays an essential role in cAMP regulation and gap junctional coupling in the photoreceptors, where DRD4 expression is under circadian control. Previous in vitro transfection studies of human DRD4 desensitization have reported that DRD4 is not internalized upon dopamine stimulation when beta-arrestin is co-transfected with DRD4. We hypothesized that the visual arrestins, ARR1 and ARR4, play a modulatory role in DRD4 desensitization in the photoreceptors. METHODS To test this hypothesis, immunohistochemistry analysis of mouse retinas was used to determine the cellular localization of beta-arrestins and DRD4 in photoreceptors. In vitro studies were performed in HEK293T cells transiently transfected with human DRD4 and arrestins. First, co-immunoprecipitation experiments were executed to test protein-protein interactions and to investigate the effect of dopamine stimulation. Second, immunohistochemistry analysis was implemented to study DRD4 internalization and translocation of ARR4. RESULTS Immunohistochemistry studies of mouse retinas confirmed the expression of beta-arrestin 2, ARR1 and ARR4, as well as DRD4 in mouse cone photoreceptor inner segments. Co-immunoprecipitation experiments revealed a dopamine-dependent protein-protein interaction between human DRD4 and ARR4. In vitro internalization experiments showed that no detectable internalization of DRD4 was observed with any single arrestin co-transfected. However, a dopamine-dependent internalization of DRD4 was observed with three out of six sets of two arrestins co-transfected with DRD4. Each of these pairs of arrestins contained one visual arrestin and one beta-arrestin, and no internalization was observed with either two visual arrestins or two beta-arrestins. Additional time-course experiments revealed that in vitro, ARR4 translocates to co-localize with DRD4 at the plasma membrane in response to 30min of dopamine stimulation. CONCLUSIONS The results have functional implications and we hypothesize that the desensitization and internalization of DRD4 in photoreceptors are synergistically mediated by both visual and beta-arrestins. These results are additionally unique because they demonstrate for the first time that at least one G-protein coupled receptor, DRD4, requires two arrestins for desensitization and internalization, and opens up the possibility that other G-protein coupled receptors may require more than one arrestin for desensitization and/or internalization.
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Affiliation(s)
- Janise D Deming
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Annex 215, Los Angeles, CA 90033, USA.
| | - Jung-A Shin
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Annex 215, Los Angeles, CA 90033, USA; Department of Anatomy, School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea.
| | - Kayleen Lim
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Annex 215, Los Angeles, CA 90033, USA.
| | - Eun-Jin Lee
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Annex 215, Los Angeles, CA 90033, USA; Department of Biomedical Engineering, University of Southern California Viterbi School of Engineering, 1042 Downey Way, Los Angeles, CA 90089-1111, USA.
| | - Kathleen Van Craenenbroeck
- Laboratory of GPCR Expression and Signal Transduction (L-GEST), Ghent University-UGent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
| | - Cheryl Mae Craft
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Annex 215, Los Angeles, CA 90033, USA; Department of Cell & Neurobiology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Center 135H, Los Angeles, CA 90033, USA.
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