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Zhang C, Tong F, Zhou B, He M, Liu S, Zhou X, Ma Q, Feng T, Du WJ, Yang H, Xu H, Xiao L, Xu ZZ, Zhu C, Wu R, Wang YQ, Han Q. TMC6 functions as a GPCR-like receptor to sense noxious heat via Gαq signaling. Cell Discov 2024; 10:66. [PMID: 38886367 PMCID: PMC11183229 DOI: 10.1038/s41421-024-00678-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 04/08/2024] [Indexed: 06/20/2024] Open
Abstract
Thermosensation is vital for the survival, propagation, and adaption of all organisms, but its mechanism is not fully understood yet. Here, we find that TMC6, a membrane protein of unknown function, is highly expressed in dorsal root ganglion (DRG) neurons and functions as a Gαq-coupled G protein-coupled receptor (GPCR)-like receptor to sense noxious heat. TMC6-deficient mice display a substantial impairment in noxious heat sensation while maintaining normal perception of cold, warmth, touch, and mechanical pain. Further studies show that TMC6 interacts with Gαq via its intracellular C-terminal region spanning Ser780 to Pro810. Specifically disrupting such interaction using polypeptide in DRG neurons, genetically ablating Gαq, or pharmacologically blocking Gαq-coupled GPCR signaling can replicate the phenotype of TMC6 deficient mice regarding noxious heat sensation. Noxious heat stimulation triggers intracellular calcium release from the endoplasmic reticulum (ER) of TMC6- but not control vector-transfected HEK293T cell, which can be significantly inhibited by blocking PLC or IP3R. Consistently, noxious heat-induced intracellular Ca2+ release from ER and action potentials of DRG neurons largely reduced when ablating TMC6 or blocking Gαq/PLC/IP3R signaling pathway as well. In summary, our findings indicate that TMC6 can directly function as a Gαq-coupled GPCR-like receptor sensing noxious heat.
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Affiliation(s)
- Chen Zhang
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Fang Tong
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Bin Zhou
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Mingdong He
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Shuai Liu
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Xiaomeng Zhou
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Qiang Ma
- School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Tianyu Feng
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Wan-Jie Du
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Huan Yang
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Hao Xu
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Lei Xiao
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Zhen-Zhong Xu
- School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Cheng Zhu
- Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, School of Life Sciences, Tianjin University, Tianjin, China
| | - Ruiqi Wu
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China.
| | - Yan-Qing Wang
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China.
| | - Qingjian Han
- Shanghai Stomatological Hospital & School of Stomatology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China.
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China.
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2
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Sugiura M, Kandori H. Photoisomerization pathway of the microbial rhodopsin chromophore in solution. Photochem Photobiol Sci 2024:10.1007/s43630-024-00602-w. [PMID: 38886314 DOI: 10.1007/s43630-024-00602-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 06/07/2024] [Indexed: 06/20/2024]
Abstract
Photoisomerization is a key photochemical reaction in microbial and animal rhodopsins. It is well established that such photoisomerization is highly selective; all-trans to 13-cis, and 11-cis to all-trans forms in microbial and animal rhodopsins, respectively. Nevertheless, unusual photoisomerization pathways have been discovered recently in microbial rhodopsins. In an enzymerhodopsin NeoR, the all-trans chromophore is isomerized into the 7-cis form exclusively, which is stable at room temperature. Although, the 7-cis form is produced by illumination of retinal, formation of the 7-cis form was never reported for a protonated Schiff base of all-trans retinal in solution. Present HPLC analysis of retinal oximes prepared by hydroxylamine reaction revealed that all-trans and 7-cis forms cannot be separated from the syn peaks under the standard HPLC conditions, while it is possible by the analysis of the anti-peaks. Consequently, we found formation of the 7-cis form by the photoreaction of all-trans chromophore in solution, regardless of the protonation state of the Schiff base. Upon light absorption of all-trans protonated retinal Schiff base in solution, excited-state relaxation accompanies double-bond isomerization, producing 7-cis, 9-cis, 11-cis, or 13-cis form. In contrast, specific chromophore-protein interaction enforces selective isomerization into the 13-cis form in many microbial rhodopsins, but into 7-cis in NeoR.
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Affiliation(s)
- Masahiro Sugiura
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan.
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan.
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3
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Solano YJ, Everett MP, Dang KS, Abueg J, Kiser PD. Carotenoid cleavage enzymes evolved convergently to generate the visual chromophore. Nat Chem Biol 2024; 20:779-788. [PMID: 38355721 PMCID: PMC11142922 DOI: 10.1038/s41589-024-01554-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 01/12/2024] [Indexed: 02/16/2024]
Abstract
The retinal light response in animals originates from the photoisomerization of an opsin-coupled 11-cis-retinaldehyde chromophore. This visual chromophore is enzymatically produced through the action of carotenoid cleavage dioxygenases. Vertebrates require two carotenoid cleavage dioxygenases, β-carotene oxygenase 1 and retinal pigment epithelium 65 (RPE65), to form 11-cis-retinaldehyde from carotenoid substrates, whereas invertebrates such as insects use a single enzyme known as Neither Inactivation Nor Afterpotential B (NinaB). RPE65 and NinaB couple trans-cis isomerization with hydrolysis and oxygenation, respectively, but the mechanistic relationship of their isomerase activities remains unknown. Here we report the structure of NinaB, revealing details of its active site architecture and mode of membrane binding. Structure-guided mutagenesis studies identify a residue cluster deep within the NinaB substrate-binding cleft that controls its isomerization activity. Our data demonstrate that isomerization activity is mediated by distinct active site regions in NinaB and RPE65-an evolutionary convergence that deepens our understanding of visual system diversity.
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Affiliation(s)
- Yasmeen J Solano
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, CA, USA
| | - Michael P Everett
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, CA, USA
- Research Service, VA Long Beach Healthcare System, Long Beach, CA, USA
| | - Kelly S Dang
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, CA, USA
| | - Jude Abueg
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, CA, USA
| | - Philip D Kiser
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, CA, USA.
- Research Service, VA Long Beach Healthcare System, Long Beach, CA, USA.
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine School of Medicine, Irvine, CA, USA.
- Department of Clinical Pharmacy Practice, University of California Irvine School of Pharmacy and Pharmaceutical Sciences, Irvine, CA, USA.
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4
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Szukiewicz D. CX3CL1 (Fractalkine)-CX3CR1 Axis in Inflammation-Induced Angiogenesis and Tumorigenesis. Int J Mol Sci 2024; 25:4679. [PMID: 38731899 PMCID: PMC11083509 DOI: 10.3390/ijms25094679] [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: 03/28/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
The chemotactic cytokine fractalkine (FKN, chemokine CX3CL1) has unique properties resulting from the combination of chemoattractants and adhesion molecules. The soluble form (sFKN) has chemotactic properties and strongly attracts T cells and monocytes. The membrane-bound form (mFKN) facilitates diapedesis and is responsible for cell-to-cell adhesion, especially by promoting the strong adhesion of leukocytes (monocytes) to activated endothelial cells with the subsequent formation of an extracellular matrix and angiogenesis. FKN signaling occurs via CX3CR1, which is the only known member of the CX3C chemokine receptor subfamily. Signaling within the FKN-CX3CR1 axis plays an important role in many processes related to inflammation and the immune response, which often occur simultaneously and overlap. FKN is strongly upregulated by hypoxia and/or inflammation-induced inflammatory cytokine release, and it may act locally as a key angiogenic factor in the highly hypoxic tumor microenvironment. The importance of the FKN/CX3CR1 signaling pathway in tumorigenesis and cancer metastasis results from its influence on cell adhesion, apoptosis, and cell migration. This review presents the role of the FKN signaling pathway in the context of angiogenesis in inflammation and cancer. The mechanisms determining the pro- or anti-tumor effects are presented, which are the cause of the seemingly contradictory results that create confusion regarding the therapeutic goals.
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Affiliation(s)
- Dariusz Szukiewicz
- Department of Biophysics, Physiology & Pathophysiology, Faculty of Health Sciences, Medical University of Warsaw, 02-004 Warsaw, Poland
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5
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Rajala A, Rajala RVS. Age-Related Changes in the Glycolytic Enzymes of M2-Isoform of Pyruvate Kinase and Fructose-1,6-Bisphosphate Aldolase: Implications to Age-Related Macular Degeneration. Aging Dis 2024:AD.2024.0077. [PMID: 38739943 DOI: 10.14336/ad.2024.0077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 04/19/2024] [Indexed: 05/16/2024] Open
Abstract
Prior studies have emphasized a bioenergetic crisis in the retinal pigment epithelium (RPE) as a critical factor in the development of age-related macular degeneration (AMD). The isoforms Fructose-1,6-bisphosphate aldolase C (ALDOC) and pyruvate kinase M2 (PKM2) have been proposed to play a role in AMD pathogenesis. While PKM2 and ALDOC are crucial for aerobic glycolysis in the neural retina, they are not as essential for the RPE. In this study, we examined the expression and activity of PKM2 and ALDOC in both young and aged RPE cells, as well as in the retina and RPE tissue of mice, including an experimentally induced AMD mouse model. Our findings reveal an upregulation in PKM2 and ALDOC expression, accompanied by increased pyruvate kinase activity, in the aged and AMD mouse RPE. Conversely, there is a decrease in ALDOC expression but an increase in PKM2 expression and pyruvate kinase activity in the aged and AMD retina. Overall, our study indicates that aged and AMD RPE cells tend to favor aerobic glycolysis, while this tendency is diminished in the aged and AMD retina. These results underscore the significance of targeting PKM2 and ALDOC in the RPE as a promising therapeutic approach to address the bioenergetic crisis and prevent vision loss in AMD.
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Affiliation(s)
- Ammaji Rajala
- Department of Ophthalmology, Oklahoma, Oklahoma 73104, USA
- Dean McGee Eye Institute, Oklahoma, Oklahoma 73104, USA
| | - Raju V S Rajala
- Department of Ophthalmology, Oklahoma, Oklahoma 73104, USA
- Department of Biochemistry and Physiology, and Oklahoma, Oklahoma 73104, USA
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma, Oklahoma 73104, USA
- Dean McGee Eye Institute, Oklahoma, Oklahoma 73104, USA
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6
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Rose K, Chen N, Andreev A, Chen J, Kefalov VJ, Chen J. Light regulation of rhodopsin distribution during outer segment renewal in murine rod photoreceptors. Curr Biol 2024; 34:1492-1505.e6. [PMID: 38508186 PMCID: PMC11003846 DOI: 10.1016/j.cub.2024.02.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/11/2024] [Accepted: 02/28/2024] [Indexed: 03/22/2024]
Abstract
Vision under dim light relies on primary cilia elaborated by rod photoreceptors in the retina. This specialized sensory structure, called the rod outer segment (ROS), comprises hundreds of stacked, membranous discs containing the light-sensitive protein rhodopsin, and the incorporation of new discs into the ROS is essential for maintaining the rod's health and function. ROS renewal appears to be primarily regulated by extrinsic factors (light); however, results vary depending on different model organisms. We generated two independent transgenic mouse lines where rhodopsin's fate is tracked by a fluorescently labeled rhodopsin fusion protein (Rho-Timer) and show that rhodopsin incorporation into nascent ROS discs appears to be regulated by both external lighting cues and autonomous retinal clocks. Live-cell imaging of the ROS isolated from mice exposed to six unique lighting conditions demonstrates that ROS formation occurs in a periodic manner in cyclic light, constant darkness, and artificial light/dark cycles. This alternating bright/weak banding of Rho-Timer along the length of the ROS relates to inhomogeneities in rhodopsin density and potential points of structural weakness. In addition, we reveal that prolonged dim ambient light exposure impacts not only the rhodopsin content of new discs but also that of older discs, suggesting a dynamic interchange of material between new and old discs. Furthermore, we show that rhodopsin incorporation into the ROS is greatly altered in two autosomal recessive retinitis pigmentosa mouse models, potentially contributing to the pathogenesis. Our findings provide insights into how extrinsic (light) and intrinsic (retinal clocks and genetic mutation) factors dynamically regulate mammalian ROS renewal.
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Affiliation(s)
- Kasey Rose
- Zilkha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Natalie Chen
- Zilkha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Andrey Andreev
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jiayan Chen
- Zilkha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Vladimir J Kefalov
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine CA 92697, USA
| | - Jeannie Chen
- Zilkha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA.
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7
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Sasaki T, Katayama K, Imai H, Kandori H. Glu102 2.53-Mediated Early Conformational Changes in the Process of Light-Induced Green Cone Pigment Activation. Biochemistry 2024; 63:843-854. [PMID: 38458614 PMCID: PMC10993417 DOI: 10.1021/acs.biochem.3c00594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 02/21/2024] [Accepted: 02/21/2024] [Indexed: 03/10/2024]
Abstract
Ligand-triggered activation of G protein-coupled receptors (GPCRs) relies on the phenomenon of loose allosteric coupling, which involves conformational alterations spanning from the extracellular ligand-binding domain to the cytoplasmic region, where interactions with G proteins occur. During the GPCR activation process, several intermediate and equilibrium states orchestrate the movement of the flexible and rigid transmembrane (TM) segments of the GPCR. Monitoring early conformational changes is important in unraveling the structural intricacies of the loose allosteric coupling. Here, we focus on the lumi intermediate formed by thermal relaxation from the initial photointermediate, batho in primate green cone pigment (MG), a light-sensitive GPCR responsible for color vision. Our findings from light-induced Fourier transform infrared difference spectroscopy reveal its similarity with rhodopsin, which mediates twilight vision, specifically involving the flip motion of the β-ionone ring, the relaxation of the torsional structure of the retinal, and local perturbations in the α-helix upon lumi intermediate formation. Conversely, we observe a hydrogen bond modification specific to MG's protonated carboxylic acid, identifying its origin as Glu1022.53 situated in TM2. The weakening of the hydrogen bond strength at Glu1022.53 during the transition from the batho to the lumi intermediates corresponds to a slight outward movement of TM2. Additionally, within the X-ray crystal structure of the rhodopsin lumi intermediate, we note the relocation of the Met862.53 side chain in TM2, expanding the volume of the retinal binding pocket. Consequently, the position of 2.53 emerges as the early step in the conformational shift toward light-induced activation. Moreover, given the prevalence of IR-insensitive hydrophobic amino acids at position 2.53 in many rhodopsin-like GPCRs, including rhodopsin, the hydrogen bond alteration in the C═O stretching band at Glu1022.53 of MG can be used as a probe for tracing conformational changes during the GPCR activation process.
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Affiliation(s)
- Takuma Sasaki
- Department
of Life Science and Applied Chemistry, Nagoya
Institute of Technology, Showa-ku,Nagoya 466-8555, Japan
| | - Kota Katayama
- Department
of Life Science and Applied Chemistry, Nagoya
Institute of Technology, Showa-ku,Nagoya 466-8555, Japan
- OptoBioTechnology
Research Center, Nagoya Institute of Technology, Showa-ku,Nagoya 466-8555, Japan
- PRESTO,
Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Hiroo Imai
- Center
for the Evolutionary Origins of Human Behavior, Kyoto University, Inuyama 484-8506, Japan
| | - Hideki Kandori
- Department
of Life Science and Applied Chemistry, Nagoya
Institute of Technology, Showa-ku,Nagoya 466-8555, Japan
- OptoBioTechnology
Research Center, Nagoya Institute of Technology, Showa-ku,Nagoya 466-8555, Japan
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8
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Abrams KL, Ward DA, Sabiniewicz A, Hummel T. Olfaction evaluation in dogs with sudden acquired retinal degeneration syndrome. Vet Ophthalmol 2024; 27:127-138. [PMID: 37399129 DOI: 10.1111/vop.13121] [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: 12/15/2022] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 07/05/2023]
Abstract
PURPOSE To evaluate olfaction in dogs with sudden acquired retinal degeneration syndrome (SARDS) compared with sighted dogs and blind dogs without SARDS as control groups. ANIMALS STUDIED Forty client-owned dogs. PROCEDURE Olfactory threshold testing was performed on three groups: SARDS, sighted, and blind/non-SARDS using eugenol as the test odorant. The olfactory threshold was determined when subjects indicated the detection of a specific eugenol concentration with behavioral responses. Olfactory threshold, age, body weight, and environmental room factors were evaluated. RESULTS Sixteen dogs with SARDS, 12 sighted dogs, and 12 blind/non-SARDS dogs demonstrated mean olfactory threshold pen numbers of 2.8 (SD = 1.4), 13.8 (SD = 1.4), and 13.4 (SD = 1.1), respectively, which correspond to actual mean concentrations of 0.017 g/mL, 1.7 × 10-13 g/mL and 4.26 × 10-13 g/mL, respectively. Dogs with SARDS had significantly poorer olfactory threshold scores compared with the two control groups (p < .001), with no difference between the control groups (p = .5). Age, weight, and room environment did not differ between the three groups. CONCLUSIONS Dogs with SARDS have severely decreased olfaction capabilities compared with sighted dogs and blind/non-SARDS dogs. This finding supports the suspicion that SARDS is a systemic disease causing blindness, endocrinopathy, and hyposmia. Since the molecular pathways are similar in photoreceptors, olfactory receptors, and steroidogenesis with all using G-protein coupled receptors in the cell membrane, the cause of SARDS may exist at the G-protein associated interactions with intracellular cyclic nucleotides. Further investigations into G-protein coupled receptors pathway and canine olfactory receptor genes in SARDS patients may be valuable in revealing the cause of SARDS.
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Affiliation(s)
- Kenneth L Abrams
- Veterinary Ophthalmology Services, North Kingstown, Rhode Island, USA
| | - Daniel A Ward
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, USA
| | - Agnieszka Sabiniewicz
- Department of Otorhinolaryngology, Smell and Taste Clinic, Technische Universität Dresden, Dresden, Germany
- Institute of Psychology, University of Wrocław, Wrocław, Poland
| | - Thomas Hummel
- Department of Otorhinolaryngology, Smell and Taste Clinic, Technische Universität Dresden, Dresden, Germany
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9
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Zhang Z, Shi C, Han J, Ge X, Li N, Liu Y, Huang J, Chen S. Nonvisual system-mediated body color change in fish reveals nonvisual function of Opsin 3 in skin. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2024; 252:112861. [PMID: 38335869 DOI: 10.1016/j.jphotobiol.2024.112861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 01/25/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
Body-color changes in many poikilothermic animals can occur quickly. This color change is generally initiated by visual system, followed by neuromuscular or neuroendocrine control. We have previously showed that the ventral skin color of the large yellow croaker (Larimichthys crocea) presents golden yellow in dark environment and quickly changes to silvery white in light environment. In the present study, we found that the light-induced whitening of ventral skin color was independent of visual input. Using light-emitting diode sources of different wavelength with same luminance (150 lx) but different absolute irradiance (0.039-0.333 mW/cm2), we further found that the blue light (λmax = 480 nm, 0.107 mW/cm2) is more effectively in induction of whitening of ventral skin color in compare with other light sources. Interestingly, the result of RT-PCR showed opsin 3 transcripts expressed in xanthophores. Recombinant protein of Opsin 3 with 11-cis retinal formed functional blue-sensitive pigment, with an absorption maximum at 468 nm. The HEK293T cells transfected with Opsin 3 showed a blue light-evoked Ca2+ response. Knock-down of Opsin 3 expression blocked the light-induced xanthosomes aggregation in vitro. Moreover, the light-induced xanthosomes aggregation was mediated via Ca2+-PKC and Ca2+-CaMKII pathways, and relied on microtubules and dynein. Decrease of cAMP levels was a prerequisite for xanthosomes aggregation. Our results provide a unique organism model exhibiting light-induced quick body color change, which was independent of visual input but rather rely on non-visual function of Opsin 3 within xanthophore.
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Affiliation(s)
- Zihao Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Chenchen Shi
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Jian Han
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China; Key laboratory of fish applied biology and aquaculture in North China, College of Fisheries and Life Science, Dalian Ocean University, Dalian, Liaoning 116023, China
| | - Xiaoyu Ge
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Na Li
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Yang Liu
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Jing Huang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Shixi Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China.
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10
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Sun X, Liang C, Chen Y, Cui T, Han J, Dai M, Zhang Y, Zhou Q, Li W. Knockout and Replacement Gene Surgery to Treat Rhodopsin-Mediated Autosomal Dominant Retinitis Pigmentosa. Hum Gene Ther 2024; 35:151-162. [PMID: 38368562 DOI: 10.1089/hum.2023.201] [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] [Indexed: 02/19/2024] Open
Abstract
Mutations in the rhodopsin (RHO) gene are the predominant causes of autosomal dominant retinitis pigmentosa (adRP). Given the diverse gain-of-function mutations, therapeutic strategies targeting specific sequences face significant challenges. Here, we provide a universal approach to conquer this problem: we have devised a CRISPR-Cas12i-based, mutation-independent gene knockout and replacement compound therapy carried by a dual AAV2/8 system. In this study, we successfully delayed the progression of retinal degeneration in the classic mouse disease model RhoP23H, and also RhoP347S, a new native mouse mutation model we developed. Our research expands the horizon of potential options for future treatments of RHO-mediated adRP.
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Affiliation(s)
- Xuehan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Organ Regeneration and Reconstruction, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China; and
| | - Chen Liang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Organ Regeneration and Reconstruction, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China; and
| | - Yangcan Chen
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Organ Regeneration and Reconstruction, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Tongtong Cui
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Organ Regeneration and Reconstruction, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Jiabao Han
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Organ Regeneration and Reconstruction, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China; and
| | - Moyu Dai
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Organ Regeneration and Reconstruction, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China; and
| | - Ying Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Organ Regeneration and Reconstruction, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Qi Zhou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Organ Regeneration and Reconstruction, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China; and
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Organ Regeneration and Reconstruction, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China; and
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
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11
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Miller WE, O'Connor CM. CMV-encoded GPCRs in infection, disease, and pathogenesis. Adv Virus Res 2024; 118:1-75. [PMID: 38461029 DOI: 10.1016/bs.aivir.2024.01.001] [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] [Indexed: 03/11/2024]
Abstract
G protein coupled receptors (GPCRs) are seven-transmembrane domain proteins that modulate cellular processes in response to external stimuli. These receptors represent the largest family of membrane proteins, and in mammals, their signaling regulates important physiological functions, such as vision, taste, and olfaction. Many organisms, including yeast, slime molds, and viruses encode GPCRs. Cytomegaloviruses (CMVs) are large, betaherpesviruses, that encode viral GPCRs (vGPCRs). Human CMV (HCMV) encodes four vGPCRs, including UL33, UL78, US27, and US28. Each of these vGPCRs, as well as their rodent and primate orthologues, have been investigated for their contributions to viral infection and disease. Herein, we discuss how the CMV vGPCRs function during lytic and latent infection, as well as our understanding of how they impact viral pathogenesis.
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Affiliation(s)
- William E Miller
- Department of Molecular and Cellular Bioscience, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Christine M O'Connor
- Infection Biology, Sheikha Fatima bint Mubarak Global Center for Pathogen and Human Health Research, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States; Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, OH, United States; Case Comprehensive Cancer Center, Cleveland, OH, United States.
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12
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Aplin C, Cerione RA. Probing the mechanism by which the retinal G protein transducin activates its biological effector PDE6. J Biol Chem 2024; 300:105608. [PMID: 38159849 PMCID: PMC10838916 DOI: 10.1016/j.jbc.2023.105608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 11/23/2023] [Accepted: 12/14/2023] [Indexed: 01/03/2024] Open
Abstract
Phototransduction in retinal rods occurs when the G protein-coupled photoreceptor rhodopsin triggers the activation of phosphodiesterase 6 (PDE6) by GTP-bound alpha subunits of the G protein transducin (GαT). Recently, we presented a cryo-EM structure for a complex between two GTP-bound recombinant GαT subunits and native PDE6, that included a bivalent antibody bound to the C-terminal ends of GαT and the inhibitor vardenafil occupying the active sites on the PDEα and PDEβ subunits. We proposed GαT-activated PDE6 by inducing a striking reorientation of the PDEγ subunits away from the catalytic sites. However, questions remained including whether in the absence of the antibody GαT binds to PDE6 in a similar manner as observed when the antibody is present, does GαT activate PDE6 by enabling the substrate cGMP to access the catalytic sites, and how does the lipid membrane enhance PDE6 activation? Here, we demonstrate that 2:1 GαT-PDE6 complexes form with either recombinant or retinal GαT in the absence of the GαT antibody. We show that GαT binding is not necessary for cGMP nor competitive inhibitors to access the active sites; instead, occupancy of the substrate binding sites enables GαT to bind and reposition the PDE6γ subunits to promote catalytic activity. Moreover, we demonstrate by reconstituting GαT-stimulated PDE6 activity in lipid bilayer nanodiscs that the membrane-induced enhancement results from an increase in the apparent binding affinity of GαT for PDE6. These findings provide new insights into how the retinal G protein stimulates rapid catalytic turnover by PDE6 required for dim light vision.
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Affiliation(s)
- Cody Aplin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
| | - Richard A Cerione
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA; Department of Molecular Medicine, Cornell University, Ithaca, New York, USA.
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13
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Eria-Oliveira AS, Folacci M, Chassot AA, Fedou S, Thézé N, Zabelskii D, Alekseev A, Bamberg E, Gordeliy V, Sandoz G, Vivaudou M. Hijacking of internal calcium dynamics by intracellularly residing viral rhodopsins. Nat Commun 2024; 15:65. [PMID: 38167346 PMCID: PMC10761956 DOI: 10.1038/s41467-023-44548-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024] Open
Abstract
Rhodopsins are ubiquitous light-driven membrane proteins with diverse functions, including ion transport. Widely distributed, they are also coded in the genomes of giant viruses infecting phytoplankton where their function is not settled. Here, we examine the properties of OLPVR1 (Organic Lake Phycodnavirus Rhodopsin) and two other type 1 viral channelrhodopsins (VCR1s), and demonstrate that VCR1s accumulate exclusively intracellularly, and, upon illumination, induce calcium release from intracellular IP3-dependent stores. In vivo, this light-induced calcium release is sufficient to remote control muscle contraction in VCR1-expressing tadpoles. VCR1s natively confer light-induced Ca2+ release, suggesting a distinct mechanism for reshaping the response to light of virus-infected algae. The ability of VCR1s to photorelease calcium without altering plasma membrane electrical properties marks them as potential precursors for optogenetics tools, with potential applications in basic research and medicine.
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Affiliation(s)
- Ana-Sofia Eria-Oliveira
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
- Université Côte d'Azur, CNRS, INSERM, iBV, Nice, France
- Laboratories of Excellence, Ion Channel Science and Therapeutics, Nice, France
- Fédération Hospitalo-Universitaire InovPain, Cote d'Azur University, University Hospital Center Nice, Nice, France
| | - Mathilde Folacci
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
- Laboratories of Excellence, Ion Channel Science and Therapeutics, Nice, France
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Anne Amandine Chassot
- Université Côte d'Azur, CNRS, INSERM, iBV, Nice, France
- Laboratories of Excellence, Ion Channel Science and Therapeutics, Nice, France
- Fédération Hospitalo-Universitaire InovPain, Cote d'Azur University, University Hospital Center Nice, Nice, France
| | - Sandrine Fedou
- Univ. Bordeaux, Inserm, BRIC, UMR, 1312, Bordeaux, France
| | - Nadine Thézé
- Univ. Bordeaux, Inserm, BRIC, UMR, 1312, Bordeaux, France
| | | | - Alexey Alekseev
- Advanced Optogenes Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Ernst Bamberg
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Valentin Gordeliy
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
| | - Guillaume Sandoz
- Université Côte d'Azur, CNRS, INSERM, iBV, Nice, France.
- Laboratories of Excellence, Ion Channel Science and Therapeutics, Nice, France.
- Fédération Hospitalo-Universitaire InovPain, Cote d'Azur University, University Hospital Center Nice, Nice, France.
| | - Michel Vivaudou
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France.
- Laboratories of Excellence, Ion Channel Science and Therapeutics, Nice, France.
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14
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Gaspar CJ, Gomes T, Martins JC, Melo MN, Adrain C, Cordeiro TN, Domingos PM. Xport-A functions as a chaperone by stabilizing the first five transmembrane domains of rhodopsin-1. iScience 2023; 26:108309. [PMID: 38025784 PMCID: PMC10663829 DOI: 10.1016/j.isci.2023.108309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 04/21/2023] [Accepted: 10/20/2023] [Indexed: 12/01/2023] Open
Abstract
Rhodopsin-1 (Rh1), the main photosensitive protein of Drosophila, is a seven-transmembrane domain protein, which is inserted co-translationally in the endoplasmic reticulum (ER) membrane. Biogenesis of Rh1 occurs in the ER, where various chaperones interact with Rh1 to aid in its folding and subsequent transport from the ER to the rhabdomere, the light-sensing organelle of the photoreceptors. Xport-A has been proposed as a chaperone/transport factor for Rh1, but the exact molecular mechanism for Xport-A activity upon Rh1 is unknown. Here, we propose a model where Xport-A functions as a chaperone during the biogenesis of Rh1 in the ER by stabilizing the first five transmembrane domains (TMDs) of Rh1.
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Affiliation(s)
- Catarina J. Gaspar
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa (ITQB-NOVA), Av. da República, 2780-157 Oeiras, Portugal
- Membrane Traffic Lab, Instituto Gulbenkian de Ciência (IGC), 2780-156 Oeiras, Portugal
| | - Tiago Gomes
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa (ITQB-NOVA), Av. da República, 2780-157 Oeiras, Portugal
| | - Joana C. Martins
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa (ITQB-NOVA), Av. da República, 2780-157 Oeiras, Portugal
| | - Manuel N. Melo
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa (ITQB-NOVA), Av. da República, 2780-157 Oeiras, Portugal
| | - Colin Adrain
- Membrane Traffic Lab, Instituto Gulbenkian de Ciência (IGC), 2780-156 Oeiras, Portugal
- Patrick G Johnston Centre for Cancer Research, Queen’s University Belfast, 97 Lisburn Road, BT9 7AE Belfast, UK
| | - Tiago N. Cordeiro
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa (ITQB-NOVA), Av. da República, 2780-157 Oeiras, Portugal
| | - Pedro M. Domingos
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa (ITQB-NOVA), Av. da República, 2780-157 Oeiras, Portugal
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15
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Zheng Y, Sun C, Zhang X, Ruzycki PA, Chen S. Missense mutations in CRX homeodomain cause dominant retinopathies through two distinct mechanisms. eLife 2023; 12:RP87147. [PMID: 37963072 PMCID: PMC10645426 DOI: 10.7554/elife.87147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023] Open
Abstract
Homeodomain transcription factors (HD TFs) are instrumental to vertebrate development. Mutations in HD TFs have been linked to human diseases, but their pathogenic mechanisms remain elusive. Here, we use Cone-Rod Homeobox (CRX) as a model to decipher the disease-causing mechanisms of two HD mutations, p.E80A and p.K88N, that produce severe dominant retinopathies. Through integrated analysis of molecular and functional evidence in vitro and in knock-in mouse models, we uncover two novel gain-of-function mechanisms: p.E80A increases CRX-mediated transactivation of canonical CRX target genes in developing photoreceptors; p.K88N alters CRX DNA-binding specificity resulting in binding at ectopic sites and severe perturbation of CRX target gene expression. Both mechanisms produce novel retinal morphological defects and hinder photoreceptor maturation distinct from loss-of-function models. This study reveals the distinct roles of E80 and K88 residues in CRX HD regulatory functions and emphasizes the importance of transcriptional precision in normal development.
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Affiliation(s)
- Yiqiao Zheng
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
| | - Chi Sun
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
| | - Xiaodong Zhang
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
| | - Philip A Ruzycki
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Genetics, Washington University in St LouisSaint LouisUnited States
| | - Shiming Chen
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Developmental Biology, Washington University in St LouisSaint LouisUnited States
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16
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Ros-Rocher N, Brunet T. What is it like to be a choanoflagellate? Sensation, processing and behavior in the closest unicellular relatives of animals. Anim Cogn 2023; 26:1767-1782. [PMID: 37067637 PMCID: PMC10770216 DOI: 10.1007/s10071-023-01776-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/05/2023] [Accepted: 04/07/2023] [Indexed: 04/18/2023]
Abstract
All animals evolved from a single lineage of unicellular precursors more than 600 million years ago. Thus, the biological and genetic foundations for animal sensation, cognition and behavior must necessarily have arisen by modifications of pre-existing features in their unicellular ancestors. Given that the single-celled ancestors of the animal kingdom are extinct, the only way to reconstruct how these features evolved is by comparing the biology and genomic content of extant animals to their closest living relatives. Here, we reconstruct the Umwelt (the subjective, perceptive world) inhabited by choanoflagellates, a group of unicellular (or facultatively multicellular) aquatic microeukaryotes that are the closest living relatives of animals. Although behavioral research on choanoflagellates remains patchy, existing evidence shows that they are capable of chemosensation, photosensation and mechanosensation. These processes often involve specialized sensorimotor cellular appendages (cilia, microvilli, and/or filopodia) that resemble those that underlie perception in most animal sensory cells. Furthermore, comparative genomics predicts an extensive "sensory molecular toolkit" in choanoflagellates, which both provides a potential basis for known behaviors and suggests the existence of a largely undescribed behavioral complexity that presents exciting avenues for future research. Finally, we discuss how facultative multicellularity in choanoflagellates might help us understand how evolution displaced the locus of decision-making from a single cell to a collective, and how a new space of behavioral complexity might have become accessible in the process.
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Affiliation(s)
- Núria Ros-Rocher
- Evolutionary Cell Biology and Evolution of Morphogenesis Unit, Institut Pasteur, Université Paris-Cité, CNRS UMR3691, 25-28 Rue du Docteur Roux, 75015, Paris, France
| | - Thibaut Brunet
- Evolutionary Cell Biology and Evolution of Morphogenesis Unit, Institut Pasteur, Université Paris-Cité, CNRS UMR3691, 25-28 Rue du Docteur Roux, 75015, Paris, France.
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17
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Senapati S, Park PSH. Understanding the Rhodopsin Worldview Through Atomic Force Microscopy (AFM): Structure, Stability, and Activity Studies. CHEM REC 2023; 23:e202300113. [PMID: 37265335 PMCID: PMC10908267 DOI: 10.1002/tcr.202300113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/12/2023] [Indexed: 06/03/2023]
Abstract
Rhodopsin is a G protein-coupled receptor (GPCR) present in the rod outer segment (ROS) of photoreceptor cells that initiates the phototransduction cascade required for scotopic vision. Due to the remarkable advancements in technological tools, the chemistry of rhodopsin has begun to unravel especially over the past few decades, but mostly at the ensemble scale. Atomic force microscopy (AFM) is a tool capable of providing critical information from a single-molecule point of view. In this regard, to bolster our understanding of rhodopsin at the nanoscale level, AFM-based imaging, force spectroscopy, and nano-indentation techniques were employed on ROS disc membranes containing rhodopsin, isolated from vertebrate species both in normal and diseased states. These AFM studies on samples from native retinal tissue have provided fundamental insights into the structure and function of rhodopsin under normal and dysfunctional states. We review here the findings from these AFM studies that provide important insights on the supramolecular organization of rhodopsin within the membrane and factors that contribute to this organization, the molecular interactions stabilizing the structure of the receptor and factors that can modify those interactions, and the mechanism underlying constitutive activity in the receptor that can cause disease.
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Affiliation(s)
- Subhadip Senapati
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
- Prayoga Institute of Education Research, Bengaluru, KA 560116, India
| | - Paul S-H Park
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
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18
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Qiu L, Wei S, Wang Y, Zhang R, Ru S, Zhang X. Mechanism of thyroid hormone and its structurally similar contaminant bisphenol S exposure on retinoid metabolism in zebrafish larval eyes. ENVIRONMENT INTERNATIONAL 2023; 180:108217. [PMID: 37748373 DOI: 10.1016/j.envint.2023.108217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/25/2023] [Accepted: 09/18/2023] [Indexed: 09/27/2023]
Abstract
The photoreceptor necessitates the retinoids metabolism processes in visual cycle pathway to regenerate visual pigments and sustain vision. Bisphenol S (BPS), with similar structure of thyroid hormone (TH), was reported to impair the light-sensing function of zebrafish larvae via disturbing TH-thyroid hormone receptor β (TRβ) signaling pathway. However, it remains unknown whether TRβ could modulate the toxicity of BPS on retinoid metabolism in visual cycle. This study showed that BPS diminished the optokinetic response of zebrafish larvae and had a stimulative effect on all-trans-retinoic acid (atRA) metabolism, like exogenous T3 exposure. By modulating CYP26A1 and TRβ expression, it was found that CYP26A1 played a crucial role in catalyzing oxidative metabolism of atRA and retinoids regeneration in visual cycle, and TRβ mediated cyp26a1 expression in zebrafish eyes. Similar with 10 nM T3 treatment, cyp26a1 expression could be induced by BPS in the presence of TRβ. Further, in CYP26A1 and TRβ- deficient eyes, 100 μg/L BPS could no longer promote atRA metabolism, or decrease the all-trans-retinol and 11-cis retinal contents in visual cycle, demonstrating that BPS exposure disturbed CYP26A1-mediated visual retinoids metabolism via TRβ. Overall, this study highlights the role of TRβ in mediating the retinoids homeostasis disruption caused by BPS, and provides new clues for exploring molecular targets of visual toxicity under pollutants stress.
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Affiliation(s)
- Liguo Qiu
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Shuhui Wei
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yunsheng Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Rui Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Shaoguo Ru
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Xiaona Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
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19
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Hong JD, Palczewski K. A short story on how chromophore is hydrolyzed from rhodopsin for recycling. Bioessays 2023; 45:e2300068. [PMID: 37454357 PMCID: PMC10614701 DOI: 10.1002/bies.202300068] [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: 04/18/2023] [Revised: 05/24/2023] [Accepted: 05/30/2023] [Indexed: 07/18/2023]
Abstract
The photocycle of visual opsins is essential to maintain the light sensitivity of the retina. The early physical observations of the rhodopsin photocycle by Böll and Kühne in the 1870s inspired over a century's worth of investigations on rhodopsin biochemistry. A single photon isomerizes the Schiff-base linked 11-cis-retinylidene chromophore of rhodopsin, converting it to the all-trans agonist to elicit phototransduction through photoactivated rhodopsin (Rho*). Schiff base hydrolysis of the agonist is a key step in the photocycle, not only diminishing ongoing phototransduction but also allowing for entry and binding of fresh 11-cis chromophore to regenerate the rhodopsin pigment and maintain light sensitivity. Many challenges have been encountered in measuring the rate of this hydrolysis, but recent advancements have facilitated studies of the hydrolysis within the native membrane environment of rhodopsin. These techniques can now be applied to study hydrolysis of agonist in other opsin proteins that mediate phototransduction or chromophore turnover. In this review, we discuss the progress that has been made in characterizing the rhodopsin photocycle and the journey to characterize the hydrolysis of its all-trans-retinylidene agonist.
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Affiliation(s)
- John D. Hong
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California Irvine, Irvine, CA 92697, USA
- Department of Chemistry, University of California Irvine, Irvine, CA 92697, USA
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California Irvine, Irvine, CA 92697, USA
- Department of Chemistry, University of California Irvine, Irvine, CA 92697, USA
- Department of Physiology and Biophysics, University of California Irvine, Irvine, CA 92697, USA
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, CA 92697, USA
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20
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Park B, Bang S, Hwang KS, Cha YK, Kwak J, Tran NL, Kim HS, Park S, Oh SJ, Im M, Chung S, Kim J, Park TH, Song HS, Kim HN, Kim JH. Eye-Mimicked Neural Network Composed of Photosensitive Neural Spheroids with Human Opsin Proteins. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302996. [PMID: 37377148 DOI: 10.1002/adma.202302996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 06/29/2023]
Abstract
An in vitro model, composed of the short-wavelength human opsins and rhodopsins, is created. Two types of photosensitive neural spheroids are transfected for selective reaction under bluish-purple and green lights. These are employed to two devices with intact neuron and neural-spheroid to study the interaction. By photostimulation, the photosensitive spheroid initiated photoactivation, and the signal generated from its body is transmitted to adjacent neural networks. Specifically, the signal traveled through the axon bundle in narrow gap from photosensitive spheroid to intact spheroid as an eye-to-brain model including optic nerve. The whole process with photosensitive spheroid is monitored by calcium ion detecting fluorescence images. The results of this study can be applied to examine vision restoration and novel photosensitive biological systems with spectral sensitivity.
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Affiliation(s)
- Byeongho Park
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Seokyoung Bang
- Department of Biomedical Engineering, Dongguk University, Goyang, 10326, Republic of Korea
| | - Kyeong Seob Hwang
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- School of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Yeon Kyung Cha
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Jisung Kwak
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Na Ly Tran
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology, Seoul, 02792, Republic of Korea
| | - Hyo-Suk Kim
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Subeen Park
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Seung Ja Oh
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology, Seoul, 02792, Republic of Korea
| | - Maesoon Im
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Sooyoung Chung
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Jongbaeg Kim
- School of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Tai Hyun Park
- Department of Nutritional Science and Food Management, Ewha Womans University, Seodaemun-gu, Seoul, 03760, Republic of Korea
| | - Hyun Seok Song
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Hong Nam Kim
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- School of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology, Seoul, 02792, Republic of Korea
- Yonsei-KIST Convergence Research Institute, Yonsei University, Seoul, 03722, Republic of Korea
| | - Jae Hun Kim
- Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
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21
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Sun C, Ruzycki PA, Chen S. Rho enhancers play unexpectedly minor roles in Rhodopsin transcription and rod cell integrity. Sci Rep 2023; 13:12899. [PMID: 37558693 PMCID: PMC10412641 DOI: 10.1038/s41598-023-39979-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 08/02/2023] [Indexed: 08/11/2023] Open
Abstract
Enhancers function with a basal promoter to control the transcription of target genes. Enhancer regulatory activity is often studied using reporter-based transgene assays. However, unmatched results have been reported when selected enhancers are silenced in situ. In this study, using genomic deletion analysis in mice, we investigated the roles of two previously identified enhancers and the promoter of the Rho gene that codes for the visual pigment rhodopsin. The Rho gene is robustly expressed by rod photoreceptors of the retina, and essential for the subcellular structure and visual function of rod photoreceptors. Mutations in RHO cause severe vision loss in humans. We found that each Rho regulatory region can independently mediate local epigenomic changes, but only the promoter is absolutely required for establishing active Rho chromatin configuration and transcription and maintaining the cell integrity and function of rod photoreceptors. To our surprise, two Rho enhancers that enable strong promoter activation in reporter assays are largely dispensable for Rho expression in vivo. Only small and age-dependent impact is detectable when both enhancers are deleted. Our results demonstrate context-dependent roles of enhancers and highlight the importance of studying functions of cis-regulatory regions in the native genomic context.
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Affiliation(s)
- Chi Sun
- Department of Ophthalmology and Visual Sciences, Washington University, Saint Louis, MO, USA
| | - Philip A Ruzycki
- Department of Ophthalmology and Visual Sciences, Washington University, Saint Louis, MO, USA.
- Department of Genetics, Washington University, 660 South Euclid Avenue, MSC 8096-0006-11, Saint Louis, MO, 63110, USA.
| | - Shiming Chen
- Department of Ophthalmology and Visual Sciences, Washington University, Saint Louis, MO, USA.
- Department of Developmental Biology, Washington University, 660 South Euclid Avenue, MSC 8096-0006-06, Saint Louis, MO, 63110, USA.
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22
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Krishnamoorthi A, Khosh Abady K, Dhankhar D, Rentzepis PM. Ultrafast Transient Absorption Spectra and Kinetics of Rod and Cone Visual Pigments. Molecules 2023; 28:5829. [PMID: 37570798 PMCID: PMC10421382 DOI: 10.3390/molecules28155829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/13/2023] Open
Abstract
Rods and cones are the photoreceptor cells containing the visual pigment proteins that initiate visual phototransduction following the absorption of a photon. Photon absorption induces the photochemical transformation of a visual pigment, which results in the sequential formation of distinct photo-intermediate species on the femtosecond to millisecond timescales, whereupon a visual electrical signal is generated and transmitted to the brain. Time-resolved spectroscopic studies of the rod and cone photo-intermediaries enable the detailed understanding of initial events in vision, namely the key differences that underlie the functionally distinct scotopic (rod) and photopic (cone) visual systems. In this paper, we review our recent ultrafast (picoseconds to milliseconds) transient absorption studies of rod and cone visual pigments with a detailed comparison of the transient molecular spectra and kinetics of their respective photo-intermediaries. Key results include the characterization of the porphyropsin (carp fish rhodopsin) and human green-cone opsin photobleaching sequences, which show significant spectral and kinetic differences when compared against that of bovine rhodopsin. These results altogether reveal a rather strong interplay between the visual pigment structure and its corresponding photobleaching sequence, and relevant outstanding questions that will be further investigated through a forthcoming study of the human blue-cone visual pigment are discussed.
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Affiliation(s)
- Arjun Krishnamoorthi
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Keyvan Khosh Abady
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Dinesh Dhankhar
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
- Thermo Fisher Scientific, Hillsboro, OR 97124, USA
| | - Peter M. Rentzepis
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
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23
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Sp S, Mitra RN, Zheng M, Chrispell JD, Wang K, Kwon YS, Weiss ER, Han Z. Gene augmentation for autosomal dominant retinitis pigmentosa using rhodopsin genomic loci nanoparticles in the P23H +/- knock-in murine model. Gene Ther 2023; 30:628-640. [PMID: 36935427 DOI: 10.1038/s41434-023-00394-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 02/13/2023] [Accepted: 02/28/2023] [Indexed: 03/21/2023]
Abstract
Gene therapy for autosomal dominant retinitis pigmentosa (adRP) is challenged by the dominant inheritance of the mutant genes, which would seemingly require a combination of mutant suppression and wild-type replacement of the appropriate gene. We explore the possibility that delivery of a nanoparticle (NP)-mediated full-length mouse genomic rhodopsin (gRho) or human genomic rhodopsin (gRHO) locus can overcome the dominant negative effects of the mutant rhodopsin in the clinically relevant P23H+/--knock-in heterozygous mouse model. Our results demonstrate that mice in both gRho and gRHO NP-treated groups exhibit significant structural and functional recovery of the rod photoreceptors, which lasted for 3 months post-injection, indicating a promising reduction in photoreceptor degeneration. We performed miRNA transcriptome analysis using next generation sequencing and detected differentially expressed miRNAs as a first step towards identifying miRNAs that could potentially be used as rhodopsin gene expression enhancers or suppressors for sustained photoreceptor rescue. Our results indicate that delivering an intact genomic locus as a transgene has a greater chance of success compared to the use of the cDNA for treatment of this model of adRP, emphasizing the importance of gene augmentation using a gDNA that includes regulatory elements.
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Affiliation(s)
- Simna Sp
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Rajendra N Mitra
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Min Zheng
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jared D Chrispell
- Department of Cell Biology and Physiology, the University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Kai Wang
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Yong-Su Kwon
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Ellen R Weiss
- Department of Cell Biology and Physiology, the University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Zongchao Han
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Carolina Institute for NanoMedicine, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Division of Pharmacoengineering & Molecular Pharmaceutics, Eshelman School of Pharmacy, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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24
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Helbing J, Hamm P. Versatile Femtosecond Laser Synchronization for Multiple-Timescale Transient Infrared Spectroscopy. J Phys Chem A 2023. [PMID: 37478282 DOI: 10.1021/acs.jpca.3c03526] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
Several ways to electronically synchronize different types of amplified femtosecond laser systems are presented based on a single freely programmable electronics hardware: arbitrary-detuning asynchronous optical sampling (ADASOPS), as well as actively locking two femtosecond laser oscillators, albeit not necessarily to the same round-trip frequency. They allow us to rapidly probe a very wide range of timescales, from picoseconds to potentially seconds, in a single transient absorption experiment without the need to move any delay stage. Experiments become possible that address a largely unexplored aspect of many photochemical reactions, in particular in the context of photo-catalysis as well as photoactive proteins, where an initial femtosecond trigger very often initiates a long-lasting cascade of follow-up processes. The approach is very versatile and allows us to synchronize very different lasers, such as a Ti:Sa amplifier and a 100 kHz Yb-laser system. The jitter of the synchronization, and therewith the time-resolution in the transient experiment, lies in the range from 1 to 3 ps, depending on the method. For illustration, transient IR measurements of the excited state solvation and decay of a metal carbonyl complex as well as the full reaction cycle of bacteriorhodopsin are shown. The pros and cons of the various methods are discussed, with regard to the scientific question one might want to address, and also with regard to the laser systems that might be already existent in a laser lab.
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Affiliation(s)
- Jan Helbing
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Peter Hamm
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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25
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Zheng Y, Sun C, Zhang X, Ruzycki PA, Chen S. Missense mutations in CRX homeodomain cause dominant retinopathies through two distinct mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526652. [PMID: 36778408 PMCID: PMC9915647 DOI: 10.1101/2023.02.01.526652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Homeodomain transcription factors (HD TFs) are instrumental to vertebrate development. Mutations in HD TFs have been linked to human diseases, but their pathogenic mechanisms remain elusive. Here we use Cone-Rod Homeobox (CRX) as a model to decipher the disease-causing mechanisms of two HD mutations, p.E80A and p.K88N, that produce severe dominant retinopathies. Through integrated analysis of molecular and functional evidence in vitro and in knock-in mouse models, we uncover two novel gain-of-function mechanisms: p.E80A increases CRX-mediated transactivation of canonical CRX target genes in developing photoreceptors; p.K88N alters CRX DNA-binding specificity resulting in binding at ectopic sites and severe perturbation of CRX target gene expression. Both mechanisms produce novel retinal morphological defects and hinder photoreceptor maturation distinct from loss-of-function models. This study reveals the distinct roles of E80 and K88 residues in CRX HD regulatory functions and emphasizes the importance of transcriptional precision in normal development.
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Affiliation(s)
- Yiqiao Zheng
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Chi Sun
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Xiaodong Zhang
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Philip A. Ruzycki
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Genetics, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Shiming Chen
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Developmental Biology, Washington University in St Louis, Saint Louis, Missouri, USA
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26
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Marwan M, Dawood M, Ullah M, Shah IU, Khan N, Hassan MT, Karam M, Rawlins LE, Baple EL, Crosby AH, Saleha S. Unravelling the genetic basis of retinal dystrophies in Pakistani consanguineous families. BMC Ophthalmol 2023; 23:205. [PMID: 37165311 PMCID: PMC10170854 DOI: 10.1186/s12886-023-02948-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 04/26/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND Retinitis Pigmentosa (RP) is a clinically and genetically progressive retinal dystrophy associated with severe visual impairments and sometimes blindness, the most common syndromic form of which is Usher syndrome (USH). This study aimed to further increase understanding of the spectrum of RP in the Khyber Pakhtunkhwa region of Pakistan. METHODOLOGY Four consanguineous families of Pashtun ethnic group were investigated which were referred by the local collaborating ophthalmologists. In total 42 individuals in four families were recruited and investigated using whole exome and dideoxy sequencing. Among them, 20 were affected individuals including 6 in both family 1 and 2, 5 in family 3 and 3 in family 4. RESULT Pathogenic gene variants were identified in all four families, including two in cone dystrophy and RP genes in the same family (PDE6C; c.480delG, p.Asn161ThrfsTer33 and TULP1; c.238 C > T, p.Gln80Ter) with double-homozygous individuals presenting with more severe disease. Other pathogenic variants were identified in MERTK (c.2194C > T, p.Arg732Ter), RHO (c.448G > A, p.Glu150Lys) associated with non-syndromic RP, and MYO7A (c.487G > A, p.Gly163Arg) associated with USH. In addition, the reported variants were of clinical significance as the PDE6C variant was detected novel, whereas TULP1, MERTK, and MYO7A variants were detected rare and first time found segregating with retinal dystrophies in Pakistani consanguineous families. CONCLUSIONS This study increases knowledge of the genetic basis of retinal dystrophies in families from Pakistan providing information important for genetic testing and diagnostic provision particularly from the Khyber Pakhtunkhwa region.
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Affiliation(s)
- Muhammad Marwan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Muhammad Dawood
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Mukhtar Ullah
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, 4031, Switzerland
- Department of Ophthalmology, University of Basel, Basel, 4056, Switzerland
| | - Irfan Ullah Shah
- Department of Ophthalmology, KMU Institute of Medical Sciences KIMS, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Niamat Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Muhammad Taimur Hassan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Muhammad Karam
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Lettie E Rawlins
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, EX2 5DW, UK
- Peninsula Clinical Genetics Service, Royal Devon & Exeter Hospital (Heavitree), Exeter, UK
| | - Emma L Baple
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, EX2 5DW, UK
| | - Andrew H Crosby
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, EX2 5DW, UK
| | - Shamim Saleha
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan.
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27
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Abstract
Rhodopsin is the photoreceptor in human rod cells responsible for dim-light vision. The visual receptors are part of the large superfamily of G protein-coupled receptors (GPCRs) that mediate signal transduction in response to diverse diffusible ligands. The high level of sequence conservation within the transmembrane helices of the visual receptors and the family A GPCRs has long been considered evidence for a common pathway for signal transduction. I review recent studies that reveal a comprehensive mechanism for how light absorption by the retinylidene chromophore drives rhodopsin activation and highlight those features of the mechanism that are conserved across the ligand-activated GPCRs.
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Affiliation(s)
- Steven O Smith
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York, USA;
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28
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Inukai S, Katayama K, Koyanagi M, Terakita A, Kandori H. Counterion at an atypical position: Investigating the mechanism of photoisomerization in jellyfish rhodopsin. J Biol Chem 2023; 299:104726. [PMID: 37094700 DOI: 10.1016/j.jbc.2023.104726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/11/2023] [Accepted: 04/15/2023] [Indexed: 04/26/2023] Open
Abstract
The position of the counterion in animal rhodopsins plays a crucial role in maintaining visible light sensitivity and facilitating the photoisomerization of their retinal chromophore. The counterion displacement is thought to be closely related to the evolution of rhodopsins, with different positions found in invertebrates and vertebrates. Interestingly, box jellyfish rhodopsin (JelRh) acquired the counterion in transmembrane 2 (TM2) independently. This is a unique feature, as in most animal rhodopsins, the counterion is found in a different location. In this study, we used Fourier Transform Infrared spectroscopy to examine the structural changes that occur in the early photointermediate state of JelRh. We aimed to determine whether the photochemistry of JelRh is similar to that of other animal rhodopsins by comparing its spectra to those of vertebrate bovine rhodopsin (BovRh) and invertebrate squid rhodopsin (SquRh). We observed that the N-D stretching band of the retinal Schiff base was similar to that of BovRh, indicating the interaction between the Schiff base and the counterion is similar in both rhodopsins, despite their different counterion positions. Furthermore, we found that the chemical structure of the retinal in JelRh is similar to that in BovRh, including the changes in the hydrogen-out-of-plane band that indicates a retinal distortion. Overall, the protein conformational changes induced by the photoisomerization of JelRh yielded spectra that resemble an intermediate between BovRh and SquRh, suggesting a unique spectral property of JelRh, and making it the only animal rhodopsin with a counterion in TM2 and an ability to activate Gs protein.
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Affiliation(s)
- Shino Inukai
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Kota Katayama
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan; OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan; PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
| | - Mitsumasa Koyanagi
- Department of Biology, Graduate School of Science, Osaka Metropolitan University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Akihisa Terakita
- Department of Biology, Graduate School of Science, Osaka Metropolitan University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan; OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan.
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29
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Hanai S, Nagata T, Katayama K, Inukai S, Koyanagi M, Inoue K, Terakita A, Kandori H. Difference FTIR Spectroscopy of Jumping Spider Rhodopsin-1 at 77 K. Biochemistry 2023; 62:1347-1359. [PMID: 37001008 DOI: 10.1021/acs.biochem.3c00022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Animal visual rhodopsins can be classified into monostable and bistable rhodopsins, which are typically found in vertebrates and invertebrates, respectively. The former example is bovine rhodopsin (BovRh), whose structures and functions have been extensively studied. On the other hand, those of bistable rhodopsins are less known, despite their importance in optogenetics. Here, low-temperature Fourier-transform infrared (FTIR) spectroscopy was applied to jumping spider rhodopsin-1 (SpiRh1) at 77 K, and the obtained light-induced spectral changes were compared with those of squid rhodopsin (SquRh) and BovRh. Although chromophore distortion of the resting state monitored by HOOP vibrations is not distinctive between invertebrate and vertebrate rhodopsins, distortion of the all-trans chromophore after photoisomerization is unique for BovRh, and the distortion was localized at the center of the chromophore in SpiRh1 and SquRh. Highly conserved aspartate (D83 in BovRh) does not change the hydrogen-bonding environment in invertebrate rhodopsins. Thus, present FTIR analysis provides specific structural changes, leading to activation of invertebrate and vertebrate rhodopsins. On the other hand, the analysis of O-D stretching vibrations in D2O revealed unique features of protein-bound water molecules. Numbers of water bands in SpiRh1 and SquRh were less and more than those in BovRh. The X-ray crystal structure of SpiRh1 observed a bridged water molecule between the protonated Schiff base and its counterion (E194), but strongly hydrogen-bonded water molecules were never detected in SpiRh1, as well as SquRh and BovRh. Thus, absence of strongly hydrogen-bonded water molecules is substantial for animal rhodopsins, which is distinctive from microbial rhodopsins.
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30
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Palczewska G, Wojtkowski M, Palczewski K. From mouse to human: Accessing the biochemistry of vision in vivo by two-photon excitation. Prog Retin Eye Res 2023; 93:101170. [PMID: 36787681 PMCID: PMC10463242 DOI: 10.1016/j.preteyeres.2023.101170] [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: 12/11/2022] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 02/13/2023]
Abstract
The eye is an ideal organ for imaging by a multi-photon excitation approach, because ocular tissues such as the sclera, cornea, lens and neurosensory retina, are highly transparent to infrared (IR) light. The interface between the retina and the retinal pigment epithelium (RPE) is especially informative, because it reflects the health of the visual (retinoid) cycle and its changes in response to external stress, genetic manipulations, and drug treatments. Vitamin A-derived retinoids, like retinyl esters, are natural fluorophores that respond to multi-photon excitation with near IR light, bypassing the filter-like properties of the cornea, lens, and macular pigments. Also, during natural aging some retinoids form bisretinoids, like diretinoid-pyridiniumethanolamine (A2E), that are highly fluorescent. These bisretinoids appear to be elevated concurrently with aging. Vitamin A-derived retinoids and bisretinoidss are detected by two-photon ophthalmoscopy (2PO), using a new class of light sources with adjustable spatial, temporal, and spectral properties. Furthermore, the two-photon (2P) absorption of IR light by the visual pigments in rod and cone photoreceptors can initiate visual transduction by cis-trans isomerization of retinal, enabling parallel functional studies. Recently we overcame concerns about safety, data interpretation and complexity of the 2P-based instrumentation, the major roadblocks toward advancing this modality to the clinic. These imaging and retina-function assessment advancements have enabled us to conduct the first 2P studies with humans.
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Affiliation(s)
- Grazyna Palczewska
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA; International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland; Polgenix, Inc., Department of Medical Devices, Cleveland, OH, USA; Department of Physical Chemistry of Biological Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland.
| | - Maciej Wojtkowski
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland; Department of Physical Chemistry of Biological Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland; Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun, Poland.
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA; Department of Physiology & Biophysics, School of Medicine, And Chemistry, Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
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31
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Rajala A, Bhat MA, Teel K, Gopinadhan Nair GK, Purcell L, Rajala RVS. The function of lactate dehydrogenase A in retinal neurons: implications to retinal degenerative diseases. PNAS NEXUS 2023; 2:pgad038. [PMID: 36896135 PMCID: PMC9991461 DOI: 10.1093/pnasnexus/pgad038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 01/28/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023]
Abstract
The postmitotic retina is highly metabolic and the photoreceptors depend on aerobic glycolysis for an energy source and cellular anabolic activities. Lactate dehydrogenase A (LDHA) is a key enzyme in aerobic glycolysis, which converts pyruvate to lactate. Here we show that cell-type-specific actively translating mRNA purification by translating ribosome affinity purification shows a predominant expression of LDHA in rods and cones and LDHB in the retinal pigment epithelium and Müller cells. We show that genetic ablation of LDHA in the retina resulted in diminished visual function, loss of structure, and a loss of dorsal-ventral patterning of the cone-opsin gradient. Loss of LDHA in the retina resulted in increased glucose availability, promoted oxidative phosphorylation, and upregulated the expression of glutamine synthetase (GS), a neuron survival factor. However, lacking LDHA in Müller cells does not affect visual function in mice. Glucose shortage is associated with retinal diseases, such as age-related macular degeneration (AMD), and regulating the levels of LDHA may have therapeutic relevance. These data demonstrate the unique and unexplored roles of LDHA in the maintenance of a healthy retina.
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Affiliation(s)
- Ammaji Rajala
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
| | - Mohd A Bhat
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
| | - Kenneth Teel
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
| | - Gopa Kumar Gopinadhan Nair
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
| | - Lindsey Purcell
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
| | - Raju V S Rajala
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
- Department of Physiology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
- Department of Cell Biology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma City, OK 73104, USA
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32
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Poria D, Kolesnikov AV, Lee TJ, Salom D, Palczewski K, Kefalov VJ. Investigating the Role of Rhodopsin F45L Mutation in Mouse Rod Photoreceptor Signaling and Survival. eNeuro 2023; 10:ENEURO.0330-22.2023. [PMID: 36823167 PMCID: PMC9997694 DOI: 10.1523/eneuro.0330-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 01/16/2023] [Accepted: 01/24/2023] [Indexed: 02/25/2023] Open
Abstract
Rhodopsin is the critical receptor molecule which enables vertebrate rod photoreceptor cells to detect a single photon of light and initiate a cascade of molecular events leading to visual perception. Recently, it has been suggested that the F45L mutation in the transmembrane helix of rhodopsin disrupts its dimerization in vitro To determine whether this mutation of rhodopsin affects its signaling properties in vivo, we generated knock-in mice expressing the rhodopsin F45L mutant. We then examined the function of rods in the mutant mice versus wild-type controls, using in vivo electroretinography and transretinal and single cell suction recordings, combined with morphologic analysis and spectrophotometry. Although we did not evaluate the effect of the F45L mutation on the state of dimerization of the rhodopsin in vivo, our results revealed that F45L-mutant mice exhibit normal retinal morphology, normal rod responses as measured both in vivo and ex vivo, and normal rod dark adaptation. We conclude that the F45L mutation does not affect the signaling properties of rhodopsin in its natural setting.
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Affiliation(s)
- Deepak Poria
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA 92697
| | - Alexander V Kolesnikov
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA 92697
| | - Tae Jun Lee
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110
| | - David Salom
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA 92697
| | - Krzysztof Palczewski
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA 92697
- Department of Chemistry, University of California, Irvine, CA 92697
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697
| | - Vladimir J Kefalov
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA 92697
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697
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Wu KY, Kulbay M, Toameh D, Xu AQ, Kalevar A, Tran SD. Retinitis Pigmentosa: Novel Therapeutic Targets and Drug Development. Pharmaceutics 2023; 15:685. [PMID: 36840007 PMCID: PMC9963330 DOI: 10.3390/pharmaceutics15020685] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/12/2023] [Accepted: 02/16/2023] [Indexed: 02/19/2023] Open
Abstract
Retinitis pigmentosa (RP) is a heterogeneous group of hereditary diseases characterized by progressive degeneration of retinal photoreceptors leading to progressive visual decline. It is the most common type of inherited retinal dystrophy and has a high burden on both patients and society. This condition causes gradual loss of vision, with its typical manifestations including nyctalopia, concentric visual field loss, and ultimately bilateral central vision loss. It is one of the leading causes of visual disability and blindness in people under 60 years old and affects over 1.5 million people worldwide. There is currently no curative treatment for people with RP, and only a small group of patients with confirmed RPE65 mutations are eligible to receive the only gene therapy on the market: voretigene neparvovec. The current therapeutic armamentarium is limited to retinoids, vitamin A supplements, protection from sunlight, visual aids, and medical and surgical interventions to treat ophthalmic comorbidities, which only aim to slow down the progression of the disease. Considering such a limited therapeutic landscape, there is an urgent need for developing new and individualized therapeutic modalities targeting retinal degeneration. Although the heterogeneity of gene mutations involved in RP makes its target treatment development difficult, recent fundamental studies showed promising progress in elucidation of the photoreceptor degeneration mechanism. The discovery of novel molecule therapeutics that can selectively target specific receptors or specific pathways will serve as a solid foundation for advanced drug development. This article is a review of recent progress in novel treatment of RP focusing on preclinical stage fundamental research on molecular targets, which will serve as a starting point for advanced drug development. We will review the alterations in the molecular pathways involved in the development of RP, mainly those regarding endoplasmic reticulum (ER) stress and apoptotic pathways, maintenance of the redox balance, and genomic stability. We will then discuss the therapeutic approaches under development, such as gene and cell therapy, as well as the recent literature identifying novel potential drug targets for RP.
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Affiliation(s)
- Kevin Y. Wu
- Division of Ophthalmology, Department of Surgery, University of Sherbrooke, Sherbrooke, QC J1G 2E8, Canada
| | - Merve Kulbay
- Faculty of Medicine, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Dana Toameh
- Faculty of Medicine, McGill University, Montreal, QC H3G 2M1, Canada
| | - An Qi Xu
- Faculty of Medicine, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Ananda Kalevar
- Division of Ophthalmology, Department of Surgery, University of Sherbrooke, Sherbrooke, QC J1G 2E8, Canada
| | - Simon D. Tran
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC H3A 1G1, Canada
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Kojima K, Sudo Y. Convergent evolution of animal and microbial rhodopsins. RSC Adv 2023; 13:5367-5381. [PMID: 36793294 PMCID: PMC9923458 DOI: 10.1039/d2ra07073a] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/05/2023] [Indexed: 02/15/2023] Open
Abstract
Rhodopsins, a family of photoreceptive membrane proteins, contain retinal as a chromophore and were firstly identified as reddish pigments from frog retina in 1876. Since then, rhodopsin-like proteins have been identified mainly from animal eyes. In 1971, a rhodopsin-like pigment was discovered from the archaeon Halobacterium salinarum and named bacteriorhodopsin. While it was believed that rhodopsin- and bacteriorhodopsin-like proteins were expressed only in animal eyes and archaea, respectively, before the 1990s, a variety of rhodopsin-like proteins (called animal rhodopsins or opsins) and bacteriorhodopsin-like proteins (called microbial rhodopsins) have been progressively identified from various tissues of animals and microorganisms, respectively. Here, we comprehensively introduce the research conducted on animal and microbial rhodopsins. Recent analysis has revealed that the two rhodopsin families have common molecular properties, such as the protein structure (i.e., 7-transmembrane structure), retinal structure (i.e., binding ability to cis- and trans-retinal), color sensitivity (i.e., UV- and visible-light sensitivities), and photoreaction (i.e., triggering structural changes by light and heat), more than what was expected at the early stages of rhodopsin research. Contrastingly, their molecular functions are distinctively different (e.g., G protein-coupled receptors and photoisomerases for animal rhodopsins and ion transporters and phototaxis sensors for microbial rhodopsins). Therefore, based on their similarities and dissimilarities, we propose that animal and microbial rhodopsins have convergently evolved from their distinctive origins as multi-colored retinal-binding membrane proteins whose activities are regulated by light and heat but independently evolved for different molecular and physiological functions in the cognate organism.
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Affiliation(s)
- Keiichi Kojima
- Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Japan
| | - Yuki Sudo
- Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Japan
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Gulati S, Palczewski K. Structural view of G protein-coupled receptor signaling in the retinal rod outer segment. Trends Biochem Sci 2023; 48:172-186. [PMID: 36163145 PMCID: PMC9868064 DOI: 10.1016/j.tibs.2022.08.010] [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: 04/15/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 01/26/2023]
Abstract
Visual phototransduction is the most extensively studied G protein-coupled receptor (GPCR) signaling pathway because of its quantifiable stimulus, non-redundancy of genes, and immense importance in vision. We summarize recent discoveries that have advanced our understanding of rod outer segment (ROS) morphology and the pathological basis of retinal diseases. We have combined recently published cryo-electron tomography (cryo-ET) data on the ROS with structural knowledge on individual proteins to define the precise spatial limitations under which phototransduction occurs. Although hypothetical, the reconstruction of the rod phototransduction system highlights the potential roles of phosphodiesterase 6 (PDE6) and guanylate cyclases (GCs) in maintaining the spacing between ROS discs, suggesting a plausible mechanism by which intrinsic optical signals are generated in the retina.
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Affiliation(s)
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute and the Department of Ophthalmology, Center for Translational Vision Research, Department of Physiology and Biophysics, Department of Chemistry, Molecular Biology, and Biochemistry, University of California Irvine, 850 Health Sciences Road, Irvine, CA 92697-4375, USA.
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Ultrafast spectra and kinetics of human green-cone visual pigment at room temperature. Proc Natl Acad Sci U S A 2023; 120:e2214276120. [PMID: 36577071 PMCID: PMC9910472 DOI: 10.1073/pnas.2214276120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Rhodopsin is the pigment that enables night vision, whereas cone opsins are the pigments responsible for color vision in bright-light conditions. Despite their importance for vision, cone opsins are poorly characterized at the molecular level compared to rhodopsin. Spectra and kinetics of the intermediate states of human green-cone visual pigment (mid-wavelength sensitive, or MWS opsin) were measured and compared with the intermediates and kinetics of bovine rhodopsin. All the major intermediates of the MWS opsin were recorded in the picosecond to millisecond time range. Several intermediates in MWS opsin appear to have characteristics similar to the intermediates of bovine rhodopsin; however, there are some marked differences. One of the most striking differences is in their kinetics, where the kinetics of the MWS opsin intermediates are slower compared to those of the bovine rhodopsin intermediates.
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Karamali F, Behtaj S, Babaei-Abraki S, Hadady H, Atefi A, Savoj S, Soroushzadeh S, Najafian S, Nasr Esfahani MH, Klassen H. Potential therapeutic strategies for photoreceptor degeneration: the path to restore vision. J Transl Med 2022; 20:572. [PMID: 36476500 PMCID: PMC9727916 DOI: 10.1186/s12967-022-03738-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 10/29/2022] [Indexed: 12/12/2022] Open
Abstract
Photoreceptors (PRs), as the most abundant and light-sensing cells of the neuroretina, are responsible for converting light into electrical signals that can be interpreted by the brain. PR degeneration, including morphological and functional impairment of these cells, causes significant diminution of the retina's ability to detect light, with consequent loss of vision. Recent findings in ocular regenerative medicine have opened promising avenues to apply neuroprotective therapy, gene therapy, cell replacement therapy, and visual prostheses to the challenge of restoring vision. However, successful visual restoration in the clinical setting requires application of these therapeutic approaches at the appropriate stage of the retinal degeneration. In this review, firstly, we discuss the mechanisms of PR degeneration by focusing on the molecular mechanisms underlying cell death. Subsequently, innovations, recent developments, and promising treatments based on the stage of disorder progression are further explored. Then, the challenges to be addressed before implementation of these therapies in clinical practice are considered. Finally, potential solutions to overcome the current limitations of this growing research area are suggested. Overall, the majority of current treatment modalities are still at an early stage of development and require extensive additional studies, both pre-clinical and clinical, before full restoration of visual function in PR degeneration diseases can be realized.
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Affiliation(s)
- Fereshteh Karamali
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sanaz Behtaj
- grid.1022.10000 0004 0437 5432Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia ,grid.1022.10000 0004 0437 5432Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia
| | - Shahnaz Babaei-Abraki
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Hanieh Hadady
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Atefeh Atefi
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Soraya Savoj
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sareh Soroushzadeh
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Samaneh Najafian
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Mohammad Hossein Nasr Esfahani
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Henry Klassen
- grid.266093.80000 0001 0668 7243Gavin Herbert Eye Institute, Irvine, CA USA
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Mizuno Y, Katayama K, Imai H, Kandori H. Early Proton Transfer Reaction in a Primate Blue-Sensitive Visual Pigment. Biochemistry 2022; 61:2698-2708. [PMID: 36399519 PMCID: PMC9730847 DOI: 10.1021/acs.biochem.2c00483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 10/19/2022] [Indexed: 11/19/2022]
Abstract
The proton transfer reaction belongs to one of the key triggers for the functional expression of membrane proteins. Rod and cone opsins are light-sensitive G-protein-coupled receptors (GPCRs) that undergo the cis-trans isomerization of the retinal chromophore in response to light. The isomerization event initiates a conformational change in the opsin protein moiety, which propagates the downstream effector signaling. The final step of receptor activation is the deprotonation of the retinal Schiff base, a proton transfer reaction which has been believed to be identical among the cone opsins. Here, we report an unexpected proton transfer reaction occurring in the early photoreaction process of primate blue-sensitive pigment (MB). By using low-temperature UV-visible spectroscopy, we found that the Lumi intermediate of MB formed in transition from the BL intermediate shows an absorption maximum in the UV region, indicating the deprotonation of the retinal Schiff base. Comparison of the light-induced difference FTIR spectra of Batho, BL, and Lumi showed significant α-helical backbone C=O stretching and protonated carboxylate C=O stretching vibrations only in the Lumi intermediate. The transition from BL to Lumi thus involves dramatic changes in protein environment with a proton transfer reaction between the Schiff base and the counterion resulting in an absorption maximum in the UV region.
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Affiliation(s)
- Yosuke Mizuno
- Department
of Life Science and Applied Chemistry, Nagoya
Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Kota Katayama
- Department
of Life Science and Applied Chemistry, Nagoya
Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
- OptoBioTechnology
Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
- PRESTO, Japan
Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Hiroo Imai
- Center
for the Evolutionary Origins of Human Behavior, Kyoto University, Inuyama 484-8506, Japan
| | - Hideki Kandori
- Department
of Life Science and Applied Chemistry, Nagoya
Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
- OptoBioTechnology
Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
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High-performance optical control of GPCR signaling by bistable animal opsins MosOpn3 and LamPP in a molecular property-dependent manner. Proc Natl Acad Sci U S A 2022; 119:e2204341119. [PMID: 36417444 PMCID: PMC9889881 DOI: 10.1073/pnas.2204341119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Optical control of G protein-coupled receptor (GPCR) signaling is a highly valuable approach for comprehensive understanding of GPCR-based physiologies and controlling them precisely. However, optogenetics for GPCR signaling is still developing and requires effective and versatile tools with performance evaluation from their molecular properties. Here, we systematically investigated performance of two bistable opsins that activate Gi/Go-type G protein (mosquito Opn3 (MosOpn3) and lamprey parapinopsin (LamPP)) in optical control in vivo using Caenorhabditis elegans. Transgenic worms expressing MosOpn3, which binds 13-cis retinal to form photopigments, in nociceptor neurons showed light-induced avoidance responses in the presence of all-trans retinal, a retinal isomer ubiquitously present in every tissue, like microbial rhodopsins and unlike canonical vertebrate opsins. Remarkably, transgenic worms expressing MosOpn3 were ~7,000 times more sensitive to light than transgenic worms expressing ChR2 in this light-induced behavior, demonstrating the advantage of MosOpn3 as a light switch. LamPP is a UV-sensitive bistable opsin having complete photoregenerative ability by green light. Accordingly, transgenic worms expressing LamPP in cholinergic motor neurons stopped moving upon violet light illumination and restored coordinate movement upon green light illumination, demonstrating color-dependent control of behavior using LamPP. Furthermore, we applied molecular engineering to produce MosOpn3-based tools enabling light-dependent upregulation of cAMP or Ca2+ levels and LamPP-based tool enabling clamping cAMP levels color dependently and context independently, extending their usability. These findings define the capacity of two bistable opsins with similar retinal requirement as ChR2, providing numerous strategies for optical control of various GPCR-based physiologies as well as GPCR signaling itself.
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Picarazzi F, Zuanon M, Pasqualetto G, Cammarone S, Romeo I, Young MT, Brancale A, Bassetto M, Mori M. Identification of Small Molecular Chaperones Binding P23H Mutant Opsin through an In Silico Structure-Based Approach. J Chem Inf Model 2022; 62:5794-5805. [PMID: 36367985 DOI: 10.1021/acs.jcim.2c01040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
N-terminal P23H opsin mutation accounts for most of retinitis pigmentosa (RP) cases. P23H functions and folding can be rescued by small chaperone ligands, which contributes to validate mutant opsin as a suitable target for pharmacological treatment of RP. However, the lack of structural details on P23H mutant opsin strongly impairs drug design, and new chemotypes of effective chaperones of P23H opsin are in high demand. Here, a computational-boosted workflow combining homology modeling with molecular dynamics (MD) simulations and virtual screening was used to select putative P23H opsin chaperones among different libraries through a structure-based approach. In vitro studies corroborated the reliability of the structural model generated in this work and identified a number of novel chemotypes of safe and effective chaperones able to promote P23H opsin trafficking to the outer cell membrane.
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Affiliation(s)
- Francesca Picarazzi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Marika Zuanon
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Gaia Pasqualetto
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK
| | - Silvia Cammarone
- Dipartimento di Chimica e Tecnologie del Farmaco, Facoltà di Farmacia e Medicina, "Sapienza" Università di Roma, P. le Aldo Moro 5, 00185 Roma, Italy
| | - Isabella Romeo
- Dipartimento di Chimica e Tecnologie del Farmaco, Facoltà di Farmacia e Medicina, "Sapienza" Università di Roma, P. le Aldo Moro 5, 00185 Roma, Italy
| | - Mark T Young
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK.,Vysoká Škola Chemicko-Technologiká v Praze, Prague 166 28, Czech Republic
| | - Marcella Bassetto
- Department of Chemistry, Faculty of Science and Engineering, Swansea University, Swansea SA2 8PP, UK
| | - Mattia Mori
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
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Chromophore hydrolysis and release from photoactivated rhodopsin in native membranes. Proc Natl Acad Sci U S A 2022; 119:e2213911119. [PMID: 36322748 PMCID: PMC9659404 DOI: 10.1073/pnas.2213911119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
For sustained vision, photoactivated rhodopsin (Rho*) must undergo hydrolysis and release of all-trans-retinal, producing substrate for the visual cycle and apo-opsin available for regeneration with 11-cis-retinal. The kinetics of this hydrolysis has yet to be described for rhodopsin in its native membrane environment. We developed a method consisting of simultaneous denaturation and chromophore trapping by isopropanol/borohydride, followed by exhaustive protein digestion, complete extraction, and liquid chromatography-mass spectrometry. Using our method, we tracked Rho* hydrolysis, the subsequent formation of N-retinylidene-phosphatidylethanolamine (N-ret-PE) adducts with the released all-trans-retinal, and the reduction of all-trans-retinal to all-trans-retinol. We found that hydrolysis occurred faster in native membranes than in detergent micelles typically used to study membrane proteins. The activation energy of the hydrolysis in native membranes was determined to be 17.7 ± 2.4 kcal/mol. Our data support the interpretation that metarhodopsin II, the signaling state of rhodopsin, is the primary species undergoing hydrolysis and release of its all-trans-retinal. In the absence of NADPH, free all-trans-retinal reacts with phosphatidylethanolamine (PE), forming a substantial amount of N-ret-PE (∼40% of total all-trans-retinal at physiological pH), at a rate that is an order of magnitude faster than Rho* hydrolysis. However, N-ret-PE formation was highly attenuated by NADPH-dependent reduction of all-trans-retinal to all-trans-retinol. Neither N-ret-PE formation nor all-trans-retinal reduction affected the rate of hydrolysis of Rho*. Our study provides a comprehensive picture of the hydrolysis of Rho* and the release of all-trans-retinal and its reentry into the visual cycle, a process in which alteration can lead to severe retinopathies.
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Human cone elongation responses can be explained by photoactivated cone opsin and membrane swelling and osmotic response to phosphate produced by RGS9-catalyzed GTPase. Proc Natl Acad Sci U S A 2022; 119:e2202485119. [PMID: 36122241 PMCID: PMC9522364 DOI: 10.1073/pnas.2202485119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Optical coherence tomography has established that human cone photoreceptor outer segments elongate in response to stimuli bleaching large fractions of their visual pigment. Elongation responses are completely described over their 200-fold bleaching range as the sum of two exponentially rising components differing 13-fold in time constants and 4-fold in light sensitivity. Bleaching measurements of individual cones with adaptive optics scanning laser ophthalmoscopy (SLO) suggest that component 2 arises from cone opsin and disk membrane swelling triggered by photoactivation. Application of a model of phototransduction suggests that component 1 corresponds to free phosphate generated by regulator of G-protein signaling 9 (RGS9)-catalyzed hydrolysis of guanosine triphosphate (GTP) in the α-subunit of G protein complexed with phosphodiesterase. Human cone outer segment (COS) length changes in response to stimuli bleaching up to 99% of L- and M-cone opsins were measured with high resolution, phase-resolved optical coherence tomography (OCT). Responses comprised a fast phase (∼5 ms), during which COSs shrink, and two slower phases (1.5 s), during which COSs elongate. The slower components saturated in amplitude (∼425 nm) and initial rate (∼3 nm ms−1) and are well described over the 200-fold bleaching range as the sum of two exponentially rising functions with time constants of 80 to 90 ms (component 1) and 1,000 to 1,250 ms (component 2). Measurements with adaptive optics reflection densitometry revealed component 2 to be linearly related to cone pigment bleaching, and the hypothesis is proposed that it arises from cone opsin and disk membrane swelling triggered by isomerization and rate-limited by chromophore hydrolysis and its reduction to membrane-localized all-trans retinol. The light sensitivity and kinetics of component 1 suggested that the underlying mechanism is an osmotic response to an amplified soluble by-product of phototransduction. The hypotheses that component 1 corresponds to G-protein subunits dissociating from the membrane, metabolites of cyclic guanosine monophosphate (cGMP) hydrolysis, or by-products of activated guanylate cyclase are rejected, while the hypothesis that it corresponds to phosphate produced by regulator of G-protein signaling 9 (RGS9)-catalyzed hydrolysis of guanosine triphosphate (GTP) in G protein–phosphodiesterase complexes was found to be consistent with the results. These results provide a basis for the assessment with optoretinography of phototransduction in individual cone photoreceptors in health and during disease progression and therapeutic interventions.
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Fasciani I, Carli M, Petragnano F, Colaianni F, Aloisi G, Maggio R, Scarselli M, Rossi M. GPCRs in Intracellular Compartments: New Targets for Drug Discovery. Biomolecules 2022; 12:1343. [PMID: 36291552 PMCID: PMC9599219 DOI: 10.3390/biom12101343] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 08/02/2023] Open
Abstract
The architecture of eukaryotic cells is defined by extensive membrane-delimited compartments, which entails separate metabolic processes that would otherwise interfere with each other, leading to functional differences between cells. G protein-coupled receptors (GPCRs) are the largest class of cell surface receptors, and their signal transduction is traditionally viewed as a chain of events initiated from the plasma membrane. Furthermore, their intracellular trafficking, internalization, and recycling were considered only to regulate receptor desensitization and cell surface expression. On the contrary, accumulating data strongly suggest that GPCRs also signal from intracellular compartments. GPCRs localize in the membranes of endosomes, nucleus, Golgi and endoplasmic reticulum apparatuses, mitochondria, and cell division compartments. Importantly, from these sites they have shown to orchestrate multiple signals that regulate different cell pathways. In this review, we summarize the current knowledge of this fascinating phenomenon, explaining how GPCRs reach the intracellular sites, are stimulated by the endogenous ligands, and their potential physiological/pathophysiological roles. Finally, we illustrate several mechanisms involved in the modulation of the compartmentalized GPCR signaling by drugs and endogenous ligands. Understanding how GPCR signaling compartmentalization is regulated will provide a unique opportunity to develop novel pharmaceutical approaches to target GPCRs and potentially lead the way towards new therapeutic approaches.
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Affiliation(s)
- Irene Fasciani
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Marco Carli
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
| | - Francesco Petragnano
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Francesco Colaianni
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Gabriella Aloisi
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Roberto Maggio
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Marco Scarselli
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
| | - Mario Rossi
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
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Lewin AS, Smith WC. Gene Therapy for Rhodopsin Mutations. Cold Spring Harb Perspect Med 2022; 12:a041283. [PMID: 35940643 PMCID: PMC9435570 DOI: 10.1101/cshperspect.a041283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mutations in RHO, the gene for rhodopsin, account for a large fraction of autosomal-dominant retinitis pigmentosa (adRP). Patients fall into two clinical classes, those with early onset, pan retinal photoreceptor degeneration, and those who experience slowly progressive disease. The latter class of patients are candidates for photoreceptor-directed gene therapy, while former may be candidates for delivery of light-responsive proteins to interneurons or retinal ganglion cells. Gene therapy for RHO adRP may be targeted to the mutant gene at the DNA or RNA level, while other therapies preserve the viability of photoreceptors without addressing the underlying mutation. Correcting the RHO gene and replacing the mutant RNA show promise in animal models, while sustaining viable photoreceptors has the potential to delay the loss of central vision and may preserve photoreceptors for gene-directed treatments.
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Affiliation(s)
- Alfred S Lewin
- Departments of Molecular Genetics and Microbiology and Ophthalmology, University of Florida College of Medicine, Gainesville, Florida 32610, USA
| | - W Clay Smith
- Departments of Molecular Genetics and Microbiology and Ophthalmology, University of Florida College of Medicine, Gainesville, Florida 32610, USA
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Takatani N, Beppu F, Yamano Y, Maoka T, Miyashita K, Hosokawa M. Preparation of Apoastaxanthinals and Evaluation of Their Anti-inflammatory Action against Lipopolysaccharide-Stimulated Macrophages and Adipocytes. ACS OMEGA 2022; 7:22341-22350. [PMID: 35811858 PMCID: PMC9260902 DOI: 10.1021/acsomega.2c01164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
Apocarotenoids are carotenoid derivatives in which the polyene chain is cleaved via enzymatic or nonenzymatic action. They are found in animal tissues and carotenoid-containing foods. However, limited information on the biological functions of apocarotenoids is available. Here, we prepared apocarotenoids from astaxanthin via chemical oxidation and evaluated their anti-inflammatory action against macrophages and adipocytes. A series of astaxanthin-derived apoastaxanthinals, apo-11-, apo-15-, apo-14'-, apo-12'-, apo-10'-, and apo-8'-astaxanthinals, were successfully characterized by chromatography and spectroscopic analysis. The apoastaxanthinals inhibited inflammatory cytokine production and mRNA expression against lipopolysaccharide-stimulated RAW 264.7 macrophages. Apoastaxanthinals suppressed interleukin-6 overexpression in an in vitro model with macrophages and adipocytes in the following cultures: (1) contact coculture of 3T3-L1 adipocytes and RAW264.7 macrophages and (2) 3T3-L1 adipocytes in a RAW264.7-derived conditioned media. These results indicate that the apoastaxanthinals have the potential for regulation of adipose tissue inflammation observed in obesity.
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Affiliation(s)
- Naoki Takatani
- Faculty
of Fisheries Sciences, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido 041-8611, Japan
| | - Fumiaki Beppu
- Faculty
of Fisheries Sciences, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido 041-8611, Japan
| | - Yumiko Yamano
- Comprehensive
Education and Research Center, Kobe Pharmaceutical
University, 4-19-1 Motoyamakita-machi, Higashinada-ku, Kobe 658-8558, Japan
| | - Takashi Maoka
- Research
Institute for Production and Development, 15 Shimogamo-morimoto-cho, Sakyo-ku, Kyoto 606-0805, Japan
| | - Kazuo Miyashita
- Faculty
of Fisheries Sciences, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido 041-8611, Japan
| | - Masashi Hosokawa
- Faculty
of Fisheries Sciences, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido 041-8611, Japan
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Shi WJ, Long XB, Li SY, Ma DD, Liu F, Zhang JG, Lu ZJ, Ying GG. Dydrogesterone and levonorgestrel at environmentally relevant concentrations have antagonist effects with rhythmic oscillation in brain and eyes of zebrafish. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2022; 248:106177. [PMID: 35512552 DOI: 10.1016/j.aquatox.2022.106177] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/17/2022] [Accepted: 04/19/2022] [Indexed: 06/14/2023]
Abstract
Synthetic progestins levonorgestrel (LNG) and dydrogesterone (DDG) are frequency detected in surface water. Combined effects of LNG and DDG on gonad differentiation are similar to LNG single exposure in juvenile zebrafish. However, LNG and DDG mixtures have stronger effects on spermatogenesis in testes of adult zebrafish, which show variable at different life stage. Effects of LNG and DDG mixtures on eyes and brain remain unknown. Here we investigated effects of LNG, DDG and their mixtures on eyes and brain. Zebrafish were exposed to LNG, DDG and their mixtures from 2 hpf to 144 dpf. Rhythm and vision related biological processes were enriched in eyes and brain in LNG and DDG treatments, which indicated rhythmic oscillation in eyes and brain. The qPCR data revealed that both LNG and DDG decreased transcription of arntl2 and clocka, while increased transcription of per1a, per1b, rpe65a and tefa in eyes and brain. However, DDG and LNG mixtures had slight effect on transcription of genes related to rhythm and vision. In addition, LNG and DDG reduced the thickness of inner nuclear layer in the eyes. Bliss independent model revealed that LNG and DDG had antagonist effects on transcription and histology in eyes and brain. Moreover, LNG and DDG formed the same hydrogen bonds with green-sensitive opsin-4 and rhodopsin kinase GRK7a. Taken together, LNG and DDG competed with each other for the same binding residues resulting in antagonist effect in their mixtures treatments, and have significant ecological implications to assess combined effects of progestins mixtures on fish in different organs.
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Affiliation(s)
- Wen-Jun Shi
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Xiao-Bing Long
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Si-Ying Li
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Dong-Dong Ma
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Fang Liu
- School of Geography, South China Normal University, Guangzhou 510631, China.
| | - Jin-Ge Zhang
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Zhi-Jie Lu
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Guang-Guo Ying
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
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de Grip WJ, Ganapathy S. Rhodopsins: An Excitingly Versatile Protein Species for Research, Development and Creative Engineering. Front Chem 2022; 10:879609. [PMID: 35815212 PMCID: PMC9257189 DOI: 10.3389/fchem.2022.879609] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/16/2022] [Indexed: 01/17/2023] Open
Abstract
The first member and eponym of the rhodopsin family was identified in the 1930s as the visual pigment of the rod photoreceptor cell in the animal retina. It was found to be a membrane protein, owing its photosensitivity to the presence of a covalently bound chromophoric group. This group, derived from vitamin A, was appropriately dubbed retinal. In the 1970s a microbial counterpart of this species was discovered in an archaeon, being a membrane protein also harbouring retinal as a chromophore, and named bacteriorhodopsin. Since their discovery a photogenic panorama unfolded, where up to date new members and subspecies with a variety of light-driven functionality have been added to this family. The animal branch, meanwhile categorized as type-2 rhodopsins, turned out to form a large subclass in the superfamily of G protein-coupled receptors and are essential to multiple elements of light-dependent animal sensory physiology. The microbial branch, the type-1 rhodopsins, largely function as light-driven ion pumps or channels, but also contain sensory-active and enzyme-sustaining subspecies. In this review we will follow the development of this exciting membrane protein panorama in a representative number of highlights and will present a prospect of their extraordinary future potential.
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Affiliation(s)
- Willem J. de Grip
- Leiden Institute of Chemistry, Department of Biophysical Organic Chemistry, Leiden University, Leiden, Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Srividya Ganapathy
- Department of Imaging Physics, Delft University of Technology, Netherlands
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Mercey O, Kostic C, Bertiaux E, Giroud A, Sadian Y, Gaboriau DCA, Morrison CG, Chang N, Arsenijevic Y, Guichard P, Hamel V. The connecting cilium inner scaffold provides a structural foundation that protects against retinal degeneration. PLoS Biol 2022; 20:e3001649. [PMID: 35709082 PMCID: PMC9202906 DOI: 10.1371/journal.pbio.3001649] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/27/2022] [Indexed: 12/17/2022] Open
Abstract
Inherited retinal degeneration due to loss of photoreceptor cells is a leading cause of human blindness. These cells possess a photosensitive outer segment linked to the cell body through the connecting cilium (CC). While structural defects of the CC have been associated with retinal degeneration, its nanoscale molecular composition, assembly, and function are barely known. Here, using expansion microscopy and electron microscopy, we reveal the molecular architecture of the CC and demonstrate that microtubules are linked together by a CC inner scaffold containing POC5, CENTRIN, and FAM161A. Dissecting CC inner scaffold assembly during photoreceptor development in mouse revealed that it acts as a structural zipper, progressively bridging microtubule doublets and straightening the CC. Furthermore, we show that Fam161a disruption in mouse leads to specific CC inner scaffold loss and triggers microtubule doublet spreading, prior to outer segment collapse and photoreceptor degeneration, suggesting a molecular mechanism for a subtype of retinitis pigmentosa. Inherited retinal degeneration due to loss of photoreceptor cells is a leading cause of human blindness. Ultrastructure expansion microscopy on mouse retina reveals the presence of a novel structure inside the photoreceptor connecting cilium, the inner scaffold, that protects the outer segment against degeneration.
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Affiliation(s)
- Olivier Mercey
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Corinne Kostic
- Group for Retinal Disorder Research, Department of Ophthalmology, University Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Eloïse Bertiaux
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Alexia Giroud
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Yashar Sadian
- CryoGenic Facility, University of Geneva, Geneva, Switzerland
| | - David C. A. Gaboriau
- Centre for Chromosome Biology, National University of Ireland Galway, Galway, Ireland
| | - Ciaran G. Morrison
- Centre for Chromosome Biology, National University of Ireland Galway, Galway, Ireland
| | - Ning Chang
- Unit of Retinal Degeneration and Regeneration, Department of Ophthalmology, University Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Yvan Arsenijevic
- Unit of Retinal Degeneration and Regeneration, Department of Ophthalmology, University Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Paul Guichard
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
- * E-mail: (PG); (VH)
| | - Virginie Hamel
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
- * E-mail: (PG); (VH)
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Manoj KM, Tamagawa H, Bazhin N, Jaeken L, Nirusimhan V, Faraci F, Gideon DA. Murburn model of vision: Precepts and proof of concept. J Cell Physiol 2022; 237:3338-3355. [PMID: 35662017 DOI: 10.1002/jcp.30786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/05/2022] [Accepted: 05/14/2022] [Indexed: 11/08/2022]
Abstract
The classical paradigm of visual physiology comprises of the following features: (i) rod/cone cells located at the rear end of the retina serve as the primary transducers of incoming photo-information, (ii) cis-trans retinal (C20 H28 O) transformations on rhodopsin act as the transduction switch to generate a transmittable signal, (iii) signal amplification occurs via GDP-GTP exchange at transducin, and (iv) the amplified signal is relayed (as an action potential) as a flux-based ripple of Na-K ions along the axons of neurons. Fundamental physical principles, chemical kinetics, and awareness of architecture of eye/retina prompt a questioning of these classical assumptions. In lieu, based on experimental and in silico findings, a simple space-time resolved murburn model for the physiology of phototransduction in the retina is presented wherein molecular oxygen plays key roles. It is advocated that: (a) photo-induced oxygen to superoxide conversion serves as the key step in signal transduction in the visual cycle, (b) all photoactive cells of the retina serve as photoreceptors and rods/cones serve as the ultimate electron source in the retina (deriving oxygen and nutrients from retinal pigmented epithelium), (c) signal amplification is through superoxide mediated phosphorylation of GDP bound to inactive transducin, thereby activating a GDP-based cascade (a new mechanism for trimeric G-proteins), and (d) signal relay is primarily an electron movement along the neuron, from dendritic source to synaptic sink. In particular, we specify the roles for the various modules of transducin and GDP-based activation of phosphodiesterase-6 in the physiology of visual transduction.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Shoranur-2 (PO), Palakkad District, Kerala, India
| | | | - Nikolai Bazhin
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk, Russia
| | - Laurent Jaeken
- Karel de Grote-Hogeschool, Association University and High Schools Antwerp, Antwerpen, Belgium
| | - Vijay Nirusimhan
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Shoranur-2 (PO), Palakkad District, Kerala, India
| | - Federico Faraci
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Shoranur-2 (PO), Palakkad District, Kerala, India
| | - Daniel A Gideon
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Shoranur-2 (PO), Palakkad District, Kerala, India
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50
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Jahagirdar D, Yadav S, Gore M, Korpale V, Mathpati CS, Chidambaram S, Majumder A, Jain R, Dandekar P. Compartmentalized microfluidic device for in vitro co‐culture of retinal cells. Biotechnol J 2022; 17:e2100530. [DOI: 10.1002/biot.202100530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 06/01/2022] [Accepted: 06/01/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Devashree Jahagirdar
- Department of Pharmaceutical Sciences and Technology Institute of Chemical Technology Mumbai 400019 India
| | - Shital Yadav
- Department of Chemical Engineering Indian Institute of Technology Mumbai 400076 India
| | - Manish Gore
- Department of Pharmaceutical Sciences and Technology Institute of Chemical Technology Mumbai 400019 India
| | - Vikram Korpale
- Department of Chemical Engineering Institute of Chemical Technology Mumbai 400019 India
| | - C S Mathpati
- Department of Chemical Engineering Institute of Chemical Technology Mumbai 400019 India
| | - Subbulakshmi Chidambaram
- Dept. of Biochemistry and Molecular Biology Pondicherry Central University Puducherry 605014 India
| | - Abhijit Majumder
- Department of Chemical Engineering Indian Institute of Technology Mumbai 400076 India
| | - Ratnesh Jain
- Department of Chemical Engineering Institute of Chemical Technology Mumbai 400019 India
| | - Prajakta Dandekar
- Department of Pharmaceutical Sciences and Technology Institute of Chemical Technology Mumbai 400019 India
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