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Liu X, Shi P, Ge J. Analysis of PDE6G mutations in a patient with retinitis pigmentosa. BMC Ophthalmol 2024; 24:353. [PMID: 39160471 PMCID: PMC11334475 DOI: 10.1186/s12886-024-03623-2] [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: 05/01/2024] [Accepted: 08/07/2024] [Indexed: 08/21/2024] Open
Abstract
BACKGROUND Mutations in PDE6A and PDE6B are known to cause autosomal recessive RP in humans, On the other hand, mutations in PDE6G are rare but can lead to severe early-onset RP. CASE PRESENTATION An 8-year-old Chinese boy was referred to our hospital for poor vision issues. Refraction with cycloplegia showed high hyperopia with astigmatism both eyes. Funduscopic examination revealed typical bone spicule-type pigment deposits in the periphery and midperiphery. The patient was given glasses and a whole exome sequencing containing mitochondrial genes was performed. The results of genetic testing showed that there was a heterozygous frameshift mutation and a segment deletion in the proband's PDE6G gene. Analysis of the parental genes showed that frameshift mutation was inherited from the proband's mother and segment deletion from his father. CONCLUSIONS In this paper, we give a firsthand report that the complex heterozygous mutations of PDE6G gene can causes autosomal recessiveRP (arRP), which expands the understanding of the pathogenic genes of RP.
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Affiliation(s)
- Xiaona Liu
- Jinan Mingshui Eye Hospital, Longquan Road 5601, Zhangqiu District, Jinan, China
| | - Peiyan Shi
- Jinan Mingshui Eye Hospital, Longquan Road 5601, Zhangqiu District, Jinan, China
| | - Jinling Ge
- Jinan Mingshui Eye Hospital, Longquan Road 5601, Zhangqiu District, Jinan, China.
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2
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Liu Y, Zong X, Cao W, Zhang W, Zhang N, Yang N. Gene Therapy for Retinitis Pigmentosa: Current Challenges and New Progress. Biomolecules 2024; 14:903. [PMID: 39199291 DOI: 10.3390/biom14080903] [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: 06/21/2024] [Revised: 07/14/2024] [Accepted: 07/23/2024] [Indexed: 09/01/2024] Open
Abstract
Retinitis pigmentosa (RP) poses a significant threat to eye health worldwide, with prevalence rates of 1 in 5000 worldwide. This genetically diverse retinopathy is characterized by the loss of photoreceptor cells and atrophy of the retinal pigment epithelium. Despite the involvement of more than 3000 mutations across approximately 90 genes in its onset, finding an effective treatment has been challenging for a considerable time. However, advancements in scientific research, especially in gene therapy, are significantly expanding treatment options for this most prevalent inherited eye disease, with the discovery of new compounds, gene-editing techniques, and gene loci offering hope for more effective treatments. Gene therapy, a promising technology, utilizes viral or non-viral vectors to correct genetic defects by either replacing or silencing disease-causing genes, potentially leading to complete recovery. In this review, we primarily focus on the latest applications of gene editing research in RP. We delve into the most prevalent genes associated with RP and discuss advancements in genome-editing strategies currently employed to correct various disease-causing mutations.
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Affiliation(s)
- Yuchen Liu
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
| | - Xin Zong
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
| | - Wenye Cao
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
| | - Wenxi Zhang
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
| | - Ningzhi Zhang
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
| | - Ning Yang
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
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Ashok S, Ramachandra Rao S. Updates on protein-prenylation and associated inherited retinopathies. FRONTIERS IN OPHTHALMOLOGY 2024; 4:1410874. [PMID: 39026984 PMCID: PMC11254824 DOI: 10.3389/fopht.2024.1410874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 06/13/2024] [Indexed: 07/20/2024]
Abstract
Membrane-anchored proteins play critical roles in cell signaling, cellular architecture, and membrane biology. Hydrophilic proteins are post-translationally modified by a diverse range of lipid molecules such as phospholipids, glycosylphosphatidylinositol, and isoprenes, which allows their partition and anchorage to the cell membrane. In this review article, we discuss the biochemical basis of isoprenoid synthesis, the mechanisms of isoprene conjugation to proteins, and the functions of prenylated proteins in the neural retina. Recent discovery of novel prenyltransferases, prenylated protein chaperones, non-canonical prenylation-target motifs, and reversible prenylation is expected to increase the number of inherited systemic and blinding diseases with aberrant protein prenylation. Recent important investigations have also demonstrated the role of several unexpected regulators (such as protein charge, sequence/protein-chaperone interaction, light exposure history) in the photoreceptor trafficking of prenylated proteins. Technical advances in the investigation of the prenylated proteome and its application in vision research are discussed. Clinical updates and technical insights into known and putative prenylation-associated retinopathies are provided herein. Characterization of non-canonical prenylation mechanisms in the retina and retina-specific prenylated proteome is fundamental to the understanding of the pathogenesis of protein prenylation-associated inherited blinding disorders.
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Affiliation(s)
- Sudhat Ashok
- Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY, United States
| | - Sriganesh Ramachandra Rao
- Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY, United States
- Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY, United States
- Research Service, VA Western New York Healthcare System, Buffalo, NY, United States
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4
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Nouri Z, Sarmadi A, Narrei S, Kianersi H, Kianersi F, Tabatabaiefar MA. Clinical characterizations and molecular genetic study of two co-segregating variants in PDZD7 and PDE6C genes leading simultaneously to non-syndromic hearing loss and achromatopsia. BMC Med Genomics 2024; 17:173. [PMID: 38956522 PMCID: PMC11218353 DOI: 10.1186/s12920-024-01942-3] [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: 10/08/2023] [Accepted: 06/19/2024] [Indexed: 07/04/2024] Open
Abstract
BACKGROUND Autosomal recessive non-syndromic hearing loss (NSHL) and cone dystrophies (CODs) are highly genetically and phenotypically heterogeneous disorders. In this study, we applied the whole exome sequencing (WES) to find the cause of HL and COD in an Iranian consanguineous family with three affected individuals. METHODS Three members from an Iranian consanguineous family who were suffering from NSHL and visual impairment were ascertained in this study. Comprehensive clinical evaluations and genetic analysis followed by bioinformatic and co-segregation studies were performed to diagnose the cause of these phenotypes. Data were collected from 2020 to 2022. RESULTS All cases showed congenital bilateral NSHL, decreased visual acuity, poor color discrimination, photophobia and macular atrophy. Moreover, cornea, iris and anterior vitreous were within normal limit in both eyes, decreased foveal sensitivity, central scotoma and generalized depression of visual field were seen in three cases. WES results showed two variants, a novel null variant (p.Trp548Ter) in the PDE6C gene causing COD type 4 (Achromatopsia) and a previously reported variant (p.Ile84Thr) in the PDZD7 gene causing NSHL. Both variants were found in the cis configuration on chromosome 10 with a genetic distance of about 8.3 cM, leading to their co-inheritance. However, two diseases could appear independently in subsequent generations due to crossover during meiosis. CONCLUSIONS Here, we could successfully determine the etiology of a seemingly complex phenotype in two adjacent genes. We identified a novel variant in the PDE6C gene, related to achromatopsia. Interestingly, this variant could cooperatively cause visual disorders: cone dystrophy and cone-rod dystrophy.
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Affiliation(s)
- Zahra Nouri
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
- Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Akram Sarmadi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
- Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sina Narrei
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Research and Development, Harmonic Medical Genetics Lab, Isfahan, Iran
| | - Hamidreza Kianersi
- Isfahan Eye Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Farzan Kianersi
- Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammad Amin Tabatabaiefar
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
- Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
- University of Medical Sciences, Isfahan, 81746-73461, Iran.
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5
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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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6
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Sbornova I, van der Sande E, Milosavljevic S, Amurrio E, Burbano SD, Das PK, Do HH, Fisher JL, Kargbo P, Patel J, Porcher L, De Zeeuw CI, Meester-Smoor MA, Winkelman BHJ, Klaver CCW, Pocivavsek A, Kelly MP. The Sleep Quality- and Myopia-Linked PDE11A-Y727C Variant Impacts Neural Physiology by Reducing Catalytic Activity and Altering Subcellular Compartmentalization of the Enzyme. Cells 2023; 12:2839. [PMID: 38132157 PMCID: PMC10742168 DOI: 10.3390/cells12242839] [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: 11/17/2023] [Revised: 12/04/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
Recently, a Y727C variant in the dual-specific 3',5'-cyclic nucleotide phosphodiesterase 11A (PDE11A-Y727C) was linked to increased sleep quality and reduced myopia risk in humans. Given the well-established role that the PDE11 substrates cAMP and cGMP play in eye physiology and sleep, we determined if (1) PDE11A protein is expressed in the retina or other eye segments in mice, (2) PDE11A-Y7272C affects catalytic activity and/or subcellular compartmentalization more so than the nearby suicide-associated PDE11A-M878V variant, and (3) Pde11a deletion alters eye growth or sleep quality in male and female mice. Western blots show distinct protein expression of PDE11A4, but not PDE11A1-3, in eyes of Pde11a WT, but not KO mice, that vary by eye segment and age. In HT22 and COS-1 cells, PDE11A4-Y727C reduces PDE11A4 catalytic activity far more than PDE11A4-M878V, with both variants reducing PDE11A4-cAMP more so than PDE11A4-cGMP activity. Despite this, Pde11a deletion does not alter age-related changes in retinal or lens thickness or axial length, nor vitreous or anterior chamber depth. Further, Pde11a deletion only minimally changes refractive error and sleep quality. That said, both variants also dramatically alter the subcellular compartmentalization of human and mouse PDE11A4, an effect occurring independently of dephosphorylating PDE11A4-S117/S124 or phosphorylating PDE11A4-S162. Rather, re-compartmentalization of PDE11A4-Y727C is due to the loss of the tyrosine changing how PDE11A4 is packaged/repackaged via the trans-Golgi network. Therefore, the protective impact of the Y727C variant may reflect a gain-of-function (e.g., PDE11A4 displacing another PDE) that warrants further investigation in the context of reversing/preventing sleep disturbances or myopia.
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Affiliation(s)
- Irina Sbornova
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA (P.K.D.); (J.P.)
| | - Emilie van der Sande
- Department of Ophthalmology, Erasmus Medical Center, Wytemaweg 40, 3015 CN Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Wytemaweg 40, 3015 CN Rotterdam, The Netherlands
- The Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Art & Science (KNAW), Meibergdreef 47, 1105 AZ Amsterdam, The Netherlands
| | - Snezana Milosavljevic
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Garners Ferry Rd., Columbia, SC 29209, USA
| | - Elvis Amurrio
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA (P.K.D.); (J.P.)
| | - Steven D. Burbano
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA (P.K.D.); (J.P.)
| | - Prosun K. Das
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA (P.K.D.); (J.P.)
| | - Helen H. Do
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA (P.K.D.); (J.P.)
| | - Janet L. Fisher
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Garners Ferry Rd., Columbia, SC 29209, USA
| | - Porschderek Kargbo
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA (P.K.D.); (J.P.)
| | - Janvi Patel
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA (P.K.D.); (J.P.)
| | - Latarsha Porcher
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA (P.K.D.); (J.P.)
| | - Chris I. De Zeeuw
- The Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Art & Science (KNAW), Meibergdreef 47, 1105 AZ Amsterdam, The Netherlands
- Department of Neuroscience, Erasmus Medical Center, Wytemaweg 40, 3015 CN Rotterdam, The Netherlands
| | - Magda A. Meester-Smoor
- Department of Ophthalmology, Erasmus Medical Center, Wytemaweg 40, 3015 CN Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Wytemaweg 40, 3015 CN Rotterdam, The Netherlands
| | - Beerend H. J. Winkelman
- Department of Ophthalmology, Erasmus Medical Center, Wytemaweg 40, 3015 CN Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Wytemaweg 40, 3015 CN Rotterdam, The Netherlands
- The Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Art & Science (KNAW), Meibergdreef 47, 1105 AZ Amsterdam, The Netherlands
- Department of Neuroscience, Erasmus Medical Center, Wytemaweg 40, 3015 CN Rotterdam, The Netherlands
| | - Caroline C. W. Klaver
- Department of Ophthalmology, Erasmus Medical Center, Wytemaweg 40, 3015 CN Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Wytemaweg 40, 3015 CN Rotterdam, The Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
- Institute of Molecular and Clinical Ophthalmology, Mittlere Strasse 91, 4070 Basel, Switzerland
| | - Ana Pocivavsek
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Garners Ferry Rd., Columbia, SC 29209, USA
| | - Michy P. Kelly
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA (P.K.D.); (J.P.)
- Center for Research on Aging, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA
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7
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Sbornova I, van der Sande E, Milosavljevic S, Amurrio E, Burbano SD, Das P, Do H, Fisher JL, Kargbo P, Patel J, Porcher L, De Zeeuw CI, Meester-Smoor MA, Winkelman BH, Klaver CC, Pocivavsek A, Kelly MP. The sleep quality- and myopia-linked PDE11A-Y727C variant impacts neural physiology by reducing catalytic activity and altering subcellular compartmentalization of the enzyme. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.16.567422. [PMID: 38014312 PMCID: PMC10680747 DOI: 10.1101/2023.11.16.567422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Recently, a Y727C variant in the dual-specific 3',5'-cyclic nucleotide phosphodiesterase 11A (PDE11A-Y727C) was linked to increased sleep quality and reduced myopia risk in humans. Given the well-established role that the PDE11 substrates cAMP and cGMP play in eye physiology and sleep, we determined if 1) PDE11A protein is expressed in the retina or other eye segments in mouse, 2) PDE11A-Y7272C affects catalytic activity and/or subcellular compartmentalization more so than the nearby suicide-associated PDE11A-M878V variant, and 3) Pde11a deletion alters eye growth or sleep quality in male and female mice. Western blots show distinct protein expression of PDE11A4, but not PDE11A1-3, in eyes of Pde11a WT-but not KO mice-that vary by eye segment and age. In HT22 and COS-1 cells, PDE11A4-Y727C reduces PDE11A4 catalytic activity far more than PDE11A4-M878V, with both variants reducing PDE11A4-cAMP more so than PDE11A4-cGMP activity. Despite this, Pde11a deletion does not alter age-related changes in retinal or lens thickness, axial length, nor vitreous or anterior chamber depth. Further, Pde11a deletion only minimally changes refractive error and sleep quality. That said, both variants also dramatically alter the subcellular compartmentalization of human and mouse PDE11A4, an effect occurring independently of dephosphorylating PDE11A4-S117/S124 or phosphorylating PDE11A4-S162. Rather, re-compartmentalization of PDE11A4-Y727C is due to the loss of the tyrosine changing how PDE11A4 is packaged/repackaged via the trans-Golgi network. Therefore, the protective impact of the Y727C variant may reflect a gain-of-function (e.g., PDE11A4 displacing another PDE) that warrants further investigation in the context of reversing/preventing sleep disturbances or myopia.
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Affiliation(s)
- Irina Sbornova
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201
| | - Emilie van der Sande
- Department of Ophthalmology, Erasmus Medical Center, Wytemaweg 40, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Wytemaweg 40, Rotterdam, The Netherlands
- The Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Art & Science (KNAW), Meibergdreef 47, Amsterdam, The Netherlands
| | - Snezana Milosavljevic
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Garners Ferry Rd, Columbia, SC
| | - Elvis Amurrio
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201
| | - Steven D. Burbano
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201
| | - Prosun Das
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201
| | - Helen Do
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201
| | - Janet L. Fisher
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Garners Ferry Rd, Columbia, SC
| | - Porschderek Kargbo
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201
| | - Janvi Patel
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201
| | - Latarsha Porcher
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201
| | - Chris I. De Zeeuw
- The Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Art & Science (KNAW), Meibergdreef 47, Amsterdam, The Netherlands
- Department of Neuroscience, Erasmus Medical Center, Wytemaweg 40, Rotterdam, The Netherlands
| | - Magda A Meester-Smoor
- Department of Ophthalmology, Erasmus Medical Center, Wytemaweg 40, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Wytemaweg 40, Rotterdam, The Netherlands
| | - Beerend H.J. Winkelman
- Department of Ophthalmology, Erasmus Medical Center, Wytemaweg 40, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Wytemaweg 40, Rotterdam, The Netherlands
- The Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Art & Science (KNAW), Meibergdreef 47, Amsterdam, The Netherlands
- Department of Neuroscience, Erasmus Medical Center, Wytemaweg 40, Rotterdam, The Netherlands
| | - Caroline C.W. Klaver
- Department of Ophthalmology, Erasmus Medical Center, Wytemaweg 40, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Wytemaweg 40, Rotterdam, The Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Geert Grooteplein Zuid 10, Nijmegen, The Netherlands
- Institute of Molecular and Clinical Ophthalmology, Mittlere Strasse 91, Basel, Switzerland
| | - Ana Pocivavsek
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Garners Ferry Rd, Columbia, SC
| | - Michy P. Kelly
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201
- Center for Research on Aging, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201
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Badawi A, Magliyah M, Alabbasi O, AlAbdi L, Alkuraya FS, Schatz P, ALBalawi HB, Mura M. Cone dystrophy associated with autoimmune polyglandular syndrome type 1. Sci Rep 2023; 13:11223. [PMID: 37433860 DOI: 10.1038/s41598-023-38419-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 07/07/2023] [Indexed: 07/13/2023] Open
Abstract
To report the association of autoimmune polyglandular syndrome type 1 (APS1) with cone dystrophy in a large Saudi family. This is a Retrospective chart review and prospective genetic testing and ophthalmic examination of a large multiplex consanguineous family. Genetic testing was performed on 14 family members, seven of whom had detailed ophthalmic examinations. Medical history, ocular history and evaluation, visual field testing, full-field electroretinogram (ERG), and Whole Exome Sequencing (WES) results were analyzed. Three family members were homozygous for c.205_208dupCAGG;p.(Asp70Alafs*148) in AIRE and homozygous for c.481-1G>A in PDE6C. One additional family member was homozygous for only the AIRE variant and another additional family member was homozygous for only the PDE6C variant. All patients with homozygosity for the PDE6C variant had cone dystrophy, and all patients with homozygosity for the AIRE variant had APS1. In addition, two of the family members who were homozygous for the PDE6C and AIRE variants had reduced rod function on ERG. We report the co-inheritance for APS1 and PDE6C-related cone dystrophy, an unusual example of two seemingly independent recessive conditions coinciding within a family. Dual molecular diagnosis must be taken into account by ophthalmologists facing unusual constellations of findings, especially in consanguineous families.
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Affiliation(s)
- Abdulrahman Badawi
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Moustafa Magliyah
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
- Ophthalmology Department, Prince Mohammed Medical City, AlJouf, Saudi Arabia
| | - Omar Alabbasi
- Ophthalmology Department, Almadinah Almonawwarah Hospital, Madinah, Saudi Arabia
| | - Lama AlAbdi
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Department of Zoology, Collage of Science, King Saud University, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Patrik Schatz
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
- Department of Ophthalmology, Clinical Sciences, Skane University Hospital, University of Lund, Lund, Sweden
| | - Hani Basher ALBalawi
- Ophthalmology Division, Department of Surgery, Faculty of Medicine, University of Tabuk, Tabuk City, Saudi Arabia.
| | - Marco Mura
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
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9
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Li S, Ma H, Yang F, Ding X. cGMP Signaling in Photoreceptor Degeneration. Int J Mol Sci 2023; 24:11200. [PMID: 37446378 PMCID: PMC10342299 DOI: 10.3390/ijms241311200] [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: 05/23/2023] [Revised: 07/04/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Photoreceptors in the retina are highly specialized neurons with photosensitive molecules in the outer segment that transform light into chemical and electrical signals, and these signals are ultimately relayed to the visual cortex in the brain to form vision. Photoreceptors are composed of rods and cones. Rods are responsible for dim light vision, whereas cones are responsible for bright light, color vision, and visual acuity. Photoreceptors undergo progressive degeneration over time in many hereditary and age-related retinal diseases. Despite the remarkable heterogeneity of disease-causing genes, environmental factors, and pathogenesis, the progressive death of rod and cone photoreceptors ultimately leads to loss of vision/blindness. There are currently no treatments available for retinal degeneration. Cyclic guanosine 3', 5'-monophosphate (cGMP) plays a pivotal role in phototransduction. cGMP governs the cyclic nucleotide-gated (CNG) channels on the plasma membrane of the photoreceptor outer segments, thereby regulating membrane potential and signal transmission. By gating the CNG channels, cGMP regulates cellular Ca2+ homeostasis and signal transduction. As a second messenger, cGMP activates the cGMP-dependent protein kinase G (PKG), which regulates numerous targets/cellular events. The dysregulation of cGMP signaling is observed in varieties of photoreceptor/retinal degenerative diseases. Abnormally elevated cGMP signaling interferes with various cellular events, which ultimately leads to photoreceptor degeneration. In line with this, strategies to reduce cellular cGMP signaling result in photoreceptor protection in mouse models of retinal degeneration. The potential mechanisms underlying cGMP signaling-induced photoreceptor degeneration involve the activation of PKG and impaired Ca2+ homeostasis/Ca2+ overload, resulting from overactivation of the CNG channels, as well as the subsequent activation of the downstream cellular stress/death pathways. Thus, targeting the cellular cGMP/PKG signaling and the Ca2+-regulating pathways represents a significant strategy for photoreceptor protection in retinal degenerative diseases.
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Affiliation(s)
| | | | | | - Xiqin Ding
- Department of Cell Biology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.L.); (H.M.); (F.Y.)
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10
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Munezero D, Aliff H, Salido E, Saravanan T, Sanzhaeva U, Guan T, Ramamurthy V. HSP90α is needed for the survival of rod photoreceptors and regulates the expression of rod PDE6 subunits. J Biol Chem 2023; 299:104809. [PMID: 37172722 PMCID: PMC10250166 DOI: 10.1016/j.jbc.2023.104809] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 05/15/2023] Open
Abstract
Heat shock protein 90 (HSP90) is an abundant molecular chaperone that regulates the stability of a small set of proteins essential in various cellular pathways. Cytosolic HSP90 has two closely related paralogs: HSP90α and HSP90β. Due to the structural and sequence similarities of cytosolic HSP90 paralogs, identifying the unique functions and substrates in the cell remains challenging. In this article, we assessed the role of HSP90α in the retina using a novel HSP90α murine knockout model. Our findings show that HSP90α is essential for rod photoreceptor function but was dispensable in cone photoreceptors. In the absence of HSP90α, photoreceptors developed normally. We observed rod dysfunction in HSP90α knockout at 2 months with the accumulation of vacuolar structures, apoptotic nuclei, and abnormalities in the outer segments. The decline in rod function was accompanied by progressive degeneration of rod photoreceptors that was complete at 6 months. The deterioration in cone function and health was a "bystander effect" that followed the degeneration of rods. Tandem mass tag proteomics showed that HSP90α regulates the expression levels of <1% of the retinal proteome. More importantly, HSP90α was vital in maintaining rod PDE6 and AIPL1 cochaperone levels in rod photoreceptor cells. Interestingly, cone PDE6 levels were unaffected. The robust expression of HSP90β paralog in cones likely compensates for the loss of HSP90α. Overall, our study demonstrated the critical need for HSP90α chaperone in the maintenance of rod photoreceptors and showed potential substrates regulated by HSP90α in the retina.
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Affiliation(s)
- Daniella Munezero
- Department of Pharmaceutical and Pharmacological Sciences, West Virginia University, Morgantown, West Virginia, USA; Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, USA
| | - Hunter Aliff
- Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, USA; Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, USA
| | - Ezequiel Salido
- Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, USA; Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, USA
| | - Thamaraiselvi Saravanan
- Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, USA; Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, USA
| | - Urikhan Sanzhaeva
- Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, USA; Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, USA
| | - Tongju Guan
- Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, USA; Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, USA
| | - Visvanathan Ramamurthy
- Department of Pharmaceutical and Pharmacological Sciences, West Virginia University, Morgantown, West Virginia, USA; Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, USA; Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, USA.
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11
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Srivastava D, Yadav RP, Singh S, Boyd K, Artemyev NO. Unique interface and dynamics of the complex of HSP90 with a specialized cochaperone AIPL1. Structure 2023; 31:309-317.e5. [PMID: 36657440 PMCID: PMC9992320 DOI: 10.1016/j.str.2022.12.014] [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: 10/17/2022] [Revised: 12/06/2022] [Accepted: 12/23/2022] [Indexed: 01/19/2023]
Abstract
Photoreceptor phosphodiesterase PDE6 is central for visual signal transduction. Maturation of PDE6 depends on a specialized chaperone complex of HSP90 with aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1). Disruption of PDE6 maturation underlies a severe form of retina degeneration. Here, we report a 3.9 Å cryoelectron microscopy (cryo-EM) structure of the complex of HSP90 with AIPL1. This structure reveals a unique interaction of the FK506-binding protein (FKBP)-like domain of AIPL1 with HSP90 at its dimer interface. Unusually, the N terminus AIPL1 inserts into the HSP90 lumen in a manner that was observed previously for HSP90 clients. Deletion of the 7 N-terminal residues of AIPL1 decreased its ability to cochaperone PDE6. Multi-body refinement of the cryo-EM data indicated large swing-like movements of AIPL1-FKBP. Modeling the complex of HSP90 with AIPL1 using crosslinking constraints indicated proximity of the mobile tetratricopeptide repeat (TPR) domain with the C-terminal domain of HSP90. Our study establishes a framework for future structural studies of PDE6 maturation.
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Affiliation(s)
- Dhiraj Srivastava
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Ravi P Yadav
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Sneha Singh
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Kimberly Boyd
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Nikolai O Artemyev
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Department of Ophthalmology and Visual Sciences, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
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12
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Yang X, Xu Z, Hu S, Shen J. Perspectives of PDE inhibitor on treating idiopathic pulmonary fibrosis. Front Pharmacol 2023; 14:1111393. [PMID: 36865908 PMCID: PMC9973527 DOI: 10.3389/fphar.2023.1111393] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/03/2023] [Indexed: 02/16/2023] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease (ILD) without an identifiable cause. If not treated after diagnosis, the average life expectancy is 3-5 years. Currently approved drugs for the treatment of IPF are Pirfenidone and Nintedanib, as antifibrotic drugs, which can reduce the decline rate of forced vital capacity (FVC) and reduce the risk of acute exacerbation of IPF. However these drugs can not relieve the symptoms associated with IPF, nor improve the overall survival rate of IPF patients. We need to develop new, safe and effective drugs to treat pulmonary fibrosis. Previous studies have shown that cyclic nucleotides participate in the pathway and play an essential role in the process of pulmonary fibrosis. Phosphodiesterase (PDEs) is involved in cyclic nucleotide metabolism, so PDE inhibitors are candidates for pulmonary fibrosis. This paper reviews the research progress of PDE inhibitors related to pulmonary fibrosis, so as to provide ideas for the development of anti-pulmonary fibrosis drugs.
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Affiliation(s)
- Xudan Yang
- Department of Respiratory and Critical Care Medicine, The Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, China
| | | | - Songhua Hu
- Department of Respiratory and Critical Care Medicine, The Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, China
| | - Juan Shen
- Department of Respiratory and Critical Care Medicine, The Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, China
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13
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Inhibition of the MAPK/c-Jun-EGR1 Pathway Decreases Photoreceptor Cell Death in the rd1 Mouse Model for Inherited Retinal Degeneration. Int J Mol Sci 2022; 23:ijms232314600. [PMID: 36498926 PMCID: PMC9740268 DOI: 10.3390/ijms232314600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/17/2022] [Accepted: 11/20/2022] [Indexed: 11/24/2022] Open
Abstract
Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies that typically results in photoreceptor cell death and vision loss. Here, we explored the effect of early growth response-1 (EGR1) expression on photoreceptor cell death in Pde6brd1 (rd1) mice and its mechanism of action. To this end, single-cell RNA-seq (scRNA-seq) was used to identify differentially expressed genes in rd1 and congenic wild-type (WT) mice. Chromatin immunoprecipitation (ChIP), the dual-luciferase reporter gene assay, and western blotting were used to verify the relationship between EGR1 and poly (ADP-ribose) polymerase-1 (PARP1). Immunofluorescence staining was used to assess PARP1 expression after silencing or overexpression of EGR1. Photoreceptor cell death was assessed using the TUNEL assay following silencing/overexpression of EGR1 or administration of MAPK/c-Jun pathway inhibitors tanzisertib and PD98059. Our results showed differential expression of ERG1 in rd1 and WT mice via scRNA-seq analysis. The ChIP assay demonstrated EGR1 binding to the PARP1 promoter region. The dual-luciferase reporter gene assay and western blotting results revealed that EGR1 upregulated PARP1 expression. Additionally, the TUNEL assay showed that silencing EGR1 effectively reduced photoreceptor cell death. Similarly, the addition of tanzisertib and PD98059 reduced the expression of c-Jun and EGR1 and decreased photoreceptor cell death. Our study revealed that inhibition of the MAPK/c-Jun pathway reduced the expression of EGR1 and PARP1 and prevented photoreceptor cell death. These results highlight the importance of EGR1 for photoreceptor cell death and identify a new avenue for therapeutic interventions in RP.
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14
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Bhardwaj A, Yadav A, Yadav M, Tanwar M. Genetic dissection of non-syndromic retinitis pigmentosa. Indian J Ophthalmol 2022; 70:2355-2385. [PMID: 35791117 PMCID: PMC9426071 DOI: 10.4103/ijo.ijo_46_22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Retinitis pigmentosa (RP) belongs to a group of pigmentary retinopathies. It is the most common form of inherited retinal dystrophy, characterized by progressive degradation of photoreceptors that leads to nyctalopia, and ultimately, complete vision loss. RP is distinguished by the continuous retinal degeneration that progresses from the mid-periphery to the central and peripheral retina. RP was first described and named by Franciscus Cornelius Donders in the year 1857. It is one of the leading causes of bilateral blindness in adults, with an incidence of 1 in 3000 people worldwide. In this review, we are going to focus on the genetic heterogeneity of this disease, which is provided by various inheritance patterns, numerosity of variations and inter-/intra-familial variations based upon penetrance and expressivity. Although over 90 genes have been identified in RP patients, the genetic cause of approximately 50% of RP cases remains unknown. Heterogeneity of RP makes it an extremely complicated ocular impairment. It is so complicated that it is known as “fever of unknown origin”. For prognosis and proper management of the disease, it is necessary to understand its genetic heterogeneity so that each phenotype related to the various genetic variations could be treated.
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Affiliation(s)
- Aarti Bhardwaj
- Department of Genetics, M. D. University, Rohtak, Haryana, India
| | - Anshu Yadav
- Department of Genetics, M. D. University, Rohtak, Haryana, India
| | - Manoj Yadav
- Department of Genetics, M. D. University, Rohtak, Haryana, India
| | - Mukesh Tanwar
- Department of Genetics, M. D. University, Rohtak, Haryana, India
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15
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Yadav RP, Boyd K, Artemyev NO. Molecular insights into the maturation of phosphodiesterase 6 by the specialized chaperone complex of HSP90 with AIPL1. J Biol Chem 2022; 298:101620. [PMID: 35065964 PMCID: PMC8857470 DOI: 10.1016/j.jbc.2022.101620] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 12/18/2022] Open
Abstract
Phosphodiesterase 6 (PDE6) is a key effector enzyme in vertebrate phototransduction, and its maturation and function are known to critically depend on a specialized chaperone, aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1). Defects in PDE6 and AIPL1 underlie several severe retinal diseases, including retinitis pigmentosa and Leber congenital amaurosis. Here, we characterize the complex of AIPL1 with HSP90 and demonstrate its essential role in promoting the functional conformation of nascent PDE6. Our analysis suggests that AIPL1 preferentially binds to HSP90 in the closed state with a stoichiometry of 1:2, with the tetratricopeptide repeat domain and the tetratricopeptide repeat helix 7 extension of AIPL1 being the main contributors to the AIPL1/HSP90 interface. We demonstrate that mutations of these determinants markedly diminished both the affinity of AIPL1 for HSP90 and the ability of AIPL1 to cochaperone the maturation of PDE6 in a heterologous expression system. In addition, the FK506-binding protein (FKBP) domain of AIPL1 encloses a unique prenyl-binding site that anchors AIPL1 to posttranslational lipid modifications of PDE6. A mouse model with rod PDE6 lacking farnesylation of its PDE6A subunit revealed normal expression, trafficking, and signaling of the enzyme. Furthermore, AIPL1 was unexpectedly capable of inducing the maturation of unprenylated cone PDE6C, whereas mutant AIPL1 deficient in prenyl binding competently cochaperoned prenylated PDE6C. Thus, we conclude neither sequestration of the prenyl modifications is required for PDE6 maturation to proceed, nor is the FKBP-lipid interaction involved in the conformational switch of the enzyme into the functional state.
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Affiliation(s)
- Ravi P Yadav
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Kimberly Boyd
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Nikolai O Artemyev
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, Iowa, USA; Department of Ophthalmology and Visual Sciences, The University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
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16
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Xu W, Li Y, Dong Y, Xiao L, Li L, Jiao K. Integrative RNA-seq and ATAC-seq analyses of phosphodiesterase 6 mutation-induced retinitis pigmentosa. Int Ophthalmol 2022; 42:2385-2395. [PMID: 35147831 DOI: 10.1007/s10792-022-02238-0] [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: 07/20/2021] [Accepted: 01/13/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE Inhibition of poly-ADP-ribose polymerase 1 (PARP1) could relieve phosphodiesterase 6 mutation-induced retinitis pigmentosa (RP). However, the mechanism related to PARP1 overexpression in the RP has not been clarified. We attempted to explore the potential mechanism related to PARP1 regulating RP. METHODS ATAC-seq and RNA-seq were performed for retina tissues of C3H and rd1 mice. The differentially expressed genes (DEGs) were identified, followed by the construction of PARP1-DEG co-expression and protein-protein interaction (PPI) networks. Gene ontology-biological process and pathway enrichment of DEGs were performed by clusterProfiler software. The overlapped genes that might play regulatory roles in PARP1 expression were mined by integrated analysis of RNA-seq and ATAC-seq data. RESULTS A total of 1061 DEGs were identified between C3H and rd1 group. Co-expression network was constructed with 313 PARP1-gene co-expression pairs. The down-regulated DEGs were closely related to visual perception and light stimulus-related biological process, while the up-regulated DEGs were significantly enriched in phototransduction and PPAR signaling pathway. PPI network was constructed with 202 nodes and 375 edges, which was clustered into 3 modules. Module 1 genes were closely related to detection of light stimulus, visual perception related biological process and phototransduction pathway (involved with Gnat1/Guca1b/Gnat2/Sag/Pde6g). By integrated analysis of the RNA-seq and ATAC-seq, the overlapped up-regulated genes were Asxl3 and Nyap2, while the down-regulated genes were Tmem136 and Susd3. CONCLUSION Gnat1 may play a key role in RP development by interacting with PARP1. Susd3 may play a regulatory role in PARP1 expression and affect RP formation.
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Affiliation(s)
- Wenrong Xu
- Kunming Medical University, Kunming, 650500, Yunnan, China
- Department of Ophthalmology, The Affiliated Calmette Hospital of Kunming Medical University, 650024, Kunming, Yunnan, China
| | - Yan Li
- Department of Ophthalmology, Affiliated Hospital of Yunnan University, Yunnan University, 650021, Kunming, China
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Yunnan University, 176 Qingnian, Kunming, 650021, China
| | - Yujie Dong
- Kunming Medical University, Kunming, 650500, Yunnan, China
- Department of Ophthalmology, Affiliated Hospital of Yunnan University, Yunnan University, 650021, Kunming, China
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Yunnan University, 176 Qingnian, Kunming, 650021, China
| | - Libo Xiao
- Kunming Medical University, Kunming, 650500, Yunnan, China
- Department of Ophthalmology, Affiliated Hospital of Yunnan University, Yunnan University, 650021, Kunming, China
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Yunnan University, 176 Qingnian, Kunming, 650021, China
| | - Lan Li
- Kunming Medical University, Kunming, 650500, Yunnan, China.
- Department of Ophthalmology, The Affiliated Calmette Hospital of Kunming Medical University, 650024, Kunming, Yunnan, China.
| | - Kangwei Jiao
- Kunming Medical University, Kunming, 650500, Yunnan, China.
- Department of Ophthalmology, Affiliated Hospital of Yunnan University, Yunnan University, 650021, Kunming, China.
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Yunnan University, 176 Qingnian, Kunming, 650021, China.
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17
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Madeira C, Godinho G, Grangeia A, Falcão M, Silva R, Carneiro Â, Brandão E, Magalhães A, Falcão-Reis F, Estrela-Silva S. Two Novel Disease-Causing Variants in the PDE6C Gene Underlying Achromatopsia. Case Rep Ophthalmol 2021; 12:749-760. [PMID: 34720973 PMCID: PMC8460892 DOI: 10.1159/000512284] [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: 07/02/2020] [Accepted: 10/10/2020] [Indexed: 12/03/2022] Open
Abstract
We report the clinical phenotype and genetic findings of two variants in PDE6C underlying achromatopsia (ACHM). Four patients with the variant c.1670G>A in exon 13 of the PDE6C gene were identified. Additionally, one had compound heterozygous genotype, with two variants in the PDE6C gene, a variant of c.2192G>A in exon 18 and c.1670G>A in exon 13. All patients presented the symptomatic triad of decreased visual acuity, severe photophobia, and colour vision disturbances. SD-OCT showed an absence of the ellipsoid zone, creating an optically empty cavity at the fovea in three patients. The patient with the compound heterozygous genotype presented a more severe subfoveal outer retina atrophy. ERG recordings showed extinguished responses under photopic and 30-Hz flicker stimulation, with a normal rod response. We identified two new variants in the PDE6C gene that leads to ACHM.
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Affiliation(s)
- Carolina Madeira
- Department of Ophthalmology, Centro Hospitalar e Universitário de São João Hospital, Porto, Portugal
| | - Gonçalo Godinho
- Department of Ophthalmology, Centro Hospitalar e Universitário de São João Hospital, Porto, Portugal
| | - Ana Grangeia
- Department of Genetics, Centro Hospitalar e Universitário de São João Hospital, Porto, Portugal
| | - Manuel Falcão
- Department of Ophthalmology, Centro Hospitalar e Universitário de São João Hospital, Porto, Portugal.,Department of Surgery and Physiology, Faculty of Medicine of University of Porto, Porto, Portugal
| | - Renato Silva
- Department of Ophthalmology, Centro Hospitalar e Universitário de São João Hospital, Porto, Portugal.,Department of Surgery and Physiology, Faculty of Medicine of University of Porto, Porto, Portugal
| | - Ângela Carneiro
- Department of Ophthalmology, Centro Hospitalar e Universitário de São João Hospital, Porto, Portugal.,Department of Surgery and Physiology, Faculty of Medicine of University of Porto, Porto, Portugal
| | - Elisete Brandão
- Department of Ophthalmology, Centro Hospitalar e Universitário de São João Hospital, Porto, Portugal
| | - Augusto Magalhães
- Department of Ophthalmology, Centro Hospitalar e Universitário de São João Hospital, Porto, Portugal
| | - Fernando Falcão-Reis
- Department of Ophthalmology, Centro Hospitalar e Universitário de São João Hospital, Porto, Portugal.,Department of Surgery and Physiology, Faculty of Medicine of University of Porto, Porto, Portugal
| | - Sérgio Estrela-Silva
- Department of Ophthalmology, Centro Hospitalar e Universitário de São João Hospital, Porto, Portugal.,Department of Surgery and Physiology, Faculty of Medicine of University of Porto, Porto, Portugal
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18
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Daich Varela M, Ullah E, Yousaf S, Brooks BP, Hufnagel RB, Huryn LA. PDE6C: Novel Mutations, Atypical Phenotype, and Differences Among Children and Adults. Invest Ophthalmol Vis Sci 2021; 61:1. [PMID: 33001157 PMCID: PMC7545085 DOI: 10.1167/iovs.61.12.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Purpose Genetic variation in PDE6C is associated with achromatopsia and cone dystrophy, with only a few reports of cone-rod dystrophy in the literature. We describe two pediatric and two adult patients with PDE6C related cone and cone-rod dystrophy and the first longitudinal data of a pediatric patient with PDE6C-related cone dystrophy. Methods This cohort of four patients underwent comprehensive ophthalmologic evaluation at the National Eye Institute's Ophthalmic Genetics clinic, including visual field testing, retinal imaging and electroretinogram (ERG). Next-generation sequencing-based genetic testing was performed and subsequent analysis of the variants was done through three-dimensional protein models generated by Phyre2 and Chimera. Results All cases shared decreased best-corrected visual acuity and poor color discrimination. Three of the four patients had a cone-rod dystrophy, presenting with an ERG showing decreased amplitude on both photopic and scotopic waveforms and a mild to moderately constricted visual field. One of the children was diagnosed with cone dystrophy, having a preserved peripheral field. The children had none to minor structural retinal changes, whereas the adults had clear macular dystrophy. Conclusions PDE6C-related cone-rod dystrophy consists of a severe phenotype characterized by early-onset nystagmus, decreased best-corrected visual acuity, poor color discrimination, progressive constriction of the visual field, and night blindness. Our work contributes with valuable information toward understanding the visual prognosis and allelic heterogeneity of PDE6C-related cone and cone-rod dystrophy.
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Affiliation(s)
- Malena Daich Varela
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Ehsan Ullah
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Sairah Yousaf
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Laryssa A Huryn
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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19
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Li S, Datta S, Brabbit E, Love Z, Woytowicz V, Flattery K, Capri J, Yao K, Wu S, Imboden M, Upadhyay A, Arumugham R, Thoreson WB, DeAngelis MM, Haider NB. Nr2e3 is a genetic modifier that rescues retinal degeneration and promotes homeostasis in multiple models of retinitis pigmentosa. Gene Ther 2021; 28:223-241. [PMID: 32123325 PMCID: PMC7483267 DOI: 10.1038/s41434-020-0134-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 02/05/2020] [Accepted: 02/18/2020] [Indexed: 12/21/2022]
Abstract
Recent advances in viral vector engineering, as well as an increased understanding of the cellular and molecular mechanism of retinal diseases, have led to the development of novel gene therapy approaches. Furthermore, ease of accessibility and ocular immune privilege makes the retina an ideal target for gene therapies. In this study, the nuclear hormone receptor gene Nr2e3 was evaluated for efficacy as broad-spectrum therapy to attenuate early to intermediate stages of retinal degeneration in five unique mouse models of retinitis pigmentosa (RP). RP is a group of heterogenic inherited retinal diseases associated with over 150 gene mutations, affecting over 1.5 million individuals worldwide. RP varies in age of onset, severity, and rate of progression. In addition, ~40% of RP patients cannot be genetically diagnosed, confounding the ability to develop personalized RP therapies. Remarkably, Nr2e3 administered therapy resulted in reduced retinal degeneration as observed by increase in photoreceptor cells, improved electroretinogram, and a dramatic molecular reset of key transcription factors and associated gene networks. These therapeutic effects improved retinal homeostasis in diseased tissue. Results of this study provide evidence that Nr2e3 can serve as a broad-spectrum therapy to treat multiple forms of RP.
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Affiliation(s)
- Sujun Li
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Shyamtanu Datta
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Emily Brabbit
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Zoe Love
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Victoria Woytowicz
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Kyle Flattery
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Jessica Capri
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Katie Yao
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Siqi Wu
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | | | | | | | - Wallace B Thoreson
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, USA
| | | | - Neena B Haider
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
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20
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Photoreceptor phosphodiesterase (PDE6): activation and inactivation mechanisms during visual transduction in rods and cones. Pflugers Arch 2021; 473:1377-1391. [PMID: 33860373 DOI: 10.1007/s00424-021-02562-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/27/2021] [Accepted: 03/30/2021] [Indexed: 01/16/2023]
Abstract
Rod and cone photoreceptors of the vertebrate retina utilize cGMP as the primary intracellular messenger for the visual signaling pathway that converts a light stimulus into an electrical response. cGMP metabolism in the signal-transducing photoreceptor outer segment reflects the balance of cGMP synthesis (catalyzed by guanylyl cyclase) and degradation (catalyzed by the photoreceptor phosphodiesterase, PDE6). Upon light stimulation, rapid activation of PDE6 by the heterotrimeric G-protein (transducin) triggers a dramatic drop in cGMP levels that lead to cell hyperpolarization. Following cessation of the light stimulus, the lifetime of activated PDE6 is also precisely regulated by additional processes. This review summarizes recent advances in the structural characterization of the rod and cone PDE6 catalytic and regulatory subunits in the context of previous biochemical studies of the enzymological properties and allosteric regulation of PDE6. Emphasis is given to recent advances in understanding the structural and conformational changes underlying the mechanism by which the activated transducin α-subunit binds to-and relieves inhibition of-PDE6 catalysis that is controlled by its intrinsically disordered, inhibitory γ-subunit. The role of the regulator of G-protein signaling 9-1 (RGS9-1) in regulating the lifetime of the transducin-PDE6 is also briefly covered. The therapeutic potential of pharmacological compounds acting as inhibitors or activators targeting PDE6 is discussed in the context of inherited retinal diseases resulting from mutations in rod and cone PDE6 genes as well as other inherited defects that arise from excessive cGMP accumulation in retinal photoreceptor cells.
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21
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Gupta R, Liu Y, Wang H, Nordyke CT, Puterbaugh RZ, Cui W, Varga K, Chu F, Ke H, Vashisth H, Cote RH. Structural Analysis of the Regulatory GAF Domains of cGMP Phosphodiesterase Elucidates the Allosteric Communication Pathway. J Mol Biol 2020; 432:5765-5783. [PMID: 32898583 PMCID: PMC7572642 DOI: 10.1016/j.jmb.2020.08.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/28/2020] [Accepted: 08/31/2020] [Indexed: 12/26/2022]
Abstract
Regulation of photoreceptor phosphodiesterase (PDE6) activity is responsible for the speed, sensitivity, and recovery of the photoresponse during visual signaling in vertebrate photoreceptor cells. It is hypothesized that physiological differences in the light responsiveness of rods and cones may result in part from differences in the structure and regulation of the distinct isoforms of rod and cone PDE6. Although rod and cone PDE6 catalytic subunits share a similar domain organization consisting of tandem GAF domains (GAFa and GAFb) and a catalytic domain, cone PDE6 is a homodimer whereas rod PDE6 consists of two homologous catalytic subunits. Here we provide the x-ray crystal structure of cone GAFab regulatory domain solved at 3.3 Å resolution, in conjunction with chemical cross-linking and mass spectrometric analysis of conformational changes to GAFab induced upon binding of cGMP and the PDE6 inhibitory γ-subunit (Pγ). Ligand-induced changes in cross-linked residues implicate multiple conformational changes in the GAFa and GAFb domains in forming an allosteric communication network. Molecular dynamics simulations of cone GAFab revealed differences in conformational dynamics of the two subunits forming the homodimer and allosteric perturbations on cGMP binding. Cross-linking of Pγ to GAFab in conjunction with solution NMR spectroscopy of isotopically labeled Pγ identified the central polycationic region of Pγ interacting with the GAFb domain. These results provide a mechanistic basis for developing allosteric activators of PDE6 with therapeutic implications for halting the progression of several retinal degenerative diseases.
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Affiliation(s)
- Richa Gupta
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, 46 College Rd., Durham, NH 03824, USA
| | - Yong Liu
- Department of Chemical Engineering, University of New Hampshire, 33 Academic Way, Durham, NH 03824, USA
| | - Huanchen Wang
- Signal Transduction Laboratory, NIEHS/NIH, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Christopher T Nordyke
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, 46 College Rd., Durham, NH 03824, USA
| | - Ryan Z Puterbaugh
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, 46 College Rd., Durham, NH 03824, USA
| | - Wenjun Cui
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Krisztina Varga
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, 46 College Rd., Durham, NH 03824, USA
| | - Feixia Chu
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, 46 College Rd., Durham, NH 03824, USA
| | - Hengming Ke
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Harish Vashisth
- Department of Chemical Engineering, University of New Hampshire, 33 Academic Way, Durham, NH 03824, USA
| | - Rick H Cote
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, 46 College Rd., Durham, NH 03824, USA.
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Yuan S, Qi R, Fang X, Wang X, Zhou L, Sheng X. Two novel PDE6C gene mutations in Chinese family with achromatopsia. Ophthalmic Genet 2020; 41:591-598. [PMID: 32787476 DOI: 10.1080/13816810.2020.1802762] [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: 10/23/2022]
Abstract
Background: Achromatopsia (ACHM) is an inherited retinal disease affecting the cone cell function. To date, six pathogenic genes of ACHM have been identified. However, the diagnostic and therapeutic methods of this disorder remain limited. Herein, to characterize the clinical features and genetic causes of three affected siblings in a Chinese family with ACHM, we used target next-generation sequencing (NGS) and found new pathogenic factors associated with ACHM in this family. Materials and methods: Three patients with ACHM and three healthy family members were included in this study. All participants received comprehensive ophthalmic tests. NGS approach was performed on the patients to determine the causative mutation for this family. The silico analysis was also applied to predict the pathogenesis of identified mutations. Results: Genetic assessments revealed compound heterozygous mutations of the PDE6C gene (c.1413 + 1 G > C, c.305 G > A), carried by all three patients. Both mutations were novel and predicted to be deleterious by six types of online predictive software. The heterozygous PDE6C missense mutation (c.305 G > A) was found from the mother and the heterozygous PDE6C splice site mutation (c.1413 + 1 G > C) was found in the father and all the children. All patients in the family showed typical signs and symptoms of ACHM. Conclusions: We report novel compound heterozygous PDE6C mutations in causing ACHM and further confirm the clinical diagnosis. Our study extends the genotypic spectrums for PDE6C-ACHM and better illustrates its genotype-phenotype correlations, which would help the ACHM patients with better genetic diagnosis, prognosis, and gene treatment.
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Affiliation(s)
- Shiqin Yuan
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Rui Qi
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China.,Aier Eye Hospital Group, Hubin Aier Eye Hospital , Binzhou, Shangdong, China
| | - Xinhe Fang
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Xiaoguang Wang
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Liang Zhou
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Xunlun Sheng
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
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Progressive Effects of Sildenafil on Visual Processing in Rats. Neuroscience 2020; 441:131-141. [PMID: 32615234 DOI: 10.1016/j.neuroscience.2020.06.033] [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: 02/04/2020] [Revised: 05/26/2020] [Accepted: 06/23/2020] [Indexed: 10/24/2022]
Abstract
Photoreceptors are light-sensitive cells in the retina converting visual stimuli into electrochemical signals. These signals are evaluated and interpreted in the visual pathway, a process referred to as visual processing. Phosphodiesterase type 5 and 6 (PDE5 and 6) are abundant enzymes in retinal vessels and notably photoreceptors where PDE6 is exclusively present. The effects of the PDE inhibitor sildenafil on the visual system, have been studied using electroretinography and a variety of clinical visual tasks. Here we evaluate effects of sildenafil administration by electrophysiological recordings of flash visual evoked potentials (VEPs) and steady-state visual evoked potentials (SSVEPs) from key regions in the rodent visual pathway. Progressive changes were investigated in female Sprague-Dawley rats at 10 timepoints from 30 min to 28 h after peroral administration of sildenafil (50 mg/kg). Sildenafil caused a significant reduction in the amplitude of VEPs in both visual cortex and superior colliculus, and a significant delay of the VEPs as demonstrated by increased latency of several VEP peaks. Also, sildenafil-treatment significantly reduced the signal-to-noise ratio of SSVEPs. The effects of sildenafil were dependent on the wavelength condition in both assays. Our results support the observation that while PDE6 is a key player in phototransduction, near full inhibition of PDE6 is not enough to abolish the complex process of visual processing. Taken together, VEPs and SSVEPs are effective in demonstrating progressive effects of drug-induced changes in visual processing in rats and as the same paradigms may be applied in humans, representing a promising tool for translational research.
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24
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Bushehri A, Zare-Abdollahi D, Hashemian H, Safavizadeh L, Effati J, Khorram Khorshid HR. Novel Bi-allelic PDE6C Variant Leads to Congenital Achromatopsia. IRANIAN BIOMEDICAL JOURNAL 2020; 24:257-63. [PMID: 32306724 PMCID: PMC7275818 DOI: 10.29252/ibj.24.4.257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 08/14/2019] [Indexed: 10/31/2022]
Abstract
Background The clinical phenotyping of patients with achromatopsia harboring variants in phosphordiesterase 6C (PDE6C) has poorly been described in the literature. PDE6C encodes the catalytic subunit of the cone phosphodiesterase, which hydrolyzes the cyclic guanosine monophosphate that proceeds with the hyperpolarization of photoreceptor cell membranes, as the final step of the phototransduction cascade. Methods In the current study, two patients from a consanguineous family underwent full ophthalmologic examination and molecular investigations including WES. The impact of the variant on the functionality of the protein has been analyzed using in silico molecular modeling. Results The patients identified with achromatopsia segregated a homozygous missense variant (c.C1775A:p.A592D) in PDE6C gene located on chromosome 10q23. Molecular modeling demonstrated that the variant would cause a protein conformational change and result in reduced phosphodiesterase activity. Conclusion Our data extended the phenotypic spectrum of retinal disorders caused by PDE6C variants and provided new clinical and genetic information on achromatopsia.
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Affiliation(s)
- Ata Bushehri
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Davood Zare-Abdollahi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Hesam Hashemian
- Department of Ophthalmology, Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Ladan Safavizadeh
- Department of Opthomology, Ophthalmic Research Centre, Shahid Beheshti University (M.C.), Tehran, Iran
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Saddala MS, Lennikov A, Bouras A, Huang H. RNA-Seq reveals differential expression profiles and functional annotation of genes involved in retinal degeneration in Pde6c mutant Danio rerio. BMC Genomics 2020; 21:132. [PMID: 32033529 PMCID: PMC7006399 DOI: 10.1186/s12864-020-6550-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 01/31/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Retinal degenerative diseases affect millions of people and represent the leading cause of vision loss around the world. Retinal degeneration has been attributed to a wide variety of causes, such as disruption of genes involved in phototransduction, biosynthesis, folding of the rhodopsin molecule, and the structural support of the retina. The molecular pathogenesis of the biological events in retinal degeneration is unclear; however, the molecular basis of the retinal pathological defect can be potentially determined by gene-expression profiling of the whole retina. In the present study, we analyzed the differential gene expression profile of the retina from a wild-type zebrafish and phosphodiesterase 6c (pde6c) mutant. RESULTS The datasets were downloaded from the Sequence Read Archive (SRA), and adaptors and unbiased bases were removed, and sequences were checked to ensure the quality. The reads were further aligned to the reference genome of zebrafish, and the gene expression was calculated. The differentially expressed genes (DEGs) were filtered based on the log fold change (logFC) (±4) and p-values (p < 0.001). We performed gene annotation (molecular function [MF], biological process [BP], cellular component [CC]), and determined the functional pathways Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for the DEGs. Our result showed 216 upregulated and 3527 downregulated genes between normal and pde6c mutant zebrafish. These DEGs are involved in various KEGG pathways, such as the phototransduction (12 genes), mRNA surveillance (17 genes), phagosome (25 genes), glycolysis/gluconeogenesis (15 genes), adrenergic signaling in cardiomyocytes (29 genes), ribosome (20 genes), the citrate cycle (TCA cycle; 8 genes), insulin signaling (24 genes), oxidative phosphorylation (20 genes), and RNA transport (22 genes) pathways. Many more of all the pathway genes were down-regulated, while fewer were up-regulated in the retina of pde6c mutant zebrafish. CONCLUSIONS Our data strongly indicate that, among these genes, the above-mentioned pathways' genes as well as calcium-binding, neural damage, peptidase, immunological, and apoptosis proteins are mostly involved in the retinal and neural degeneration that cause abnormalities in photoreceptors or retinal pigment epithelium (RPE) cells.
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Affiliation(s)
- Madhu Sudhana Saddala
- School of Medicine, Department Ophthalmology, Mason Eye Institute, University of Missouri-Columbia, One Hospital Drive, MA102C, Columbia, MO, 65212, USA
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Anton Lennikov
- School of Medicine, Department Ophthalmology, Mason Eye Institute, University of Missouri-Columbia, One Hospital Drive, MA102C, Columbia, MO, 65212, USA
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Adam Bouras
- School of Medicine, Department Ophthalmology, Mason Eye Institute, University of Missouri-Columbia, One Hospital Drive, MA102C, Columbia, MO, 65212, USA
| | - Hu Huang
- School of Medicine, Department Ophthalmology, Mason Eye Institute, University of Missouri-Columbia, One Hospital Drive, MA102C, Columbia, MO, 65212, USA.
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA.
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26
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Chakrabarty S, Savantre SB, Ramachandra Bhat C, Satyamoorthy K. Multiple genetic mutations implicate spectrum of phenotypes in Bardet-Biedl syndrome. Gene 2020; 725:144164. [PMID: 31639430 DOI: 10.1016/j.gene.2019.144164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 09/14/2019] [Accepted: 10/08/2019] [Indexed: 11/17/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a clinically and genetically heterogeneous ciliopathy with several clinical features including retinitis pigmentosa, obesity, kidney dysfunction, postaxial polydactyly, behavioral dysfunction and hypogonadism with wide spectrum of additional features. With multiple phenotypes and heterogeneous distribution, it is unlikely that BBS is caused by single gene defect. We have performed clinical and genetic diagnosis of two individuals from an Indian family with classical BBS symptoms. Whole exome sequencing identified homozygous missense mutation in BBS10 gene, hemizygous missense AR and homozygous missense PDE6B mutations in the proband and affected sibling with BBS. Identification of BBS10 mutation along with AR and PDE6B gene mutation will expand the genetic and phenotypic spectrum in individuals with BBS.
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Affiliation(s)
- Sanjiban Chakrabarty
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Swheta B Savantre
- Department of Medicine, K.V.G. Medical College & Hospital, Dakshina Kannada, Sullia 574327, India
| | - C Ramachandra Bhat
- Department of Medicine, K.V.G. Medical College & Hospital, Dakshina Kannada, Sullia 574327, India
| | - Kapaettu Satyamoorthy
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India.
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27
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Power M, Das S, Schütze K, Marigo V, Ekström P, Paquet-Durand F. Cellular mechanisms of hereditary photoreceptor degeneration - Focus on cGMP. Prog Retin Eye Res 2019; 74:100772. [PMID: 31374251 DOI: 10.1016/j.preteyeres.2019.07.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 07/25/2019] [Accepted: 07/29/2019] [Indexed: 12/21/2022]
Abstract
The cellular mechanisms underlying hereditary photoreceptor degeneration are still poorly understood, a problem that is exacerbated by the enormous genetic heterogeneity of this disease group. However, the last decade has yielded a wealth of new knowledge on degenerative pathways and their diversity. Notably, a central role of cGMP-signalling has surfaced for photoreceptor cell death triggered by a subset of disease-causing mutations. In this review, we examine key aspects relevant for photoreceptor degeneration of hereditary origin. The topics covered include energy metabolism, epigenetics, protein quality control, as well as cGMP- and Ca2+-signalling, and how the related molecular and metabolic processes may trigger photoreceptor demise. We compare and integrate evidence on different cell death mechanisms that have been associated with photoreceptor degeneration, including apoptosis, necrosis, necroptosis, and PARthanatos. A special focus is then put on the mechanisms of cGMP-dependent cell death and how exceedingly high photoreceptor cGMP levels may cause activation of Ca2+-dependent calpain-type proteases, histone deacetylases and poly-ADP-ribose polymerase. An evaluation of the available literature reveals that a large group of patients suffering from hereditary photoreceptor degeneration carry mutations that are likely to trigger cGMP-dependent cell death, making this pathway a prime target for future therapy development. Finally, an outlook is given into technological and methodological developments that will with time likely contribute to a comprehensive overview over the entire metabolic complexity of photoreceptor cell death. Building on such developments, new imaging technology and novel biomarkers may be used to develop clinical test strategies, that fully consider the genetic heterogeneity of hereditary retinal degenerations, in order to facilitate clinical testing of novel treatment approaches.
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Affiliation(s)
- Michael Power
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany; Centre for Integrative Neurosciences (CIN), University of Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), University of Tübingen, Germany
| | - Soumyaparna Das
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), University of Tübingen, Germany
| | | | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, Italy
| | - Per Ekström
- Ophthalmology, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Sweden
| | - François Paquet-Durand
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany.
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Wang X, Plachetzki DC, Cote RH. The N termini of the inhibitory γ-subunits of phosphodiesterase-6 (PDE6) from rod and cone photoreceptors differentially regulate transducin-mediated PDE6 activation. J Biol Chem 2019; 294:8351-8360. [PMID: 30962282 DOI: 10.1074/jbc.ra119.007520] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 04/02/2019] [Indexed: 12/26/2022] Open
Abstract
Phosphodiesterase-6 (PDE6) plays a central role in both rod and cone phototransduction pathways. In the dark, PDE6 activity is suppressed by its inhibitory γ-subunit (Pγ). Rhodopsin-catalyzed activation of the G protein transducin relieves this inhibition and enhances PDE6 catalysis. We hypothesized that amino acid sequence differences between rod- and cone-specific Pγs underlie transducin's ability to more effectively activate cone-specific PDE6 than rod PDE6. To test this, we analyzed rod and cone Pγ sequences from all major vertebrate and cyclostome lineages and found that rod Pγ loci are far more conserved than cone Pγ sequences and that most of the sequence differences are located in the N-terminal region. Next we reconstituted rod PDE6 catalytic dimer (Pαβ) with various rod or cone Pγ variants and analyzed PDE6 activation upon addition of the activated transducin α-subunit (Gtα*-GTPγS). This analysis revealed a rod-specific Pγ motif (amino acids 9-18) that reduces the ability of Gtα*-GTPγS to activate the reconstituted PDE6. In cone Pγ, Asn-13 and Gln-14 significantly enhanced Gtα*-GTPγS activation of cone Pγ truncation variants. Moreover, we observed that the first four amino acids of either rod or cone Pγ contribute to Gtα*-GTPγS-mediated activation of PDE6. We conclude that physiological differences between rod and cone photoreceptor light responsiveness can be partially ascribed to ancient, highly conserved amino acid differences in the N-terminal regions of Pγ isoforms, demonstrating for the first time a functional role for this region of Pγ in the differential activation of rod and cone PDE6 by transducin.
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Affiliation(s)
- Xin Wang
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire 03824
| | - David C Plachetzki
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire 03824
| | - Rick H Cote
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire 03824.
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29
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PDE10A mutations help to unwrap the neurobiology of hyperkinetic disorders. Cell Signal 2019; 60:31-38. [PMID: 30951862 DOI: 10.1016/j.cellsig.2019.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/31/2019] [Accepted: 04/01/2019] [Indexed: 12/31/2022]
Abstract
The dual-specific cAMP/cGMP phosphodiesterase PDE10A is exclusively localised to regions of the brain and specific cell types that control crucial brain circuits and behaviours. The downside to this expression pattern is that PDE10A is also positioned to be a key player in pathology when its function is perturbed. The last decade of research has seen a clear role emerge for PDE10A inhibition in modifying behaviours in animal models of psychosis and Huntington's disease. Unfortunately, this has not translated to the human diseases as expected. More recently, a series of families with hyperkinetic movement disorders have been identified with mutations altering the PDE10A protein sequence. As these mutations have been analysed and characterised in other model systems, we are beginning to learn more about PDE10A function and perhaps catch a glimpse into how PDE10A activity could be modified for therapeutic benefit.
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30
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Yu L, Yadav RP, Artemyev NO. NMR resonance assignments of the TPR domain of human aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1). BIOMOLECULAR NMR ASSIGNMENTS 2019; 13:79-83. [PMID: 30341566 PMCID: PMC6440825 DOI: 10.1007/s12104-018-9856-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 10/14/2018] [Indexed: 06/08/2023]
Abstract
Aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1) is a photoreceptor-specific chaperone of phosphodiesterase-6, a key effector enzyme in the phototransduction cascade. It contains an N-terminal FK506-binding protein (FKBP) domain and a C-terminal tetratricopeptide repeat (TPR) domain. Mutations in AIPL1, including many missense mutations in both FKBP and TPR domains, have been associated with Leber congenital amaurosis, a severe inherited retinopathy that causes blindness. TPR-domain containing proteins are known to interact with HSP90. However, the structure of AIPL1-TPR domain is presently not determined and little is known about the contribution of the TPR domain to the chaperone function of AIPL1. Here, we report the backbone and sidechain assignments of the TPR domain of AIPL1. These assignments reveal that AIPL1-TPR is an α-helical protein containing seven α-helices connected via short loops. Peak broadening or structural disorder is observed for a cluster of hydrophobic residues of W218, W222 and L223. Therefore, these assignments provide a framework for further structural determination of AIPL1-TPR domain and its interactions with various binding partners for elucidation of the mechanism of TPR contribution to the chaperone function of AIPL1.
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Affiliation(s)
- Liping Yu
- Department of Biochemistry, University of Iowa Carver College of Medicine, B291 CBRB, 285 Newton Road, Iowa City, IA, 52242, USA.
- CCOM NMR Core Facility, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
| | - Ravi P Yadav
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, 5-532 BSB, 51 Newton Road, Iowa City, IA, 52242, USA
| | - Nikolai O Artemyev
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, 5-532 BSB, 51 Newton Road, Iowa City, IA, 52242, USA.
- Department of Ophthalmology and Visual Sciences, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
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31
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Moshiri A, Chen R, Kim S, Harris RA, Li Y, Raveendran M, Davis S, Liang Q, Pomerantz O, Wang J, Garzel L, Cameron A, Yiu G, Stout JT, Huang Y, Murphy CJ, Roberts J, Gopalakrishna KN, Boyd K, Artemyev NO, Rogers J, Thomasy SM. A nonhuman primate model of inherited retinal disease. J Clin Invest 2019; 129:863-874. [PMID: 30667376 PMCID: PMC6355306 DOI: 10.1172/jci123980] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 11/15/2018] [Indexed: 12/30/2022] Open
Abstract
Inherited retinal degenerations are a common cause of untreatable blindness worldwide, with retinitis pigmentosa and cone dystrophy affecting approximately 1 in 3500 and 1 in 10,000 individuals, respectively. A major limitation to the development of effective therapies is the lack of availability of animal models that fully replicate the human condition. Particularly for cone disorders, rodent, canine, and feline models with no true macula have substantive limitations. By contrast, the cone-rich macula of a nonhuman primate (NHP) closely mirrors that of the human retina. Consequently, well-defined NHP models of heritable retinal diseases, particularly cone disorders that are predictive of human conditions, are necessary to more efficiently advance new therapies for patients. We have identified 4 related NHPs at the California National Primate Research Center with visual impairment and findings from clinical ophthalmic examination, advanced retinal imaging, and electrophysiology consistent with achromatopsia. Genetic sequencing confirmed a homozygous R565Q missense mutation in the catalytic domain of PDE6C, a cone-specific phototransduction enzyme associated with achromatopsia in humans. Biochemical studies demonstrate that the mutant mRNA is translated into a stable protein that displays normal cellular localization but is unable to hydrolyze cyclic GMP (cGMP). This NHP model of a cone disorder will not only serve as a therapeutic testing ground for achromatopsia gene replacement, but also for optimization of gene editing in the macula and of cone cell replacement in general.
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Affiliation(s)
- Ala Moshiri
- Department of Ophthalmology & Vision Science, School of Medicine, UC Davis, Sacramento, California, USA
| | - Rui Chen
- Human Genome Sequencing Center and Department of Molecular and Human Genetics, and.,Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Soohyun Kim
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - R Alan Harris
- Human Genome Sequencing Center and Department of Molecular and Human Genetics, and
| | - Yumei Li
- Human Genome Sequencing Center and Department of Molecular and Human Genetics, and
| | | | - Sarah Davis
- California National Primate Research Center, Davis, California, USA
| | - Qingnan Liang
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Ori Pomerantz
- California National Primate Research Center, Davis, California, USA
| | - Jun Wang
- Human Genome Sequencing Center and Department of Molecular and Human Genetics, and
| | - Laura Garzel
- California National Primate Research Center, Davis, California, USA
| | - Ashley Cameron
- California National Primate Research Center, Davis, California, USA
| | - Glenn Yiu
- Department of Ophthalmology & Vision Science, School of Medicine, UC Davis, Sacramento, California, USA
| | - J Timothy Stout
- Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA
| | | | - Christopher J Murphy
- Department of Ophthalmology & Vision Science, School of Medicine, UC Davis, Sacramento, California, USA.,Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, USA.,EyeKor Inc., Madison, Wisconsin, USA
| | - Jeffrey Roberts
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, USA.,California National Primate Research Center, Davis, California, USA
| | | | - Kimberly Boyd
- Department of Molecular Physiology and Biophysics, and
| | - Nikolai O Artemyev
- Department of Molecular Physiology and Biophysics, and.,Department of Ophthalmology and Visual Sciences, The University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Jeffrey Rogers
- Human Genome Sequencing Center and Department of Molecular and Human Genetics, and
| | - Sara M Thomasy
- Department of Ophthalmology & Vision Science, School of Medicine, UC Davis, Sacramento, California, USA.,Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
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Sokolov M, Yadav RP, Brooks C, Artemyev NO. Chaperones and retinal disorders. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2018; 114:85-117. [PMID: 30635087 DOI: 10.1016/bs.apcsb.2018.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Defects in protein folding and trafficking are a common cause of photoreceptor degeneration, causing blindness. Photoreceptor cells present an unusual challenge to the protein folding and transport machinery due to the high rate of protein synthesis, trafficking and the renewal of the outer segment, a primary cilium that has been modified into a specialized light-sensing compartment. Phototransduction components, such as rhodopsin and cGMP-phosphodiesterase, and multimeric ciliary transport complexes, such as the BBSome, are hotspots for mutations that disrupt proteostasis and lead to the death of photoreceptors. In this chapter, we review recent studies that advance our understanding of the chaperone and transport machinery of phototransduction proteins.
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Affiliation(s)
- Maxim Sokolov
- Department of Ophthalmology, West Virginia University, Morgantown, WV, United States
| | - Ravi P Yadav
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Celine Brooks
- Department of Ophthalmology, West Virginia University, Morgantown, WV, United States
| | - Nikolai O Artemyev
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, IA, United States; Department of Ophthalmology and Visual Sciences, The University of Iowa Carver College of Medicine, Iowa City, IA, United States.
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Mittal R, Bencie N, Parrish JM, Liu G, Mittal J, Yan D, Liu XZ. An Update on Phosphodiesterase Mutations Underlying Genetic Etiology of Hearing Loss and Retinitis Pigmentosa. Front Genet 2018; 9:9. [PMID: 29472945 PMCID: PMC5809491 DOI: 10.3389/fgene.2018.00009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 01/09/2018] [Indexed: 12/24/2022] Open
Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Nicole Bencie
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - James M Parrish
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - George Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Jeenu Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States.,Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, United States
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Yadav RP, Artemyev NO. AIPL1: A specialized chaperone for the phototransduction effector. Cell Signal 2017; 40:183-189. [PMID: 28939106 PMCID: PMC6022367 DOI: 10.1016/j.cellsig.2017.09.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/11/2017] [Accepted: 09/18/2017] [Indexed: 12/12/2022]
Abstract
Molecular chaperones play pivotal roles in protein folding, quality control, assembly of multimeric protein complexes, protein trafficking, stress responses, and other essential cellular processes. Retinal photoreceptor rod and cone cells have an unusually high demand for production, quality control, and trafficking of key phototransduction components, and thus, require a robust and specialized chaperone machinery to ensure the fidelity of sensing and transmission of visual signals. Misfolding and/or mistrafficking of photoreceptor proteins are known causes for debilitating blinding diseases. Phosphodiesterase 6, the effector enzyme of the phototransduction cascade, relies on a unique chaperone aryl hydrocarbon receptor (AhR)-interacting protein-like 1 (AIPL1) for its stability and function. The structure of AIPL1 and its relationship with the client remained obscure until recently. This review summarizes important recent advances in understanding the mechanisms underlying normal function of AIPL1 and the protein perturbations caused by pathogenic mutations.
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Affiliation(s)
- Ravi P Yadav
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, United States
| | - Nikolai O Artemyev
- Department of Molecular Physiology and Biophysics, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, United States; Department of Ophthalmology and Visual Sciences, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, United States.
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