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Starr CR, Gorbatyuk MS. Posttranslational modifications of proteins in diseased retina. Front Cell Neurosci 2023; 17:1150220. [PMID: 37066080 PMCID: PMC10097899 DOI: 10.3389/fncel.2023.1150220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Posttranslational modifications (PTMs) are known to constitute a key step in protein biosynthesis and in the regulation of protein functions. Recent breakthroughs in protein purification strategies and current proteome technologies make it possible to identify the proteomics of healthy and diseased retinas. Despite these advantages, the research field identifying sets of posttranslationally modified proteins (PTMomes) related to diseased retinas is significantly lagging, despite knowledge of the major retina PTMome being critical to drug development. In this review, we highlight current updates regarding the PTMomes in three retinal degenerative diseases-namely, diabetic retinopathy (DR), glaucoma, and retinitis pigmentosa (RP). A literature search reveals the necessity to expedite investigations into essential PTMomes in the diseased retina and validate their physiological roles. This knowledge would accelerate the development of treatments for retinal degenerative disorders and the prevention of blindness in affected populations.
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Affiliation(s)
| | - Marina S. Gorbatyuk
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
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2
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Hu R, Cui R, Lan D, Wang F, Wang Y. Acyl Chain Specificity of Marine Streptomyces klenkii PhosPholipase D and Its Application in Enzymatic Preparation of Phosphatidylserine. Int J Mol Sci 2021; 22:10580. [PMID: 34638918 PMCID: PMC8508628 DOI: 10.3390/ijms221910580] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 02/04/2023] Open
Abstract
Mining of phospholipase D (PLD) with altered acyl group recognition except its head group specificity is also useful in terms of specific acyl size phospholipid production and as diagnostic reagents for quantifying specific phospholipid species. Microbial PLDs from Actinomycetes, especially Streptomyces, best fit this process requirements. In the present studies, a new PLD from marine Streptomyces klenkii (SkPLD) was purified and biochemically characterized. The optimal reaction temperature and pH of SkPLD were determined to be 60 °C and 8.0, respectively. Kinetic analysis showed that SkPLD had the relatively high catalytic efficiency toward phosphatidylcholines (PCs) with medium acyl chain length, especially 12:0/12:0-PC (67.13 S-1 mM-1), but lower catalytic efficiency toward PCs with long acyl chain (>16 fatty acids). Molecular docking results indicated that the different catalytic efficiency was related to the increased steric hindrance of long acyl-chains in the substrate-binding pockets and differences in hydrogen-bond interactions between the acyl chains and substrate-binding pockets. The enzyme displayed suitable transphosphatidylation activity and the reaction process showed 26.18% yield with L-serine and soybean PC as substrates. Present study not only enriched the PLD enzyme library but also provide guidance for the further mining of PLDs with special phospholipids recognition properties.
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Affiliation(s)
| | | | | | - Fanghua Wang
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China; (R.H.); (R.C.); (D.L.)
| | - Yonghua Wang
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China; (R.H.); (R.C.); (D.L.)
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3
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Yan X, Kumar K, Miclette Lamarche R, Youssef H, Shaw GS, Marcotte I, DeWolf CE, Warschawski DE, Boisselier E. Interactions between the Cell Membrane Repair Protein S100A10 and Phospholipid Monolayers and Bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:9652-9663. [PMID: 34339205 DOI: 10.1021/acs.langmuir.1c00342] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Protein S100A10 participates in different cellular mechanisms and has different functions, especially at the membrane. Among those, it forms a ternary complex with annexin A2 and the C-terminal of AHNAK and then joins the dysferlin membrane repair complex. Together, they act as a platform enabling membrane repair. Both AHNAK and annexin A2 have been shown to have membrane binding properties. However, the membrane binding abilities of S100A10 are not clear. In this paper, we aimed to study the membrane binding of S100A10 in order to better understand its role in the cell membrane repair process. S100A10 was overexpressed by E. coli and purified by affinity chromatography. Using a Langmuir monolayer as a model membrane, the binding parameters and ellipsometric angles of the purified S100A10 were measured using surface tensiometry and ellipsometry, respectively. Phosphorus-31 solid-state nuclear magnetic resonance spectroscopy was also used to study the interaction of S100A10 with lipid bilayers. In the presence of a lipid monolayer, S100A10 preferentially interacts with unsaturated phospholipids. In addition, its behavior in the presence of a bilayer model suggests that S100A10 interacts more with the negatively charged polar head groups than the zwitterionic ones. This work offers new insights on the binding of S100A10 to different phospholipids and advances our understanding of the parameters influencing its membrane behavior.
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Affiliation(s)
- Xiaolin Yan
- Department of Ophthalmology, Faculty of Medicine, Université Laval, Quebec City, QC, G1S 4L8 Canada
- CUO-Recherche, Centre de Recherche du CHU de Québec, Hôpital du Saint-Sacrement, CHU de Québec, Quebec City, QC, G1S 4L8 Canada
| | - Kiran Kumar
- Departement of Chemistry, Faculty of Sciences, Université du Québec à Montréal, Montreal, QC, H2V 0B3 Canada
| | - Renaud Miclette Lamarche
- Department of Chemistry and Biochemistry and Centre for NanoScience Research, Concordia University, Montreal, QC, H4B 1R6 Canada
| | - Hala Youssef
- Department of Chemistry and Biochemistry and Centre for NanoScience Research, Concordia University, Montreal, QC, H4B 1R6 Canada
| | - Gary S Shaw
- Departement of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, N6A 5C1 Canada
| | - Isabelle Marcotte
- Departement of Chemistry, Faculty of Sciences, Université du Québec à Montréal, Montreal, QC, H2V 0B3 Canada
| | - Christine E DeWolf
- Department of Chemistry and Biochemistry and Centre for NanoScience Research, Concordia University, Montreal, QC, H4B 1R6 Canada
| | - Dror E Warschawski
- Departement of Chemistry, Faculty of Sciences, Université du Québec à Montréal, Montreal, QC, H2V 0B3 Canada
- Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, École Normale Supérieure, PSL University, Paris, 75 005 France
| | - Elodie Boisselier
- Department of Ophthalmology, Faculty of Medicine, Université Laval, Quebec City, QC, G1S 4L8 Canada
- CUO-Recherche, Centre de Recherche du CHU de Québec, Hôpital du Saint-Sacrement, CHU de Québec, Quebec City, QC, G1S 4L8 Canada
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Schmidt TF, Riske KA, Caseli L, Salesse C. Dengue fusion peptide in Langmuir monolayers: A binding parameter study. Biophys Chem 2021; 271:106553. [PMID: 33626461 DOI: 10.1016/j.bpc.2021.106553] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/08/2021] [Accepted: 01/27/2021] [Indexed: 10/22/2022]
Abstract
Membrane fusion is known to be the primary mechanism of entry of flaviviruses into host cells. Several studies reported the investigation of the membrane fusion mechanism mediated by the fusion peptide, a component of the membrane protein surrounding the flaviviruses. In this study, we investigated the interaction of Dengue fusion peptide (FLAg) with Langmuir monolayers to uncover the role of membrane charges and organization in its membrane binding. Binding parameters of FLAg were obtained by measuring its adsorption onto Langmuir monolayers of different types of individual lipids, as well as their mixtures. Specific peptide binding was observed in the presence of charged lipid monolayers at different pHs, revealing that the lipid composition of the membrane modulates peptide interaction, and the preference of the peptide for negatively charged lipids.
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Affiliation(s)
- Thaís F Schmidt
- Universidade Federal de São Paulo, Biophysics Department, São Paulo, SP, Brazil; Universidade Federal de São Paulo, Chemistry Department, Diadema, SP, Brazil; CUO-Recherche, Centre de recherche du CHU de Québec-Université Laval and Département d'ophtalmologie, Faculté de médecine, and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, Canada.
| | - Karin A Riske
- Universidade Federal de São Paulo, Biophysics Department, São Paulo, SP, Brazil
| | - Luciano Caseli
- Universidade Federal de São Paulo, Chemistry Department, Diadema, SP, Brazil
| | - Christian Salesse
- CUO-Recherche, Centre de recherche du CHU de Québec-Université Laval and Département d'ophtalmologie, Faculté de médecine, and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, Canada
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5
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Bernier SC, Millette MA, Roy S, Cantin L, Coutinho A, Salesse C. Structural information and membrane binding of truncated RGS9-1 Anchor Protein and its C-terminal hydrophobic segment. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183566. [PMID: 33453187 DOI: 10.1016/j.bbamem.2021.183566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/22/2020] [Accepted: 01/10/2021] [Indexed: 01/19/2023]
Abstract
Visual phototransduction takes place in photoreceptor cells. Light absorption by rhodopsin leads to the activation of transducin as a result of the exchange of its GDP for GTP. The GTP-bound ⍺-subunit of transducin then activates phosphodiesterase (PDE), which in turn hydrolyzes cGMP leading to photoreceptor hyperpolarization. Photoreceptors return to the dark state upon inactivation of these proteins. In particular, PDE is inactivated by the protein complex R9AP/RGS9-1/Gβ5. R9AP (RGS9-1 anchor protein) is responsible for the membrane anchoring of this protein complex to photoreceptor outer segment disk membranes most likely by the combined involvement of its C-terminal hydrophobic domain as well as other types of interactions. This study thus aimed to gather information on the structure and membrane binding of the C-terminal hydrophobic segment of R9AP as well as of truncated R9AP (without its C-terminal domain, R9AP∆TM). Circular dichroism and infrared spectroscopic measurements revealed that the secondary structure of R9AP∆TM mainly includes ⍺-helical structural elements. Moreover, intrinsic fluorescence measurements of native R9AP∆TM and individual mutants lacking one tryptophan demonstrated that W79 is more buried than W173 but that they are both located in a hydrophobic environment. This method also revealed that membrane binding of R9AP∆TM does not involve regions near its tryptophan residues, while infrared spectroscopy validated its binding to lipid vesicles. Additional fluorescence measurements showed that the C-terminal segment of R9AP is membrane embedded. Maximum insertion pressure and synergy data using Langmuir monolayers suggest that interactions with specific phospholipids could be involved in the membrane binding of R9AP∆TM.
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Affiliation(s)
- Sarah C Bernier
- CUO-Recherche, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de Médecine, and Regroupement Stratégique PROTEO, Université Laval, Québec, Québec, Canada
| | - Marc-Antoine Millette
- CUO-Recherche, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de Médecine, and Regroupement Stratégique PROTEO, Université Laval, Québec, Québec, Canada
| | - Sarah Roy
- CUO-Recherche, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de Médecine, and Regroupement Stratégique PROTEO, Université Laval, Québec, Québec, Canada
| | - Line Cantin
- CUO-Recherche, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de Médecine, and Regroupement Stratégique PROTEO, Université Laval, Québec, Québec, Canada
| | - Ana Coutinho
- iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Department of Chemistry and Biochemistry, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Christian Salesse
- CUO-Recherche, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de Médecine, and Regroupement Stratégique PROTEO, Université Laval, Québec, Québec, Canada.
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Yan X, Noël F, Marcotte I, DeWolf CE, Warschawski DE, Boisselier E. AHNAK C-Terminal Peptide Membrane Binding-Interactions between the Residues 5654-5673 of AHNAK and Phospholipid Monolayers and Bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:362-369. [PMID: 31825630 DOI: 10.1021/acs.langmuir.9b02973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The dysferlin membrane repair complex contains a small complex, S100A10-annexin A2, which initiates membrane repair by recruiting the protein AHNAK to the membrane, where it interacts via binding sites in the C-terminal region. However, no molecular data are available for the membrane binding of the various proteins involved in this complex. Therefore, the present study investigated the membrane binding of AHNAK to elucidate its role in the cell membrane repair process. A chemically synthesized peptide (pAHNAK), comprising the 20 amino acids in the C-terminal domain of AHNAK, was applied to Langmuir monolayer models, and the binding parameters and insertion angles were measured with surface tensiometry and ellipsometry. The interaction of pAHNAK with lipid bilayers was studied using 31P solid-state nuclear magnetic resonance. pAHNAK preferentially and strongly interacted with phospholipids that comprised negatively charged polar head groups with unsaturated lipids. This finding provides a better understanding of AHNAK membrane behavior and the parameters that influence its function in membrane repair.
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Affiliation(s)
- Xiaolin Yan
- Department of Ophthalmology, Faculty of Medicine , Université Laval , Quebec City , QC G1V 0A6 , Canada
- CUO-Recherche, Centre de Recherche du CHU de Québec, Hôpital du Saint-Sacrement , CHU de Québec , Quebec City , G1S 4L8 , Canada
| | - Francis Noël
- Department of Ophthalmology, Faculty of Medicine , Université Laval , Quebec City , QC G1V 0A6 , Canada
- CUO-Recherche, Centre de Recherche du CHU de Québec, Hôpital du Saint-Sacrement , CHU de Québec , Quebec City , G1S 4L8 , Canada
| | - Isabelle Marcotte
- Department of Chemistry, Faculty of Sciences , Université du Québec à Montréal , Montreal , H2X 2J6 , Canada
| | - Christine E DeWolf
- Department of Chemistry and Biochemistry and Centre for NanoScience Research , Concordia University , Montreal , H4B 1R6 , Canada
| | - Dror E Warschawski
- Department of Chemistry, Faculty of Sciences , Université du Québec à Montréal , Montreal , H2X 2J6 , Canada
- UMR 7099, CNRS-Université Paris Diderot, Institut de Biologie Physico-Chimique , Paris 75005 , France
| | - Elodie Boisselier
- Department of Ophthalmology, Faculty of Medicine , Université Laval , Quebec City , QC G1V 0A6 , Canada
- CUO-Recherche, Centre de Recherche du CHU de Québec, Hôpital du Saint-Sacrement , CHU de Québec , Quebec City , G1S 4L8 , Canada
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7
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Hoareau E, Belley N, Klinker K, Desbat B, Boisselier É. Characterization of neurocalcin delta membrane binding by biophysical methods. Colloids Surf B Biointerfaces 2019; 174:291-299. [DOI: 10.1016/j.colsurfb.2018.11.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/02/2018] [Accepted: 11/07/2018] [Indexed: 01/19/2023]
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8
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Function of C-terminal peptides on enzymatic and interfacial adsorption properties of lipase from Gibberella zeae. Biochim Biophys Acta Gen Subj 2018; 1862:2623-2631. [PMID: 30025859 DOI: 10.1016/j.bbagen.2018.07.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 07/12/2018] [Accepted: 07/13/2018] [Indexed: 11/23/2022]
Abstract
BACKGROUND The crystal structure of lipase from Gibberella zeae (GZEL) indicates that its C-terminal extension is composed of a loop and a α-helix. This structure is unique, possibly providing novel evidence on lipase mechanisms. METHODS Two C-terminally truncated mutants (GZEL-Δ(α-helix) and GZEL-Δ(α-helix+loop)) were constructed. The role of these secondary structure segments on enzymatic activities and interfacial binding properties of GZEL was investigated by using conventional pH-stat method and monomolecular film techniques. In addition, inactive variants (Ser144Ala) of wild-type GZEL and two truncated mutants were constructed and produced specifically for interfacial binding experiments. RESULTS Compared to the wild-type GZEL, lipase and phospholipase activities were significantly decreased in the two mutants. Deletion of the α-helix had great influence on the lipase activity of GZEL, resulting in residual 7.3% activity; the additional deletion of the loop led to 8.1% lipase activity. As for the phospholipase function, residual activities of 63.0% and 35.4% were maintained for GZEL-Δ(α-helix) and GZEL-Δ(α-helix+loop), respectively. Findings obtained with monomolecular film experiments further indicated that the reduction in phospholipase activity occurred with the anionic phospholipid as substrate, but was not seen with zwitterionic phospholipid. Results of the maximum insertion pressure, synergy factor and binding kinetic parameters documented that the α-helix structure of GZEL strongly influence the binding and insertion of enzyme to the phospholipid monolayer. Moreover, the interfacial binding function of α-helix was partly conformed by connecting to the C-terminal of Aspergillus oryzae lipase. GENERAL SIGNIFICANCE Our results provide important information on the understanding of the structure-function relationship of GZEL.
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Boisselier É, Demers É, Cantin L, Salesse C. How to gather useful and valuable information from protein binding measurements using Langmuir lipid monolayers. Adv Colloid Interface Sci 2017; 243:60-76. [PMID: 28372794 DOI: 10.1016/j.cis.2017.03.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 03/14/2017] [Accepted: 03/15/2017] [Indexed: 12/22/2022]
Abstract
This review presents data on the influence of various experimental parameters on the binding of proteins onto Langmuir lipid monolayers. The users of the Langmuir methodology are often unaware of the importance of choosing appropriate experimental conditions to validate the data acquired with this method. The protein Retinitis pigmentosa 2 (RP2) has been used throughout this review to illustrate the influence of these experimental parameters on the data gathered with Langmuir monolayers. The methods detailed in this review include the determination of protein binding parameters from the measurement of adsorption isotherms, infrared spectra of the protein in solution and in monolayers, ellipsometric isotherms and fluorescence micrographs.
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Affiliation(s)
- Élodie Boisselier
- CUO-Recherche, Hôpital du Saint-Sacrement, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de médecine, and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, Canada.
| | - Éric Demers
- CUO-Recherche, Hôpital du Saint-Sacrement, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de médecine, and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, Canada
| | - Line Cantin
- CUO-Recherche, Hôpital du Saint-Sacrement, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de médecine, and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, Canada
| | - Christian Salesse
- CUO-Recherche, Hôpital du Saint-Sacrement, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de médecine, and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, Canada.
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10
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Calvez P, Schmidt TF, Cantin L, Klinker K, Salesse C. Phosphatidylserine Allows Observation of the Calcium–Myristoyl Switch of Recoverin and Its Preferential Binding. J Am Chem Soc 2016; 138:13533-13540. [DOI: 10.1021/jacs.6b04218] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Philippe Calvez
- CUO-Recherche, Centre de
recherche du CHU de Québec, Hôpital du Saint-Sacrement,
Département d’ophtalmologie, Faculté de Médecine,
and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, G1S 4L8 Canada
| | - Thaís F. Schmidt
- CUO-Recherche, Centre de
recherche du CHU de Québec, Hôpital du Saint-Sacrement,
Département d’ophtalmologie, Faculté de Médecine,
and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, G1S 4L8 Canada
| | - Line Cantin
- CUO-Recherche, Centre de
recherche du CHU de Québec, Hôpital du Saint-Sacrement,
Département d’ophtalmologie, Faculté de Médecine,
and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, G1S 4L8 Canada
| | - Kristina Klinker
- CUO-Recherche, Centre de
recherche du CHU de Québec, Hôpital du Saint-Sacrement,
Département d’ophtalmologie, Faculté de Médecine,
and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, G1S 4L8 Canada
| | - Christian Salesse
- CUO-Recherche, Centre de
recherche du CHU de Québec, Hôpital du Saint-Sacrement,
Département d’ophtalmologie, Faculté de Médecine,
and Regroupement stratégique PROTEO, Université Laval, Québec, Québec, G1S 4L8 Canada
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Li L, Rao KN, Zheng-Le Y, Hurd TW, Lillo C, Khanna H. Loss of retinitis pigmentosa 2 (RP2) protein affects cone photoreceptor sensory cilium elongation in mice. Cytoskeleton (Hoboken) 2015; 72:447-54. [PMID: 26383048 DOI: 10.1002/cm.21255] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 09/11/2015] [Accepted: 09/15/2015] [Indexed: 02/03/2023]
Abstract
Degeneration of photoreceptors (rods and cones) results in blindness. As we rely almost entirely on our daytime vision mediated by the cones, it is the loss of these photoreceptors that results in legal blindness and poor quality of life. Cone dysfunction is usually observed due to two mechanisms: noncell-autonomous due to the secondary effect of rod death if the causative gene is specifically expressed in rods and cell autonomous, if the mutation is in a cone-specific gene. However, it is difficult to dissect cone autonomous effect of mutations in the genes that are expressed in both rods and cones. Here we report a property of murine cone photoreceptors, which is a cone-autonomous effect of the genetic perturbation of the retinitis pigmentosa 2 (Rp2) gene mutated in human X-linked RP. Constitutive loss of Rp2 results in abnormal extension of the cone outer segment (COS). This effect is phenocopied when the Rp2 gene is ablated specifically in cones but not when ablated in rods. Furthermore, the elongated COS exhibits abnormal ultrastructure with disorganized lamellae. Additionally, elongation of both the outer segment membrane and the microtubule cytoskeleton was observed in the absence of RP2. Taken together, our studies identify a cone morphological defect in retinal degeneration due to ablation of RP2 and will assist in understanding cone-autonomous responses during disease and develop targeted therapies.
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Affiliation(s)
- Linjing Li
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Kollu Nageswara Rao
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Yun Zheng-Le
- Department of Medicine, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma
| | | | - Concepción Lillo
- Institute of Neurosciences of Castilla Y León-INCyL, Institute of Biomedical Research of Salamanca-IBSAL, Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
| | - Hemant Khanna
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts
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