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Videv P, Mladenova K, Andreeva TD, Park JH, Moskova-Doumanova V, Petrova SD, Doumanov JA. Cholesterol Alters the Phase Separation in Model Membranes Containing hBest1. Molecules 2022; 27:molecules27134267. [PMID: 35807512 PMCID: PMC9268032 DOI: 10.3390/molecules27134267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 06/24/2022] [Accepted: 06/29/2022] [Indexed: 02/04/2023] Open
Abstract
Human retinal pigment epithelial (RPE) cells express the transmembrane Ca2+-dependent Cl− channel bestrophin-1 (hBest1) of the plasma membrane. Mutations in the hBest1 protein are associated with the development of distinct pathological conditions known as bestrophinopathies. The interactions between hBest1 and plasma membrane lipids (cholesterol (Chol), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and sphingomyelin (SM)) determine its lateral organization and surface dynamics, i.e., their miscibility or phase separation. Using the surface pressure/mean molecular area (π/A) isotherms, hysteresis and compressibility moduli (Cs−1) of hBest1/POPC/Chol and hBest1/SM/Chol composite Langmuir monolayers, we established that the films are in an LE (liquid-expanded) or LE-LC (liquid-condensed) state, the components are well-mixed and the Ca2+ ions have a condensing effect on the surface molecular organization. Cholesterol causes a decrease in the elasticity of both films and a decrease in the ΔGmixπ values (reduction of phase separation) of hBest1/POPC/Chol films. For the hBest1/SM/Chol monolayers, the negative values of ΔGmixπ are retained and equalized with the values of ΔGmixπ in the hBest1/POPC/Chol films. Shifts in phase separation/miscibility by cholesterol can lead to changes in the structure and localization of hBest1 in the lipid rafts and its channel functions.
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Affiliation(s)
- Pavel Videv
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
| | - Kirilka Mladenova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
| | - Tonya D. Andreeva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria;
- Faculty of Applied Chemistry, Reutlingen University, Alteburgstraße 150, 72762 Reutlingen, Germany
| | - Jong Hun Park
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
| | - Veselina Moskova-Doumanova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
| | - Svetla D. Petrova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
| | - Jordan A. Doumanov
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
- Correspondence: ; Tel.: +359-2-8167-262; Fax: +359-2-8656-641
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Self-organization and surface properties of hBest1 in models of biological membranes. Adv Colloid Interface Sci 2022; 302:102619. [PMID: 35276535 DOI: 10.1016/j.cis.2022.102619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/19/2022] [Accepted: 02/20/2022] [Indexed: 11/22/2022]
Abstract
The transmembrane Ca2+ - activated Cl- channel - human bestrophin-1 (hBest1) is expressed in retinal pigment epithelium and mutations of BEST1 gene cause ocular degenerative diseases colectivelly referred to as "bestrophinopathies". A large number of genetical, biochemical, biophysical and molecular biological studies have been performed to understand the relationship between structure and function of the hBest1 protein and its pathophysiological significance. Here, we review the current understanding of hBest1 surface organization, interactions with membrane lipids in model membranes, and its association with microdomains of cellular membranes. These highlights are significant for modulation of channel activity in cells.
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Schwieters MS, Mathieu-Gaedke M, Westphal M, Dalpke R, Dirksen M, Qi D, Grull M, Bick T, Taßler S, Sauer DF, Bonn M, Wendler P, Hellweg T, Beyer A, Gölzhäuser A, Schwaneberg U, Glebe U, Böker A. Protein Nanopore Membranes Prepared by a Simple Langmuir-Schaefer Approach. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2102975. [PMID: 34643032 DOI: 10.1002/smll.202102975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 07/26/2021] [Indexed: 06/13/2023]
Abstract
Filtration through membranes with nanopores is typically associated with high transmembrane pressures and high energy consumption. This problem can be addressed by reducing the respective membrane thickness. Here, a simple procedure is described to prepare ultrathin membranes based on protein nanopores, which exhibit excellent water permeance, two orders of magnitude superior to comparable, industrially applied membranes. Furthermore, incorporation of either closed or open protein nanopores allows tailoring the membrane's ion permeability. To form such membranes, the transmembrane protein ferric hydroxamate uptake protein component A (FhuA) or its open-pore variant are assembled at the air-water interface of a Langmuir trough, compressed to a dense film, crosslinked by glutaraldehyde, and transferred to various support materials. This approach allows to prepare monolayer or multilayer membranes with a very high density of protein nanopores. Freestanding membranes covering holes up to 5 μm in diameter are visualized by atomic force microscopy (AFM), helium ion microscopy, and transmission electron microscopy. AFM PeakForce quantitative nanomechanical property mapping (PeakForce QNM) demonstrates remarkable mechanical stability and elastic properties of freestanding monolayer membranes with a thickness of only 5 nm. The new protein membrane can pave the way to energy-efficient nanofiltration.
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Affiliation(s)
- Magnus S Schwieters
- Fraunhofer Institute for Applied Polymer Research IAP, Geiselbergstr. 69, 14476, Potsdam-Golm, Germany
- Polymer Engineering/Polymer Physics, Berlin Institute of Technology (TU Berlin), Ernst-Reuter-Platz 1, 10587, Berlin, Germany
| | - Maria Mathieu-Gaedke
- Fraunhofer Institute for Applied Polymer Research IAP, Geiselbergstr. 69, 14476, Potsdam-Golm, Germany
- Chair of Polymer Materials and Polymer Technologies, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam-Golm, Germany
| | - Michael Westphal
- Physics of Supramolecular Systems and Surfaces, Faculty of Physics, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Raphael Dalpke
- Physics of Supramolecular Systems and Surfaces, Faculty of Physics, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Maxim Dirksen
- Department of Physical and Biophysical Chemistry, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Daizong Qi
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Marco Grull
- Institute of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074, Aachen, Germany
| | - Thomas Bick
- Department of Biochemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam-Golm, Germany
| | - Stephanie Taßler
- Synchrotron SOLEIL, L'Orme des Merisiers, BP48, Gif-Sur-Yvette, Saint-Aubin, 91192, France
| | - Daniel F Sauer
- Institute of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074, Aachen, Germany
| | - Mischa Bonn
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Petra Wendler
- Department of Biochemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam-Golm, Germany
| | - Thomas Hellweg
- Department of Physical and Biophysical Chemistry, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - André Beyer
- Physics of Supramolecular Systems and Surfaces, Faculty of Physics, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Armin Gölzhäuser
- Physics of Supramolecular Systems and Surfaces, Faculty of Physics, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074, Aachen, Germany
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056, Aachen, Germany
| | - Ulrich Glebe
- Fraunhofer Institute for Applied Polymer Research IAP, Geiselbergstr. 69, 14476, Potsdam-Golm, Germany
| | - Alexander Böker
- Fraunhofer Institute for Applied Polymer Research IAP, Geiselbergstr. 69, 14476, Potsdam-Golm, Germany
- Chair of Polymer Materials and Polymer Technologies, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam-Golm, Germany
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Videv P, Mladenov N, Andreeva T, Mladenova K, Moskova-Doumanova V, Nikolaev G, Petrova SD, Doumanov JA. Condensing Effect of Cholesterol on hBest1/POPC and hBest1/SM Langmuir Monolayers. MEMBRANES 2021; 11:membranes11010052. [PMID: 33451008 PMCID: PMC7828479 DOI: 10.3390/membranes11010052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 11/22/2022]
Abstract
Human bestrophin-1 protein (hBest1) is a transmembrane channel associated with the calcium-dependent transport of chloride ions in the retinal pigment epithelium as well as with the transport of glutamate and GABA in nerve cells. Interactions between hBest1, sphingomyelins, phosphatidylcholines and cholesterol are crucial for hBest1 association with cell membrane domains and its biological functions. As cholesterol plays a key role in the formation of lipid rafts, motional ordering of lipids and modeling/remodeling of the lateral membrane structure, we examined the effect of different cholesterol concentrations on the surface tension of hBest1/POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) and hBest1/SM Langmuir monolayers in the presence/absence of Ca2+ ions using surface pressure measurements and Brewster angle microscopy studies. Here, we report that cholesterol: (1) has negligible condensing effect on pure hBest1 monolayers detected mainly in the presence of Ca2+ ions, and; (2) induces a condensing effect on composite hBest1/POPC and hBest1/SM monolayers. These results offer evidence for the significance of intermolecular protein–lipid interactions for the conformational dynamics of hBest1 and its biological functions as multimeric ion channel.
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Affiliation(s)
- Pavel Videv
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
| | - Nikola Mladenov
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
- Faculty of Medicine, Medical University-Sofia, 1 Sv. Georgi Sofiiski Str., 1431 Sofia, Bulgaria
| | - Tonya Andreeva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria;
- Faculty of Applied Chemistry, Reutlingen University, Alteburgstraße 150, 72762 Reutlingen, Germany
| | - Kirilka Mladenova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
| | - Veselina Moskova-Doumanova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
| | - Georgi Nikolaev
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
| | - Svetla D. Petrova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
| | - Jordan A. Doumanov
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
- Correspondence: ; Tel.: +359-2-8167262
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Sensing through Non-Sensing Ocular Ion Channels. Int J Mol Sci 2020; 21:ijms21186925. [PMID: 32967234 PMCID: PMC7554890 DOI: 10.3390/ijms21186925] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/12/2022] Open
Abstract
Ion channels are membrane-spanning integral proteins expressed in multiple organs, including the eye. In the eye, ion channels are involved in various physiological processes, like signal transmission and visual processing. A wide range of mutations have been reported in the corresponding genes and their interacting subunit coding genes, which contribute significantly to an array of blindness, termed ocular channelopathies. These mutations result in either a loss- or gain-of channel functions affecting the structure, assembly, trafficking, and localization of channel proteins. A dominant-negative effect is caused in a few channels formed by the assembly of several subunits that exist as homo- or heteromeric proteins. Here, we review the role of different mutations in switching a “sensing” ion channel to “non-sensing,” leading to ocular channelopathies like Leber’s congenital amaurosis 16 (LCA16), cone dystrophy, congenital stationary night blindness (CSNB), achromatopsia, bestrophinopathies, retinitis pigmentosa, etc. We also discuss the various in vitro and in vivo disease models available to investigate the impact of mutations on channel properties, to dissect the disease mechanism, and understand the pathophysiology. Innovating the potential pharmacological and therapeutic approaches and their efficient delivery to the eye for reversing a “non-sensing” channel to “sensing” would be life-changing.
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Miscibility of hBest1 and sphingomyelin in surface films - A prerequisite for interaction with membrane domains. Colloids Surf B Biointerfaces 2020; 189:110893. [PMID: 32113084 DOI: 10.1016/j.colsurfb.2020.110893] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/08/2020] [Accepted: 02/20/2020] [Indexed: 01/07/2023]
Abstract
Human bestrophin-1 (hBest1) is a transmembrane Ca2+- dependent anion channel, associated with the transport of Cl-, HCO3- ions, γ-aminobutiric acid (GABA), glutamate (Glu), and regulation of retinal homeostasis. Its mutant forms cause retinal degenerative diseases, defined as Bestrophinopathies. Using both physicochemical - surface pressure/mean molecular area (π/A) isotherms, hysteresis, compressibility moduli of hBest1/sphingomyelin (SM) monolayers, Brewster angle microscopy (BAM) studies, and biological approaches - detergent membrane fractionation, Laurdan (6-dodecanoyl-N,N-dimethyl-2-naphthylamine) and immunofluorescence staining of stably transfected MDCK-hBest1 and MDCK II cells, we report: 1) Ca2+, Glu and GABA interact with binary hBest1/SM monolayers at 35 °C, resulting in changes in hBest1 surface conformation, structure, self-organization and surface dynamics. The process of mixing in hBest1/SM monolayers is spontaneous and the effect of protein on binary films was defined as "fluidizing", hindering the phase-transition of monolayer from liquid-expanded to intermediate (LE-M) state; 2) in stably transfected MDCK-hBest1 cells, bestrophin-1 was distributed between detergent resistant (DRM) and detergent-soluble membranes (DSM) - up to 30 % and 70 %, respectively; in alive cells, hBest1 was visualized in both liquid-ordered (Lo) and liquid-disordered (Ld) fractions, quantifying protein association up to 35 % and 65 % with Lo and Ld. Our results indicate that the spontaneous miscibility of hBest1 and SM is a prerequisite to diverse protein interactions with membrane domains, different structural conformations and biological functions.
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Action of Vipoxin and its separated components on monomolecular film of Dilauroylphosphatidylcholine at the air/water interface. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2018.11.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Effects of Ca2+, Glu and GABA on hBest1 and composite hBest1/POPC surface films. Colloids Surf B Biointerfaces 2018; 161:192-199. [DOI: 10.1016/j.colsurfb.2017.10.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 10/11/2017] [Accepted: 10/17/2017] [Indexed: 12/22/2022]
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Lin Y, Li T, Gao H, Lian Y, Chen C, Zhu Y, Li Y, Liu B, Zhou W, Jiang H, Liu X, Zhao X, Liang X, Jin C, Huang X, Lu L. Bestrophin 1 gene analysis and associated clinical findings in a Chinese patient with Best vitelliform macular dystrophy. Mol Med Rep 2017; 16:4751-4755. [PMID: 28791410 PMCID: PMC5647057 DOI: 10.3892/mmr.2017.7174] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 06/15/2017] [Indexed: 01/21/2023] Open
Abstract
The aim of the present study was to investigate the clinical characteristics and the underlying genetic causes of Best vitelliform macular dystrophy (BVMD) in a sporadic case in a Chinese patient. A 10‑year‑old boy was diagnosed with BVMD; complete ophthalmic examinations were performed, including best‑corrected visual acuity, intraocular pressure, slit‑lamp examination, fundus photograph, optical coherence tomography and fundus fluorescein angiography imaging. Genomic DNA was extracted from leukocytes of the peripheral blood collected from this patient and his family members. DNA samples from 200 unrelated subjects from the Chinese population were used as controls. A total of 11 exons of the bestrophin 1 (BEST1) gene were amplified by polymerase chain reaction and directly sequenced. The results revealed that the patient presented with yellowish lesions in the macular area. Heterozygous mutations c.292G>A (p.Glu98Lys) in exon 4 and c.1608C>T (p.Thr536Thr) in exon 10 of the BEST1 gene were identified in this sporadic case; however, this was not identified in any of his unaffected family members or in the normal controls. The c.292G>A (p.Glu98Lys) mutation has not been previously reported, whereas the c.1608C>T (p.Thr536Thr) mutation is a previously characterized single nucleotide polymorphism (SNP). In conclusion, BEST1 gene mutations and polymorphisms have been reported in diverse ethnic groups, and the present study identified a novel BEST1 gene mutation and an SNP that occurred simultaneously in a Chinese patient with BVMD.
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Affiliation(s)
- Ying Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Tao Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Hongbin Gao
- Guangdong Laboratory Animals Monitoring Institute, Key Laboratory of Guangdong Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
| | - Yu Lian
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Chuan Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Yi Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Yonghao Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Bingqian Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Wenli Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Hongye Jiang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510000, P.R. China
| | - Xialin Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Xiujuan Zhao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Xiaoling Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Chenjin Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Xinhua Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Lin Lu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
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Johnson AA, Guziewicz KE, Lee CJ, Kalathur RC, Pulido JS, Marmorstein LY, Marmorstein AD. Bestrophin 1 and retinal disease. Prog Retin Eye Res 2017; 58:45-69. [PMID: 28153808 DOI: 10.1016/j.preteyeres.2017.01.006] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/23/2017] [Accepted: 01/25/2017] [Indexed: 12/18/2022]
Abstract
Mutations in the gene BEST1 are causally associated with as many as five clinically distinct retinal degenerative diseases, which are collectively referred to as the "bestrophinopathies". These five associated diseases are: Best vitelliform macular dystrophy, autosomal recessive bestrophinopathy, adult-onset vitelliform macular dystrophy, autosomal dominant vitreoretinochoroidopathy, and retinitis pigmentosa. The most common of these is Best vitelliform macular dystrophy. Bestrophin 1 (Best1), the protein encoded by the gene BEST1, has been the subject of a great deal of research since it was first identified nearly two decades ago. Today we know that Best1 functions as both a pentameric anion channel and a regulator of intracellular Ca2+ signaling. Best1 is an integral membrane protein which, within the eye, is uniquely expressed in the retinal pigment epithelium where it predominantly localizes to the basolateral plasma membrane. Within the brain, Best1 expression has been documented in both glial cells and astrocytes where it functions in both tonic GABA release and glutamate transport. The crystal structure of Best1 has revealed critical information about how Best1 functions as an ion channel and how Ca2+ regulates that function. Studies using animal models have led to critical insights into the physiological roles of Best1 and advances in stem cell technology have allowed for the development of patient-derived, "disease in a dish" models. In this article we review our knowledge of Best1 and discuss prospects for near-term clinical trials to test therapies for the bestrophinopathies, a currently incurable and untreatable set of diseases.
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Affiliation(s)
- Adiv A Johnson
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, USA; Nikon Instruments, Melville, NY, USA
| | - Karina E Guziewicz
- Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - C Justin Lee
- Center for Neuroscience and Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
| | - Ravi C Kalathur
- New York Structural Biology Center, New York Consortium on Membrane Protein Structure, New York, NY, USA
| | - Jose S Pulido
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, USA
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