1
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Miller AP, O'Neill SE, Lampi KJ, Reichow SL. The α-crystallin Chaperones Undergo a Quasi-ordered Co-aggregation Process in Response to Saturating Client Interaction. J Mol Biol 2024; 436:168499. [PMID: 38401625 PMCID: PMC11001518 DOI: 10.1016/j.jmb.2024.168499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 02/26/2024]
Abstract
Small heat shock proteins (sHSPs) are ATP-independent chaperones vital to cellular proteostasis, preventing protein aggregation events linked to various human diseases including cataract. The α-crystallins, αA-crystallin (αAc) and αB-crystallin (αBc), represent archetypal sHSPs that exhibit complex polydispersed oligomeric assemblies and rapid subunit exchange dynamics. Yet, our understanding of how this plasticity contributes to chaperone function remains poorly understood. Using biochemical and biophysical analyses combined with single-particle electron microscopy (EM), we examined structural changes in αAc, αBc and native heteromeric lens α-crystallins (αLc) in their apo-states and at varying degree of chaperone saturation leading to co-aggregation, using lysozyme and insulin as model clients. Quantitative single-particle analysis unveiled a continuous spectrum of oligomeric states formed during the co-aggregation process, marked by significant client-triggered expansion and quasi-ordered elongation of the sHSP oligomeric scaffold, whereby the native cage-like sHSP assembly displays a directional growth to accommodate saturating conditions of client sequestration. These structural modifications culminated in an apparent amorphous collapse of chaperone-client complexes, resulting in the creation of co-aggregates capable of scattering visible light. Intriguingly, these co-aggregates maintain internal morphological features of highly elongated sHSP oligomers with striking resemblance to polymeric α-crystallin species isolated from aged lens tissue. This mechanism appears consistent across αAc, αBc and αLc, albeit with varying degrees of susceptibility to client-induced co-aggregation. Importantly, our findings suggest that client-induced co-aggregation follows a distinctive mechanistic and quasi-ordered trajectory, distinct from a purely amorphous process. These insights reshape our understanding of the physiological and pathophysiological co-aggregation processes of α-crystallins, carrying potential implications for a pathway toward cataract formation.
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Affiliation(s)
- Adam P Miller
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA; Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA; Department of Chemistry, Portland State University, Portland, OR 97201, USA
| | - Susan E O'Neill
- Department of Chemistry, Portland State University, Portland, OR 97201, USA
| | - Kirsten J Lampi
- Biomaterial and Biomedical Sciences, Oregon Health & Science University, Portland, OR 97239, USA
| | - Steve L Reichow
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA; Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA; Department of Chemistry, Portland State University, Portland, OR 97201, USA.
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2
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Khadka NK, Hazen P, Haemmerle D, Mainali L. Interaction of β L- and γ-Crystallin with Phospholipid Membrane Using Atomic Force Microscopy. Int J Mol Sci 2023; 24:15720. [PMID: 37958704 PMCID: PMC10649403 DOI: 10.3390/ijms242115720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
Highly concentrated lens proteins, mostly β- and γ-crystallin, are responsible for maintaining the structure and refractivity of the eye lens. However, with aging and cataract formation, β- and γ-crystallin are associated with the lens membrane or other lens proteins forming high-molecular-weight proteins, which further associate with the lens membrane, leading to light scattering and cataract development. The mechanism by which β- and γ-crystallin are associated with the lens membrane is unknown. This work aims to study the interaction of β- and γ-crystallin with the phospholipid membrane with and without cholesterol (Chol) with the overall goal of understanding the role of phospholipid and Chol in β- and γ-crystallin association with the membrane. Small unilamellar vesicles made of Chol/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (Chol/POPC) membranes with varying Chol content were prepared using the rapid solvent exchange method followed by probe tip sonication and then dispensed on freshly cleaved mica disk to prepare a supported lipid membrane. The βL- and γ-crystallin from the cortex of the bovine lens was used to investigate the time-dependent association of βL- and γ-crystallin with the membrane by obtaining the topographical images using atomic force microscopy. Our study showed that βL-crystallin formed semi-transmembrane defects, whereas γ-crystallin formed transmembrane defects on the phospholipid membrane. The size of semi-transmembrane defects increases significantly with incubation time when βL-crystallin interacts with the membrane. In contrast, no significant increase in transmembrane defect size was observed in the case of γ-crystallin. Our result shows that Chol inhibits the formation of membrane defects when βL- and γ-crystallin interact with the Chol/POPC membrane, where the degree of inhibition depends upon the amount of Chol content in the membrane. At a Chol/POPC mixing ratio of 0.3, membrane defects were observed when both βL- and γ-crystallin interacted with the membrane. However, at a Chol/POPC mixing ratio of 1, no association of γ-crystallin with the membrane was observed, which resulted in a defect-free membrane, and the severity of the membrane defect was decreased when βL-crystallin interacted with the membrane. The semi-transmembrane or transmembrane defects formed by the interaction of βL- and γ-crystallin on phospholipid membrane might be responsible for light scattering and cataract formation. However, Chol suppressed the formation of such defects in the membrane, likely maintaining lens membrane homeostasis and protecting against cataract formation.
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Affiliation(s)
- Nawal K. Khadka
- Department of Physics, Boise State University, Boise, ID 83725, USA; (N.K.K.); (D.H.)
| | - Preston Hazen
- Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725, USA;
| | - Dieter Haemmerle
- Department of Physics, Boise State University, Boise, ID 83725, USA; (N.K.K.); (D.H.)
| | - Laxman Mainali
- Department of Physics, Boise State University, Boise, ID 83725, USA; (N.K.K.); (D.H.)
- Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725, USA;
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3
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Attia SA, Truong AT, Phan A, Lee SJ, Abanmai M, Markanovic M, Avila H, Luo H, Ali A, Sreekumar PG, Kannan R, MacKay JA. αB-Crystallin Peptide Fused with Elastin-like Polypeptide: Intracellular Activity in Retinal Pigment Epithelial Cells Challenged with Oxidative Stress. Antioxidants (Basel) 2023; 12:1817. [PMID: 37891896 PMCID: PMC10604459 DOI: 10.3390/antiox12101817] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/19/2023] [Accepted: 09/22/2023] [Indexed: 10/29/2023] Open
Abstract
BACKGROUND Oxidative stress-induced retinal degeneration is among the main contributing factors of serious ocular pathologies that can lead to irreversible blindness. αB-crystallin (cry) is an abundant component of the visual pathway in the vitreous humor, which modulates protein and cellular homeostasis. Within this protein exists a 20 amino acid fragment (mini-cry) with both chaperone and antiapoptotic activity. This study fuses this mini-cry peptide to two temperature-sensitive elastin-like polypeptides (ELP) with the goal of prolonging its activity in the retina. METHODS The biophysical properties and chaperone activity of cry-ELPs were confirmed by mass spectrometry, cloud-point determination, and dynamic light scattering 'DLS'. For the first time, this work compares a simpler ELP architecture, cry-V96, with a previously reported ELP diblock copolymer, cry-SI. Their relative mechanisms of cellular uptake and antiapoptotic potential were tested using retinal pigment epithelial cells (ARPE-19). Oxidative stress was induced with H2O2 and comparative internalization of both cry-ELPs was made using 2D and 3D culture models. We also explored the role of lysosomal membrane permeabilization by confocal microscopy. RESULTS The results indicated successful ELP fusion, cellular association with both 2D and 3D cultures, which were enhanced by oxidative stress. Both constructs suppressed apoptotic signaling (cleaved caspase-3); however, cry-V96 exhibited greater lysosomal escape. CONCLUSIONS ELP architecture is a critical factor to optimize delivery of therapeutic peptides, such as the anti-apoptotic mini-cry peptide; furthermore, the protection of mini-cry via ELPs is enhanced by lysosomal membrane permeabilization.
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Affiliation(s)
- Sara Aly Attia
- Department of Pharmacology and Pharmaceutical Sciences, Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (S.A.A.); (A.T.T.); (A.P.); (M.A.); (M.M.); (H.A.); (H.L.); (A.A.)
| | - Anh Tan Truong
- Department of Pharmacology and Pharmaceutical Sciences, Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (S.A.A.); (A.T.T.); (A.P.); (M.A.); (M.M.); (H.A.); (H.L.); (A.A.)
| | - Alvin Phan
- Department of Pharmacology and Pharmaceutical Sciences, Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (S.A.A.); (A.T.T.); (A.P.); (M.A.); (M.M.); (H.A.); (H.L.); (A.A.)
| | - Shin-Jae Lee
- Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA;
| | - Manal Abanmai
- Department of Pharmacology and Pharmaceutical Sciences, Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (S.A.A.); (A.T.T.); (A.P.); (M.A.); (M.M.); (H.A.); (H.L.); (A.A.)
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam bin Abdulaziz University, Al Kharj 11942, Saudi Arabia
| | - Marinella Markanovic
- Department of Pharmacology and Pharmaceutical Sciences, Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (S.A.A.); (A.T.T.); (A.P.); (M.A.); (M.M.); (H.A.); (H.L.); (A.A.)
| | - Hugo Avila
- Department of Pharmacology and Pharmaceutical Sciences, Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (S.A.A.); (A.T.T.); (A.P.); (M.A.); (M.M.); (H.A.); (H.L.); (A.A.)
| | - Haozhong Luo
- Department of Pharmacology and Pharmaceutical Sciences, Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (S.A.A.); (A.T.T.); (A.P.); (M.A.); (M.M.); (H.A.); (H.L.); (A.A.)
| | - Atham Ali
- Department of Pharmacology and Pharmaceutical Sciences, Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (S.A.A.); (A.T.T.); (A.P.); (M.A.); (M.M.); (H.A.); (H.L.); (A.A.)
| | | | - Ram Kannan
- Doheny Eye Institute, Pasadena, CA 91103, USA; (P.G.S.); (R.K.)
- Stein Eye Institute, Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - J. Andrew MacKay
- Department of Pharmacology and Pharmaceutical Sciences, Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (S.A.A.); (A.T.T.); (A.P.); (M.A.); (M.M.); (H.A.); (H.L.); (A.A.)
- Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA;
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
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4
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Rolland AD, Takata T, Donor MT, Lampi KJ, Prell JS. Eye lens β-crystallins are predicted by native ion mobility-mass spectrometry and computations to form compact higher-ordered heterooligomers. Structure 2023; 31:1052-1064.e3. [PMID: 37453416 PMCID: PMC10528727 DOI: 10.1016/j.str.2023.06.013] [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: 10/24/2022] [Revised: 05/04/2023] [Accepted: 06/20/2023] [Indexed: 07/18/2023]
Abstract
Eye lens α- and β-/γ-crystallin proteins are not replaced after fiber cell denucleation and maintain lens transparency and refractive properties. The exceptionally high (∼400-500 mg/mL) concentration of crystallins in mature lens tissue and multiple other factors impede precise characterization of β-crystallin interactions, oligomer composition, size, and topology. Native ion mobility-mass spectrometry is used here to probe β-crystallin association and provide insight into homo- and heterooligomerization kinetics for these proteins. These experiments include separation and characterization of higher-order β-crystallin oligomers and illustrate the unique advantages of native IM-MS. Recombinantly expressed βB1, βB2, and βA3 isoforms are found to have different homodimerization propensities, and only βA3 forms larger homooligomers. Heterodimerization of βB2 with βA3 occurs ∼3 times as fast as that of βB1 with βA3, and βB1 and βB2 heterodimerize less readily. Ion mobility experiments, molecular dynamics simulations, and PISA analysis together reveal that observed oligomers are consistent with predominantly compact, ring-like topologies.
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Affiliation(s)
- Amber D Rolland
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene, OR 97403-1253, USA
| | - Takumi Takata
- Kyoto University, Research Reactor Institute 2, Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
| | - Micah T Donor
- Department of Biological & Molecular Sciences, George Fox University, 414 N Meridian St, Newberg, OR 97132, USA
| | - Kirsten J Lampi
- Integrative Biosciences, School of Dentistry, 3181 SW Sam Jackson Park Road, Oregon Health & Science University, Portland, OR 97239-3098, USA.
| | - James S Prell
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene, OR 97403-1253, USA; Materials Science Institute, 1252 University of Oregon, Eugene, OR 97403-1252, USA.
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5
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Miller AP, O'Neill SE, Lampi KJ, Reichow SL. The α-crystallin chaperones undergo a quasi-ordered co-aggregation process in response to saturating client interaction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.15.553435. [PMID: 37645910 PMCID: PMC10462102 DOI: 10.1101/2023.08.15.553435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Small heat shock proteins (sHSPs) are ATP-independent chaperones vital to cellular proteostasis, preventing protein aggregation events linked to various human diseases including cataract. The α-crystallins, αA-crystallin (αAc) and αB-crystallin (αBc), represent archetypal sHSPs that exhibit complex polydispersed oligomeric assemblies and rapid subunit exchange dynamics. Yet, our understanding of how this plasticity contributes to chaperone function remains poorly understood. This study investigates structural changes in αAc and αBc during client sequestration under varying degree of chaperone saturation. Using biochemical and biophysical analyses combined with single-particle electron microscopy (EM), we examined αAc and αBc in their apo-states and at various stages of client-induced co-aggregation, using lysozyme as a model client. Quantitative single-particle analysis unveiled a continuous spectrum of oligomeric states formed during the co-aggregation process, marked by significant client-triggered expansion and quasi-ordered elongation of the sHSP scaffold. These structural modifications culminated in an apparent amorphous collapse of chaperone-client complexes, resulting in the creation of co-aggregates capable of scattering visible light. Intriguingly, these co-aggregates maintain internal morphological features of highly elongated sHSP scaffolding with striking resemblance to polymeric α-crystallin species isolated from aged lens tissue. This mechanism appears consistent across both αAc and αBc, albeit with varying degrees of susceptibility to client-induced co-aggregation. Importantly, our findings suggest that client-induced co-aggregation follows a distinctive mechanistic and quasi-ordered trajectory, distinct from a purely amorphous process. These insights reshape our understanding of the physiological and pathophysiological co-aggregation processes of sHSPs, carrying potential implications for a pathway toward cataract formation.
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Affiliation(s)
- Adam P Miller
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, USA
- Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
- Department of Chemistry, Portland State University, Portland, Oregon 97201, USA
| | - Susan E O'Neill
- Department of Chemistry, Portland State University, Portland, Oregon 97201, USA
| | - Kirsten J Lampi
- Integrative Biosciences, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Steve L Reichow
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, USA
- Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
- Department of Chemistry, Portland State University, Portland, Oregon 97201, USA
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6
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Minaeva O, Sarangi S, Ledoux DM, Moncaster JA, Parsons DS, Washicosky KJ, Black CA, Weng FJ, Ericsson M, Moir RD, Tripodis Y, Clark JI, Tanzi RE, Hunter DG, Goldstein LE. In Vivo Quasi-Elastic Light Scattering Eye Scanner Detects Molecular Aging in Humans. J Gerontol A Biol Sci Med Sci 2021; 75:e53-e62. [PMID: 32515825 DOI: 10.1093/gerona/glaa121] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Indexed: 12/30/2022] Open
Abstract
The absence of clinical tools to evaluate individual variation in the pace of aging represents a major impediment to understanding aging and maximizing health throughout life. The human lens is an ideal tissue for quantitative assessment of molecular aging in vivo. Long-lived proteins in lens fiber cells are expressed during fetal life, do not undergo turnover, accumulate molecular alterations throughout life, and are optically accessible in vivo. We used quasi-elastic light scattering (QLS) to measure age-dependent signals in lenses of healthy human subjects. Age-dependent QLS signal changes detected in vivo recapitulated time-dependent changes in hydrodynamic radius, protein polydispersity, and supramolecular order of human lens proteins during long-term incubation (~1 year) and in response to sustained oxidation (~2.5 months) in vitro. Our findings demonstrate that QLS analysis of human lens proteins provides a practical technique for noninvasive assessment of molecular aging in vivo.
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Affiliation(s)
- Olga Minaeva
- Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.,Department of Ophthalmology, Boston Children's Hospital, Massachusetts
| | - Srikant Sarangi
- Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.,Department of Biomedical Engineering, Boston University, Massachusetts
| | - Danielle M Ledoux
- Department of Ophthalmology, Boston Children's Hospital, Massachusetts.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Juliet A Moncaster
- Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.,Boston University Photonics Center, Boston University, Massachusetts
| | - Douglas S Parsons
- Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.,Boston University Photonics Center, Boston University, Massachusetts
| | - Kevin J Washicosky
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown
| | - Caitlin A Black
- Department of Ophthalmology, Boston Children's Hospital, Massachusetts
| | - Frank J Weng
- Department of Ophthalmology, Boston Children's Hospital, Massachusetts
| | - Maria Ericsson
- Electron Microscopy Facility, Harvard Medical School, Boston, Massachusetts
| | - Robert D Moir
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Neurology, Harvard Medical School, Boston, Massachusetts
| | - Yorghos Tripodis
- Department of Biostatistics, Boston University School of Public Health, Massachusetts
| | - John I Clark
- Department of Biological Structure, University of Washington, Seattle
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Neurology, Harvard Medical School, Boston, Massachusetts
| | - David G Hunter
- Department of Ophthalmology, Boston Children's Hospital, Massachusetts.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Lee E Goldstein
- Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.,Boston University Alzheimer's Disease Center, Massachusetts
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7
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Guseman AJ, Whitley MJ, González JJ, Rathi N, Ambarian M, Gronenborn AM. Assessing the Structures and Interactions of γD-Crystallin Deamidation Variants. Structure 2020; 29:284-291.e3. [PMID: 33264606 DOI: 10.1016/j.str.2020.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 10/12/2020] [Accepted: 11/06/2020] [Indexed: 11/25/2022]
Abstract
Cataracts involve the deposition of the crystallin proteins in the vertebrate eye lens, causing opacification and blindness. They are associated with either genetic mutation or protein damage that accumulates over the lifetime of the organism. Deamidation of Asn residues in several different crystallins has been observed and is frequently invoked as a cause of cataract. Here, we investigated the properties of Asp variants, deamidation products of γD-crystallin, by solution NMR, X-ray crystallography, and other biophysical techniques. No substantive structural or stability changes were noted for all seven Asn to Asp γD-crystallins. Importantly, no changes in diffusion interaction behavior could be detected. Our combined experimental results demonstrate that introduction of single Asp residues on the surface of γD-crystallin by deamidation is unlikely to be the driver of cataract formation in the eye lens.
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Affiliation(s)
- Alex J Guseman
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Matthew J Whitley
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Jeremy J González
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Nityam Rathi
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Mikayla Ambarian
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Angela M Gronenborn
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
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8
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Forsythe HM, Vetter CJ, Jara KA, Reardon PN, David LL, Barbar EJ, Lampi KJ. Altered Protein Dynamics and Increased Aggregation of Human γS-Crystallin Due to Cataract-Associated Deamidations. Biochemistry 2019; 58:4112-4124. [PMID: 31490062 PMCID: PMC10693687 DOI: 10.1021/acs.biochem.9b00593] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Deamidation is a major age-related modification in the human lens that is highly prevalent in crystallins isolated from the insoluble fraction of cataractous lenses and also causes protein aggregation in vitro. However, the mechanism by which deamidation causes proteins to become insoluble is not known because only subtle structural changes were observed in vitro. We have identified Asn14 and Asn76 of γS-crystallin as highly deamidated in insoluble proteins isolated from aged lenses. These sites are on the surface of the N-terminal domain and were mimicked by replacing the Asn with Asp residues in order to generate recombinant human γS and deamidated mutants. Both N14D and N76D had increased light scattering compared to wild-type γS (WT) and increased aggregation during thermal-induced denaturation. Aggregation was enhanced by oxidized glutathione, suggesting deamidation may increase susceptibility to form disulfide bonds. These changes were correlated to changes in protein dynamics determined by NMR spectroscopy. Heteronuclear NMR spectroscopy was used to measure amide hydrogen exchange and 15N relaxation dynamics to identify regions with increased dynamics compared to γS WT. Residue-specific changes in solvent accessibility and dynamics were both near and distant from the sites of deamidation, suggesting that deamidation had both local and global effects on the protein structure at slow (ms to s) and fast (μs to ps) time scales. Thus, a potential mechanism for γS deamidation-induced insolubilization in cataractous lenses is altered dynamics due to local regions of unfolding and increased flexibility in both the N- and C-terminal domains particularly at surface helices. This conformational flexibility increases the likelihood of aggregation, which would be enhanced in the oxidizing cytoplasm of the aged and cataractous lens. The NMR data combined with the in vivo insolubility and in vitro aggregation findings support a model that deamidation drives changes in protein dynamics that facilitate protein aggregation associated with cataracts.
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Affiliation(s)
| | - Calvin J. Vetter
- Integrative Biosciences, Oregon Health & Science University, Portland, OR
| | - Kayla Ann Jara
- Biochemistry & Biophysics, Oregon State University, Corvallis, OR
| | - Patrick N. Reardon
- Nuclear Magnetic Resonance Facility, Oregon State University, Corvallis, OR
| | - Larry L. David
- Biochemistry & Molecular Biology, Oregon Health & Science University, Portland, OR
| | - Elisar J. Barbar
- Biochemistry & Biophysics, Oregon State University, Corvallis, OR
| | - Kirsten J. Lampi
- Integrative Biosciences, Oregon Health & Science University, Portland, OR
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9
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Hao P, Adav SS, Gallart-Palau X, Sze SK. Recent advances in mass spectrometric analysis of protein deamidation. MASS SPECTROMETRY REVIEWS 2017; 36:677-692. [PMID: 26763661 DOI: 10.1002/mas.21491] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Revised: 12/28/2015] [Accepted: 12/28/2015] [Indexed: 06/05/2023]
Abstract
Protein deamidation has been proposed to represent a "molecular clock" that progressively disrupts protein structure and function in human degenerative diseases and natural aging. Importantly, this spontaneous process can also modify therapeutic proteins by altering their purity, stability, bioactivity, and antigenicity during drug synthesis and storage. Deamidation occurs non-enzymatically in vivo, but can also take place spontaneously in vitro, hence artificial deamidation during proteomic sample preparation can hamper efforts to identify and quantify endogenous deamidation of complex proteomes. To overcome this, mass spectrometry (MS) can be used to conduct rigorous site-specific characterization of protein deamidation due to the high sensitivity, speed, and specificity offered by this technique. This article reviews recent progress in MS analysis of protein deamidation and discusses the strengths and limitations of common "top-down" and "bottom-up" approaches. Recent advances in sample preparation methods, chromatographic separation, MS technology, and data processing have for the first time enabled the accurate and reliable characterization of protein modifications in complex biological samples, yielding important new data on how deamidation occurs across the entire proteome of human cells and tissues. These technological advances will lead to a better understanding of how deamidation contributes to the pathology of biological aging and major degenerative diseases. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 36:677-692, 2017.
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Affiliation(s)
- Piliang Hao
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Sunil S Adav
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Xavier Gallart-Palau
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
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10
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Ghaffari Sharaf M, Cetinel S, Semenchenko V, Damji KF, Unsworth LD, Montemagno C. Peptides for targeting βB2-crystallin fibrils. Exp Eye Res 2017; 165:109-117. [PMID: 28986145 DOI: 10.1016/j.exer.2017.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 09/20/2017] [Accepted: 10/01/2017] [Indexed: 01/24/2023]
Abstract
Crystallins are a major family of proteins located within the lens of the eye. Cataracts are thought to be due to the formation of insoluble fibrillar aggregates, which are largely composed of proteins from the crystallin family. Today the only cataract treatment that exists is surgery and this can be difficult to access for individuals in the developing world. Development of novel pharmacotherapeutic approaches for the treatment of cataract rests on the specific targeting of these structures. βB2-crystallin, a member of β-crystallin family, is a large component of the crystallin proteins within the lens, and as such was used to form model fibrils in vitro. Peptides were identified, using phage display techniques, that bound to these fibrils with high affinity. Fibrillation of recombinantly expressed human βB2-crystallin was performed in 10% (v/v) trifluoroethanol (TFE) solution (pH 2.0) at various temperatures, and its amyloid-like structure was confirmed using Thioflavin-T (ThT) assay, transmission electron microscopy (TEM), and X-ray fiber diffraction (XRFD) analysis. Affinity of identified phage-displayed peptides were analyzed using enzyme-linked immunosorbent assay (ELISA). Specific binding of a cyclic peptide (CKQFKDTTC) showed the highest affinity, which was confirmed using a competitive inhibition assay.
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Affiliation(s)
- Mehdi Ghaffari Sharaf
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada; Ingenuity Lab, University of Alberta, Edmonton, AB, Canada
| | - Sibel Cetinel
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada; Ingenuity Lab, University of Alberta, Edmonton, AB, Canada
| | - Valentyna Semenchenko
- National Institute of Nanotechnology, National Research Council, Edmonton, AB, Canada
| | - Karim F Damji
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, AB, Canada
| | - Larry D Unsworth
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada; National Institute of Nanotechnology, National Research Council, Edmonton, AB, Canada.
| | - Carlo Montemagno
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada; National Institute of Nanotechnology, National Research Council, Edmonton, AB, Canada; Ingenuity Lab, University of Alberta, Edmonton, AB, Canada.
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11
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Dabbaghizadeh A, Finet S, Morrow G, Moutaoufik MT, Tanguay RM. Oligomeric structure and chaperone-like activity of Drosophila melanogaster mitochondrial small heat shock protein Hsp22 and arginine mutants in the alpha-crystallin domain. Cell Stress Chaperones 2017; 22:577-588. [PMID: 28389817 PMCID: PMC5465034 DOI: 10.1007/s12192-017-0784-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 02/24/2017] [Accepted: 02/28/2017] [Indexed: 01/17/2023] Open
Abstract
The structure and chaperone function of DmHsp22WT, a small Hsp of Drosophila melanogaster localized within mitochondria were examined. Mutations of conserved arginine mutants within the alpha-crystallin domain (ACD) domain (R105G, R109G, and R110G) were introduced, and their effects on oligomerization and chaperone function were assessed. Arginine to glycine mutations do not induce significant changes in tryptophan fluorescence, and the mutated proteins form oligomers that are of equal or smaller size than the wild-type protein. They all form oligomer with one single peak as determined by size exclusion chromatography. While all mutants demonstrate the same efficiency as the DmHsp22WT in a DTT-induced insulin aggregation assay, all are more efficient chaperones to prevent aggregation of malate dehydrogenase. Arginine mutants of DmHsp22 are efficient chaperones to retard aggregation of CS and Luc. In summary, this study shows that mutations of arginine to glycine in DmHsp22 ACD induce a number of structural changes, some of which differ from those described in mammalian sHsps. Interestingly, only the R110G-DmHsp22 mutant, and not the expected R109G equivalent to human R140-HspB1, R116-HspB4, and R120-HspB5, showed different structural properties compared with the DmHsp22WT.
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Affiliation(s)
- Afrooz Dabbaghizadeh
- Laboratoire de génétique cellulaire et développementale, Département de biologie moléculaire, de biochimie médicale et de pathologie, Faculté de médecine, Institut de biologie intégrative et des systèmes (IBIS) and PROTEO, Université Laval, Québec, Québec, G1V 0A6, Canada
| | - Stéphanie Finet
- IMPMC UMR7590, CNRS, Sorbonne-Universités, MNHN, IRD, 4 place Jussieu, Paris, France
| | - Genevieve Morrow
- Laboratoire de génétique cellulaire et développementale, Département de biologie moléculaire, de biochimie médicale et de pathologie, Faculté de médecine, Institut de biologie intégrative et des systèmes (IBIS) and PROTEO, Université Laval, Québec, Québec, G1V 0A6, Canada
| | - Mohamed Taha Moutaoufik
- Laboratoire de génétique cellulaire et développementale, Département de biologie moléculaire, de biochimie médicale et de pathologie, Faculté de médecine, Institut de biologie intégrative et des systèmes (IBIS) and PROTEO, Université Laval, Québec, Québec, G1V 0A6, Canada
| | - Robert M Tanguay
- Laboratoire de génétique cellulaire et développementale, Département de biologie moléculaire, de biochimie médicale et de pathologie, Faculté de médecine, Institut de biologie intégrative et des systèmes (IBIS) and PROTEO, Université Laval, Québec, Québec, G1V 0A6, Canada.
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12
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Roskamp KW, Montelongo DM, Anorma CD, Bandak DN, Chua JA, Malecha KT, Martin RW. Multiple Aggregation Pathways in Human γS-Crystallin and Its Aggregation-Prone G18V Variant. Invest Ophthalmol Vis Sci 2017; 58:2397-2405. [PMID: 28444328 PMCID: PMC5407245 DOI: 10.1167/iovs.16-20621] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Purpose Cataract results from the formation of light-scattering precipitates due to point mutations or accumulated damage in the structural crystallins of the eye lens. Although excised cataracts are predominantly amorphous, in vitro studies show that crystallins are capable of adopting a variety of morphologies depending on the preparation method. Here we characterize thermal, pH-dependent, and UV-irradiated aggregates from wild-type human γS-crystallin (γS-WT) and its aggregation-prone variant, γS-G18V. Methods Aggregates of γS-WT and γS-G18V were prepared under acidic, neutral, and basic pH conditions and held at 25°C or 37°C for 48 hours. UV-induced aggregates were produced by irradiation with a 355-nm laser. Aggregation and fibril formation were monitored via turbidity and thioflavin T (ThT) assays. Aggregates were characterized using intrinsic aromatic fluorescence, powder x-ray diffraction, and mass spectrometry. Results γS-crystallin aggregates displayed different characteristics depending on the preparation method. γS-G18V produced a larger amount of detectable aggregates than did γS-WT and at less-extreme conditions. Aggregates formed under basic and acidic conditions yielded elevated ThT fluorescence; however, aggregates formed at low pH did not produce strongly turbid solutions. UV-induced aggregates produced highly turbid solutions but displayed only moderate ThT fluorescence. X-ray diffraction confirms amyloid character in low-pH samples and UV-irradiated samples, although the relative amounts vary. Conclusions γS-G18V demonstrates increased aggregation propensity compared to γS-WT when treated with heat, acid, or UV light. The resulting aggregates differ in their ThT fluorescence and turbidity, suggesting that at least two different aggregation pathways are accessible to both proteins under the conditions tested.
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Affiliation(s)
- Kyle W Roskamp
- Department of Chemistry, University of California, Irvine, Irvine, California, United States
| | - David M Montelongo
- Department of Chemistry, University of California, Irvine, Irvine, California, United States
| | - Chelsea D Anorma
- Department of Chemistry, University of California, Irvine, Irvine, California, United States
| | - Diana N Bandak
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, California, United States
| | - Janine A Chua
- Department of Chemistry, University of California, Irvine, Irvine, California, United States
| | - Kurtis T Malecha
- Department of Chemistry, University of California, Irvine, Irvine, California, United States
| | - Rachel W Martin
- Department of Chemistry, University of California, Irvine, Irvine, California, United States 2Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, California, United States
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13
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Wu SY, Zou P, Fuller AW, Mishra S, Wang Z, Schey KL, Mchaourab HS. Expression of Cataract-linked γ-Crystallin Variants in Zebrafish Reveals a Proteostasis Network That Senses Protein Stability. J Biol Chem 2016; 291:25387-25397. [PMID: 27770023 DOI: 10.1074/jbc.m116.749606] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/21/2016] [Indexed: 11/06/2022] Open
Abstract
The refractivity and transparency of the ocular lens is dependent on the stability and solubility of the crystallins in the fiber cells. A number of mutations of lens crystallins have been associated with dominant cataracts in humans and mice. Of particular interest were γB- and γD-crystallin mutants linked to dominant cataracts in mouse models. Although thermodynamically destabilized and aggregation-prone, these mutants were found to have weak affinity to the resident chaperone α-crystallin in vitro To better understand the mechanism of the cataract phenotype, we transgenically expressed different γD-crystallin mutants in the zebrafish lens and observed a range of lens defects that arise primarily from the aggregation of the mutant proteins. Unlike mouse models, a strong correlation was observed between the severity and penetrance of the phenotype and the level of destabilization of the mutant. We interpret this result to reflect the presence of a proteostasis network that can "sense" protein stability. In the more destabilized mutants, the capacity of this network is overwhelmed, leading to the observed increase in phenotypic penetrance. Overexpression of αA-crystallin had no significant effects on the penetrance of lens defects, suggesting that its chaperone capacity is not limiting. Although consistent with the prevailing hypothesis that a chaperone network is required for lens transparency, our results suggest that αA-crystallin may not be efficient to inhibit aggregation of lens γ-crystallin. Furthermore, our work implicates additional inputs/factors in this underlying proteostasis network and demonstrates the utility of zebrafish as a platform to delineate mechanisms of cataract.
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Affiliation(s)
- Shu-Yu Wu
- From the Departments of Molecular Physiology and Biophysics and
| | - Ping Zou
- From the Departments of Molecular Physiology and Biophysics and
| | | | - Sanjay Mishra
- From the Departments of Molecular Physiology and Biophysics and
| | - Zhen Wang
- Biochemistry and.,the Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Kevin L Schey
- Biochemistry and.,the Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
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14
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Bourrelle-Langlois M, Morrow G, Finet S, Tanguay RM. In Vitro Structural and Functional Characterization of the Small Heat Shock Proteins (sHSP) of the Cyanophage S-ShM2 and Its Host, Synechococcus sp. WH7803. PLoS One 2016; 11:e0162233. [PMID: 27643500 PMCID: PMC5028025 DOI: 10.1371/journal.pone.0162233] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 08/21/2016] [Indexed: 11/22/2022] Open
Abstract
We previously reported the in silico characterization of Synechococcus sp. phage 18 kDa small heat shock protein (HspSP-ShM2). This small heat shock protein (sHSP) contains a highly conserved core alpha crystalline domain of 92 amino acids and relatively short N- and C-terminal arms, the later containing the classical C-terminal anchoring module motif (L-X-I/L/V). Here we establish the oligomeric profile of HspSP-ShM2 and its structural dynamics under in vitro experimental conditions using size exclusion chromatography (SEC/FPLC), gradient native gels electrophoresis and dynamic light scattering (DLS). Under native conditions, HspSP-ShM2 displays the ability to form large oligomers and shows a polydisperse profile. At higher temperatures, it shows extensive structural dynamics and undergoes conformational changes through an increased of subunit rearrangement and formation of sub-oligomeric species. We also demonstrate its capacity to prevent the aggregation of citrate synthase, malate dehydrogenase and luciferase under heat shock conditions through the formation of stable and soluble hetero-oligomeric complexes (sHSP:substrate). In contrast, the host cyanobacteria Synechococcus sp. WH7803 15 kDa sHSP (HspS-WH7803) aggregates when in the same conditions as HspSP-ShM2. However, its solubility can be maintained in the presence of non-ionic detergent Triton™X-100 and forms an oligomeric structure estimated to be between dimer and tetramer but exhibits no apparent inducible structural dynamics neither chaperon-like activity in all the assays and molar ratios tested. SEC/FPLC and thermal aggregation prevention assays results indicate no formation of hetero-oligomeric complex or functional interactions between both sHSPs. Taken together these in vitro results portray the phage HspSP-ShM2 as a classical sHSP and suggest that it may be functional at the in vivo level while behaving differently than its host amphitropic sHSP.
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Affiliation(s)
- Maxime Bourrelle-Langlois
- Laboratoire de Biologie Cellulaire et Moléculaire, Institut de Biologie Intégrative et des Systémes (IBIS) and PROTEO, Département de biologie moléculaire, biochimie médicale et pathologie, Faculté de Médecine, Québec, Canada
| | - Geneviève Morrow
- Laboratoire de Biologie Cellulaire et Moléculaire, Institut de Biologie Intégrative et des Systémes (IBIS) and PROTEO, Département de biologie moléculaire, biochimie médicale et pathologie, Faculté de Médecine, Québec, Canada
| | - Stéphanie Finet
- IMPMC UMR7590, CNRS/Sorbonne-Universités, UPMC/IRD/MNHN Paris 6, Paris, France
| | - Robert M. Tanguay
- Laboratoire de Biologie Cellulaire et Moléculaire, Institut de Biologie Intégrative et des Systémes (IBIS) and PROTEO, Département de biologie moléculaire, biochimie médicale et pathologie, Faculté de Médecine, Québec, Canada
- * E-mail:
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15
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Abstract
Cataract produces vision loss due to opacification of the lens. Two possible reasons for cataract formation are insolubility of crystallin proteins and fibril (aggregate) formation. Currently, the only available treatment is surgical replacement of the lens with a synthetic one. An alternative treatment that is both economically and technologically accessible is needed in developing countries where untreated cataract and coincident blindness is high, access to trained surgeons is limited, and the cost of surgery may be prohibitive. We present current progress toward the development of a nonsurgical treatment strategy focusing on promoting protein solubility and/or dissolving fibrillar aggregates.
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16
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Serebryany E, King JA. The βγ-crystallins: native state stability and pathways to aggregation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 115:32-41. [PMID: 24835736 DOI: 10.1016/j.pbiomolbio.2014.05.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 04/30/2014] [Accepted: 05/02/2014] [Indexed: 01/26/2023]
Abstract
The βγ-crystallins are among the most stable and long-lived proteins in the human body. With increasing age, however, they transform to high molecular weight light-scattering aggregates, resulting in cataracts. This occurs despite the presence in the lens of high concentrations of the a-crystallin chaperones. Aggregation of crystallins can be induced in vitro by a variety of stresses, including acidic pH, ultraviolet light, oxidative damage, heating or freezing, and specific amino acid substitutions. Accumulating evidence points to the existence of specific biochemical pathways of protein: protein interaction and polymerization. We review the methods used for studying crystallin stability and aggregation and discuss the sometimes counterintuitive relationships between factors that favor native state stability and those that favor non-native aggregation. We discuss the behavior of βγ-crystallins in mixtures and their chaperone ability; the consequences of missense mutations and covalent damage to the side-chains; and the evolutionary strategies that have shaped these proteins. Efforts are ongoing to reveal the nature of cataractous crystallin aggregates and understand the mechanisms of aggregation in the context of key models of protein polymerization: amyloid, native-state, and domain-swapped. Such mechanistic understanding is likely to be of value for the development of therapeutic interventions and draw attention to unanswered questions about the relationship between a protein's native state stability and its transformation to an aggregated state.
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Affiliation(s)
- Eugene Serebryany
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States.
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17
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Andley UP, Malone JP, Townsend RR. In vivo substrates of the lens molecular chaperones αA-crystallin and αB-crystallin. PLoS One 2014; 9:e95507. [PMID: 24760011 PMCID: PMC3997384 DOI: 10.1371/journal.pone.0095507] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 03/26/2014] [Indexed: 12/11/2022] Open
Abstract
αA-crystallin and αB-crystallin are members of the small heat shock protein family and function as molecular chaperones and major lens structural proteins. Although numerous studies have examined their chaperone-like activities in vitro, little is known about the proteins they protect in vivo. To elucidate the relationships between chaperone function, substrate binding, and human cataract formation, we used proteomic and mass spectrometric methods to analyze the effect of mutations associated with hereditary human cataract formation on protein abundance in αA-R49C and αB-R120G knock-in mutant lenses. Compared with age-matched wild type lenses, 2-day-old αA-R49C heterozygous lenses demonstrated the following: increased crosslinking (15-fold) and degradation (2.6-fold) of αA-crystallin; increased association between αA-crystallin and filensin, actin, or creatine kinase B; increased acidification of βB1-crystallin; increased levels of grifin; and an association between βA3/A1-crystallin and αA-crystallin. Homozygous αA-R49C mutant lenses exhibited increased associations between αA-crystallin and βB3-, βA4-, βA2-crystallins, and grifin, whereas levels of βB1-crystallin, gelsolin, and calpain 3 decreased. The amount of degraded glutamate dehydrogenase, α-enolase, and cytochrome c increased more than 50-fold in homozygous αA-R49C mutant lenses. In αB-R120G mouse lenses, our analyses identified decreased abundance of phosphoglycerate mutase, several β- and γ-crystallins, and degradation of αA- and αB-crystallin early in cataract development. Changes in the abundance of hemoglobin and histones with the loss of normal α-crystallin chaperone function suggest that these proteins also play important roles in the biochemical mechanisms of hereditary cataracts. Together, these studies offer a novel insight into the putative in vivo substrates of αA- and αB-crystallin.
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Affiliation(s)
- Usha P. Andley
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
| | - James P. Malone
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - R. Reid Townsend
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
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18
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Sergeeva OA, Yang J, King JA, Knee KM. Group II archaeal chaperonin recognition of partially folded human γD-crystallin mutants. Protein Sci 2014; 23:693-702. [PMID: 24615724 DOI: 10.1002/pro.2452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 02/24/2014] [Accepted: 03/04/2014] [Indexed: 11/12/2022]
Abstract
The features in partially folded intermediates that allow the group II chaperonins to distinguish partially folded from native states remain unclear. The archaeal group II chaperonin from Methanococcus Mauripaludis (Mm-Cpn) assists the in vitro refolding of the well-characterized β-sheet lens protein human γD-crystallin (HγD-Crys). The domain interface and buried cores of this Greek key conformation include side chains, which might be exposed in partially folded intermediates. We sought to assess whether particular features buried in the native state, but absent from the native protein surface, might serve as recognition signals. The features tested were (a) paired aromatic side chains, (b) side chains in the interface between the duplicated domains of HγD-Crys, and (c) side chains in the buried core which result in congenital cataract when substituted. We tested the Mm-Cpn suppression of aggregation of these HγD-Crys mutants upon dilution out of denaturant. Mm-Cpn was capable of suppressing the off-pathway aggregation of the three classes of mutants indicating that the buried residues were not recognition signals. In fact, Mm-Cpn recognized the HγD-Crys mutants better than (wild-type) WT and refolded most mutant HγD-Crys to levels twice that of WT HγD-Crys. This presumably represents the increased population or longer lifetimes of the partially folded intermediates of the mutant proteins. The results suggest that Mm-Cpn does not recognize the features of HγD-Crys tested-paired aromatics, exposed domain interface, or destabilized core-but rather recognizes other features of the partially folded β-sheet conformation that are absent or inaccessible in the native state of HγD-Crys.
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Affiliation(s)
- Oksana A Sergeeva
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139
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19
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Lampi KJ, Wilmarth PA, Murray MR, David LL. Lens β-crystallins: the role of deamidation and related modifications in aging and cataract. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 115:21-31. [PMID: 24613629 DOI: 10.1016/j.pbiomolbio.2014.02.004] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 02/12/2014] [Accepted: 02/14/2014] [Indexed: 11/26/2022]
Abstract
Crystallins are the major proteins in the lens of the eye and function to maintain transparency of the lens. Of the human crystallins, α, β, and γ, the β-crystallins remain the most elusive in their structural significance due to their greater number of subunits and possible oligomer formations. The β-crystallins are also heavily modified during aging. This review focuses on the functional significance of deamidation and the related modifications of racemization and isomerization, the major modifications in β-crystallins of the aged human lens. Elucidating the role of these modifications in cataract formation has been slow, because they are analytically among the most difficult post-translational modifications to study. Recent results suggest that many amides deamidate to similar extent in normal aged and cataractous lenses, while others may undergo greater deamidation in cataract. Mimicking deamidation at critical structural regions induces structural changes that disrupt the stability of the β-crystallins and lead to their aggregation in vitro. Deamidations at the surface disrupt interactions with other crystallins. Additionally, the α-crystallin chaperone is unable to completely prevent deamidated β-crystallins from insolubilization. Therefore, deamidation of β-crystallins may enhance their precipitation and light scattering in vivo contributing to cataract formation. Future experiments are needed to quantify differences in deamidation rates at all Asn and Gln residues within crystallins from aged and cataractous lenses, as well as racemization and isomerization which potentially perturb protein structure greater than deamidation alone. Quantitative data is greatly needed to investigate the importance of these major age-related modifications in cataract formation.
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Affiliation(s)
- Kirsten J Lampi
- Oregon Health & Science University, Integrative Biosciences, 611 SW Campus Drive, Portland, OR 97239, USA.
| | - Phillip A Wilmarth
- Oregon Health & Science University, Biochemistry and Molecular Biology, 3181 Sam Jackson Park Road, Portland, OR 97239-3098, USA
| | - Matthew R Murray
- Oregon Health & Science University, Integrative Biosciences, 611 SW Campus Drive, Portland, OR 97239, USA
| | - Larry L David
- Oregon Health & Science University, Biochemistry and Molecular Biology, 3181 Sam Jackson Park Road, Portland, OR 97239-3098, USA
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20
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Lampi KJ, Fox CB, David LL. Changes in solvent accessibility of wild-type and deamidated βB2-crystallin following complex formation with αA-crystallin. Exp Eye Res 2012; 104:48-58. [PMID: 22982024 DOI: 10.1016/j.exer.2012.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Revised: 09/01/2012] [Accepted: 09/03/2012] [Indexed: 10/27/2022]
Abstract
Aberrant protein interactions can lead to aggregation and insolubilization, such as occurs during cataract formation. Deamidation, a prevalent age-related modification in the lens of the eye, decreases stability of the major lens proteins, crystallins. The mechanism of deamidation altering interactions between αA-crystallin and βB2-crystallin was investigated by detecting changes in solvent accessibility upon complex formation during heating. Solvent accessibility was determined by measuring hydrogen/deuterium exchange levels of backbone amides by high-resolution mass spectrometry. Deuterium levels in wild type βB2-crystallin increased 50-60% in both domains following complex formation with αA-crystallin. This increased solvent accessibility indicated a general loosening along the backbone amides. Peptides with the greatest deuterium increases were located at the buried monomer-monomer interface, suggesting that the βB2 dimer was disrupted. The only region where the deuterium levels decreased was in βB2 peptide 123-139, containing an outside loop, and may be a potential site of interaction with αA. Mimicking deamidation at the βB2 dimer interface prevented complex formation with αA. When temperatures were lowered, an αA/βB2 Q70E/Q162E complex formed with similar solvent accessibilities as αA/WT βB2. Deamidation did not disrupt specific αA/βB2 interactions but favored aggregation before complex formation with αA. We conclude that deamidation contributes to cataract formation through destabilization of crystallins before they can be rescued by α-crystallin.
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Affiliation(s)
- Kirsten J Lampi
- Oregon Health and Science University, Integrative Biosciences, 611 SW Campus Dr., Portland, OR 97239, USA.
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21
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Cataract-causing defect of a mutant γ-crystallin proceeds through an aggregation pathway which bypasses recognition by the α-crystallin chaperone. PLoS One 2012; 7:e37256. [PMID: 22655036 PMCID: PMC3360035 DOI: 10.1371/journal.pone.0037256] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Accepted: 04/18/2012] [Indexed: 11/19/2022] Open
Abstract
Background The transparency of the eye lens depends upon maintenance of the native state of the γ- and β-crystallins, which is aided by the abundant chaperones αA- and αB-crystallin. Mature onset cataract, the leading cause of blindness worldwide, involves the polymerization of covalently damaged or partially unfolded crystallins into light-scattering aggregates. A number of single amino acid substitutions and truncations of γ-crystallins result in congenital cataract in both humans and mice, though in many cases the coupling between the protein alterations and the accumulation of aggregates is poorly defined. Methodology/Principal Findings We have studied the aggregation properties and chaperone interactions of human γD-crystallin carrying substitutions of two buried core mutants, I90F and V75D, which cause congenital cataract in mice. The in vitro aggregation pathway competing with productive refolding was not altered by either substitution. Furthermore, this aggregation pathway for both mutant proteins–originating from a partially folded intermediate–was efficiently suppressed by αB-crystallin. Thus the cataract pathology was unlikely to be associated with a direct folding defect. The native state of wild-type human γD-crystallin exhibited no tendency to aggregate under physiological conditions. However both I90F and V75D native-like proteins exhibited slow (days) aggregation to high molecular weight aggregates under physiological conditions. The perturbed conformation of I90F was recognized and bound by both αA and αB chaperones. In contrast, the aggregation derived from the perturbed state of V75D was not suppressed by either chaperone, and the aggregating species were not bound by the chaperone. Conclusions/Significance The cataract phenotype of I90F in mice may be due to premature saturation of the finite α- crystallin pool. The V75D aggregation pathway and its escape from chaperone surveillance and aggregation suppression can account for the congenital cataract pathology of this mutant. Failure of chaperone recognition may be an important source of pathology for many other protein folding defects.
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22
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Skouri-Panet F, Michiel M, Férard C, Duprat E, Finet S. Structural and functional specificity of small heat shock protein HspB1 and HspB4, two cellular partners of HspB5: Role of the in vitro hetero-complex formation in chaperone activity. Biochimie 2012; 94:975-84. [DOI: 10.1016/j.biochi.2011.12.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 12/20/2011] [Indexed: 11/16/2022]
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23
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Wang S, Leng XY, Yan YB. The Benefits of Being β-Crystallin Heteromers: βB1-Crystallin Protects βA3-Crystallin against Aggregation during Co-refolding. Biochemistry 2011; 50:10451-61. [DOI: 10.1021/bi201375p] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Sha Wang
- State Key
Laboratory of Biomembrane and Membrane Biotechnology, School of Life
Sciences, Tsinghua University, Beijing
100084, China
| | - Xiao-Yao Leng
- State Key
Laboratory of Biomembrane and Membrane Biotechnology, School of Life
Sciences, Tsinghua University, Beijing
100084, China
| | - Yong-Bin Yan
- State Key
Laboratory of Biomembrane and Membrane Biotechnology, School of Life
Sciences, Tsinghua University, Beijing
100084, China
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24
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Linetsky M, Kaid Johar SR, Meltretter J, Padmanabha S, Parmar T, Vasavada AR, Pischetsrieder M, Nagaraj RH. Determination of dideoxyosone precursors of AGEs in human lens proteins. Arch Biochem Biophys 2011; 514:16-26. [PMID: 21820400 DOI: 10.1016/j.abb.2011.07.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 07/19/2011] [Indexed: 11/18/2022]
Abstract
Dideoxyosones (DDOs) are intermediates in the synthesis of advanced glycation endproducts (AGEs), such as pentosidine and glucosepane. Although the formation of pentosidine and glucosepane in the human lens has been firmly established, the formation of DDOs has not been demonstrated. The aim of this study was to develop a reliable method to detect DDOs in lens proteins. A specific DDO trapping agent, biotinyl-diaminobenzene (3,4-diamino-N-(3-[5-(2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanoyl]aminopropyl)benzamide) (BDAB) was added during in vitro protein glycation or during protein extraction from human lenses. In vitro glycated human lens protein showed strong reaction in monomeric and polymeric crosslinked proteins by Western blot and ELISA. Glycation of BSA in the presence of BDAB resulted in covalent binding of BDAB to the protein and inhibited pentosidine formation. Mass spectrometric analysis of lysozyme glycated in the presence of BDAB showed the presence of quinoxalines at lysine residues at positions K1, K33, K96, and K116. The ELISA results indicated that cataractous lens proteins contain significantly higher levels of DDO than non-cataractous lenses (101.9±67.8 vs. 31.7±19.5AU/mg protein, p<0.0001). This study provides first direct evidence of DDO presence in human tissue proteins and establishes that AGE crosslink synthesis in the human lens occurs via DDO intermediates.
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Affiliation(s)
- Mikhail Linetsky
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, USA.
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25
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Takata T, Smith JP, Arbogast B, David LL, Lampi KJ. Solvent accessibility of betaB2-crystallin and local structural changes due to deamidation at the dimer interface. Exp Eye Res 2010; 91:336-46. [PMID: 20639133 PMCID: PMC2926248 DOI: 10.1016/j.exer.2010.05.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2009] [Revised: 05/24/2010] [Accepted: 05/25/2010] [Indexed: 10/19/2022]
Abstract
In the lens of the eye the ordered arrangement of the major proteins, the crystallins, contributes to lens transparency. Members of the beta/gamma-crystallin family share common beta-sheet rich domains and hydrophobic regions at the monomer-monomer or domain-domain interfaces. Disruption of these interfaces, due to post-translational modifications, such as deamidation, decreases the stability of the crystallins. Previous experiments have failed to define the structural changes associated with this decreased stability. Using hydrogen/deuterium exchange with mass spectrometry (HDMS), deamidation-induced local structural changes in betaB2-crystallin were identified. Deamidation was mimicked by replacing glutamines with glutamic acids at homologous residues 70 and 162 in the monomer-monomer interface of the betaB2-crystallin dimer. The exchange-in of deuterium was determined from 15 s to 24 h and the global and local changes in solvent accessibility were measured. In the wild type betaB2-crystallin (WT), only about 20% of the backbone amide hydrogen was exchanged, suggesting an overall low accessibility of betaB2-crystallin in solution. This is consistent with a tightly packed domain structure observed in the crystal structure. Deuterium levels were initially greater in N-terminal domain (N-td) peptides than in homologous peptides in the C-terminal domain (C-td). The more rapid incorporation suggests a greater solvent accessibility of the N-td. In the betaB2-crystallin crystal structure, interface Gln are oriented towards their opposite domain. When deamidation was mimicked at Gln70 in the N-td, deuterium levels increased at the interface peptide in the C-td. A similar effect in the N-td was not observed when deamidation was mimicked at the homologous residue, Gln162, in the C-td. This difference in the mutants can be explained by deamidation at Gln70 disrupting the more compact C-td and increasing the solvent accessibility in the C-td interface peptides. When deamidation was mimicked at both interface Gln, deuterium incorporation increased in the C-td, similar to deamidation at Gln70 alone. In addition, deuterium incorporation was decreased in the N-td in an outside loop peptide adjacent to the mutation site. This decreased accessibility may be due to newly exposed charge groups facilitating ionic interactions or to peptides becoming more buried when other regions became more exposed. The highly sensitive HDMS methods used here detected local structural changes in solution that had not been previously identified and provide a mechanism for the associated decrease in stability due to deamidation. Changes in accessibility due to deamidation at the interface led to structural perturbations elsewhere in the protein. The cumulative effects of multiple deamidation sites perturbing the structure both locally and distant from the site of deamidation may contribute to aggregation and precipitation during aging and cataractogenesis in the lens.
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Affiliation(s)
- Takumi Takata
- Oregon Health and Science University, Integrative Biosciences, 611 SW Campus Drive, Portland, OR 97239, USA
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