1
|
Li B, Dettmer U. Interactions of alpha-synuclein with membranes in Parkinson's disease: Mechanisms and therapeutic strategies. Neurobiol Dis 2024; 201:106646. [PMID: 39181187 DOI: 10.1016/j.nbd.2024.106646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 07/30/2024] [Accepted: 08/19/2024] [Indexed: 08/27/2024] Open
Abstract
Parkinson's disease (PD), the second most common neurodegenerative disease worldwide, is marked by the presence of Lewy bodies and Lewy neurites, neuronal lesions containing large amounts of the synaptic protein alpha-synuclein (αS). While the underlying mechanisms of disease progression in PD remain unclear, increasing evidence supports the importance of interactions between αS and cellular membranes in PD pathology. Therefore, understanding the αS-membrane interplay in health and disease is crucial for the development of therapeutic strategies. In this review, we (1) discuss key scenarios of pathological αS-membrane interactions; (2) present in detail therapeutic strategies explicitly reported to modify αS-membrane interactions; and (3) introduce additional therapeutic strategies that may involve aspects of interfering with αS-membrane interaction. This way, we aim to provide a holistic perspective on this important aspect of disease-modifying strategies for PD and other α-synucleinopathies.
Collapse
Affiliation(s)
- Baoyi Li
- Wycombe Abbey, Buckinghamshire HP11 1PE, UK
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
2
|
Wang Q, Gu X, Yang L, Jiang Y, Zhang J, He J. Emerging perspectives on precision therapy for Parkinson's disease: multidimensional evidence leading to a new breakthrough in personalized medicine. Front Aging Neurosci 2024; 16:1417515. [PMID: 39026991 PMCID: PMC11254646 DOI: 10.3389/fnagi.2024.1417515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 06/17/2024] [Indexed: 07/20/2024] Open
Abstract
PD is a prevalent and progressive neurodegenerative disorder characterized by both motor and non-motor symptoms. Genes play a significant role in the onset and progression of the disease. While the complexity and pleiotropy of gene expression networks have posed challenges for gene-targeted therapies, numerous pathways of gene variant expression show promise as therapeutic targets in preclinical studies, with some already in clinical trials. With the recognition of the numerous genes and complex pathways that can influence PD, it may be possible to take a novel approach to choose a treatment for the condition. This approach would be based on the symptoms, genomics, and underlying mechanisms of the disease. We discuss the utilization of emerging genetic and pathological knowledge of PD patients to categorize the disease into subgroups. Our long-term objective is to generate new insights for the therapeutic approach to the disease, aiming to delay and treat it more effectively, and ultimately reduce the burden on individuals and society.
Collapse
Affiliation(s)
- Qiaoli Wang
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Xuan Gu
- Department of Trauma center, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Le Yang
- Department of Endocrinology, The People’s Hospital of Jilin Province, Changchun, China
| | - Yan Jiang
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Jiao Zhang
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Jinting He
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, China
| |
Collapse
|
3
|
Ashby G, Keng KE, Hayden CC, Stachowiak JC. A live cell imaging-based assay for tracking particle uptake by clathrin-mediated endocytosis. Methods Enzymol 2024; 700:413-454. [PMID: 38971609 DOI: 10.1016/bs.mie.2024.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2024]
Abstract
A popular strategy for therapeutic delivery to cells and tissues is to encapsulate therapeutics inside particles that cells internalize via endocytosis. The efficacy of particle uptake by endocytosis is often studied in bulk using flow cytometry and Western blot analysis and confirmed using confocal microscopy. However, these techniques do not reveal the detailed dynamics of particle internalization and how the inherent heterogeneity of many types of particles may impact their endocytic uptake. Toward addressing these gaps, here we present a live-cell imaging-based method that utilizes total internal reflection fluorescence microscopy to track the uptake of a large ensemble of individual particles in parallel, as they interact with the cellular endocytic machinery. To analyze the resulting data, we employ an open-source tracking algorithm in combination with custom data filters. This analysis reveals the dynamic interactions between particles and endocytic structures, which determine the probability of particle uptake. In particular, our approach can be used to examine how variations in the physical properties of particles (size, targeting, rigidity), as well as heterogeneity within the particle population, impact endocytic uptake. These data impact the design of particles toward more selective and efficient delivery of therapeutics to cells.
Collapse
Affiliation(s)
- Grant Ashby
- Department of Biomedical Engineering, The University of Texas at Austin
| | - Kayla E Keng
- Department of Biomedical Engineering, The University of Texas at Austin
| | - Carl C Hayden
- Department of Biomedical Engineering, The University of Texas at Austin
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, The University of Texas at Austin; Department of Chemical Engineering, The University of Texas at Austin.
| |
Collapse
|
4
|
Xie P, Zhang H, Qin Y, Xiong H, Shi C, Zhou Z. Membrane Proteins and Membrane Curvature: Mutual Interactions and a Perspective on Disease Treatments. Biomolecules 2023; 13:1772. [PMID: 38136643 PMCID: PMC10741411 DOI: 10.3390/biom13121772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/30/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
The pathogenesis of various diseases often involves an intricate interplay between membrane proteins and membrane curvature. Understanding the underlying mechanisms of this interaction could offer novel perspectives on disease treatment. In this review, we provide an introduction to membrane curvature and its association with membrane proteins. Furthermore, we delve into the impact and potential implications of this interaction in the context of disease treatment. Lastly, we discuss the prospects and challenges associated with harnessing these interactions for effective disease management, aiming to provide fresh insights into therapeutic strategies.
Collapse
Affiliation(s)
| | | | | | | | | | - Zijian Zhou
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory & Center for Molecular Imaging and Translational Medicine, School of Public Health, Shenzhen Research Institute of Xiamen University, Xiamen University, Xiamen 361102, China; (P.X.); (H.Z.); (Y.Q.); (H.X.); (C.S.)
| |
Collapse
|
5
|
Singh AN, Nice JB, Brown AC, Wittenberg NJ. Identifying size-dependent toxin sorting in bacterial outer membrane vesicles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.03.539273. [PMID: 37205353 PMCID: PMC10187208 DOI: 10.1101/2023.05.03.539273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Gram-negative bacteria produce outer membrane vesicles (OMVs) that play a critical role in cell-cell communication and virulence. Despite being isolated from a single population of bacteria, OMVs can exhibit heterogeneous size and toxin content, which can be obscured by assays that measure ensemble properties. To address this issue, we utilize fluorescence imaging of individual OMVs to reveal size-dependent toxin sorting. Our results showed that the oral bacterium Aggregatibacter actinomycetemcomitans (A.a.) produces OMVs with a bimodal size distribution, where larger OMVs were much more likely to possess leukotoxin (LtxA). Among the smallest OMVs (< 100 nm diameter), the fraction that are toxin positive ranges from 0-30%, while the largest OMVs (> 200 nm diameter) are between 70-100% toxin positive. Our single OMV imaging method provides a non-invasive way to observe OMV surface heterogeneity at the nanoscale level and determine size-based heterogeneities without the need for OMV fraction separation.
Collapse
Affiliation(s)
- Aarshi N. Singh
- Department of Chemistry, Lehigh University, Bethlehem, PA, U.S.A
| | - Justin B Nice
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, U.S.A
| | - Angela C. Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, U.S.A
| | | |
Collapse
|
6
|
van Hilten N, Methorst J, Verwei N, Risselada HJ. Physics-based generative model of curvature sensing peptides; distinguishing sensors from binders. SCIENCE ADVANCES 2023; 9:eade8839. [PMID: 36930719 PMCID: PMC10022891 DOI: 10.1126/sciadv.ade8839] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Proteins can specifically bind to curved membranes through curvature-induced hydrophobic lipid packing defects. The chemical diversity among such curvature "sensors" challenges our understanding of how they differ from general membrane "binders" that bind without curvature selectivity. Here, we combine an evolutionary algorithm with coarse-grained molecular dynamics simulations (Evo-MD) to resolve the peptide sequences that optimally recognize the curvature of lipid membranes. We subsequently demonstrate how a synergy between Evo-MD and a neural network (NN) can enhance the identification and discovery of curvature sensing peptides and proteins. To this aim, we benchmark a physics-trained NN model against experimental data and show that we can correctly identify known sensors and binders. We illustrate that sensing and binding are phenomena that lie on the same thermodynamic continuum, with only subtle but explainable differences in membrane binding free energy, consistent with the serendipitous discovery of sensors.
Collapse
Affiliation(s)
- Niek van Hilten
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden, 2333 CC, Netherlands
| | - Jeroen Methorst
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden, 2333 CC, Netherlands
| | - Nino Verwei
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden, 2333 CC, Netherlands
| | - Herre Jelger Risselada
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden, 2333 CC, Netherlands
- Department of Physics, Technical University Dortmund, Otto-Hahn-Strasse 4, Dortmund, 44227, Germany
- Institute of Theoretical Physics, Georg-August-University Göttingen, Friedrich-Hund-Platz 1, Göttingen, 37077, Germany
| |
Collapse
|
7
|
Chan FY, Kurosaki R, Ganser C, Takeda T, Uchihashi T. Tip-scan high-speed atomic force microscopy with a uniaxial substrate stretching device for studying dynamics of biomolecules under mechanical stress. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:113703. [PMID: 36461522 DOI: 10.1063/5.0111017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 10/09/2022] [Indexed: 06/17/2023]
Abstract
High-speed atomic force microscopy (HS-AFM) is a powerful tool for studying the dynamics of biomolecules in vitro because of its high temporal and spatial resolution. However, multi-functionalization, such as combination with complementary measurement methods, environment control, and large-scale mechanical manipulation of samples, is still a complex endeavor due to the inherent design and the compact sample scanning stage. Emerging tip-scan HS-AFM overcame this design hindrance and opened a door for additional functionalities. In this study, we designed a motor-driven stretching device to manipulate elastic substrates for HS-AFM imaging of biomolecules under controllable mechanical stimulation. To demonstrate the applicability of the substrate stretching device, we observed a microtubule buckling by straining the substrate and actin filaments linked by α-actinin on a curved surface. In addition, a BAR domain protein BIN1 that senses substrate curvature was observed while dynamically controlling the surface curvature. Our results clearly prove that large-scale mechanical manipulation can be coupled with nanometer-scale imaging to observe biophysical effects otherwise obscured.
Collapse
Affiliation(s)
- Feng-Yueh Chan
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Ryo Kurosaki
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Christian Ganser
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Tetsuya Takeda
- Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Kita-Ku, Okayama 700-8558, Japan
| | - Takayuki Uchihashi
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| |
Collapse
|
8
|
Molecular and Cellular Interactions in Pathogenesis of Sporadic Parkinson Disease. Int J Mol Sci 2022; 23:ijms232113043. [PMID: 36361826 PMCID: PMC9657547 DOI: 10.3390/ijms232113043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 10/16/2022] [Accepted: 10/25/2022] [Indexed: 11/23/2022] Open
Abstract
An increasing number of the population all around the world suffer from age-associated neurodegenerative diseases including Parkinson’s disease (PD). This disorder presents different signs of genetic, epigenetic and environmental origin, and molecular, cellular and intracellular dysfunction. At the molecular level, α-synuclein (αSyn) was identified as the principal molecule constituting the Lewy bodies (LB). The gut microbiota participates in the pathogenesis of PD and may contribute to the loss of dopaminergic neurons through mitochondrial dysfunction. The most important pathogenetic link is an imbalance of Ca2+ ions, which is associated with redox imbalance in the cells and increased generation of reactive oxygen species (ROS). In this review, genetic, epigenetic and environmental factors that cause these disorders and their cause-and-effect relationships are considered. As a constituent of environmental factors, the example of organophosphates (OPs) is also reviewed. The role of endothelial damage in the pathogenesis of PD is discussed, and a ‘triple hit hypothesis’ is proposed as a modification of Braak’s dual hit one. In the absence of effective therapies for neurodegenerative diseases, more and more evidence is emerging about the positive impact of nutritional structure and healthy lifestyle on the state of blood vessels and the risk of developing these diseases.
Collapse
|
9
|
Sathanantham P, Zhao W, He G, Murray A, Fenech E, Diaz A, Schuldiner M, Wang X. A conserved viral amphipathic helix governs the replication site-specific membrane association. PLoS Pathog 2022; 18:e1010752. [PMID: 36048900 PMCID: PMC9473614 DOI: 10.1371/journal.ppat.1010752] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 09/14/2022] [Accepted: 07/19/2022] [Indexed: 11/18/2022] Open
Abstract
Positive-strand RNA viruses assemble their viral replication complexes (VRCs) on specific host organelle membranes, yet it is unclear how viral replication proteins recognize and what motifs or domains in viral replication proteins determine their destinations. We show here that an amphipathic helix, helix B in replication protein 1a of brome mosaic virus (BMV), is necessary for 1a’s localization to the nuclear endoplasmic reticulum (ER) membrane where BMV assembles its VRCs. Helix B is also sufficient to target soluble proteins to the nuclear ER membrane in yeast and plant cells. We further show that an equivalent helix in several plant- and human-infecting viruses of the Alsuviricetes class targets fluorescent proteins to the organelle membranes where they form their VRCs, including ER, vacuole, and Golgi membranes. Our work reveals a conserved helix that governs the localization of VRCs among a group of viruses and points to a possible target for developing broad-spectrum antiviral strategies. Positive-strand RNA viruses [(+)RNA viruses] are the largest viral class that include numerous pathogens causing important diseases in humans, animals, and plants. During their infections, (+)RNA viruses assemble their viral replication complexes (VRCs), where they multiply themselves, at specific organelle membranes. An initial step to form VRCs is to target viral replication proteins to the designated organelle membranes. For brome mosaic virus (BMV), its replication protein 1a is responsible for the VRC formation at the nuclear endoplasmic reticulum (ER) membrane. We show that an amphipathic alpha-helix, helix B, in BMV 1a is necessary for the association of BMV 1a with the nuclear ER membrane and for BMV genome amplification. In addition, Helix B is sufficient to target several soluble proteins to the nuclear ER membrane in yeast and plant cells. BMV belongs to the Alsuviricetes class that includes viruses infecting humans, animals, and plants. We further show that the helix B across members of the Alsuviricetes class is sufficient to target fluorescence proteins to the designated organelle membranes. Our results reveal a conserved feature among a group of viruses in governing the associations with replication site-specific organelle membranes and point to a target to develop broad-spectrum antivirals.
Collapse
Affiliation(s)
- Preethi Sathanantham
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Wenhao Zhao
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
| | - Guijuan He
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Austin Murray
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Emma Fenech
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Arturo Diaz
- Department of Biology, La Sierra University, Riverside, California, United States of America
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Xiaofeng Wang
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
- * E-mail:
| |
Collapse
|
10
|
van Hilten N, Stroh KS, Risselada HJ. Efficient Quantification of Lipid Packing Defect Sensing by Amphipathic Peptides: Comparing Martini 2 and 3 with CHARMM36. J Chem Theory Comput 2022; 18:4503-4514. [PMID: 35709386 PMCID: PMC9281404 DOI: 10.1021/acs.jctc.2c00222] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In biological systems, proteins can be attracted to curved or stretched regions of lipid bilayers by sensing hydrophobic defects in the lipid packing on the membrane surface. Here, we present an efficient end-state free energy calculation method to quantify such sensing in molecular dynamics simulations. We illustrate that lipid packing defect sensing can be defined as the difference in mechanical work required to stretch a membrane with and without a peptide bound to the surface. We also demonstrate that a peptide's ability to concurrently induce excess leaflet area (tension) and elastic softening─a property we call the "characteristic area of sensing" (CHAOS)─and lipid packing sensing behavior are in fact two sides of the same coin. In essence, defect sensing displays a peptide's propensity to generate tension. The here-proposed mechanical pathway is equally accurate yet, computationally, about 40 times less costly than the commonly used alchemical pathway (thermodynamic integration), allowing for more feasible free energy calculations in atomistic simulations. This enabled us to directly compare the Martini 2 and 3 coarse-grained and the CHARMM36 atomistic force fields in terms of relative binding free energies for six representative peptides including the curvature sensor ALPS and two antiviral amphipathic helices (AH). We observed that Martini 3 qualitatively reproduces experimental trends while producing substantially lower (relative) binding free energies and shallower membrane insertion depths compared to atomistic simulations. In contrast, Martini 2 tends to overestimate (relative) binding free energies. Finally, we offer a glimpse into how our end-state-based free energy method can enable the inverse design of optimal lipid packing defect sensing peptides when used in conjunction with our recently developed evolutionary molecular dynamics (Evo-MD) method. We argue that these optimized defect sensors─aside from their biomedical and biophysical relevance─can provide valuable targets for the development of lipid force fields.
Collapse
Affiliation(s)
- Niek van Hilten
- Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands
| | - Kai Steffen Stroh
- Department of Physics, Technical University Dortmund, Dortmund 44221, Germany.,Institute for Theoretical Physics, Georg-August-University Göttingen, Göttingen 37077, Germany
| | - Herre Jelger Risselada
- Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands.,Department of Physics, Technical University Dortmund, Dortmund 44221, Germany.,Institute for Theoretical Physics, Georg-August-University Göttingen, Göttingen 37077, Germany
| |
Collapse
|
11
|
Tumor protein D54 binds intracellular nanovesicles via an extended amphipathic region. J Biol Chem 2022; 298:102136. [PMID: 35714773 PMCID: PMC9270247 DOI: 10.1016/j.jbc.2022.102136] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 11/22/2022] Open
Abstract
Tumor Protein D54 (TPD54) is an abundant cytosolic protein that belongs to the TPD52 family, a family of four proteins (TPD52, 53, 54 and 55) that are overexpressed in several cancer cells. Even though the functions of these proteins remain elusive, recent investigations indicate that TPD54 binds to very small cytosolic vesicles with a diameter of ca. 30 nm, half the size of classical (e.g. COPI and COPII) transport vesicles. Here, we investigated the mechanism of intracellular nanovesicle capture by TPD54. Bioinformatical analysis suggests that TPD54 contains a small coiled-coil followed by four amphipathic helices (AH1-4), which could fold upon binding to lipid membranes. Limited proteolysis, circular dichroism (CD) spectroscopy, tryptophan fluorescence, and cysteine mutagenesis coupled to covalent binding of a membrane sensitive probe showed that binding of TPD54 to small liposomes is accompanied by large structural changes in the amphipathic helix region. Furthermore, site-directed mutagenesis indicated that AH2 and AH3 have a predominant role in TPD54 binding to membranes both in cells and using model liposomes. We found that AH3 has the physicochemical features of an Amphipathic Lipid Packing Sensor (ALPS) motif, which, in other proteins, enables membrane binding in a curvature-dependent manner. Accordingly, we observed that binding of TPD54 to liposomes is very sensitive to membrane curvature and lipid unsaturation. We conclude that TPD54 recognizes nanovesicles through a combination of ALPS-dependent and -independent mechanisms.
Collapse
|
12
|
Bashkirov PV, Kuzmin PI, Vera Lillo J, Frolov VA. Molecular Shape Solution for Mesoscopic Remodeling of Cellular Membranes. Annu Rev Biophys 2022; 51:473-497. [PMID: 35239417 PMCID: PMC10787580 DOI: 10.1146/annurev-biophys-011422-100054] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cellular membranes self-assemble from and interact with various molecular species. Each molecule locally shapes the lipid bilayer, the soft elastic core of cellular membranes. The dynamic architecture of intracellular membrane systems is based on elastic transformations and lateral redistribution of these elementary shapes, driven by chemical and curvature stress gradients. The minimization of the total elastic stress by such redistribution composes the most basic, primordial mechanism of membrane curvature-composition coupling (CCC). Although CCC is generally considered in the context of dynamic compositional heterogeneity of cellular membrane systems, in this article we discuss a broader involvement of CCC in controlling membrane deformations. We focus specifically on the mesoscale membrane transformations in open, reservoir-governed systems, such as membrane budding, tubulation, and the emergence of highly curved sites of membrane fusion and fission. We reveal that the reshuffling of molecular shapes constitutes an independent deformation mode with complex rheological properties.This mode controls effective elasticity of local deformations as well as stationary elastic stress, thus emerging as a major regulator of intracellular membrane remodeling.
Collapse
Affiliation(s)
- Pavel V Bashkirov
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
- Department of Molecular and Biological Physics, Moscow Institute of Physics and Technology, Moscow, Russia
| | - Peter I Kuzmin
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia
| | - Javier Vera Lillo
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, Leioa, Spain;
| | - Vadim A Frolov
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, Leioa, Spain;
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| |
Collapse
|
13
|
Insights into Membrane Curvature Sensing and Membrane Remodeling by Intrinsically Disordered Proteins and Protein Regions. J Membr Biol 2022; 255:237-259. [PMID: 35451616 PMCID: PMC9028910 DOI: 10.1007/s00232-022-00237-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/29/2022] [Indexed: 12/15/2022]
Abstract
Cellular membranes are highly dynamic in shape. They can rapidly and precisely regulate their shape to perform various cellular functions. The protein’s ability to sense membrane curvature is essential in various biological events such as cell signaling and membrane trafficking. As they are bound, these curvature-sensing proteins may also change the local membrane shape by one or more curvature driving mechanisms. Established curvature-sensing/driving mechanisms rely on proteins with specific structural features such as amphipathic helices and intrinsically curved shapes. However, the recent discovery and characterization of many proteins have shattered the protein structure–function paradigm, believing that the protein functions require a unique structural feature. Typically, such structure-independent functions are carried either entirely by intrinsically disordered proteins or hybrid proteins containing disordered regions and structured domains. It is becoming more apparent that disordered proteins and regions can be potent sensors/inducers of membrane curvatures. In this article, we outline the basic features of disordered proteins and regions, the motifs in such proteins that encode the function, membrane remodeling by disordered proteins and regions, and assays that may be employed to investigate curvature sensing and generation by ordered/disordered proteins.
Collapse
|
14
|
Münter R, Stavnsbjerg C, Christensen E, Thomsen ME, Stensballe A, Hansen AE, Parhamifar L, Kristensen K, Simonsen JB, Larsen JB, Andresen TL. Unravelling Heterogeneities in Complement and Antibody Opsonization of Individual Liposomes as a Function of Surface Architecture. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2106529. [PMID: 35187804 DOI: 10.1002/smll.202106529] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Coating nanoparticles with poly(ethylene glycol) (PEG) is widely used to achieve long-circulating properties after infusion. While PEG reduces binding of opsonins to the particle surface, immunogenic anti-PEG side-effects show that PEGylated nanoparticles are not truly "stealth" to surface active proteins. A major obstacle for understanding the complex interplay between opsonins and nanoparticles is the averaging effects of the bulk assays that are typically applied to study protein adsorption to nanoparticles. Here, a microscopy-based method for directly quantifying opsonization at the single nanoparticle level is presented. Various surface coatings are investigated on liposomes, including PEG, and show that opsonization by both antibodies and complement C3b is highly dependent on the surface chemistry. It is further demonstrated that this opsonization is heterogeneous, with opsonized and non-opsonized liposomes co-existing in the same ensemble. Surface coatings modify the percentage of opsonized liposomes and/or opsonin surface density on the liposomes, with strikingly different patterns for antibodies and complement. Thus, this assay provides mechanistic details about opsonization at the single nanoparticle level previously inaccessible to established bulk assays.
Collapse
Affiliation(s)
- Rasmus Münter
- Biotherapeutic Engineering and Drug Targeting, Department of Health Technology, Technical University of Denmark (DTU), Kgs. Lyngby, 2800, Denmark
| | - Camilla Stavnsbjerg
- Biotherapeutic Engineering and Drug Targeting, Department of Health Technology, Technical University of Denmark (DTU), Kgs. Lyngby, 2800, Denmark
| | - Esben Christensen
- Biotherapeutic Engineering and Drug Targeting, Department of Health Technology, Technical University of Denmark (DTU), Kgs. Lyngby, 2800, Denmark
| | - Mikkel E Thomsen
- Department of Health Science and Technology, Aalborg University, Aalborg Ø, 9220, Denmark
| | - Allan Stensballe
- Department of Health Science and Technology, Aalborg University, Aalborg Ø, 9220, Denmark
| | - Anders E Hansen
- Biotherapeutic Engineering and Drug Targeting, Department of Health Technology, Technical University of Denmark (DTU), Kgs. Lyngby, 2800, Denmark
| | - Ladan Parhamifar
- Biotherapeutic Engineering and Drug Targeting, Department of Health Technology, Technical University of Denmark (DTU), Kgs. Lyngby, 2800, Denmark
| | - Kasper Kristensen
- Biotherapeutic Engineering and Drug Targeting, Department of Health Technology, Technical University of Denmark (DTU), Kgs. Lyngby, 2800, Denmark
| | - Jens B Simonsen
- Biotherapeutic Engineering and Drug Targeting, Department of Health Technology, Technical University of Denmark (DTU), Kgs. Lyngby, 2800, Denmark
| | - Jannik B Larsen
- Biotherapeutic Engineering and Drug Targeting, Department of Health Technology, Technical University of Denmark (DTU), Kgs. Lyngby, 2800, Denmark
| | - Thomas L Andresen
- Biotherapeutic Engineering and Drug Targeting, Department of Health Technology, Technical University of Denmark (DTU), Kgs. Lyngby, 2800, Denmark
| |
Collapse
|
15
|
Simon C, Soga T, Okano HJ, Parhar I. α-Synuclein-mediated neurodegeneration in Dementia with Lewy bodies: the pathobiology of a paradox. Cell Biosci 2021; 11:196. [PMID: 34798911 PMCID: PMC8605528 DOI: 10.1186/s13578-021-00709-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 11/16/2022] Open
Abstract
Dementia with Lewy bodies (DLB) is epitomized by the pathognomonic manifestation of α-synuclein-laden Lewy bodies within selectively vulnerable neurons in the brain. By virtue of prion-like inheritance, the α-synuclein protein inexorably undergoes extensive conformational metamorphoses and culminate in the form of fibrillar polymorphs, instigating calamitous damage to the brain's neuropsychological networks. This epiphenomenon is nebulous, however, by lingering uncertainty over the quasi "pathogenic" behavior of α-synuclein conformers in DLB pathobiology. Despite numerous attempts, a monolithic "α-synuclein" paradigm that is able to untangle the enigma enshrouding the clinicopathological spectrum of DLB has failed to emanate. In this article, we review conceptual frameworks of α-synuclein dependent cell-autonomous and non-autonomous mechanisms that are likely to facilitate the transneuronal spread of degeneration through the neuraxis. In particular, we describe how the progressive demise of susceptible neurons may evolve from cellular derangements perpetrated by α-synuclein misfolding and aggregation. Where pertinent, we show how these bona fide mechanisms may mutually accentuate α-synuclein-mediated neurodegeneration in the DLB brain.
Collapse
Affiliation(s)
- Christopher Simon
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - Tomoko Soga
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - Hirotaka James Okano
- Division of Regenerative Medicine, Research Center for Medical Sciences, The Jikei University School of Medicine, Tokyo, Japan
| | - Ishwar Parhar
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| |
Collapse
|
16
|
Pathak BK, Dey S, Mozumder S, Sengupta J. The role of membranes in function and dysfunction of intrinsically disordered amyloidogenic proteins. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 128:397-434. [PMID: 35034725 DOI: 10.1016/bs.apcsb.2021.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Membrane-protein interactions play a major role in human physiology as well as in diseases pathology. Interaction of a protein with the membrane was previously thought to be dependent on well-defined three-dimensional structure of the protein. In recent decades, however, it has become evident that a large fraction of the proteome, particularly in eukaryotes, stays disordered in solution and these proteins are termed as intrinsically disordered proteins (IDPs). Also, a vast majority of human proteomes have been reported to contain substantially long disordered regions, called intrinsically disordered regions (IDRs), in addition to the structurally ordered regions. IDPs exist in an ensemble of conformations and the conformational flexibility enables IDPs to achieve functional diversity. IDPs (and IDRs) are found to be important players in cell signaling, where biological membranes act as anchors for signaling cascades. Therefore, IDPs modulate the membrane architectures, at the same time membrane composition also affects the binding of IDPs. Because of intrinsic disorders, misfolding of IDPs often leads to formation of oligomers, protofibrils and mature fibrils through progressive self-association. Accumulation of amyloid-like aggregates of some of the IDPs is a known causative agent for numerous diseases. In this chapter we highlight recent advances in understanding membrane interactions of some of the intrinsically disordered proteins involved in the pathogenesis of human diseases.
Collapse
Affiliation(s)
- Bani Kumar Pathak
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Sandip Dey
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Sukanya Mozumder
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Jayati Sengupta
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
| |
Collapse
|
17
|
Haque ME, Akther M, Azam S, Kim IS, Lin Y, Lee YH, Choi DK. Targeting α-synuclein aggregation and its role in mitochondrial dysfunction in Parkinson's disease. Br J Pharmacol 2021; 179:23-45. [PMID: 34528272 DOI: 10.1111/bph.15684] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 08/17/2021] [Accepted: 08/25/2021] [Indexed: 11/28/2022] Open
Abstract
Lewy bodies that contain aggregated α-synuclein (α-syn) in the dopaminergic (DA) neuron are the main culprit behind neurodegeneration in Parkinson's disease (PD). Besides, mitochondrial dysfunction has a well established and prominent role in the pathogenesis of PD. However, the exact mechanism by which α-syn causes dopaminergic neuronal loss was unclear. Recent evidence suggests that aggregated α-syn localises in the mitochondria and contributes to oxidative stress-mediated apoptosis in neurons. Therefore, the involvement of aggregated α-syn in mitochondrial dysfunction-mediated neuronal loss has made it an emerging drug target for the treatment of PD. However, the exact mechanism by which α-syn permeabilises through the mitochondrial membrane and affects the electron transport chain remains under investigation. In the present study, we describe mitochondria-α-syn interactions and how α-syn aggregation modulates mitochondrial homeostasis in PD pathogenesis. We also discuss recent therapeutic interventions targeting α-syn aggregation that may help researchers to design novel therapeutic treatments for PD.
Collapse
Affiliation(s)
- Md Ezazul Haque
- Department of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju, Republic of Korea
| | - Mahbuba Akther
- Department of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju, Republic of Korea
| | - Shofiul Azam
- Department of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju, Republic of Korea
| | - In-Su Kim
- Department of Biotechnology, College of Biomedical and Health Science, Research Institute of Inflammatory Disease (RID), Konkuk University, Chungju, Republic of Korea
| | - Yuxi Lin
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Ochang, Chung Buk, Republic of Korea
| | - Young-Ho Lee
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Ochang, Chung Buk, Republic of Korea.,Department of Bio-analytical Science, University of Science and Technology, Daejeon, Republic of Korea.,Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, Republic of Korea.,Research Headquarters, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Dong-Kug Choi
- Department of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju, Republic of Korea.,Department of Biotechnology, College of Biomedical and Health Science, Research Institute of Inflammatory Disease (RID), Konkuk University, Chungju, Republic of Korea
| |
Collapse
|
18
|
Kayed R, Dettmer U, Lesné SE. Soluble endogenous oligomeric α-synuclein species in neurodegenerative diseases: Expression, spreading, and cross-talk. JOURNAL OF PARKINSON'S DISEASE 2021; 10:791-818. [PMID: 32508330 PMCID: PMC7458533 DOI: 10.3233/jpd-201965] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
There is growing recognition in the field of neurodegenerative diseases that mixed proteinopathies are occurring at greater frequency than originally thought. This is particularly true for three amyloid proteins defining most of these neurological disorders, amyloid-beta (Aβ), tau, and alpha-synuclein (αSyn). The co-existence and often co-localization of aggregated forms of these proteins has led to the emergence of concepts positing molecular interactions and cross-seeding between Aβ, tau, and αSyn aggregates. Amongst this trio, αSyn has received particular attention in this context during recent years due to its ability to modulate Aβ and tau aggregation in vivo, to interact at a molecular level with Aβ and tau in vivo and to cross-seed tau in mice. Here we provide a comprehensive, critical, and accessible review about the expression, role and nature of endogenous soluble αSyn oligomers because of recent developments in the understanding of αSyn multimerization, misfolding, aggregation, cross-talk, spreading and cross-seeding in neurodegenerative disorders, including Parkinson's disease, dementia with Lewy bodies, multiple system atrophy, Alzheimer's disease, and Huntington's disease. We will also discuss our current understanding about the relative toxicity of endogenous αSyn oligomers in vivo and in vitro, and introduce potential opportunities to counter their deleterious effects.
Collapse
Affiliation(s)
- Rakez Kayed
- Departments of Neurology & Neuroscience & Cell Biology & Anatomy, University of Texas Medical Branch Galveston, Galveston, TX, USA,George and Cynthia Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch Galveston, Galveston, TX, USA
| | - Ulf Dettmer
- Department of Neurology, Harvard Medical School, Boston, MA, USA,Ann Romney Center for Neurologic Diseases, Harvard Medical School, Boston, MA, USA
| | - Sylvain E. Lesné
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA,Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA,Correspondence to: Sylvain E. Lesné, PhD, University of Minnesota, Wallin Medical Biosciences Building (Room 4-114), 2101 Sixth Street SE, CDC 2641, Minneapolis, MN 55414, USA. Tel.: +1 612 626 8341; E-mail: ; Website: https://lesnelab.org
| |
Collapse
|
19
|
Recent developments in membrane curvature sensing and induction by proteins. Biochim Biophys Acta Gen Subj 2021; 1865:129971. [PMID: 34333084 DOI: 10.1016/j.bbagen.2021.129971] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 07/11/2021] [Accepted: 07/25/2021] [Indexed: 12/22/2022]
Abstract
BACKGROUND Membrane-bound intracellular organelles have characteristic shapes attributed to different local membrane curvatures, and these attributes are conserved across species. Over the past decade, it has been confirmed that specific proteins control the large curvatures of the membrane, whereas many others due to their specific structural features can sense the curvatures and bind to the specific geometrical cues. Elucidating the interplay between sensing and induction is indispensable to understand the mechanisms behind various biological processes such as vesicular trafficking and budding. SCOPE OF REVIEW We provide an overview of major classes of membrane proteins and the mechanisms of curvature sensing and induction. We then discuss the importance of membrane elastic characteristics to induce the membrane shapes similar to intracellular organelles. Finally, we survey recently available assays developed for studying the curvature sensing and induction by many proteins. MAJOR CONCLUSIONS Recent theoretical/computational modeling along with experimental studies have uncovered fascinating connections between lipid membrane and protein interactions. However, the phenomena of protein localization and synchronization to generate spatiotemporal dynamics in membrane morphology are yet to be fully understood. GENERAL SIGNIFICANCE The understanding of protein-membrane interactions is essential to shed light on various biological processes. This further enables the technological applications of many natural proteins/peptides in therapeutic treatments. The studies of membrane dynamic shapes help to understand the fundamental functions of membranes, while the medicinal roles of various macromolecules (such as proteins, peptides, etc.) are being increasingly investigated.
Collapse
|
20
|
Makasewicz K, Wennmalm S, Stenqvist B, Fornasier M, Andersson A, Jönsson P, Linse S, Sparr E. Cooperativity of α-Synuclein Binding to Lipid Membranes. ACS Chem Neurosci 2021; 12:2099-2109. [PMID: 34076426 PMCID: PMC8291482 DOI: 10.1021/acschemneuro.1c00006] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cooperative binding is a key feature of metabolic pathways, signaling, and transport processes. It provides tight regulation over a narrow concentration interval of a ligand, thus enabling switching to be triggered by small concentration variations. The data presented in this work reveal strong positive cooperativity of α-synuclein binding to phospholipid membranes. Fluorescence cross-correlation spectroscopy, confocal microscopy, and cryo-TEM results show that in excess of vesicles α-synuclein does not distribute randomly but binds only to a fraction of all available vesicles. Furthermore, α-synuclein binding to a supported lipid bilayer observed with total internal reflection fluorescence microscopy displays a much steeper dependence of bound protein on total protein concentration than expected for independent binding. The same phenomenon was observed in the case of α-synuclein binding to unilamellar vesicles of sizes in the nm and μm range as well as to flat supported lipid bilayers, ruling out that nonuniform binding of the protein is governed by differences in membrane curvature. Positive cooperativity of α-synuclein binding to lipid membranes means that the affinity of the protein to a membrane is higher where there is already protein bound compared to a bare membrane. The phenomenon described in this work may have implications for α-synuclein function in synaptic transmission and other membrane remodeling events.
Collapse
Affiliation(s)
- Katarzyna Makasewicz
- Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Stefan Wennmalm
- Department of Applied Physics, Biophysics Group, SciLifeLab, Royal Institute of Technology-KTH, 171 65 Solna, Sweden
| | - Björn Stenqvist
- Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Marco Fornasier
- Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Alexandra Andersson
- Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Peter Jönsson
- Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Sara Linse
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, SE-22100 Lund, Sweden
| | - Emma Sparr
- Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| |
Collapse
|
21
|
Fanning S, Selkoe D, Dettmer U. Vesicle trafficking and lipid metabolism in synucleinopathy. Acta Neuropathol 2021; 141:491-510. [PMID: 32607605 DOI: 10.1007/s00401-020-02177-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/05/2020] [Accepted: 06/06/2020] [Indexed: 12/12/2022]
Abstract
The neuronal protein α-synuclein (αS) is central to the pathogenesis of Parkinson's disease and other progressive brain diseases such as Lewy body dementia and multiple system atrophy. These diseases, collectively referred to as 'synucleinopathies', have long been considered purely proteinopathies: diseases characterized by the misfolding of a protein into small and large aggregates mainly consisting of that protein (in this case: α-synuclein). However, recent morphological insights into Lewy bodies, the hallmark neuropathology of human synucleinopathies, suggests these lesions are also rich in vesicles and other membranous organelles. Moreover, αS physiology and pathology are both strongly associated with various aspects of intracellular vesicle trafficking and lipid biology. αS physiologically binds to synaptic and other small vesicles, and several functions of αS in regulating vesicle biology have been proposed. Familial PD-linked αS excess and missense mutations have been shown to impair vesicle trafficking and alter lipid homeostasis. On the other hand, vesicle trafficking and lipid-related genes have emerged as Parkinson's risk factors, suggesting a bidirectional relationship. The answer to the question "Does abnormal αS accumulation cause impaired vesicle trafficking and lipid dyshomeostasis or is αS aggregation the consequence of such impairments?" may be "Both". Here, we review current knowledge of the αS-lipid and αS-vesicle trafficking interplay, with a special focus on Parkinson's disease and Lewy body dementia.
Collapse
|
22
|
Liu C, Zhao Y, Xi H, Jiang J, Yu Y, Dong W. The Membrane Interaction of Alpha-Synuclein. Front Cell Neurosci 2021; 15:633727. [PMID: 33746714 PMCID: PMC7969880 DOI: 10.3389/fncel.2021.633727] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/28/2021] [Indexed: 12/12/2022] Open
Abstract
A presynaptic protein closely related to Parkinson's disease (PD), α-synuclein (α-Syn), has been studied extensively regarding its pathogenic mechanisms. As a physiological protein in presynapses, however, α-Syn's physiological function remains unclear. Its location in nerve terminals and effects on membrane fusion also imply its functional role in synaptic transmission, including its possible interaction with high-curvature membranes via its N-terminus and amorphous C-terminus. PD-related mutants that disrupt the membrane interaction (e.g., A30P and G51D) additionally suggest a relationship between α-Syn's pathogenic mechanisms and physiological roles through the membrane binding. Here, we summarize recent research on how α-Syn and its variants interact with membranes and influence synaptic transmission. We list several membrane-related connections between the protein's physiological function and the pathological mechanisms that stand to expand current understandings of α-Syn.
Collapse
Affiliation(s)
- Cencen Liu
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Yunfei Zhao
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Huan Xi
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Jie Jiang
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Yang Yu
- Department of Histology and Embryology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Wei Dong
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China.,Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, China.,Neurosurgical Clinical Research Center of Sichuan Province, Luzhou, China
| |
Collapse
|
23
|
Liu J, Bu B, Crowe M, Li D, Diao J, Ji B. Membrane packing defects in synaptic vesicles recruit complexin and synuclein. Phys Chem Chem Phys 2021; 23:2117-2125. [PMID: 33437978 DOI: 10.1039/d0cp03546g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Complexin-1 (Cpx) and α-synuclein (α-Syn) are involved in neurotransmitter release through an interaction with synaptic vesicles (SVs). Recent studies demonstrated that Cpx and α-Syn preferentially associate with highly curved membranes, like SVs, to correctly position them for fusion. Here, based on recent experimental results, to further propose a possible explanation for this mechanism, we performed in silico simulations probing interactions between Cpx or α-Syn and membranes of varying curvature. We found that the preferential association is attributed to smaller, curved membranes containing more packing defects that expose hydrophobic acyl tails, which may favorably interact with hydrophobic residues of Cpx and α-Syn. The number of membrane defects is proportional to the curvature and the size can be regulated by cholesterol.
Collapse
Affiliation(s)
- Jie Liu
- Biomechanics and Biomaterials Laboratory, Department of Applied Mechanics, Beijing Institute of Technology, Beijing 100081, China
| | | | | | | | | | | |
Collapse
|
24
|
Mohapatra A, Chaudhary N. N-terminal acetylation does not alter α-synuclein's interfacial properties. Int J Biol Macromol 2021; 174:69-76. [PMID: 33497695 DOI: 10.1016/j.ijbiomac.2021.01.147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/16/2021] [Accepted: 01/20/2021] [Indexed: 11/25/2022]
Abstract
Alpha-synuclein (αS) is a membrane-binding protein found predominantly in neurons and erythrocytes. The protein remains unordered in aqueous solutions but folds into an α-helical structure when bound to membranes. Besides, it gets deposited as β-sheet rich aggregates in diseases known as synucleinopathies. The native αS has been reported to be acetylated at the N-terminus. Here, we compare the interfacial properties of the N-terminal acetylated αS (Ac-αS) with non-acetylated αS (NH2-αS) at the air-water interface. Both the protein forms are highly surface-active, with surface pressure reaching up to ~30 mN/m upon compression. The pressure-area isotherms obtained from the repeated compression-expansion cycles display large hysteresis suggesting self-assembly at higher surface pressures. The expansion isotherm is characterized by a rapid decrease in surface pressure followed by a slower transition phase starting around 15-17 mN/m. These data suggest that the compressed monolayer breaks into small clusters upon expansion, followed by these clusters' loosening. The circular dichroism spectroscopic analysis of the Blodgett-deposited films suggests the protein to be in largely α-helical conformation. The linear dichroism investigations suggest the protein to be anisotropically deposited. Blodgett deposition of the Langmuir films, therefore, is a rather simple method for preparing oriented monolayers of surface-active macromolecules.
Collapse
Affiliation(s)
- Anshuman Mohapatra
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781 039, India
| | - Nitin Chaudhary
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781 039, India.
| |
Collapse
|
25
|
Kang C, Sun R. Molecular Dynamics Study of the Interaction between the N-terminal of α-Synuclein and a Lipid Bilayer Mimicking Synaptic Vesicles. J Phys Chem B 2020; 125:1036-1048. [DOI: 10.1021/acs.jpcb.0c08620] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Christopher Kang
- Department of Chemistry, University of Hawai’i at Manoa, 2545 McCarthy
Mall, Honolulu 96822-2275, Hawaii, United States
| | - Rui Sun
- Department of Chemistry, University of Hawai’i at Manoa, 2545 McCarthy
Mall, Honolulu 96822-2275, Hawaii, United States
| |
Collapse
|
26
|
McClain SM, Ojoawo AM, Lin W, Rienstra CM, Murphy CJ. Interaction of Alpha-Synuclein and Its Mutants with Rigid Lipid Vesicle Mimics of Varying Surface Curvature. ACS NANO 2020; 14:10153-10167. [PMID: 32672441 DOI: 10.1021/acsnano.0c03420] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Abnormal aggregation of alpha-synuclein (α-syn), an intrinsically disordered neuronal protein, is strongly implicated in the development of Parkinson's disease. Efforts to better understand α-syn's native function and its pathogenic role in neurodegeneration have revealed that the protein interacts with anionic lipid vesicles via adoption of an amphipathic α-helical structure; however, the ability of α-syn to remodel lipid membranes has made it difficult to decipher the role of vesicle surface curvature in protein binding behavior. In this study, sodium dodecyl sulfate (SDS)-coated gold nanoparticles (AuNPs), which mimic bilayer vesicle architecture, were synthesized in order to conduct a systematic investigation into the binding interaction of α-syn and two of its mutants (A30P and E46K) with rigid lipid vesicle mimics of defined surface curvature. By incorporating a rigid AuNP core (∼10-100 nm), the ability of α-syn to remodel the vesicle mimics was removed and their surface curvature could be fixed. Proteomics studies showed that, upon binding of free α-syn to the surface of SDS-AuNPs, the N-terminus of α-syn became less solvent accessible, whereas its C-terminus became more accessible. Interestingly, α-syn's non-amyloid-β component (NAC) region also exhibited increased solvent accessibility, suggesting that α-syn bound to rigid vesicle-like structures could possess heightened aggregation propensity and therefore pathogenicity. Additionally, both the A30P and E46K mutations were found to adopt distinct binding modes on the mimics' surface. In contrast with previous reports, similar binding affinities were observed for WT, A30P, and E46K α-syn toward SDS-AuNPs of all sizes, indicating the potential importance of vesicle deformability in determining α-syn binding behavior.
Collapse
Affiliation(s)
- Sophia M McClain
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Adedolapo M Ojoawo
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Wayne Lin
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Chad M Rienstra
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Carle-Illinois College of Medicine, University of Illinois at Urbana-Champaign, Champaign, Illinois 61820, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Catherine J Murphy
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
27
|
Saccà SC, Paluan F, Gandolfi S, Manni G, Cutolo CA, Izzotti A. Common aspects between glaucoma and brain neurodegeneration. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2020; 786:108323. [PMID: 33339584 DOI: 10.1016/j.mrrev.2020.108323] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 07/10/2020] [Indexed: 01/05/2023]
Abstract
Neurodegeneration can be defined as progressive cell damage to nervous system cells, and more specifically to neurons, which involves morphologic alterations and progressive loss of function until cell death. Glaucoma exhibits many aspects of neurodegenerative disease. This review examines the pathogenesis of glaucoma, comparing it with that of Alzheimer's disease (AD) and Parkinson's disease (PD), highlighting their common features. Indeed, in all three diseases there are not only the same types of pathogenic events, but also similarities of temporal cadences that determine neuronal damage. All three age-related illnesses have oxidative damage and mitochondrial dysfunction as the first pathogenic steps. The consequence of these alterations is the death of visual neurons in glaucoma, cognitive neurons in AD and regulatory motor neurons (substantia nigra) in PD. The study of these common pathogenic events (oxidative stress, mitochondrial dysfunction, protein degradation, apoptosis and autophagy) leads us to consider common therapeutic strategies for the treatment and prevention of these diseases. Also, examination of the genetic aspects of the pathways involved in neurodegenerative processes plays a key role in shedding light on the details of pathogenesis and can suggest new treatments. This review discusses the common molecular aspects involved in these three oxidative-stress and age-related diseases.
Collapse
Affiliation(s)
| | - Filippo Paluan
- Department of Health Sciences, University of Genoa, Genoa., Italy
| | - Stefano Gandolfi
- Ophthalmology Unit, Department of Biological, Biotechnological and Translational Sciences, University of Parma, Parma, Italy
| | - Gianluca Manni
- Dept. of Clinical Science and Translational Medicine, University Tor Vergata, Rome, Italy; IRCCS-Fondazione GB Bietti, Rome, Italy
| | | | - Alberto Izzotti
- IRCCS Policlinico San Martino, Genoa, Italy; Department of Experimental Medicine, University of Genoa, Genoa, Italy
| |
Collapse
|
28
|
Abstract
α-Synuclein is a neuronal protein with an ill-defined biological function that is central to Parkinson’s disease etiology. While considered to be involved in exocytosis, how α-synuclein facilitates synaptic vesicle fusion and release remains an open question. To address this, we investigated α-synuclein–lipid interactions at the plasma membrane through the technique of cellular unroofing, which uncovers an intact basal membrane. We conclusively show that α-synuclein is recruited to exocytic sites, preferring liquid-ordered lipid domains. Importantly, heterogeneous populations of α-synuclein conformers are revealed by measurements of fluorescence lifetime distributions, which are not adequately described by current models of α-synuclein structures. Membrane-bound α-synuclein is conformationally dynamic, exquisitely sensitive to lipid/protein composition, enabling the protein to carry out its function. Parkinson’s disease is associated with α-synuclein (α-syn), a cytosolic protein enriched in presynaptic terminals. The biological function of α-syn remains elusive; however, increasing evidence suggests that the protein is involved in the regulation of synaptic vesicle fusion, signifying the importance of α-syn–lipid interactions. We show that α-syn preferentially binds to GM1-rich, liquid-ordered lipid domains on cytoplasmic membranes by using unroofed cells, which encapsulates lipid complexity and cellular topology. Moreover, proteins (Rab3a, syntaxin-1A, and VAMP2) involved in exocytosis also localize with α-syn, supporting its proposed functional role in exocytosis. To investigate how these lipid/protein interactions influence α-syn at the residue level, α-syn was derivatized with an environmentally sensitive fluorophore (7-nitrobenz-2-oxa-1,3-diazol-4-yl [NBD]) at different N- and C-terminal sites. Measurements of NBD fluorescence lifetime distributions reveal that α-syn adopts a multitude of membrane-bound conformations, which were not recapitulated in simple micelle or vesicle models, indicating an exquisite sensitivity of the protein to the complex lipid environment. Interestingly, these data also suggest the participation of the C terminus in membrane localization, which is generally overlooked and thus emphasize the need to use cellularly derived and biologically relevant membranes for biophysical characterization. Collectively, our results demonstrate that α-syn is more conformationally dynamic at the membrane interface than previously appreciated, which may be important for both its physiological and pathological functions.
Collapse
|
29
|
Larsen J, Rosholm KR, Kennard C, Pedersen SL, Munch HK, Tkach V, Sakon JJ, Bjørnholm T, Weninger KR, Bendix PM, Jensen KJ, Hatzakis NS, Uline MJ, Stamou D. How Membrane Geometry Regulates Protein Sorting Independently of Mean Curvature. ACS CENTRAL SCIENCE 2020; 6:1159-1168. [PMID: 32724850 PMCID: PMC7379390 DOI: 10.1021/acscentsci.0c00419] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Indexed: 05/06/2023]
Abstract
Biological membranes have distinct geometries that confer specific functions. However, the molecular mechanisms underlying the phenomenological geometry/function correlations remain elusive. We studied the effect of membrane geometry on the localization of membrane-bound proteins. Quantitative comparative experiments between the two most abundant cellular membrane geometries, spherical and cylindrical, revealed that geometry regulates the spatial segregation of proteins. The measured geometry-driven segregation reached 50-fold for membranes of the same mean curvature, demonstrating a crucial and hitherto unaccounted contribution by Gaussian curvature. Molecular-field theory calculations elucidated the underlying physical and molecular mechanisms. Our results reveal that distinct membrane geometries have specific physicochemical properties and thus establish a ubiquitous mechanistic foundation for unravelling the conserved correlations between biological function and membrane polymorphism.
Collapse
Affiliation(s)
- Jannik
B. Larsen
- Bionanotecnology
and Nanomedicine Laboratory, University
of Copenhagen, Copenhagen, Denmark
- Nano-Science
Center, University of Copenhagen, Copenhagen, Denmark
- Lundbeck
Foundation Center Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
- Department
of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Kadla R. Rosholm
- Bionanotecnology
and Nanomedicine Laboratory, University
of Copenhagen, Copenhagen, Denmark
- Nano-Science
Center, University of Copenhagen, Copenhagen, Denmark
- Lundbeck
Foundation Center Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
- Department
of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Celeste Kennard
- Department
of Chemical Engineering, University of South
Carolina, Columbia, South Carolina, United States
| | - Søren L. Pedersen
- Lundbeck
Foundation Center Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
- Department
of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Henrik K. Munch
- Lundbeck
Foundation Center Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
- Department
of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Vadym Tkach
- Bionanotecnology
and Nanomedicine Laboratory, University
of Copenhagen, Copenhagen, Denmark
- Nano-Science
Center, University of Copenhagen, Copenhagen, Denmark
- Lundbeck
Foundation Center Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
- Department
of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - John J. Sakon
- Department
of Physics, North Carolina State University, Raleigh, North Carolina, United States
| | - Thomas Bjørnholm
- Bionanotecnology
and Nanomedicine Laboratory, University
of Copenhagen, Copenhagen, Denmark
- Nano-Science
Center, University of Copenhagen, Copenhagen, Denmark
- Lundbeck
Foundation Center Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
- Department
of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Keith R. Weninger
- Department
of Physics, North Carolina State University, Raleigh, North Carolina, United States
| | | | - Knud J. Jensen
- Lundbeck
Foundation Center Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
- Department
of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Nikos S Hatzakis
- Bionanotecnology
and Nanomedicine Laboratory, University
of Copenhagen, Copenhagen, Denmark
- Nano-Science
Center, University of Copenhagen, Copenhagen, Denmark
- Lundbeck
Foundation Center Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
- Department
of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Mark J. Uline
- Center
for Geometrically Engineered Cellular Systems, University of Copenhagen, Copenhagen, Denmark
- Department
of Chemical Engineering, Biomedical Engineering Program, University of South Carolina, Columbia, South Carolina, United States
- (M.J.U.) E-mail:
| | - Dimitrios Stamou
- Bionanotecnology
and Nanomedicine Laboratory, University
of Copenhagen, Copenhagen, Denmark
- Nano-Science
Center, University of Copenhagen, Copenhagen, Denmark
- Lundbeck
Foundation Center Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
- Department
of Chemistry, University of Copenhagen, Copenhagen, Denmark
- Center
for Geometrically Engineered Cellular Systems, University of Copenhagen, Copenhagen, Denmark
- (D.S.)
| |
Collapse
|
30
|
Flynn JD, Gimmen MY, Dean DN, Lacy SM, Lee JC. Terminal Alkynes as Raman Probes of α-Synuclein in Solution and in Cells. Chembiochem 2020; 21:1582-1586. [PMID: 31960993 PMCID: PMC7269816 DOI: 10.1002/cbic.202000026] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Indexed: 01/08/2023]
Abstract
Conformational changes in α-synuclein (α-syn) are central to its biological function and Parkinson's disease pathology. Here, terminal alkynes (homopropargylglycine) were employed as environmentally sensitive Raman probes at residues 1, 5, 116, and 127 to characterize soluble (disordered), micelle-bound (α-helical), and fibrillar (β-sheet) α-syn. Along with the full-length protein, a disease-related C-terminal truncation (1-115) was also studied. For the first time, β-sheet α-syn amyloid structure was detected by the amide-I band in N27 dopaminergic rat cells, where a reciprocal relationship between levels of fibrils and lipids was seen. Site-specific spectral features of the terminal alkynes also revealed the heterogeneity of the cellular environment. This work shows the versatility of Raman microspectroscopy and the power of unnatural amino acids in providing structural and residue-level insights in solution and in cells.
Collapse
Affiliation(s)
- Jessica D. Flynn
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892 (USA)
| | - Megan Y. Gimmen
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892 (USA)
| | - Dexter N. Dean
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892 (USA)
| | - Shannon M. Lacy
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892 (USA)
| | - Jennifer C. Lee
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892 (USA)
| |
Collapse
|
31
|
Cholak E, Bugge K, Khondker A, Gauger K, Pedraz-Cuesta E, Pedersen ME, Bucciarelli S, Vestergaard B, Pedersen SF, Rheinstädter MC, Langkilde AE, Kragelund BB. Avidity within the N-terminal anchor drives α-synuclein membrane interaction and insertion. FASEB J 2020; 34:7462-7482. [PMID: 32277854 DOI: 10.1096/fj.202000107r] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/02/2020] [Accepted: 03/17/2020] [Indexed: 12/25/2022]
Abstract
In the brain, α-synuclein (aSN) partitions between free unbound cytosolic and membrane bound forms modulating both its physiological and pathological role and complicating its study due to structural heterogeneity. Here, we use an interdisciplinary, synergistic approach to characterize the properties of aSN:lipid mixtures, isolated aSN:lipid co-structures, and aSN in mammalian cells. Enabled by the isolation of the membrane-bound state, we show that within the previously described N-terminal membrane anchor, membrane interaction relies both on an N-terminal tail (NTT) head group layer insertion of 14 residues and a folded-upon-binding helix at the membrane surface. Both binding events must be present; if, for example, the NTT insertion is lost, the membrane affinity of aSN is severely compromised and formation of aSN:lipid co-structures hampered. In mammalian cells, compromised cooperativity results in lowered membrane association. Thus, avidity within the N-terminal anchor couples N-terminal insertion and helical surface binding, which is crucial for aSN membrane interaction and cellular localization, and may affect membrane fusion.
Collapse
Affiliation(s)
- Ersoy Cholak
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Bugge
- Structural Biology and NMR Laboratory, The Linderstrøm-Lang Centre for Protein Science and Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
| | - Kimmie Gauger
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Elena Pedraz-Cuesta
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Saskia Bucciarelli
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Bente Vestergaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Stine F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Annette Eva Langkilde
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, The Linderstrøm-Lang Centre for Protein Science and Department of Biology, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
32
|
Lockey C, Edwards RJ, Roper DI, Dixon AM. The Extracellular Domain of Two-component System Sensor Kinase VanS from Streptomyces coelicolor Binds Vancomycin at a Newly Identified Binding Site. Sci Rep 2020; 10:5727. [PMID: 32235931 PMCID: PMC7109055 DOI: 10.1038/s41598-020-62557-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/11/2020] [Indexed: 11/24/2022] Open
Abstract
The glycopeptide antibiotic vancomycin has been widely used to treat infections of Gram-positive bacteria including Clostridium difficile and methicillin-resistant Staphylococcus aureus. However, since its introduction, high level vancomycin resistance has emerged. The genes responsible require the action of the two-component regulatory system VanSR to induce expression of resistance genes. The mechanism of detection of vancomycin by this two-component system has yet to be elucidated. Diverging evidence in the literature supports activation models in which the VanS protein binds either vancomycin, or Lipid II, to induce resistance. Here we investigated the interaction between vancomycin and VanS from Streptomyces coelicolor (VanSSC), a model Actinomycete. We demonstrate a direct interaction between vancomycin and purified VanSSC, and traced these interactions to the extracellular region of the protein, which we reveal adopts a predominantly α-helical conformation. The VanSSC-binding epitope within vancomycin was mapped to the N-terminus of the peptide chain, distinct from the binding site for Lipid II. In targeting a separate site on vancomycin, the effective VanS ligand concentration includes both free and lipid-bound molecules, facilitating VanS activation. This is the first molecular description of the VanS binding site within vancomycin, and could direct engineering of future therapeutics.
Collapse
Affiliation(s)
- Christine Lockey
- MOAC Doctoral Training Centre, University of Warwick, Coventry, CV4 7AL, UK
| | - Richard J Edwards
- Medical Research Council Doctoral Training Centre, University of Warwick, Coventry, CV4 7AL, UK
| | - David I Roper
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Ann M Dixon
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
| |
Collapse
|
33
|
Nepal B, Sepehri A, Lazaridis T. Mechanisms of negative membrane curvature sensing and generation by ESCRT III subunit Snf7. Protein Sci 2020; 29:1473-1485. [PMID: 32142182 DOI: 10.1002/pro.3851] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 12/13/2022]
Abstract
Certain proteins have the propensity to bind to negatively curved membranes and generate negative membrane curvature. The mechanism of action of these proteins is much less studied and understood than those that sense and generate positive curvature. In this work, we use implicit membrane modeling to explore the mechanism of an important negative curvature sensing and generating protein: the main ESCRT III subunit Snf7. We find that Snf7 monomers alone can sense negative curvature and that curvature sensitivity increases for dimers and trimers. We have observed spontaneous bending of Snf7 oligomers into circular structures with preferred radius of ~20 nm. The preferred curvature of Snf7 filaments is further confirmed by the simulations of preformed spirals on a cylindrical membrane surface. Snf7 filaments cannot bind with the same interface to flat and curved membranes. We find that even when a filament has the preferred radius, it is always less stable on the flat membrane surface than on the interior cylindrical membrane surface. This provides an additional energy for membrane bending which has not been considered in the spiral spring model. Furthermore, the rings on the cylindrical spirals are bridged together by helix 4 and hence are extra stabilized compared to the spirals on the flat membrane surface.
Collapse
Affiliation(s)
- Binod Nepal
- Department of Chemistry, City College of New York, New York, New York, USA
| | - Aliasghar Sepehri
- Department of Chemistry, City College of New York, New York, New York, USA
| | - Themis Lazaridis
- Department of Chemistry, City College of New York, New York, New York, USA.,Graduate Programs in Chemistry, Biochemistry, and Physics, The Graduate Center, City University of New York, New York, New York, USA
| |
Collapse
|
34
|
Townshend G, Thompson GS, White LJ, Hiscock JR, Ortega-Roldan JL. The elucidation of phospholipid bilayer–small molecule interactions using a combination of phospholipid nanodiscs and solution state NMR techniques. Chem Commun (Camb) 2020; 56:4015-4018. [DOI: 10.1039/c9cc09948d] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Quantifying phospholipid bilayer–small molecule interactions is vital to the development of new drug candidates and/or medicinal therapies.
Collapse
Affiliation(s)
- Georgina Townshend
- School of Biosciences
- University of Kent
- Canterbury
- UK
- School of Physical Sciences
| | | | | | | | | |
Collapse
|
35
|
Brooks RL, Dixon AM. Revealing the mechanism of protein-lipid interactions for a putative membrane curvature sensor in plant endoplasmic reticulum. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183160. [PMID: 31874147 DOI: 10.1016/j.bbamem.2019.183160] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/22/2019] [Accepted: 12/16/2019] [Indexed: 01/05/2023]
Abstract
Membrane curvature sensing via helical protein domains, such as those identified in Amphiphysin and ArfGAP1, have been linked to a diverse range of cellular processes. However, these regions can vary significantly between different protein families and thus remain challenging to identify from sequence alone. Greater insight into the protein-lipid interactions that drive this behavior could lead to production of therapeutics that specifically target highly curved membranes. Here we demonstrate the curvature-dependence of membrane binding for an amphipathic helix (APH) in a plant reticulon, namely RTNLB13 from A. thaliana. We utilize solution-state nuclear magnetic resonance spectroscopy to establish the exact location of the APH and map the residues involved in protein-membrane interactions at atomic resolution. We find that the hydrophobic residues making up the membrane binding site are conserved throughout all A. thaliana reticulons. Our results also provide mechanistic insight that leads us to propose that membrane binding by this APH may act as a feedback element, only forming when ER tubules reach a critical size and adding stabilization to these structures without disrupting the bilayer. A shallow hydrophobic binding interface appears to be a feature shared more broadly across helical curvature sensors and would automatically restrict the penetration depth of these structures into the membrane. We also suggest this APH is highly tuned to the composition of the membrane in which it resides, and that this property may be universal in curvature sensors thus rationalizing the variety of mechanisms reported for these functional elements.
Collapse
Affiliation(s)
- Rhiannon L Brooks
- MAS Centre for Doctoral Training, University of Warwick, Coventry CV4 7AL, UK; Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Ann M Dixon
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.
| |
Collapse
|
36
|
Gowrisankaran S, Wang Z, Morgan DG, Milosevic I, Mim C. Cells Control BIN1-Mediated Membrane Tubulation by Altering the Membrane Charge. J Mol Biol 2019; 432:1235-1250. [PMID: 31857086 DOI: 10.1016/j.jmb.2019.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 11/18/2019] [Accepted: 12/07/2019] [Indexed: 11/15/2022]
Abstract
The Bridging integrator 1 (BIN1)/Amphiphysin/Rvs (BAR) protein family is an essential part of the cell's machinery to bend membranes. BIN1 is a muscle-enriched BAR protein with an established role in muscle development and skeletal myopathies. Here, we demonstrate that BIN1, on its own, is able to form complex interconnected tubular systems in vitro, reminiscent of t-tubule system in muscle cells. We further describe how BIN1's electrostatic interactions regulate membrane bending: the ratio of negatively charged lipids in the bilayer altered membrane bending and binding properties of BIN1 and so did the manipulation of BIN1's surface charge. We show that the electrostatically mediated BIN1 membrane binding depended on the membrane curvature-it was less affected in liposomes with high curvature. Curiously, BIN1 membrane binding and bending was diminished in cells where the membrane's charge was experimentally reduced. Membrane bending was also reduced in BIN1 mutants where negative or positive charges in the BAR domain have been eliminated. This phenotype, characteristic of BIN1 mutants linked to myopathies, was rescued when the membrane charge was made more negative. The latter findings also show that cells can control tubulation at their membranes by simply altering the membrane charge and through it, the recruitment of BAR proteins and their interaction partners (e.g. dynamin).
Collapse
Affiliation(s)
- Sindhuja Gowrisankaran
- European Neuroscience Institute (ENI), A Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Synaptic Vesicle Dynamics Group, Göttingen, Germany
| | - Zuoneng Wang
- Royal Technical Institute (KTH), Dept. for Biomedical Engineering and Health Systems, Stockholm, Sweden; Karolinska Institute, Department of Nutrition and Biosciences, Huddinge, Sweden
| | - David G Morgan
- Indiana University, Electron Microscopy Center, Bloomington, IN USA
| | - Ira Milosevic
- European Neuroscience Institute (ENI), A Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Synaptic Vesicle Dynamics Group, Göttingen, Germany
| | - Carsten Mim
- Royal Technical Institute (KTH), Dept. for Biomedical Engineering and Health Systems, Stockholm, Sweden; Karolinska Institute, Department of Nutrition and Biosciences, Huddinge, Sweden.
| |
Collapse
|
37
|
Das T, Eliezer D. Membrane interactions of intrinsically disordered proteins: The example of alpha-synuclein. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2019; 1867:879-889. [PMID: 31096049 PMCID: PMC6661188 DOI: 10.1016/j.bbapap.2019.05.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/03/2019] [Accepted: 05/08/2019] [Indexed: 12/11/2022]
Abstract
Peripheral membrane proteins associate reversibly with biological membranes that, compared to protein binding partners, are structurally labile and devoid of specific binding pockets. Membranes in different subcellular compartments vary primarily in their chemical composition and physical properties, and recognition of these features is therefore critical for allowing such proteins to engage their proper membrane targets. Intrinsically disordered proteins (IDPs) are well-suited to accomplish this task using highly specific and low- to moderate-affinity interactions governed by recognition principles that are both similar to and different from those that mediate the membrane interactions of rigid proteins. IDPs have also evolved multiple mechanisms to regulate membrane (and other) interactions and achieve their impressive functional diversity. Moreover, IDP-membrane interactions may have a kinetic advantage in fast processes requiring rapid control of such interactions, such as synaptic transmission or signaling. Herein we review the biophysics, regulation and functional implications of IDP-membrane interactions and include a brief overview of some of the methods that can be used to study such interactions. At each step, we use the example of alpha-synuclein, a protein involved in the pathogenesis of Parkinson's disease and one of the best characterized membrane-binding IDP, to illustrate some of the principles discussed.
Collapse
Affiliation(s)
- Tapojyoti Das
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, United States of America
| | - David Eliezer
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, United States of America.
| |
Collapse
|
38
|
Zeno WF, Thatte AS, Wang L, Snead WT, Lafer EM, Stachowiak JC. Molecular Mechanisms of Membrane Curvature Sensing by a Disordered Protein. J Am Chem Soc 2019; 141:10361-10371. [PMID: 31180661 DOI: 10.1021/jacs.9b03927] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The ability of proteins to sense membrane curvature is essential for the initiation and assembly of curved membrane structures. Established mechanisms of curvature sensing rely on proteins with specific structural features. In contrast, it has recently been discovered that intrinsically disordered proteins, which lack a defined three-dimensional fold, can also be potent sensors of membrane curvature. How can an unstructured protein sense the structure of the membrane surface? Many disordered proteins that associate with membranes have two key physical features: a high degree of conformational entropy and a high net negative charge. Binding of such proteins to membrane surfaces results simultaneously in a decrease in conformational entropy and an increase in electrostatic repulsion by anionic lipids. Here we show that each of these effects gives rise to a distinct mechanism of curvature sensing. Specifically, as the curvature of the membrane increases, the steric hindrance between the disordered protein and membrane is reduced, leading to an increase in chain entropy. At the same time, increasing membrane curvature increases the average separation between anionic amino acids and lipids, creating an electrostatic preference for curved membranes. Using quantitative imaging of membrane vesicles, our results demonstrate that long disordered amino acid chains with low net charge sense curvature predominately through the entropic mechanism. In contrast, shorter, more highly charged amino acid chains rely largely on the electrostatic mechanism. These findings provide a roadmap for predicting and testing the curvature sensitivity of the large and diverse set of disordered proteins that function at cellular membranes.
Collapse
Affiliation(s)
- Wade F Zeno
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Ajay S Thatte
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Liping Wang
- Department of Biochemistry and Structural Biology , The University of Texas Health Science Center at San Antonio , San Antonio , Texas 78229 , United States
| | - Wilton T Snead
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Eileen M Lafer
- Department of Biochemistry and Structural Biology , The University of Texas Health Science Center at San Antonio , San Antonio , Texas 78229 , United States
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States.,Institute for Cellular and Molecular Biology , The University of Texas at Austin , Austin , Texas 78712 , United States
| |
Collapse
|
39
|
Nepal B, Leveritt J, Lazaridis T. Membrane Curvature Sensing by Amphipathic Helices: Insights from Implicit Membrane Modeling. Biophys J 2019; 114:2128-2141. [PMID: 29742406 DOI: 10.1016/j.bpj.2018.03.030] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/24/2018] [Accepted: 03/14/2018] [Indexed: 01/09/2023] Open
Abstract
Sensing and generation of lipid membrane curvature, mediated by the binding of specific proteins onto the membrane surface, play crucial roles in cell biology. A number of mechanisms have been proposed, but the molecular understanding of these processes is incomplete. All-atom molecular dynamics simulations have offered valuable insights but are extremely demanding computationally. Implicit membrane simulations could provide a viable alternative, but current models apply only to planar membranes. In this work, the implicit membrane model 1 is extended to spherical and tubular membranes. The geometric change from planar to curved shapes is straightforward but insufficient for capturing the full curvature effect, which includes changes in lipid packing. Here, these packing effects are taken into account via the lateral pressure profile. The extended implicit membrane model 1 is tested on the wild-types and mutants of the antimicrobial peptide magainin, the ALPS motif of arfgap1, α-synuclein, and an ENTH domain. In these systems, the model is in qualitative agreement with experiments. We confirm that favorable electrostatic interactions tend to weaken curvature sensitivity in the presence of strong hydrophobic interactions but may actually have a positive effect when those are weak. We also find that binding to vesicles is more favorable than binding to tubes of the same diameter and that the long helix of α-synuclein tends to orient along the axis of tubes, whereas shorter helices tend to orient perpendicular to it. Adoption of a specific orientation could provide a mechanism for coupling protein oligomerization to tubule formation.
Collapse
Affiliation(s)
- Binod Nepal
- Department of Chemistry, City College of New York, New York, New York
| | - John Leveritt
- Department of Chemistry, Newman University, Wichita, Kansas
| | - Themis Lazaridis
- Department of Chemistry, City College of New York, New York, New York; Graduate Programs in Chemistry, Biochemistry, and Physics, The Graduate Center, City University of New York, New York, New York.
| |
Collapse
|
40
|
Interaction of SNARE Mimetic Peptides with Lipid bilayers: Effects of Secondary Structure, Bilayer Composition and Lipid Anchoring. Sci Rep 2019; 9:7708. [PMID: 31118479 PMCID: PMC6531448 DOI: 10.1038/s41598-019-43418-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 04/18/2019] [Indexed: 12/24/2022] Open
Abstract
The coiled-coil forming peptides 'K' enriched in lysine and 'E' enriched in glutamic acid have been used as a minimal SNARE mimetic system for membrane fusion. Here we describe atomistic molecular dynamics simulations to characterize the interactions of these peptides with lipid bilayers for two different compositions. For neutral phosphatidylcholine (PC)/phosphatidylethanolamine (PE) bilayers the peptides experience a strong repulsive barrier against adsorption, also observed in potential of mean force (PMF) profiles calculated with umbrella sampling. For peptide K, a minimum of -12 kBT in the PMF provides an upper bound for the binding free energy whereas no stable membrane bound state could be observed for peptide E. In contrast, the electrostatic interactions with negatively charged phosphatidylglycerol (PG) lipids lead to fast adsorption of both peptides at the head-water interface. Experimental data using fluorescently labeled peptides confirm the stronger binding to PG containing bilayers. Lipid anchors have little effect on the peptide-bilayer interactions or peptide structure, when the peptide also binds to the bilayer in the absence of a lipid anchor. For peptide E, which does not bind to the PC bilayer without a lipid anchor, the presence of such an anchor strengthens the electrostatic interactions between the charged side chains and the zwitterionic head-groups and leads to a stabilization of the peptide's helical fold by the membrane.
Collapse
|
41
|
Ugalde CL, Lawson VA, Finkelstein DI, Hill AF. The role of lipids in α-synuclein misfolding and neurotoxicity. J Biol Chem 2019; 294:9016-9028. [PMID: 31064841 DOI: 10.1074/jbc.rev119.007500] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The misfolding and aggregation of α-synuclein (αsyn) in the central nervous system is associated with a group of neurodegenerative disorders referred to as the synucleinopathies. In addition to being a pathological hallmark of disease, it is now well-established that upon misfolding, αsyn acquires pathogenic properties, such as neurotoxicity, that can contribute to disease development. The mechanisms that produce αsyn misfolding and the molecular events underlying the neuronal damage caused by these misfolded species are not well-defined. A consistent observation that may be relevant to αsyn's pathogenicity is its ability to associate with lipids. This appears important not only to how αsyn aggregates, but also to the mechanism by which the misfolded protein causes intracellular damage. This review discusses the current literature reporting a role of lipids in αsyn misfolding and neurotoxicity in various synucleinopathy disorders and provides an overview of current methods to assess protein misfolding and pathogenicity both in vitro and in vivo.
Collapse
Affiliation(s)
- Cathryn L Ugalde
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia, .,the Departments of Microbiology and Immunology and.,the Howard Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia.,Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3052, Australia, and
| | | | - David I Finkelstein
- the Howard Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia
| | - Andrew F Hill
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia, .,Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3052, Australia, and
| |
Collapse
|
42
|
Selkoe DJ. Showing transmitters the door: synucleins accelerate vesicle release. Nat Neurosci 2019; 20:629-631. [PMID: 28440807 DOI: 10.1038/nn.4551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Dennis J Selkoe
- Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts, USA
| |
Collapse
|
43
|
Biochemical studies of membrane fusion at the single-particle level. Prog Lipid Res 2019; 73:92-100. [PMID: 30611882 DOI: 10.1016/j.plipres.2019.01.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 01/01/2019] [Accepted: 01/02/2019] [Indexed: 01/21/2023]
Abstract
To study membrane fusion mediated by synaptic proteins, proteoliposomes have been widely used for in vitro ensemble measurements with limited insights into the fusion mechanism. Single-particle techniques have proven to be powerful in overcoming the limitations of traditional ensemble methods. Here, we summarize current single-particle methods in biophysical and biochemical studies of fusion mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) and other synaptic proteins, together with their advantages and limitations.
Collapse
|
44
|
Dettmer U. Rationally Designed Variants of α-Synuclein Illuminate Its in vivo Structural Properties in Health and Disease. Front Neurosci 2018; 12:623. [PMID: 30319334 PMCID: PMC6167557 DOI: 10.3389/fnins.2018.00623] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/20/2018] [Indexed: 12/11/2022] Open
Abstract
α-Synuclein (αS) is a conserved and abundant neuronal protein with unusual structural properties. It appears to partition between folded and unstructured states as well as between membrane-bound and aqueously soluble states. In addition, a switch between monomeric and tetrameric/multimeric states has been observed recently. The precise composition, localization and abundance of the multimeric species are under study and remain unsettled. Yet to interfere with disease pathogenesis, we must dissect how small changes in αS homeostasis may give rise to Parkinson’s disease (PD), dementia with Lewy bodies (DLB) and other human synucleinopathies. Rationally designed αS point mutations that prevent the protein from populating all states within its normal folding repertoire have continued to be instrumental in bringing new insights into its biochemistry in vivo. This review summarizes biochemical and cell biological findings about αS homeostasis from different labs, with a special emphasis on intact-cell approaches that may preserve the complex, metastable native states of αS.
Collapse
Affiliation(s)
- Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| |
Collapse
|
45
|
The Many Faces of Amphipathic Helices. Biomolecules 2018; 8:biom8030045. [PMID: 29976879 PMCID: PMC6164224 DOI: 10.3390/biom8030045] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/02/2018] [Accepted: 07/02/2018] [Indexed: 12/14/2022] Open
Abstract
Amphipathic helices (AHs), a secondary feature found in many proteins, are defined by their structure and by the segregation of hydrophobic and polar residues between two faces of the helix. This segregation allows AHs to adsorb at polar⁻apolar interfaces such as the lipid surfaces of cellular organelles. Using various examples, we discuss here how variations within this general scheme impart membrane-interacting AHs with different interfacial properties. Among the key parameters are: (i) the size of hydrophobic residues and their density per helical turn; (ii) the nature, the charge, and the distribution of polar residues; and (iii) the length of the AH. Depending on how these parameters are tuned, AHs can deform lipid bilayers, sense membrane curvature, recognize specific lipids, coat lipid droplets, or protect membranes from stress. Via these diverse mechanisms, AHs play important roles in many cellular processes.
Collapse
|
46
|
Abstract
This review summarizes current knowledge of synaptic proteins that are central to synaptic vesicle fusion in presynaptic active zones, including SNAREs (soluble N-ethylmaleimide sensitive factor attachment protein receptors), synaptotagmin, complexin, Munc18 (mammalian uncoordinated-18), and Munc13 (mammalian uncoordinated-13), and highlights recent insights in the cooperation of these proteins for neurotransmitter release. Structural and functional studies of the synaptic fusion machinery suggest new molecular models of synaptic vesicle priming and Ca2+-triggered fusion. These studies will be a stepping-stone toward answering the question of how the synaptic vesicle fusion machinery achieves such high speed and sensitivity.
Collapse
Affiliation(s)
- Axel T Brunger
- Department of Molecular and Cellular Physiology, Department of Neurology and Neurological Sciences, Department of Structural Biology, Department of Photon Science, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA;
| | - Ucheor B Choi
- Department of Molecular and Cellular Physiology, Department of Neurology and Neurological Sciences, Department of Structural Biology, Department of Photon Science, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA;
| | - Ying Lai
- Department of Molecular and Cellular Physiology, Department of Neurology and Neurological Sciences, Department of Structural Biology, Department of Photon Science, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA;
| | - Jeremy Leitz
- Department of Molecular and Cellular Physiology, Department of Neurology and Neurological Sciences, Department of Structural Biology, Department of Photon Science, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA;
| | - Qiangjun Zhou
- Department of Molecular and Cellular Physiology, Department of Neurology and Neurological Sciences, Department of Structural Biology, Department of Photon Science, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA;
| |
Collapse
|
47
|
Peelaerts W, Bousset L, Baekelandt V, Melki R. ɑ-Synuclein strains and seeding in Parkinson's disease, incidental Lewy body disease, dementia with Lewy bodies and multiple system atrophy: similarities and differences. Cell Tissue Res 2018; 373:195-212. [PMID: 29704213 DOI: 10.1007/s00441-018-2839-5] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/28/2018] [Indexed: 12/20/2022]
Abstract
Several age-related neurodegenerative disorders are characterized by the deposition of aberrantly folded endogenous proteins. These proteins have prion-like propagation and amplification properties but so far appear nontransmissible between individuals. Because of the features they share with the prion protein, PrP, the characteristics of pathogenic protein aggregates in several progressive brain disorders, including different types of Lewy body diseases (LBDs), such as Parkinson's disease (PD), multiple system atrophy (MSA) and dementia with Lewy bodies (DLB), have been actively investigated. Even though the pleomorphic nature of these syndromes might suggest different underlying causes, ɑ-synuclein (ɑSyn) appears to play an important role in this heterogeneous group of diseases (the synucleinopathies). An attractive hypothesis is that different types of ɑSyn protein assemblies have a unique and causative role in distinct synucleinopathies. We will discuss the recent research progress on ɑSyn assemblies involved in PD, MSA and DLB; their behavior as strains; current spreading hypotheses; their ability to seed centrally and peripherally; and their implication for disease pathogenesis.
Collapse
Affiliation(s)
- W Peelaerts
- Laboratory for Neurobiology and Gene Therapy, KU Leuven, 3000, Leuven, Belgium.,Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, 49503, USA
| | - L Bousset
- Paris-Saclay Institute of Neuroscience, CNRS, 91190, Gif-sur-Yvette, France
| | - V Baekelandt
- Laboratory for Neurobiology and Gene Therapy, KU Leuven, 3000, Leuven, Belgium.
| | - R Melki
- Paris-Saclay Institute of Neuroscience, CNRS, 91190, Gif-sur-Yvette, France
| |
Collapse
|
48
|
Ammal Kaidery N, Thomas B. Current perspective of mitochondrial biology in Parkinson's disease. Neurochem Int 2018; 117:91-113. [PMID: 29550604 DOI: 10.1016/j.neuint.2018.03.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/05/2018] [Accepted: 03/06/2018] [Indexed: 12/12/2022]
Abstract
Parkinson's disease (PD) is one of the most common neurodegenerative movement disorder characterized by preferential loss of dopaminergic neurons of the substantia nigra pars compacta and the presence of Lewy bodies containing α-synuclein. Although the cause of PD remains elusive, remarkable advances have been made in understanding the possible causative mechanisms of PD pathogenesis. An explosion of discoveries during the past two decades has led to the identification of several autosomal dominant and recessive genes that cause familial forms of PD. The investigations of these familial PD gene products have shed considerable insights into the molecular pathogenesis of the more common sporadic PD. A growing body of evidence suggests that the etiology of PD is multifactorial and involves a complex interplay between genetic and environmental factors. Substantial evidence from human tissues, genetic and toxin-induced animal and cellular models indicates that mitochondrial dysfunction plays a central role in the pathophysiology of PD. Deficits in mitochondrial functions due to bioenergetics defects, alterations in the mitochondrial DNA, generation of reactive oxygen species, aberrant calcium homeostasis, and anomalies in mitochondrial dynamics and quality control are implicated in the underlying mechanisms of neuronal cell death in PD. In this review, we discuss how familial PD-linked genes and environmental factors interface the pathways regulating mitochondrial functions and thereby potentially converge both familial and sporadic PD at the level of mitochondrial integrity. We also provide an overview of the status of therapeutic strategies targeting mitochondrial dysfunction in PD. Unraveling potential pathways that influence mitochondrial homeostasis in PD may hold the key to therapeutic intervention for this debilitating neurodegenerative movement disorder.
Collapse
Affiliation(s)
| | - Bobby Thomas
- Departments of Pharmacology and Toxicology, Augusta, GA 30912, United States; Neurology Medical College of Georgia, Augusta University, Augusta, GA 30912, United States.
| |
Collapse
|
49
|
Abstract
Parkinson's disease (PD) is characterized by intracellular inclusions of aggregated and misfolded α-Synuclein (α-Syn), and the loss of dopaminergic (DA) neurons in the brain. The resulting motor abnormalities mark the progression of PD, while non-motor symptoms can already be identified during early, prodromal stages of disease. Recent studies provide evidence that during this early prodromal phase, synaptic and axonal abnormalities occur before the degenerative loss of neuronal cell bodies. These early phenotypes can be attributed to synaptic accumulation of toxic α-Syn. Under physiological conditions, α-Syn functions in its native conformation as a soluble monomer. However, PD patient brains are characterized by intracellular inclusions of insoluble fibrils. Yet, oligomers and protofibrils of α-Syn have been identified to be the most toxic species, with their accumulation at presynaptic terminals affecting several steps of neurotransmitter release. First, high levels of α-Syn alter the size of synaptic vesicle pools and impair their trafficking. Second, α-Syn overexpression can either misregulate or redistribute proteins of the presynaptic SNARE complex. This leads to deficient tethering, docking, priming and fusion of synaptic vesicles at the active zone (AZ). Third, α-Syn inclusions are found within the presynaptic AZ, accompanied by a decrease in AZ protein levels. Furthermore, α-Syn overexpression reduces the endocytic retrieval of synaptic vesicle membranes during vesicle recycling. These presynaptic alterations mediated by accumulation of α-Syn, together impair neurotransmitter exocytosis and neuronal communication. Although α-Syn is expressed throughout the brain and enriched at presynaptic terminals, DA neurons are the most vulnerable in PD, likely because α-Syn directly regulates dopamine levels. Indeed, evidence suggests that α-Syn is a negative modulator of dopamine by inhibiting enzymes responsible for its synthesis. In addition, α-Syn is able to interact with and reduce the activity of VMAT2 and DAT. The resulting dysregulation of dopamine levels directly contributes to the formation of toxic α-Syn oligomers. Together these data suggest a vicious cycle of accumulating α-Syn and deregulated dopamine that triggers synaptic dysfunction and impaired neuronal communication, ultimately causing synaptopathy and progressive neurodegeneration in Parkinson's disease.
Collapse
Affiliation(s)
- Jessika C Bridi
- King's College London, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
| | - Frank Hirth
- King's College London, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
| |
Collapse
|
50
|
Alpha-synuclein: Pathology, mitochondrial dysfunction and neuroinflammation in Parkinson’s disease. Neurobiol Dis 2018; 109:249-257. [DOI: 10.1016/j.nbd.2017.04.004] [Citation(s) in RCA: 339] [Impact Index Per Article: 56.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/29/2017] [Accepted: 04/05/2017] [Indexed: 12/12/2022] Open
|