1
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Yao J, Hong H. Steric trapping strategy for studying the folding of helical membrane proteins. Methods 2024; 225:1-12. [PMID: 38428472 PMCID: PMC11107808 DOI: 10.1016/j.ymeth.2024.02.007] [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: 11/16/2023] [Revised: 02/11/2024] [Accepted: 02/18/2024] [Indexed: 03/03/2024] Open
Abstract
Elucidating the folding energy landscape of membrane proteins is essential to the understanding of the proteins' stabilizing forces, folding mechanisms, biogenesis, and quality control. This is not a trivial task because the reversible control of folding is inherently difficult in a lipid bilayer environment. Recently, novel methods have been developed, each of which has a unique strength in investigating specific aspects of membrane protein folding. Among such methods, steric trapping is a versatile strategy allowing a reversible control of membrane protein folding with minimal perturbation of native protein-water and protein-lipid interactions. In a nutshell, steric trapping exploits the coupling of spontaneous denaturation of a doubly biotinylated protein to the simultaneous binding of bulky monovalent streptavidin molecules. This strategy has been evolved to investigate key elements of membrane protein folding such as thermodynamic stability, spontaneous denaturation rates, conformational features of the denatured states, and cooperativity of stabilizing interactions. In this review, we describe the critical methodological advancement, limitation, and outlook of the steric trapping strategy.
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Affiliation(s)
- Jiaqi Yao
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Heedeok Hong
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA; Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA.
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2
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Yang H, Zhou D, Zhou Z, Duan M, Yu H. Mechanistic Insight into the Mechanical Unfolding of the Integral Membrane Diacylglycerol Kinase. JACS AU 2024; 4:1422-1435. [PMID: 38665647 PMCID: PMC11040704 DOI: 10.1021/jacsau.3c00829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/29/2024] [Accepted: 03/01/2024] [Indexed: 04/28/2024]
Abstract
The essential forces stabilizing membrane proteins and governing their folding and unfolding are difficult to decipher. Single-molecule atomic force spectroscopy mechanically unfolds individual membrane proteins and quantifies their dynamics and energetics. However, it remains challenging to structurally assign unfolding intermediates precisely and to deduce dominant interactions between specific residues that facilitate either the localized stabilization of these intermediates or the global assembly of membrane proteins. Here, we performed force spectroscopy experiments and multiscale molecular dynamics simulations to study the unfolding pathway of diacylglycerol kinase (DGK), a small trimeric multispan transmembrane enzyme. The remarkable agreement between experiments and simulations allowed precise structural assignment and interaction analysis of unfolding intermediates, bypassing existing limitations on structural mapping, and thus provided mechanistic explanations for the formation of these states. DGK unfolding was found to proceed with structural segments varying in size that do not correlate with its secondary structure. We identified intermolecular side-chain packing interactions as one of the major contributions to the stability of unfolding intermediates. Mutagenesis creating packing defects induced a dramatic decrease in the mechano-stability of corresponding intermediates and also in the thermo-stability of DGK trimer, in good agreement with predictions from simulations. Hence, the molecular determinants of the mechano- and thermo-stability of a membrane protein can be identified at residue resolution. The accurate structural assignment established and microscopic mechanism revealed in this work may substantially expand the scope of single-molecule studies of membrane proteins.
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Affiliation(s)
- Huiying Yang
- School
of Physics, Huazhong University of Science
and Technology, Wuhan 430074, China
| | - Daihong Zhou
- School
of Physics, Huazhong University of Science
and Technology, Wuhan 430074, China
| | - Zhangyi Zhou
- School
of Physics, Huazhong University of Science
and Technology, Wuhan 430074, China
| | - Mojie Duan
- Innovation
Academy for Precision Measurement Science and Technology, Chinese
Academy of Sciences, Wuhan 430071, China
| | - Hao Yu
- School
of Physics, Huazhong University of Science
and Technology, Wuhan 430074, China
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3
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Muhammednazaar S, Yao J, Guo R, Rhee MS, Kim KH, Kang SG, Hong H. Lipid Bilayer Strengthens the Cooperative Network of a Membrane-Integral Enzyme. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542905. [PMID: 37398072 PMCID: PMC10312574 DOI: 10.1101/2023.05.30.542905] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Lipid bilayer provides a two-dimensional hydrophobic solvent milieu for membrane proteins in cells. Although the native bilayer is widely recognized as an optimal environment for folding and function of membrane proteins, the underlying physical basis remains elusive. Here, employing the intramembrane protease GlpG of Escherichia coli as a model, we elucidate how the bilayer stabilizes a membrane protein and engages the protein's residue interaction network compared to the nonnative hydrophobic medium, micelles. We find that the bilayer enhances GlpG stability by promoting residue burial in the protein interior compared to micelles. Strikingly, while the cooperative residue interactions cluster into multiple distinct regions in micelles, the whole packed regions of the protein act as a single cooperative unit in the bilayer. Molecular dynamics (MD) simulation indicates that lipids less efficiently solvate GlpG than detergents. Thus, the bilayerinduced enhancement of stability and cooperativity likely stems from the dominant intraprotein interactions outcompeting the weak lipid solvation. Our findings reveal a foundational mechanism in the folding, function, and quality control of membrane proteins. The enhanced cooperativity benefits function facilitating propagation of local structural perturbation across the membrane. However, the same phenomenon can render the proteins' conformational integrity vulnerable to missense mutations causing conformational diseases1,2.
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Affiliation(s)
| | - Jiaqi Yao
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Ruiqiong Guo
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - May S Rhee
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Kelly H Kim
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Seung-Gu Kang
- Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, NY 10598, USA
| | - Heedeok Hong
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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4
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Sihorwala AZ, Lin AJ, Stachowiak JC, Belardi B. Light-Activated Assembly of Connexon Nanopores in Synthetic Cells. J Am Chem Soc 2023; 145:3561-3568. [PMID: 36724060 PMCID: PMC10188233 DOI: 10.1021/jacs.2c12491] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
During developmental processes and wound healing, activation of living cells occurs with spatiotemporal precision and leads to rapid release of soluble molecular signals, allowing communication and coordination between neighbors. Nonliving systems capable of similar responsive release hold great promise for information transfer in materials and site-specific drug delivery. One nonliving system that offers a tunable platform for programming release is synthetic cells. Encased in a lipid bilayer structure, synthetic cells can be outfitted with molecular conduits that span the bilayer and lead to material exchange. While previous work expressing membrane pore proteins in synthetic cells demonstrated content exchange, user-defined control over release has remained elusive. In mammalian cells, connexon nanopore structures drive content release and have garnered significant interest since they can direct material exchange through intercellular contacts. Here, we focus on connexon nanopores and present activated release of material from synthetic cells in a light-sensitive fashion. To do this, we re-engineer connexon nanopores to assemble after post-translational processing by a protease. By encapsulating proteases in light-sensitive liposomes, we show that assembly of nanopores can be triggered by illumination, resulting in rapid release of molecules encapsulated within synthetic cells. Controlling connexon nanopore activity provides an opportunity for initiating communication with extracellular signals and for transferring molecular agents to the cytoplasm of living cells in a rapid, light-guided manner.
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Affiliation(s)
- Ahmed Z Sihorwala
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Alexander J Lin
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Brian Belardi
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
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5
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Cancer immune therapy using engineered ‛tail-flipping' nanoliposomes targeting alternatively activated macrophages. Nat Commun 2022; 13:4548. [PMID: 35927238 PMCID: PMC9352736 DOI: 10.1038/s41467-022-32091-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 07/13/2022] [Indexed: 11/08/2022] Open
Abstract
Alternatively-activated, M2-like tumor-associated macrophages (TAM) strongly contribute to tumor growth, invasiveness and metastasis. Technologies to disable the pro-tumorigenic function of these TAMs are of high interest to immunotherapy research. Here we show that by designing engineered nanoliposomes bio-mimicking peroxidated phospholipids that are recognised and internalised by scavenger receptors, TAMs can be targeted. Incorporation of phospholipids possessing a terminal carboxylate group at the sn-2 position into nanoliposome bilayers drives their uptake by M2 macrophages with high specificity. Molecular dynamics simulation of the lipid bilayer predicts flipping of the sn-2 tail towards the aqueous phase, while molecular docking data indicates interaction of the tail with Scavenger Receptor Class B type 1 (SR-B1). In vivo, the engineered nanoliposomes are distributed specifically to M2-like macrophages and, upon delivery of the STAT6 inhibitor (AS1517499), zoledronic acid or muramyl tripeptide, these cells promote reduction of the premetastatic niche and/or tumor growth. Altogether, we demonstrate the efficiency and versatility of our engineered “tail-flipping” nanoliposomes in a pre-clinical model, which paves the way to their development as cancer immunotherapeutics in humans. Tumor-associated macrophages are mostly pro-tumorigenic, due to their re-programming by the tumor microenvironment. Here authors show that nanoliposomes, incorporating phospholipids with a flipping-tail chain, are engulfed specifically by intratumoral, alternatively activated macrophages, while delivering a cargo that converts these cells into anti-tumor macrophages.
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6
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Corin K, Bowie JU. How physical forces drive the process of helical membrane protein folding. EMBO Rep 2022; 23:e53025. [PMID: 35133709 PMCID: PMC8892262 DOI: 10.15252/embr.202153025] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/17/2021] [Accepted: 11/24/2021] [Indexed: 11/09/2022] Open
Abstract
Protein folding is a fundamental process of life with important implications throughout biology. Indeed, tens of thousands of mutations have been associated with diseases, and most of these mutations are believed to affect protein folding rather than function. Correct folding is also a key element of design. These factors have motivated decades of research on protein folding. Unfortunately, knowledge of membrane protein folding lags that of soluble proteins. This gap is partly caused by the greater technical challenges associated with membrane protein studies, but also because of additional complexities. While soluble proteins fold in a homogenous water environment, membrane proteins fold in a setting that ranges from bulk water to highly charged to apolar. Thus, the forces that drive folding vary in different regions of the protein, and this complexity needs to be incorporated into our understanding of the folding process. Here, we review our understanding of membrane protein folding biophysics. Despite the greater challenge, better model systems and new experimental techniques are starting to unravel the forces and pathways in membrane protein folding.
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Affiliation(s)
- Karolina Corin
- Department of Chemistry and BiochemistryMolecular Biology InstituteUCLA‐DOE InstituteUniversity of CaliforniaLos AngelesCAUSA
| | - James U Bowie
- Department of Chemistry and BiochemistryMolecular Biology InstituteUCLA‐DOE InstituteUniversity of CaliforniaLos AngelesCAUSA
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7
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Hong H, Choi HK, Yoon TY. Untangling the complexity of membrane protein folding. Curr Opin Struct Biol 2022; 72:237-247. [PMID: 34995926 DOI: 10.1016/j.sbi.2021.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/15/2022]
Abstract
Delineating the folding steps of helical-bundle membrane proteins has been a challenging task. Many questions remain unanswered, including the conformation and stability of the states populated during folding, the shape of the energy barriers between the states, and the role of lipids as a solvent in mediating the folding. Recently, theoretical frames have matured to a point that permits detailed dissection of the folding steps, and advances in experimental techniques at both single-molecule and ensemble levels enable selective modulation of specific steps for quantitative determination of the folding energy landscapes. We also discuss how lipid molecules would play an active role in shaping the folding energy landscape of membrane proteins, and how folding of multi-domain membrane proteins can be understood based on our current knowledge. We conclude this review by offering an outlook for emerging questions in the study of membrane protein folding.
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Affiliation(s)
- Heedeok Hong
- Department of Chemistry, Michigan State University, East Lansing, MI, 48824, USA.
| | - Hyun-Kyu Choi
- Wallace H. Coulter Department of Biomedical Engineering and Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Tae-Young Yoon
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, 08826, South Korea.
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8
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Basu S, Assaf SS, Teheux F, Rooman M, Pucci F. BRANEart: Identify Stability Strength and Weakness Regions in Membrane Proteins. FRONTIERS IN BIOINFORMATICS 2021; 1:742843. [PMID: 36303753 PMCID: PMC9581023 DOI: 10.3389/fbinf.2021.742843] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/03/2021] [Indexed: 11/22/2022] Open
Abstract
Understanding the role of stability strengths and weaknesses in proteins is a key objective for rationalizing their dynamical and functional properties such as conformational changes, catalytic activity, and protein-protein and protein-ligand interactions. We present BRANEart, a new, fast and accurate method to evaluate the per-residue contributions to the overall stability of membrane proteins. It is based on an extended set of recently introduced statistical potentials derived from membrane protein structures, which better describe the stability properties of this class of proteins than standard potentials derived from globular proteins. We defined a per-residue membrane propensity index from combinations of these potentials, which can be used to identify residues which strongly contribute to the stability of the transmembrane region or which would, on the contrary, be more stable in extramembrane regions, or vice versa. Large-scale application to membrane and globular proteins sets and application to tests cases show excellent agreement with experimental data. BRANEart thus appears as a useful instrument to analyze in detail the overall stability properties of a target membrane protein, to position it relative to the lipid bilayer, and to rationally modify its biophysical characteristics and function. BRANEart can be freely accessed from http://babylone.3bio.ulb.ac.be/BRANEart.
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Affiliation(s)
- Sankar Basu
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels, Belgium
- Department of Microbiology, Austosh College, Under University of Calcutta, Kolkata, India
| | - Simon S. Assaf
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels, Belgium
| | - Fabian Teheux
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels, Belgium
| | - Marianne Rooman
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels, Belgium
- Interuniversity Institute of Bioinformatics in Brussels, Brussels, Belgium
- *Correspondence: Marianne Rooman, ; Fabrizio Pucci,
| | - Fabrizio Pucci
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels, Belgium
- Interuniversity Institute of Bioinformatics in Brussels, Brussels, Belgium
- *Correspondence: Marianne Rooman, ; Fabrizio Pucci,
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9
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Dongre AV, Das S, Bellur A, Kumar S, Chandrashekarmath A, Karmakar T, Balaram P, Balasubramanian S, Balaram H. Structural basis for the hyperthermostability of an archaeal enzyme induced by succinimide formation. Biophys J 2021; 120:3732-3746. [PMID: 34302792 DOI: 10.1016/j.bpj.2021.07.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/18/2021] [Accepted: 07/19/2021] [Indexed: 10/20/2022] Open
Abstract
Stability of proteins from hyperthermophiles (organisms existing under boiling water conditions) enabled by a reduction of conformational flexibility is realized through various mechanisms. A succinimide (SNN) arising from the post-translational cyclization of the side chains of aspartyl/asparaginyl residues with the backbone amide -NH of the succeeding residue would restrain the torsion angle Ψ and can serve as a new route for hyperthermostability. However, such a succinimide is typically prone to hydrolysis, transforming to either an aspartyl or β-isoaspartyl residue. Here, we present the crystal structure of Methanocaldococcus jannaschii glutamine amidotransferase and, using enhanced sampling molecular dynamics simulations, address the mechanism of its increased thermostability, up to 100°C, imparted by an unexpectedly stable succinimidyl residue at position 109. The stability of SNN109 to hydrolysis is seen to arise from its electrostatic shielding by the side-chain carboxylate group of its succeeding residue Asp110, as well as through n → π∗ interactions between SNN109 and its preceding residue Glu108, both of which prevent water access to SNN. The stable succinimidyl residue induces the formation of an α-turn structure involving 13-atom hydrogen bonding, which locks the local conformation, reducing protein flexibility. The destabilization of the protein upon replacement of SNN with a Φ-restricted prolyl residue highlights the specificity of the succinimidyl residue in imparting hyperthermostability to the enzyme. The conservation of the succinimide-forming tripeptide sequence (E(N/D)(E/D)) in several archaeal GATases strongly suggests an adaptation of this otherwise detrimental post-translational modification as a harbinger of thermostability.
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Affiliation(s)
- Aparna Vilas Dongre
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India
| | - Sudip Das
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India
| | - Asutosh Bellur
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India
| | - Sanjeev Kumar
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India; National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - Anusha Chandrashekarmath
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India
| | - Tarak Karmakar
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India; Department of Chemistry and Applied Biosciences, ETH Zurich, Lugano, Ticino, Switzerland; Facoltà di Informatica, Istituto di Scienze Computationali, Università della Svizzera Italiana, Lugano, Ticino, Switzerland
| | - Padmanabhan Balaram
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India; Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Sundaram Balasubramanian
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India.
| | - Hemalatha Balaram
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India.
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10
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Giulini M, Rigoli M, Mattiotti G, Menichetti R, Tarenzi T, Fiorentini R, Potestio R. From System Modeling to System Analysis: The Impact of Resolution Level and Resolution Distribution in the Computer-Aided Investigation of Biomolecules. Front Mol Biosci 2021; 8:676976. [PMID: 34164432 PMCID: PMC8215203 DOI: 10.3389/fmolb.2021.676976] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 05/06/2021] [Indexed: 12/18/2022] Open
Abstract
The ever increasing computer power, together with the improved accuracy of atomistic force fields, enables researchers to investigate biological systems at the molecular level with remarkable detail. However, the relevant length and time scales of many processes of interest are still hardly within reach even for state-of-the-art hardware, thus leaving important questions often unanswered. The computer-aided investigation of many biological physics problems thus largely benefits from the usage of coarse-grained models, that is, simplified representations of a molecule at a level of resolution that is lower than atomistic. A plethora of coarse-grained models have been developed, which differ most notably in their granularity; this latter aspect determines one of the crucial open issues in the field, i.e. the identification of an optimal degree of coarsening, which enables the greatest simplification at the expenses of the smallest information loss. In this review, we present the problem of coarse-grained modeling in biophysics from the viewpoint of system representation and information content. In particular, we discuss two distinct yet complementary aspects of protein modeling: on the one hand, the relationship between the resolution of a model and its capacity of accurately reproducing the properties of interest; on the other hand, the possibility of employing a lower resolution description of a detailed model to extract simple, useful, and intelligible information from the latter.
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Affiliation(s)
- Marco Giulini
- Physics Department, University of Trento, Trento, Italy.,INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, Trento, Italy
| | - Marta Rigoli
- Physics Department, University of Trento, Trento, Italy.,INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, Trento, Italy
| | - Giovanni Mattiotti
- Physics Department, University of Trento, Trento, Italy.,INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, Trento, Italy
| | - Roberto Menichetti
- Physics Department, University of Trento, Trento, Italy.,INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, Trento, Italy
| | - Thomas Tarenzi
- Physics Department, University of Trento, Trento, Italy.,INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, Trento, Italy
| | - Raffaele Fiorentini
- Physics Department, University of Trento, Trento, Italy.,INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, Trento, Italy
| | - Raffaello Potestio
- Physics Department, University of Trento, Trento, Italy.,INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, Trento, Italy
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11
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Lu W, Bueno C, Schafer NP, Moller J, Jin S, Chen X, Chen M, Gu X, Davtyan A, de Pablo JJ, Wolynes PG. OpenAWSEM with Open3SPN2: A fast, flexible, and accessible framework for large-scale coarse-grained biomolecular simulations. PLoS Comput Biol 2021; 17:e1008308. [PMID: 33577557 PMCID: PMC7906472 DOI: 10.1371/journal.pcbi.1008308] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 02/25/2021] [Accepted: 01/09/2021] [Indexed: 01/28/2023] Open
Abstract
We present OpenAWSEM and Open3SPN2, new cross-compatible implementations of coarse-grained models for protein (AWSEM) and DNA (3SPN2) molecular dynamics simulations within the OpenMM framework. These new implementations retain the chemical accuracy and intrinsic efficiency of the original models while adding GPU acceleration and the ease of forcefield modification provided by OpenMM’s Custom Forces software framework. By utilizing GPUs, we achieve around a 30-fold speedup in protein and protein-DNA simulations over the existing LAMMPS-based implementations running on a single CPU core. We showcase the benefits of OpenMM’s Custom Forces framework by devising and implementing two new potentials that allow us to address important aspects of protein folding and structure prediction and by testing the ability of the combined OpenAWSEM and Open3SPN2 to model protein-DNA binding. The first potential is used to describe the changes in effective interactions that occur as a protein becomes partially buried in a membrane. We also introduced an interaction to describe proteins with multiple disulfide bonds. Using simple pairwise disulfide bonding terms results in unphysical clustering of cysteine residues, posing a problem when simulating the folding of proteins with many cysteines. We now can computationally reproduce Anfinsen’s early Nobel prize winning experiments by using OpenMM’s Custom Forces framework to introduce a multi-body disulfide bonding term that prevents unphysical clustering. Our protein-DNA simulations show that the binding landscape is funneled towards structures that are quite similar to those found using experiments. In summary, this paper provides a simulation tool for the molecular biophysics community that is both easy to use and sufficiently efficient to simulate large proteins and large protein-DNA systems that are central to many cellular processes. These codes should facilitate the interplay between molecular simulations and cellular studies, which have been hampered by the large mismatch between the time and length scales accessible to molecular simulations and those relevant to cell biology. The cell’s most important pieces of machinery are large complexes of proteins often along with nucleic acids. From the ribosome, to CRISPR-Cas9, to transcription factors and DNA-wrangling proteins like the SMC-Kleisins, these complexes allow organisms to replicate and enable cells to respond to environmental cues. Computer simulation is a key technology that can be used to connect physical theories with biological reality. Unfortunately, the time and length scales accessible to molecular simulation have not kept pace with our ambition to study the cell’s molecular factories. Many simulation codes also unfortunately remain effectively locked away from the user community who need to modify them as more of the underlying physics is learned. In this paper, we present OpenAWSEM and Open3SPN2, two new easy-to-use and easy to modify implementations of efficient and accurate coarse-grained protein and DNA simulation forcefields that can now be run hundreds of times faster than before, thereby making studies of large biomolecular machines more facile.
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Affiliation(s)
- Wei Lu
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- Department of Physics, Rice University, Houston, Texas, United States of America
| | - Carlos Bueno
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- Department of Chemistry, Rice University, Houston, Texas, United States of America
| | - Nicholas P. Schafer
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- Department of Chemistry, Rice University, Houston, Texas, United States of America
- Schafer Science, LLC, Houston, Texas United States of America
| | - Joshua Moller
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois, United States of America
- Argonne National Laboratory, Lemont, Illinois, United States of America
| | - Shikai Jin
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- Department of Biosciences, Rice University, Houston, Texas, United States of America
| | - Xun Chen
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- Department of Chemistry, Rice University, Houston, Texas, United States of America
| | - Mingchen Chen
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
| | - Xinyu Gu
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- Department of Chemistry, Rice University, Houston, Texas, United States of America
| | - Aram Davtyan
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
| | - Juan J. de Pablo
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois, United States of America
- Argonne National Laboratory, Lemont, Illinois, United States of America
| | - Peter G. Wolynes
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- Department of Chemistry, Rice University, Houston, Texas, United States of America
- Department of Physics, Rice University, Houston, Texas, United States of America
- Department of Biosciences, Rice University, Houston, Texas, United States of America
- * E-mail:
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12
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Nicolaus F, Metola A, Mermans D, Liljenström A, Krč A, Abdullahi SM, Zimmer M, Miller Iii TF, von Heijne G. Residue-by-residue analysis of cotranslational membrane protein integration in vivo. eLife 2021; 10:64302. [PMID: 33554862 PMCID: PMC7886326 DOI: 10.7554/elife.64302] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 02/05/2021] [Indexed: 12/16/2022] Open
Abstract
We follow the cotranslational biosynthesis of three multispanning Escherichia coli inner membrane proteins in vivo using high-resolution force profile analysis. The force profiles show that the nascent chain is subjected to rapidly varying pulling forces during translation and reveal unexpected complexities in the membrane integration process. We find that an N-terminal cytoplasmic domain can fold in the ribosome exit tunnel before membrane integration starts, that charged residues and membrane-interacting segments such as re-entrant loops and surface helices flanking a transmembrane helix (TMH) can advance or delay membrane integration, and that point mutations in an upstream TMH can affect the pulling forces generated by downstream TMHs in a highly position-dependent manner, suggestive of residue-specific interactions between TMHs during the integration process. Our results support the 'sliding' model of translocon-mediated membrane protein integration, in which hydrophobic segments are continually exposed to the lipid bilayer during their passage through the SecYEG translocon.
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Affiliation(s)
- Felix Nicolaus
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Ane Metola
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Daphne Mermans
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Amanda Liljenström
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Ajda Krč
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.,Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | | | - Matthew Zimmer
- California Institute of Technology, Division of Chemistry and Chemical Engineering, Pasadena, United States
| | - Thomas F Miller Iii
- California Institute of Technology, Division of Chemistry and Chemical Engineering, Pasadena, United States
| | - Gunnar von Heijne
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.,Science for Life Laboratory Stockholm University, Solna, Sweden
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13
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Domański J, Sansom MSP, Stansfeld PJ, Best RB. Atomistic mechanism of transmembrane helix association. PLoS Comput Biol 2020; 16:e1007919. [PMID: 32497094 PMCID: PMC7272003 DOI: 10.1371/journal.pcbi.1007919] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 04/30/2020] [Indexed: 01/21/2023] Open
Abstract
Transmembrane helix association is a fundamental step in the folding of helical membrane proteins. The prototypical example of this association is formation of the glycophorin dimer. While its structure and stability have been well-characterized experimentally, the detailed assembly mechanism is harder to obtain. Here, we use all-atom simulations within phospholipid membrane to study glycophorin association. We find that initial association results in the formation of a non-native intermediate, separated by a significant free energy barrier from the dimer with a native binding interface. We have used transition-path sampling to determine the association mechanism. We find that the mechanism of the initial bimolecular association to form the intermediate state can be mediated by many possible contacts, but seems to be particularly favoured by formation of non-native contacts between the C-termini of the two helices. On the other hand, the contacts which are key to determining progression from the intermediate to the native state are those which define the native binding interface, reminiscent of the role played by native contacts in determining folding of globular proteins. As a check on the simulations, we have computed association and dissociation rates from the transition-path sampling. We obtain results in reasonable accord with available experimental data, after correcting for differences in native state stability. Our results yield an atomistic description of the mechanism for a simple prototype of helical membrane protein folding. Many important cellular functions are performed by membrane proteins, and in particular by association of proteins via transmembrane helices. However, the mechanism of how the helices associate has been challenging to study, by either experiment or simulation. Here, we use advanced molecular simulation methods to overcome the slow time scales involved in helix association and dissociation and obtain a view of the association mechanism in atomic detail. We show that association occurs via an initially non-native dimer, before proceeding to the native state, and we validate our results by comparison to available experimental kinetic data. Our methods will also aid in the study of the assembly mechanism of larger transmembrane proteins via molecular simulation.
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Affiliation(s)
- Jan Domański
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, United Kingdom
| | - Mark S. P. Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, United Kingdom
| | - Phillip J. Stansfeld
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, United Kingdom
- School of Life Sciences and Department of Chemistry, University of Warwick, Gibbet Hill Campus, Coventry, United Kingdom
| | - Robert B. Best
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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14
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Fu H, Chen H, Wang X, Chai H, Shao X, Cai W, Chipot C. Finding an Optimal Pathway on a Multidimensional Free-Energy Landscape. J Chem Inf Model 2020; 60:5366-5374. [DOI: 10.1021/acs.jcim.0c00279] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Haohao Fu
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
| | - Haochuan Chen
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
| | - Xin’ao Wang
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
| | - Hao Chai
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
| | - Xueguang Shao
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
| | - Wensheng Cai
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
| | - Christophe Chipot
- Laboratoire International Associé CNRS and University of Illinois at Urbana−Champaign, F-54506 Vandœuvre-lès-Nancy, France
- Department of Physics, University of Illinois at Urbana−Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States
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15
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Wang Z, Jumper JM, Freed KF, Sosnick TR. On the Interpretation of Force-Induced Unfolding Studies of Membrane Proteins Using Fast Simulations. Biophys J 2019; 117:1429-1441. [PMID: 31587831 DOI: 10.1016/j.bpj.2019.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 08/25/2019] [Accepted: 09/12/2019] [Indexed: 11/25/2022] Open
Abstract
Single-molecule force spectroscopy has proven extremely beneficial in elucidating folding pathways for membrane proteins. Here, we simulate these measurements, conducting hundreds of unfolding trajectories using our fast Upside algorithm for slow enough speeds to reproduce key experimental features that may be missed using all-atom methods. The speed also enables us to determine the logarithmic dependence of pulling velocities on the rupture levels to better compare to experimental values. For simulations of atomic force microscope measurements in which force is applied vertically to the C-terminus of bacteriorhodopsin, we reproduce the major experimental features including even the back-and-forth unfolding of single helical turns. When pulling laterally on GlpG to mimic the experiment, we observe quite different behavior depending on the stiffness of the spring. With a soft spring, as used in the experimental studies with magnetic tweezers, the force remains nearly constant after the initial unfolding event, and a few pathways and a high degree of cooperativity are observed in both the experiment and simulation. With a stiff spring, however, the force drops to near zero after each major unfolding event, and numerous intermediates are observed along a wide variety of pathways. Hence, the mode of force application significantly alters the perception of the folding landscape, including the number of intermediates and the degree of folding cooperativity, important issues that should be considered when designing experiments and interpreting unfolding data.
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Affiliation(s)
- Zongan Wang
- Department of Chemistry, James Franck Institute, The University of Chicago, Chicago, Illinois; Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois
| | - John M Jumper
- Department of Chemistry, James Franck Institute, The University of Chicago, Chicago, Illinois; Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois
| | - Karl F Freed
- Department of Chemistry, James Franck Institute, The University of Chicago, Chicago, Illinois.
| | - Tobin R Sosnick
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois; Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois.
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16
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Dynamic membrane topology in an unassembled membrane protein. Nat Chem Biol 2019; 15:945-948. [DOI: 10.1038/s41589-019-0356-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/31/2019] [Indexed: 11/08/2022]
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17
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Deng Y, Wu T, Wang M, Shi S, Yuan G, Li X, Chong H, Wu B, Zheng P. Enzymatic biosynthesis and immobilization of polyprotein verified at the single-molecule level. Nat Commun 2019; 10:2775. [PMID: 31235796 PMCID: PMC6591319 DOI: 10.1038/s41467-019-10696-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 05/23/2019] [Indexed: 11/09/2022] Open
Abstract
The recent development of chemical and bio-conjugation techniques allows for the engineering of various protein polymers. However, most of the polymerization process is difficult to control. To meet this challenge, we develop an enzymatic procedure to build polyprotein using the combination of a strict protein ligase OaAEP1 (Oldenlandia affinis asparaginyl endopeptidases 1) and a protease TEV (tobacco etch virus). We firstly demonstrate the use of OaAEP1-alone to build a sequence-uncontrolled ubiquitin polyprotein and covalently immobilize the coupled protein on the surface. Then, we construct a poly-metalloprotein, rubredoxin, from the purified monomer. Lastly, we show the feasibility of synthesizing protein polymers with rationally-controlled sequences by the synergy of the ligase and protease, which are verified by protein unfolding using atomic force microscopy-based single-molecule force spectroscopy (AFM-SMFS). Thus, this study provides a strategy for polyprotein engineering and immobilization.
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Affiliation(s)
- Yibing Deng
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210023, P. R. China
| | - Tao Wu
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210023, P. R. China
| | - Mengdi Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210023, P. R. China
| | - Shengchao Shi
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210023, P. R. China
| | - Guodong Yuan
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210023, P. R. China
| | - Xi Li
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210023, P. R. China
| | - Hanchung Chong
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, EMB 06-01, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Bin Wu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, EMB 06-01, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Peng Zheng
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210023, P. R. China.
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18
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Yang Y, Gunasekara M, Muhammednazaar S, Li Z, Hong H. Proteolysis mediated by the membrane-integrated ATP-dependent protease FtsH has a unique nonlinear dependence on ATP hydrolysis rates. Protein Sci 2019; 28:1262-1275. [PMID: 31008538 DOI: 10.1002/pro.3629] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 04/17/2019] [Indexed: 12/16/2022]
Abstract
ATPases associated with diverse cellular activities (AAA+) proteases utilize ATP hydrolysis to actively unfold native or misfolded proteins and translocate them into a protease chamber for degradation. This basic mechanism yields diverse cellular consequences, including the removal of misfolded proteins, control of regulatory circuits, and remodeling of protein conformation. Among various bacterial AAA+ proteases, FtsH is only membrane-integrated and plays a key role in membrane protein quality control. Previously, we have shown that FtsH has substantial unfoldase activity for degrading membrane proteins overcoming a dual energetic burden of substrate unfolding and membrane dislocation. Here, we asked how efficiently FtsH utilizes ATP hydrolysis to degrade membrane proteins. To answer this question, we measured degradation rates of the model membrane substrate GlpG at various ATP hydrolysis rates in the lipid bilayers. We find that the dependence of degradation rates on ATP hydrolysis rates is highly nonlinear: (i) FtsH cannot degrade GlpG until it reaches a threshold ATP hydrolysis rate; (ii) after exceeding the threshold, the degradation rates steeply increase and saturate at the ATP hydrolysis rates far below the maxima. During the steep increase, FtsH efficiently utilizes ATP hydrolysis for degradation, consuming only 40-60% of the total ATP cost measured at the maximal ATP hydrolysis rates. This behavior does not fundamentally change against water-soluble substrates as well as upon addition of the macromolecular crowding agent Ficoll 70. The Hill analysis shows that the nonlinearity stems from coupling of three to five ATP hydrolysis events to degradation, which represents unique cooperativity compared to other AAA+ proteases including ClpXP, HslUV, Lon, and proteasomes.
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Affiliation(s)
- Yiqing Yang
- Department of Chemistry, Michigan State University, East Lansing, Michigan, 48824
| | - Mihiravi Gunasekara
- Department of Chemistry, Michigan State University, East Lansing, Michigan, 48824
| | | | - Zhen Li
- Department of Chemistry, Michigan State University, East Lansing, Michigan, 48824
| | - Heedeok Hong
- Department of Chemistry, Michigan State University, East Lansing, Michigan, 48824.,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, 48824
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