1
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Hegde RS, Keenan RJ. A unifying model for membrane protein biogenesis. Nat Struct Mol Biol 2024:10.1038/s41594-024-01296-5. [PMID: 38811793 DOI: 10.1038/s41594-024-01296-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 03/25/2024] [Indexed: 05/31/2024]
Abstract
α-Helical integral membrane proteins comprise approximately 25% of the proteome in all organisms. The membrane proteome is highly diverse, varying in the number, topology, spacing and properties of transmembrane domains. This diversity imposes different constraints on the insertion of different regions of a membrane protein into the lipid bilayer. Here, we present a cohesive framework to explain membrane protein biogenesis, in which different parts of a nascent substrate are triaged between Oxa1 and SecY family members for insertion. In this model, Oxa1 family proteins insert transmembrane domains flanked by short translocated segments, whereas the SecY channel is required for insertion of transmembrane domains flanked by long translocated segments. Our unifying model rationalizes evolutionary, genetic, biochemical and structural data across organisms and provides a foundation for future mechanistic studies of membrane protein biogenesis.
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Affiliation(s)
- Ramanujan S Hegde
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, UK.
| | - Robert J Keenan
- Gordon Center for Integrative Science, The University of Chicago, Chicago, IL, USA.
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2
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Waeterschoot J, Gosselé W, Lemež Š, Casadevall I Solvas X. Artificial cells for in vivo biomedical applications through red blood cell biomimicry. Nat Commun 2024; 15:2504. [PMID: 38509073 PMCID: PMC10954685 DOI: 10.1038/s41467-024-46732-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 03/08/2024] [Indexed: 03/22/2024] Open
Abstract
Recent research in artificial cell production holds promise for the development of delivery agents with therapeutic effects akin to real cells. To succeed in these applications, these systems need to survive the circulatory conditions. In this review we present strategies that, inspired by the endurance of red blood cells, have enhanced the viability of large, cell-like vehicles for in vivo therapeutic use, particularly focusing on giant unilamellar vesicles. Insights from red blood cells can guide modifications that could transform these platforms into advanced drug delivery vehicles, showcasing biomimicry's potential in shaping the future of therapeutic applications.
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Affiliation(s)
- Jorik Waeterschoot
- Department of Biosystems - MeBioS, KU Leuven, Willem de Croylaan 42, 3001, Leuven, Belgium.
| | - Willemien Gosselé
- Department of Biosystems - MeBioS, KU Leuven, Willem de Croylaan 42, 3001, Leuven, Belgium
| | - Špela Lemež
- Department of Biosystems - MeBioS, KU Leuven, Willem de Croylaan 42, 3001, Leuven, Belgium
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3
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Peng Z, Iwabuchi S, Izumi K, Takiguchi S, Yamaji M, Fujita S, Suzuki H, Kambara F, Fukasawa G, Cooney A, Di Michele L, Elani Y, Matsuura T, Kawano R. Lipid vesicle-based molecular robots. LAB ON A CHIP 2024; 24:996-1029. [PMID: 38239102 PMCID: PMC10898420 DOI: 10.1039/d3lc00860f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
A molecular robot, which is a system comprised of one or more molecular machines and computers, can execute sophisticated tasks in many fields that span from nanomedicine to green nanotechnology. The core parts of molecular robots are fairly consistent from system to system and always include (i) a body to encapsulate molecular machines, (ii) sensors to capture signals, (iii) computers to make decisions, and (iv) actuators to perform tasks. This review aims to provide an overview of approaches and considerations to develop molecular robots. We first introduce the basic technologies required for constructing the core parts of molecular robots, describe the recent progress towards achieving higher functionality, and subsequently discuss the current challenges and outlook. We also highlight the applications of molecular robots in sensing biomarkers, signal communications with living cells, and conversion of energy. Although molecular robots are still in their infancy, they will unquestionably initiate massive change in biomedical and environmental technology in the not too distant future.
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Affiliation(s)
- Zugui Peng
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo185-8588, Japan.
| | - Shoji Iwabuchi
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo185-8588, Japan.
| | - Kayano Izumi
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo185-8588, Japan.
| | - Sotaro Takiguchi
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo185-8588, Japan.
| | - Misa Yamaji
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo185-8588, Japan.
| | - Shoko Fujita
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo185-8588, Japan.
| | - Harune Suzuki
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo185-8588, Japan.
| | - Fumika Kambara
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo185-8588, Japan.
| | - Genki Fukasawa
- School of Life Science and Technology, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-Ku, Tokyo 152-8550, Japan
| | - Aileen Cooney
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London W12 0BZ, UK
| | - Lorenzo Di Michele
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London W12 0BZ, UK
- FabriCELL, Molecular Sciences Research Hub, Imperial College London, London W12 0BZ, UK
| | - Yuval Elani
- Department of Chemical Engineering, Imperial College London, South Kensington, London SW7 2AZ, UK
- FabriCELL, Molecular Sciences Research Hub, Imperial College London, London W12 0BZ, UK
| | - Tomoaki Matsuura
- Earth-Life Science Institute, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-Ku, Tokyo 152-8550, Japan
| | - Ryuji Kawano
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo185-8588, Japan.
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4
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Tror S, Jeon S, Nguyen HT, Huh E, Shin K. A Self-Regenerating Artificial Cell, that is One Step Closer to Living Cells: Challenges and Perspectives. SMALL METHODS 2023; 7:e2300182. [PMID: 37246263 DOI: 10.1002/smtd.202300182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 04/29/2023] [Indexed: 05/30/2023]
Abstract
Controllable, self-regenerating artificial cells (SRACs) can be a vital advancement in the field of synthetic biology, which seeks to create living cells by recombining various biological molecules in the lab. This represents, more importantly, the first step on a long journey toward creating reproductive cells from rather fragmentary biochemical mimics. However, it is still a difficult task to replicate the complex processes involved in cell regeneration, such as genetic material replication and cell membrane division, in artificially created spaces. This review highlights recent advances in the field of controllable, SRACs and the strategies to achieve the goal of creating such cells. Self-regenerating cells start by replicating DNA and transferring it to a location where proteins can be synthesized. Functional but essential proteins must be synthesized for sustained energy generation and survival needs and function in the same liposomal space. Finally, self-division and repeated cycling lead to autonomous, self-regenerating cells. The pursuit of controllable, SRACs will enable authors to make bold advances in understanding life at the cellular level, ultimately providing an opportunity to use this knowledge to understand the nature of life.
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Affiliation(s)
- Seangly Tror
- Department of Chemistry and Institute of Biological Interfaces, Sogang University, Seoul, 04107, Republic of Korea
| | - SeonMin Jeon
- Department of Chemistry and Institute of Biological Interfaces, Sogang University, Seoul, 04107, Republic of Korea
| | - Huong Thanh Nguyen
- Department of Chemistry and Institute of Biological Interfaces, Sogang University, Seoul, 04107, Republic of Korea
| | - Eunjin Huh
- Department of Chemistry and Institute of Biological Interfaces, Sogang University, Seoul, 04107, Republic of Korea
| | - Kwanwoo Shin
- Department of Chemistry and Institute of Biological Interfaces, Sogang University, Seoul, 04107, Republic of Korea
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5
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Tosaka T, Kamiya K. Function Investigations and Applications of Membrane Proteins on Artificial Lipid Membranes. Int J Mol Sci 2023; 24:ijms24087231. [PMID: 37108393 PMCID: PMC10138308 DOI: 10.3390/ijms24087231] [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: 03/10/2023] [Revised: 04/05/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Membrane proteins play an important role in key cellular functions, such as signal transduction, apoptosis, and metabolism. Therefore, structural and functional studies of these proteins are essential in fields such as fundamental biology, medical science, pharmacology, biotechnology, and bioengineering. However, observing the precise elemental reactions and structures of membrane proteins is difficult, despite their functioning through interactions with various biomolecules in living cells. To investigate these properties, methodologies have been developed to study the functions of membrane proteins that have been purified from biological cells. In this paper, we introduce various methods for creating liposomes or lipid vesicles, from conventional to recent approaches, as well as techniques for reconstituting membrane proteins into artificial membranes. We also cover the different types of artificial membranes that can be used to observe the functions of reconstituted membrane proteins, including their structure, number of transmembrane domains, and functional type. Finally, we discuss the reconstitution of membrane proteins using a cell-free synthesis system and the reconstitution and function of multiple membrane proteins.
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Affiliation(s)
- Toshiyuki Tosaka
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Gunma 376-8515, Japan
| | - Koki Kamiya
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Gunma 376-8515, Japan
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6
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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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7
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Herianto S, Chien PJ, Ho JAA, Tu HL. Liposome-based artificial cells: From gene expression to reconstitution of cellular functions and phenotypes. BIOMATERIALS ADVANCES 2022; 142:213156. [PMID: 36302330 DOI: 10.1016/j.bioadv.2022.213156] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 10/12/2022] [Indexed: 06/16/2023]
Abstract
Bottom-up approaches in creating artificial cells that can mimic natural cells have significant implications for both basic research and translational application. Among various artificial cell models, liposome is one of the most sophisticated systems. By encapsulating proteins and associated biomolecules, they can functionally reconstitute foundational features of biological cells, such as the ability to divide, communicate, and undergo shape deformation. Yet constructing liposome artificial cells from the genetic level, which is central to generate self-sustained systems remains highly challenging. Indeed, many studies have successfully established the expression of gene-coded proteins inside liposomes. Further, recent endeavors to build a direct integration of gene-expressed proteins for reconstituting molecular functions and phenotypes in liposomes have also significantly increased. Thus, this review presents the development of liposome-based artificial cells to demonstrate the process of gene-expressed proteins and their reconstitution to perform desired molecular and cell-like functions. The molecular and cellular phenotypes discussed here include the self-production of membrane phospholipids, division, shape deformation, self-DNA/RNA replication, fusion, and intercellular communication. Together, this review gives a comprehensive overview of gene-expressing liposomes that can stimulate further research of this technology and achieve artificial cells with superior properties in the future.
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Affiliation(s)
- Samuel Herianto
- Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan; Chemical Biology and Molecular Biophysics, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan; Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Po-Jen Chien
- Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Ja-An Annie Ho
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan; BioAnalytical Chemistry and Nanobiomedicine Laboratory, Department of Biochemical Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| | - Hsiung-Lin Tu
- Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan; Chemical Biology and Molecular Biophysics, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan.
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8
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Hirschi S, Ward TR, Meier WP, Müller DJ, Fotiadis D. Synthetic Biology: Bottom-Up Assembly of Molecular Systems. Chem Rev 2022; 122:16294-16328. [PMID: 36179355 DOI: 10.1021/acs.chemrev.2c00339] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The bottom-up assembly of biological and chemical components opens exciting opportunities to engineer artificial vesicular systems for applications with previously unmet requirements. The modular combination of scaffolds and functional building blocks enables the engineering of complex systems with biomimetic or new-to-nature functionalities. Inspired by the compartmentalized organization of cells and organelles, lipid or polymer vesicles are widely used as model membrane systems to investigate the translocation of solutes and the transduction of signals by membrane proteins. The bottom-up assembly and functionalization of such artificial compartments enables full control over their composition and can thus provide specifically optimized environments for synthetic biological processes. This review aims to inspire future endeavors by providing a diverse toolbox of molecular modules, engineering methodologies, and different approaches to assemble artificial vesicular systems. Important technical and practical aspects are addressed and selected applications are presented, highlighting particular achievements and limitations of the bottom-up approach. Complementing the cutting-edge technological achievements, fundamental aspects are also discussed to cater to the inherently diverse background of the target audience, which results from the interdisciplinary nature of synthetic biology. The engineering of proteins as functional modules and the use of lipids and block copolymers as scaffold modules for the assembly of functionalized vesicular systems are explored in detail. Particular emphasis is placed on ensuring the controlled assembly of these components into increasingly complex vesicular systems. Finally, all descriptions are presented in the greater context of engineering valuable synthetic biological systems for applications in biocatalysis, biosensing, bioremediation, or targeted drug delivery.
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Affiliation(s)
- Stephan Hirschi
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland.,Molecular Systems Engineering, National Centre of Competence in Research (NCCR), 4002 Basel, Switzerland
| | - Thomas R Ward
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland.,Molecular Systems Engineering, National Centre of Competence in Research (NCCR), 4002 Basel, Switzerland
| | - Wolfgang P Meier
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland.,Molecular Systems Engineering, National Centre of Competence in Research (NCCR), 4002 Basel, Switzerland
| | - Daniel J Müller
- Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland.,Molecular Systems Engineering, National Centre of Competence in Research (NCCR), 4002 Basel, Switzerland
| | - Dimitrios Fotiadis
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland.,Molecular Systems Engineering, National Centre of Competence in Research (NCCR), 4002 Basel, Switzerland
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9
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Kajii K, Shimomura A, T Higashide M, Oki M, Tsuji G. Effects of Sugars on Giant Unilamellar Vesicle Preparation, Fusion, PCR in Liposomes, and Pore Formation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:8871-8880. [PMID: 35836326 DOI: 10.1021/acs.langmuir.2c00989] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The water-in-oil emulsion transfer method was developed for preparing giant unilamellar vesicles (GUVs) and is useful for studying cellular functions under conditions that mimic cellular environments. A shortcoming of this method for encapsulating biochemical reactions is that it requires high sugar concentrations to enable the density effect to transverse the oil-water interface. In this study, we investigated the effects of sugars on GUV preparation and several biochemical reactions. We found that changing the sugar in the inner solution from sucrose to maltose or trehalose improved GUV formation. The fusion ratio of the freeze-thaw method was better in the traditional glucose-sucrose condition compared with the other examined conditions. For the inner biochemical reaction, we performed PCR in liposomes. The presence of maltose in the inner solution improved the stability of GUVs against damage caused by thermal cycles. Finally, fructose in the outer solution reduced leakage of the inner solution via pores on the membranes of GUVs. Our findings provide new insight for optimizing sugar conditions for preparing GUVs and inner GUV reactions. This could increase the utilization of GUVs as artificial cell compartment models.
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Affiliation(s)
- Kyoka Kajii
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui City 910-8507, Fukui, Japan
| | - Ayu Shimomura
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui City 910-8507, Fukui, Japan
| | - Mika T Higashide
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui City 910-8507, Fukui, Japan
| | - Masaya Oki
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui City 910-8507, Fukui, Japan
- Life Science Innovation Center, University of Fukui, 3-9-1 Bunkyo, Fukui City 910-8507, Fukui, Japan
| | - Gakushi Tsuji
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui City 910-8507, Fukui, Japan
- Life Science Innovation Center, University of Fukui, 3-9-1 Bunkyo, Fukui City 910-8507, Fukui, Japan
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10
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Harris NJ, Pellowe GA, Blackholly LR, Gulaidi-Breen S, Findlay HE, Booth PJ. Methods to study folding of alpha-helical membrane proteins in lipids. Open Biol 2022; 12:220054. [PMID: 35855589 PMCID: PMC9297032 DOI: 10.1098/rsob.220054] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
How alpha-helical membrane proteins fold correctly in the highly hydrophobic membrane interior is not well understood. Their folding is known to be highly influenced by the lipids within the surrounding bilayer, but the majority of folding studies have focused on detergent-solubilized protein rather than protein in a lipid environment. There are different ways to study folding in lipid bilayers, and each method has its own advantages and disadvantages. This review will discuss folding methods which can be used to study alpha-helical membrane proteins in bicelles, liposomes, nanodiscs or native membranes. These folding methods include in vitro folding methods in liposomes such as denaturant unfolding studies, and single-molecule force spectroscopy studies in bicelles, liposomes and native membranes. This review will also discuss recent advances in co-translational folding studies, which use cell-free expression with liposomes or nanodiscs or are performed in vivo with native membranes.
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Affiliation(s)
- Nicola J. Harris
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London, SE1 1DB, UK
| | - Grant A. Pellowe
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London, SE1 1DB, UK
| | - Laura R. Blackholly
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London, SE1 1DB, UK
| | | | - Heather E. Findlay
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London, SE1 1DB, UK,The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Paula J. Booth
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London, SE1 1DB, UK,The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
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11
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Harris NJ, Reading E, Booth PJ. Cell-Free Synthesis Strategies to Probe Co-translational Folding of Proteins Within Lipid Membranes. Methods Mol Biol 2022; 2433:273-292. [PMID: 34985751 DOI: 10.1007/978-1-0716-1998-8_17] [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] [Indexed: 06/14/2023]
Abstract
In order to comprehend the molecular basis of transmembrane protein biogenesis, methods are required that are capable of investigating the co-translational folding of these hydrophobic proteins. Equally, in artificial cell studies, controllable methods are desirable for in situ synthesis of membrane proteins that then direct reactions in the synthetic cell membrane. Here we describe a method that exploits cell-free expression systems and tunable membrane mimetics to facilitate co-translational studies. Alteration of the lipid bilayer composition improves the efficiency of the folding system. The approach also enables membrane transport proteins to be made and inserted into artificial cell platforms such as droplet interface bilayers. Importantly, this gives a new facet to the droplet networks by enabling specific transport of molecules across the synthetic bilayer against a concentration gradient. This method also includes a protocol to pause and restart translation of membrane proteins at specified positions during their co-translational folding. This stop-start strategy provides an avenue to investigate whether the proteins fold in sequence order, or if the correct fold of N-terminal regions is reliant on the synthesis of downstream residues.
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Affiliation(s)
| | - Eamonn Reading
- Department of Chemistry, King's College London, London, UK
| | - Paula J Booth
- Department of Chemistry, King's College London, London, UK.
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12
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Controlled metabolic cascades for protein synthesis in an artificial cell. Biochem Soc Trans 2021; 49:2143-2151. [PMID: 34623386 DOI: 10.1042/bst20210175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/04/2021] [Accepted: 09/07/2021] [Indexed: 11/17/2022]
Abstract
In recent years, researchers have been pursuing a method to design and to construct life forms from scratch - in other words, to create artificial cells. In many studies, artificial cellular membranes have been successfully fabricated, allowing the research field to grow by leaps and bounds. Moreover, in addition to lipid bilayer membranes, proteins are essential factors required to construct any cellular metabolic reaction; for that reason, different cell-free expression systems under various conditions to achieve the goal of controlling the synthetic cascades of proteins in a confined area have been reported. Thus, in this review, we will discuss recent issues and strategies, enabling to control protein synthesis cascades that are being used, particularly in research on artificial cells.
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13
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Cotranslational recruitment of ribosomes in protocells recreates a translocon-independent mechanism of proteorhodopsin biogenesis. iScience 2021; 24:102429. [PMID: 33997704 PMCID: PMC8102411 DOI: 10.1016/j.isci.2021.102429] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 03/17/2021] [Accepted: 04/09/2021] [Indexed: 01/10/2023] Open
Abstract
The emergence of lipid membranes and embedded proteins was essential for the evolution of cells. Translocon complexes mediate cotranslational recruitment and membrane insertion of nascent proteins, but they already contain membrane-integral proteins. Therefore, a simpler mechanism must exist, enabling spontaneous membrane integration while preventing aggregation of unchaperoned protein in the aqueous phase. Here, we used giant unilamellar vesicles encapsulating minimal translation components to systematically interrogate the requirements for insertion of the model protein proteorhodopsin (PR) – a structurally ubiquitous membrane protein. We show that the N-terminal hydrophobic domain of PR is both necessary and sufficient for cotranslational recruitment of ribosomes to the membrane and subsequent membrane insertion of PR. Insertion of N-terminally truncated PR was restored by artificially attaching ribosomes to the membrane. Our findings offer a self-sufficient protein-inherent mechanism as a possible explanation for effective membrane protein biogenesis in a “pretranslocon” era, and they offer new opportunities for generating artificial cells. Generated a simple artificial cell model for membrane protein insertion We identified protein-inherent control of translational targeting without chaperones Ribosomes, artificially tethered to GUVs increased membrane protein insertion
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14
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Kruyer NS, Sugianto W, Tickman BI, Alba Burbano D, Noireaux V, Carothers JM, Peralta-Yahya P. Membrane Augmented Cell-Free Systems: A New Frontier in Biotechnology. ACS Synth Biol 2021; 10:670-681. [PMID: 33749249 DOI: 10.1021/acssynbio.0c00625] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Membrane proteins are present in a wide array of cellular processes from primary and secondary metabolite synthesis to electron transport and single carbon metabolism. A key barrier to applying membrane proteins industrially is their difficult functional production. Beyond expression, folding, and membrane insertion, membrane protein activity is influenced by the physicochemical properties of the associated membrane, making it difficult to achieve optimal membrane protein performance outside the endogenous host. In this review, we highlight recent work on production of membrane proteins in membrane augmented cell-free systems (CFSs) and applications thereof. CFSs lack membranes and can thus be augmented with user-specified, tunable, mimetic membranes to generate customized environments for production of functional membrane proteins of interest. Membrane augmented CFSs would enable the synthesis of more complex plant secondary metabolites, the growth and division of synthetic cells for drug delivery and cell therapeutic applications, as well as enable green energy applications including methane capture and artificial photosynthesis.
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Affiliation(s)
- Nicholas S. Kruyer
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Widianti Sugianto
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Benjamin I. Tickman
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington 98195, United States
| | - Diego Alba Burbano
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington 98195, United States
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - James M. Carothers
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington 98195, United States
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Pamela Peralta-Yahya
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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15
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Abstract
Giant unilamellar vesicles (GUVs) have gained great popularity as mimicries for cellular membranes. As their sizes are comfortably above the optical resolution limit, and their lipid composition is easily controlled, they are ideal for quantitative light microscopic investigation of dynamic processes in and on membranes. However, reconstitution of functional proteins into the lumen or the GUV membrane itself has proven technically challenging. In recent years, a selection of techniques has been introduced that tremendously improve GUV-assay development and enable the precise investigation of protein-membrane interactions under well-controlled conditions. Moreover, due to these methodological advances, GUVs are considered important candidates as protocells in bottom-up synthetic biology. In this review, we discuss the state of the art of the most important vesicle production and protein encapsulation methods and highlight some key protein systems whose functional reconstitution has advanced the field.
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Affiliation(s)
- Thomas Litschel
- Department of Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Martinsried 82152, Germany; ,
| | - Petra Schwille
- Department of Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Martinsried 82152, Germany; ,
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16
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17
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Prima GD, Librizzi F, Carrotta R. Light Scattering as an Easy Tool to Measure Vesicles Weight Concentration. MEMBRANES 2020; 10:E222. [PMID: 32899344 PMCID: PMC7558410 DOI: 10.3390/membranes10090222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/28/2020] [Accepted: 09/01/2020] [Indexed: 01/22/2023]
Abstract
Over the last few decades, liposomes have emerged as promising drug delivery systems and effective membrane models for studying biophysical and biological processes. For all applications, knowing their concentration after preparation is crucial. Thus, the development of methods for easily controlling vesicles concentration would be of great utility. A new assay is presented here, based on a suitable analysis of light scattering intensity from liposome dispersions. The method, tested for extrusion preparations, is precise, easy, fast, non-destructive and uses a tiny amount of sample. Furthermore, the scattering intensity can be measured indifferently at different angles, or even by using the elastic band obtained from a standard spectrofluorimeter. To validate the method, the measured concentrations of vesicles of different matrix compositions and sizes, measured by light scattering with different angles and instruments, were compared to the data obtained by the standard Stewart assay. Consistent results were obtained. The light scattering assay is based on the assessment of the mass fraction lost in the preparation, and can be applied for methods such as extrusion, homogenization, French press and other microfluidic procedures.
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Affiliation(s)
- Giulia Di Prima
- Institute of Biophysics, National Research Council, Via Ugo La Malfa 153, 90146 Palermo, Italy; (G.D.P.); (F.L.)
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), University of Palermo, Via Archirafi 32, 90123 Palermo, Italy
| | - Fabio Librizzi
- Institute of Biophysics, National Research Council, Via Ugo La Malfa 153, 90146 Palermo, Italy; (G.D.P.); (F.L.)
| | - Rita Carrotta
- Institute of Biophysics, National Research Council, Via Ugo La Malfa 153, 90146 Palermo, Italy; (G.D.P.); (F.L.)
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18
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Biner O, Fedor JG, Yin Z, Hirst J. Bottom-Up Construction of a Minimal System for Cellular Respiration and Energy Regeneration. ACS Synth Biol 2020; 9:1450-1459. [PMID: 32383867 PMCID: PMC7611821 DOI: 10.1021/acssynbio.0c00110] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Adenosine triphosphate (ATP), the cellular energy currency, is essential for life. The ability to provide a constant supply of ATP is therefore crucial for the construction of artificial cells in synthetic biology. Here, we describe the bottom-up assembly and characterization of a minimal respiratory system that uses NADH as a fuel to produce ATP from ADP and inorganic phosphate, and is thus capable of sustaining both upstream metabolic processes that rely on NAD+, and downstream energy-demanding processes that are powered by ATP hydrolysis. A detergent-mediated approach was used to co-reconstitute respiratory mitochondrial complex I and an F-type ATP synthase into nanosized liposomes. Addition of the alternative oxidase to the resulting proteoliposomes produced a minimal artificial "organelle" that reproduces the energy-converting catalytic reactions of the mitochondrial respiratory chain: NADH oxidation, ubiquinone cycling, oxygen reduction, proton pumping, and ATP synthesis. As a proof-of-principle, we demonstrate that our nanovesicles are capable of using an NAD+-linked substrate to drive cell-free protein expression. Our nanovesicles are both efficient and durable and may be applied to sustain artificial cells in future work.
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Affiliation(s)
- Olivier Biner
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
| | - Justin G Fedor
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
| | - Zhan Yin
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
| | - Judy Hirst
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
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19
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Transmembrane signaling on a protocell: Creation of receptor-enzyme chimeras for immunodetection of specific antibodies and antigens. Sci Rep 2019; 9:18189. [PMID: 31796769 PMCID: PMC6890649 DOI: 10.1038/s41598-019-54539-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 11/13/2019] [Indexed: 01/22/2023] Open
Abstract
It is known that digital counting of fluorescent signals generated in many small compartments can significantly improve the detection sensitivity of the enzyme-linked immunosorbent assay (ELISA). However, the reported digital ELISA systems need extensive washing steps to remove background signal, which hampers their performance. To tackle this problem, we developed a vesicle (Protocell) array wherein binding of an external protein analyte is coupled to signal amplification and intra-vesicular fluorescence readout. We chose β-glucuronidase (GUS) as a reporter enzyme as its function requires assembly of four subunits through dimerization of a pair of dimers that can be inhibited by a set of interface mutations. Using a thermostabilized GUS mutant IV-5, we screened out an interface mutant (M516K, F517W) to create IV5m - a mutant with high thermostability and activity conditional on induced dimerization. After tethering a short N-terminal tag and transmembrane (TM) sequences, the fusion protein was expressed by cell-free protein synthesis inside protocells. When a corresponding tag-specific antibody was applied outside of the protocells, a clear increase in GUS activity was observed inside vesicles by adding fluorescent substrate, probably due to spontaneous integration of the tagged TM protein into the vesicles and dimerization by the antibody bound to the displayed tag. Furthermore, using flow cytometry, quantitative digital read out was obtained by counting fluorescent protocells exposed to varying concentrations of external antibodies that included Trastuzumab. Additionally, through use of an anti-caffeine VHH-SpyCatcher fusion protein, caffeine could be detected using SpyTag-fused TM-IV5m protein expressed in protocells, suggesting utility of this platform for detection of diverse antigen types.
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20
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Santiago I, Simmel FC. Self-Propulsion Strategies for Artificial Cell-Like Compartments. NANOMATERIALS 2019; 9:nano9121680. [PMID: 31775256 PMCID: PMC6956199 DOI: 10.3390/nano9121680] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 11/13/2019] [Accepted: 11/17/2019] [Indexed: 12/14/2022]
Abstract
Reconstitution of life-like properties in artificial cells is a current research frontier in synthetic biology. Mimicking metabolism, growth, and sensing are active areas of investigation; however, achieving motility and directional taxis are also challenging in the context of artificial cells. To tackle this problem, recent progress has been made that leverages the tools of active matter physics in synthetic biology. This review surveys the most significant achievements in designing motile cell-like compartments. In this context, strategies for self-propulsion are summarized, including, compartmentalization of catalytically active particles, phoretic propulsion of vesicles and emulsion droplet motion driven by Marangoni flows. This work showcases how the realization of motile protocells may impact biomedical engineering while also aiming at answering fundamental questions in locomotion of prebiotic cells.
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21
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Katsuta S, Okano T, Koiwai K, Suzuki H. Ejection of Large Particulate Materials from Giant Unilamellar Vesicles Induced by Electropulsation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13196-13204. [PMID: 31498647 DOI: 10.1021/acs.langmuir.9b01617] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Electroporation or electropermealization is a technique to open pores in the lipid bilayer membrane of cells and vesicles transiently to increase its permeability to otherwise impermeable molecules. However, the upper size limit of the materials permeable through this operation has not been studied in the past. Here, we investigate the size of the material that can be released (ejected) from giant unilamellar vesicles (GUVs) upon electrical pulsation. We confirm that the volume of GUV shrinks in a stepwise manner upon periodical pulsation, in accordance with previous studies. When the same operation is applied to GUVs that encapsulate microbeads, we find that beads as large as 20 μm can be ejected across the membrane without rupturing the whole GUV structure. We also demonstrate that functional bioactive particulate materials, such as gel balls, vesicles, and cells can be encapsulated in and ejected from GUVs. We foresee that this phenomenon can be applied to precisely regulate the time and location of release of these particulate materials in the microenvironment.
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Affiliation(s)
- Shota Katsuta
- Dept. Precision Mechanics, Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , Tokyo 112-8551 , Japan
| | - Taiji Okano
- Dept. Precision Mechanics, Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , Tokyo 112-8551 , Japan
| | - Keiichiro Koiwai
- Dept. Precision Mechanics, Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , Tokyo 112-8551 , Japan
- Japan Society for the Promotion of Science (JSPS) , 5-3-1 Kojimachi , Chiyoda-ku , Tokyo 102-0083 , Japan
| | - Hiroaki Suzuki
- Dept. Precision Mechanics, Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , Tokyo 112-8551 , Japan
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22
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Hilburger CE, Jacobs ML, Lewis KR, Peruzzi JA, Kamat NP. Controlling Secretion in Artificial Cells with a Membrane AND Gate. ACS Synth Biol 2019; 8:1224-1230. [PMID: 31051071 DOI: 10.1021/acssynbio.8b00435] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The assembly of channel proteins into vesicle membranes is a useful strategy to control activities of vesicle-based systems. Here, we developed a membrane AND gate that responds to both a fatty acid and a pore-forming channel protein to induce the release of encapsulated cargo. We explored how membrane composition affects the functional assembly of α-hemolysin into phospholipid vesicles as a function of oleic acid content and α-hemolysin concentration. We then showed that we could induce α-hemolysin assembly when we added oleic acid micelles to a specific composition of phospholipid vesicles. Finally, we demonstrated that our membrane AND gate could be coupled to a gene expression system. Our study provides a new method to control the temporal dynamics of vesicle permeability by controlling when the functional assembly of a channel protein into synthetic vesicles occurs. Furthermore, a membrane AND gate that utilizes membrane-associating biomolecules introduces a new way to implement Boolean logic that should complement genetic logic circuits and ultimately enhance the capabilities of artificial cellular systems.
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23
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Stano P. Gene Expression Inside Liposomes: From Early Studies to Current Protocols. Chemistry 2019; 25:7798-7814. [DOI: 10.1002/chem.201806445] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Pasquale Stano
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA)University of Salento, Ecotekne 73100 Lecce Italy
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24
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Berhanu S, Ueda T, Kuruma Y. Artificial photosynthetic cell producing energy for protein synthesis. Nat Commun 2019; 10:1325. [PMID: 30902985 PMCID: PMC6430821 DOI: 10.1038/s41467-019-09147-4] [Citation(s) in RCA: 208] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 02/26/2019] [Indexed: 12/24/2022] Open
Abstract
Attempts to construct an artificial cell have widened our understanding of living organisms. Many intracellular systems have been reconstructed by assembling molecules, however the mechanism to synthesize its own constituents by self-sufficient energy has to the best of our knowledge not been developed. Here, we combine a cell-free protein synthesis system and small proteoliposomes, which consist of purified ATP synthase and bacteriorhodopsin, inside a giant unilamellar vesicle to synthesize protein by the production of ATP by light. The photo-synthesized ATP is consumed as a substrate for transcription and as an energy for translation, eventually driving the synthesis of bacteriorhodopsin or constituent proteins of ATP synthase, the original essential components of the proteoliposome. The de novo photosynthesized bacteriorhodopsin and the parts of ATP synthase integrate into the artificial photosynthetic organelle and enhance its ATP photosynthetic activity through the positive feedback of the products. Our artificial photosynthetic cell system paves the way to construct an energetically independent artificial cell.
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Affiliation(s)
- Samuel Berhanu
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan
| | - Takuya Ueda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan.
| | - Yutetsu Kuruma
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1, Ookayama, Meguro-ku, Tokyo, 152-8550, Japan. .,JST, PRESTO, Saitama, 332-0012, Japan.
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25
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Rampioni G, D'Angelo F, Leoni L, Stano P. Gene-Expressing Liposomes as Synthetic Cells for Molecular Communication Studies. Front Bioeng Biotechnol 2019; 7:1. [PMID: 30705882 PMCID: PMC6344414 DOI: 10.3389/fbioe.2019.00001] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 01/02/2019] [Indexed: 11/13/2022] Open
Abstract
The bottom-up branch of synthetic biology includes-among others-innovative studies that combine cell-free protein synthesis with liposome technology to generate cell-like systems of minimal complexity, often referred to as synthetic cells. The functions of this type of synthetic cell derive from gene expression, hence they can be programmed in a modular, progressive and customizable manner by means of ad hoc designed genetic circuits. This experimental scenario is rapidly expanding and synthetic cell research already counts numerous successes. Here, we present a review focused on the exchange of chemical signals between liposome-based synthetic cells (operating by gene expression) and biological cells, as well as between two populations of synthetic cells. The review includes a short presentation of the "molecular communication technologies," briefly discussing their promises and challenges.
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Affiliation(s)
| | | | - Livia Leoni
- Department of Science, University Roma Tre, Rome, Italy
| | - Pasquale Stano
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Lecce, Italy
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26
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Stano P. Is Research on "Synthetic Cells" Moving to the Next Level? Life (Basel) 2018; 9:E3. [PMID: 30587790 PMCID: PMC6463193 DOI: 10.3390/life9010003] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 12/15/2022] Open
Abstract
"Synthetic cells" research focuses on the construction of cell-like models by using solute-filled artificial microcompartments with a biomimetic structure. In recent years this bottom-up synthetic biology area has considerably progressed, and the field is currently experiencing a rapid expansion. Here we summarize some technical and theoretical aspects of synthetic cells based on gene expression and other enzymatic reactions inside liposomes, and comment on the most recent trends. Such a tour will be an occasion for asking whether times are ripe for a sort of qualitative jump toward novel SC prototypes: is research on "synthetic cells" moving to a next level?
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Affiliation(s)
- Pasquale Stano
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento; Ecotekne-S.P. Lecce-Monteroni, I-73100 Lecce, Italy.
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27
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Ziblat R, Weaver JC, Arriaga LR, Chong S, Weitz DA. Determining the lipid specificity of insoluble protein transmembrane domains. LAB ON A CHIP 2018; 18:3561-3569. [PMID: 30406786 DOI: 10.1039/c8lc00311d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
While the specificity of protein-lipid interactions is a key feature in the function of biological membranes, studying the specifics of these interactions is challenging because most membrane proteins are insoluble in water due to the hydrophobic nature of their transmembrane domains (TMDs). Here, we introduce a method that overcomes this solubility limitation and identifies the affinity profile of protein TMDs to specific lipid formulations. Using 5 human TMDs as a sample group, our results demonstrate that TMDs are highly selective and that these specific lipid-TMD interactions can involve either a single lipid, or the combination of multiple lipid species.
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Affiliation(s)
- R Ziblat
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
| | - J C Weaver
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA
| | - L R Arriaga
- Department of Physical Chemistry, Universidad Complutense, Madrid, 28040, Spain
| | - S Chong
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - D A Weitz
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA. and Department of Physics, Harvard University, Cambridge, MA02138, USA
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28
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In vitro synthesis of the human calcium transporter Letm1 within cell-sized liposomes and investigation of its lipid dependency. J Biosci Bioeng 2018; 127:544-548. [PMID: 30503650 DOI: 10.1016/j.jbiosc.2018.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/21/2018] [Accepted: 11/01/2018] [Indexed: 01/18/2023]
Abstract
The human mitochondrion-derived calcium transporter Letm1 was synthesized by reconstituted in vitro transcription-translation (IVTT) in cell-sized liposomes and the dependency of Letm1 on phospholipid composition was investigated. Components for IVTT were encapsulated into cell-sized vesicles together with the DNA encoding Letm1, thereby preparing proteoliposomes. The synthesis of Letm1 and pH-dependent calcium transport activity were confirmed by flow cytometry. Finally, we investigated the effect of phospholipid composition on Letm1 transport activity and found that cardiolipin present in the mitochondrial membrane plays an important role on the transport activity of Letm1.
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29
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Tsuji G, Sunami T, Ichihashi N. Production of giant unilamellar vesicles by the water-in-oil emulsion-transfer method without high internal concentrations of sugars. J Biosci Bioeng 2018; 126:540-545. [DOI: 10.1016/j.jbiosc.2018.04.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 10/16/2022]
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30
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Altamura E, Carrara P, D'Angelo F, Mavelli F, Stano P. Extrinsic stochastic factors (solute partition) in gene expression inside lipid vesicles and lipid-stabilized water-in-oil droplets: a review. Synth Biol (Oxf) 2018; 3:ysy011. [PMID: 32995519 PMCID: PMC7445889 DOI: 10.1093/synbio/ysy011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 06/18/2018] [Accepted: 06/21/2018] [Indexed: 11/13/2022] Open
Abstract
The encapsulation of transcription-translation (TX-TL) machinery inside lipid vesicles and water-in-oil droplets leads to the construction of cytomimetic systems (often called 'synthetic cells') for synthetic biology and origins-of-life research. A number of recent reports have shown that protein synthesis inside these microcompartments is highly diverse in terms of rate and amount of synthesized protein. Here, we discuss the role of extrinsic stochastic effects (i.e. solute partition phenomena) as relevant factors contributing to this pattern. We evidence and discuss cases where between-compartment diversity seems to exceed the expected theoretical values. The need of accurate determination of solute content inside individual vesicles or droplets is emphasized, aiming at validating or rejecting the predictions calculated from the standard fluctuations theory. At the same time, we promote the integration of experiments and stochastic modeling to reveal the details of solute encapsulation and intra-compartment reactions.
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Affiliation(s)
- Emiliano Altamura
- Chemistry Department, University of Bari, Via E. Orabona 4, I-70126, Bari, Italy
| | - Paolo Carrara
- Department of Sciences, Roma Tre University, Viale G. Marconi 446, I-00146, Rome, Italy
| | - Francesca D'Angelo
- Department of Sciences, Roma Tre University, Viale G. Marconi 446, I-00146, Rome, Italy
| | - Fabio Mavelli
- Chemistry Department, University of Bari, Via E. Orabona 4, I-70126, Bari, Italy
| | - Pasquale Stano
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Ecotekne, I-73100, Lecce, Italy
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31
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Uyeda A, Watanabe T, Hohsaka T, Matsuura T. Different protein localizations on the inner and outer leaflet of cell-sized liposomes using cell-free protein synthesis. Synth Biol (Oxf) 2018; 3:ysy007. [PMID: 32995515 PMCID: PMC7445883 DOI: 10.1093/synbio/ysy007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/07/2018] [Accepted: 05/09/2018] [Indexed: 12/02/2022] Open
Abstract
Membranes of living cells possess asymmetry. The inner and outer leaflets of the membrane consist of different phospholipid compositions, which are known to affect the function of membrane proteins, and the loss of the asymmetry has been reported to lead to cell apoptosis. In addition, different proteins are found on the inner and outer leaflets of the membrane, and they are essential for various biochemical reactions, including those related to signal transduction and cell morphology. While in vitro lipid bilayer reconstitution with asymmetric phospholipid compositions has been reported, the reconstitution of lipid bilayer where different proteins are localized in the inner and outer leaflet, thereby enables asymmetric protein localizations, has remained difficult. Herein, we developed a simple method to achieve this asymmetry using an in vitro transcription–translation system (IVTT). The method used a benzylguanine (BG) derivative-modified phospholipid, which forms a covalent bond with a snap-tag sequence. We show that purified snap-tagged protein can be localized to the cell-sized liposome surface via an interaction between BG and the snap-tag. We then show that IVTT-synthesized proteins can be located at the lipid membrane and that different proteins can be asymmetrically localized on the outer and inner leaflets of liposomes.
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Affiliation(s)
- Atsuko Uyeda
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takayoshi Watanabe
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Takahiro Hohsaka
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Tomoaki Matsuura
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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32
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Furusato T, Horie F, Matsubayashi HT, Amikura K, Kuruma Y, Ueda T. De Novo Synthesis of Basal Bacterial Cell Division Proteins FtsZ, FtsA, and ZipA Inside Giant Vesicles. ACS Synth Biol 2018; 7:953-961. [PMID: 29510621 DOI: 10.1021/acssynbio.7b00350] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cell division is the most dynamic event in the cell cycle. Recently, efforts have been made to reconstruct it using the individual component proteins to obtain a better understanding of the process of self-reproduction of cells. However, such reconstruction studies are frequently hampered by difficulties in preparing membrane-associated proteins. Here we demonstrate a de novo synthesis approach based on a cell-free translation system. Genes for fundamental cell division proteins, FtsZ, FtsA, and ZipA, were expressed inside the lipid compartment of giant vesicles (GVs). The synthesized proteins showed polymerization, membrane localization, and eventually membrane deformation. Notably, we found that this morphological change of the vesicle is forced by only FtsZ and ZipA, which form clusters on the membrane at the vesicle interior. Our cell-free approach provides a platform for studying protein dynamics associated with lipid membrane and paves the way to create a synthetic cell that undergoes self-reproduction.
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Affiliation(s)
- Takumi Furusato
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Fumihiro Horie
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Hideaki T. Matsubayashi
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Kazuaki Amikura
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Yutetsu Kuruma
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1, Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Takuya Ueda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
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Iwamoto M, Elfaramawy MA, Yamatake M, Matsuura T, Oiki S. Concurrent In Vitro Synthesis and Functional Detection of Nascent Activity of the KcsA Channel under a Membrane Potential. ACS Synth Biol 2018; 7:1004-1011. [PMID: 29566487 DOI: 10.1021/acssynbio.7b00454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Processes involved in the functional formation of prokaryotic membrane proteins have remained elusive. Here, we developed a new in vitro membrane protein expression system to detect nascent activities of the KcsA potassium channel in lipid bilayers under an applied membrane potential. The channel was synthesized using a reconstituted Escherichia coli-based in vitro transcription/translation system (IVTT) in a water-in-oil droplet lined by a membrane. The synthesized channels spontaneously incorporated into the membrane even without the translocon machinery (unassisted pathway) and formed functional channels with the correct orientation. The single-channel current of the first appearing nascent channel was captured, followed by the subsequent appearance of multiple channels. Notably, the first appearance time shortened substantially as the membrane potential was hyperpolarized. Under a steadily applied membrane potential, this system serves as a production line of membrane proteins via the unassisted pathway, mimicking the bacterial synthetic membrane.
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Affiliation(s)
- Masayuki Iwamoto
- Department of Molecular Physiology and Biophysics, University of Fukui, Eiheiji-cho, Fukui 910-1193, Japan
| | - Maie A. Elfaramawy
- Department of Biotechnology, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Mariko Yamatake
- Department of Molecular Physiology and Biophysics, University of Fukui, Eiheiji-cho, Fukui 910-1193, Japan
| | - Tomoaki Matsuura
- Department of Biotechnology, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shigetoshi Oiki
- Department of Molecular Physiology and Biophysics, University of Fukui, Eiheiji-cho, Fukui 910-1193, Japan
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34
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Machida K, Kanzawa K, Shigeta T, Yamamoto Y, Tsumoto K, Imataka H. Huntingtin Polyglutamine-Dependent Protein Aggregation in Reconstituted Cells. ACS Synth Biol 2018; 7:377-383. [PMID: 29232946 DOI: 10.1021/acssynbio.7b00372] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One of the aims of synthetic biology is bottom-up construction of reconstituted human cells for medical uses. To that end, we generated giant unilamellar vesicles (GUVs) that contained a HeLa cell extract, which comprises a cell-free protein synthesis (CFPS) system. Then we expressed Huntingtin protein fragments that contained polyglutamine (polyQ) sequences (Htt-polyQ), a hallmark of Huntington's disease. That system produced polyQ-dependent protein aggregates, as previously demonstrated in living cells. We next simplified the system by generating GUVs that contained purified human factors, which reconstituted a CFPS system. Htt-polyQ fragments expressed in these GUVs also formed protein aggregates. Moreover, an N-terminal deletion mutant, which had failed to form protein aggregates in living cells, also failed to form protein aggregates in the reconstituted GUVs. Thus, the GUV systems that encapsulated a human CFPS system could serve as reconstituted cells for studying neurological diseases.
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Affiliation(s)
- Kodai Machida
- Department
of Applied Chemistry, Graduate School of Engineering, University of Hyogo, Himeji 671-2201, Japan
- RIKEN Center for Life Science Technologies, Yokohama 230-0045, Japan
| | - Kuru Kanzawa
- Department
of Applied Chemistry, Graduate School of Engineering, University of Hyogo, Himeji 671-2201, Japan
| | - Tomoaki Shigeta
- Department
of Applied Chemistry, Graduate School of Engineering, University of Hyogo, Himeji 671-2201, Japan
| | - Yuki Yamamoto
- Department
of Applied Chemistry, Graduate School of Engineering, University of Hyogo, Himeji 671-2201, Japan
| | - Kanta Tsumoto
- Division
of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu 514-8507, Japan
| | - Hiroaki Imataka
- Department
of Applied Chemistry, Graduate School of Engineering, University of Hyogo, Himeji 671-2201, Japan
- RIKEN Center for Life Science Technologies, Yokohama 230-0045, Japan
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35
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Okano T, Inoue K, Koseki K, Suzuki H. Deformation Modes of Giant Unilamellar Vesicles Encapsulating Biopolymers. ACS Synth Biol 2018; 7:739-747. [PMID: 29382193 DOI: 10.1021/acssynbio.7b00460] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The shapes of giant unilamellar vesicles (GUVs) enclosing polymer molecules at relatively high concentration, used as a model cytoplasm, significantly differ from those containing only small molecules. Here, we investigated the effects of the molecular weights and concentrations of polymers such as polyethylene glycol (PEG), bovine serum albumin (BSA), and DNA on the morphology of GUVs deflated by osmotic pressure. Although small PEG (MW < 1000) does not alter the mode of shape transformation even at >10% (w/w), PEG with MW > 6000 induces budding and pearling transformation at above 1% (w/w). Larger PEG frequently induced small buddings and tubulation from the membrane of mother GUVs. A similar trend was observed with BSA, indicating that the effect is irrelevant to the chemical nature of polymers. More surprisingly, long strands of DNA (>105 bp) enclosed in GUVs induced budding transformation at concentrations as low as 0.01-0.1% (w/w). We expect that this molecular size dependency arises mainly from the depletion volume effect. Our results showed that curving, budding, and tubulation of lipid membranes, which are ubiquitous in living cells, can result from simple cell-mimics consisting of the membrane and cytosolic macromolecules, but without specific shape-determining proteins.
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Affiliation(s)
- Taiji Okano
- Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Koya Inoue
- Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Kaoru Koseki
- Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Hiroaki Suzuki
- Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
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36
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Perrier DL, Rems L, Boukany PE. Lipid vesicles in pulsed electric fields: Fundamental principles of the membrane response and its biomedical applications. Adv Colloid Interface Sci 2017; 249:248-271. [PMID: 28499600 DOI: 10.1016/j.cis.2017.04.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/24/2017] [Accepted: 04/25/2017] [Indexed: 01/04/2023]
Abstract
The present review focuses on the effects of pulsed electric fields on lipid vesicles ranging from giant unilamellar vesicles (GUVs) to small unilamellar vesicles (SUVs), from both fundamental and applicative perspectives. Lipid vesicles are the most popular model membrane systems for studying biophysical and biological processes in living cells. Furthermore, as vesicles are made from biocompatible and biodegradable materials, they provide a strategy to create safe and functionalized drug delivery systems in health-care applications. Exposure of lipid vesicles to pulsed electric fields is a common physical method to transiently increase the permeability of the lipid membrane. This method, termed electroporation, has shown many advantages for delivering exogenous molecules including drugs and genetic material into vesicles and living cells. In addition, electroporation can be applied to induce fusion between vesicles and/or cells. First, we discuss in detail how research on cell-size GUVs as model cell systems has provided novel insight into the basic mechanisms of cell electroporation and associated phenomena. Afterwards, we continue with a thorough overview how electroporation and electrofusion have been used as versatile methods to manipulate vesicles of all sizes in different biomedical applications. We conclude by summarizing the open questions in the field of electroporation and possible future directions for vesicles in the biomedical field.
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37
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de Jong H, Geiselmann J, Ropers D. Resource Reallocation in Bacteria by Reengineering the Gene Expression Machinery. Trends Microbiol 2017; 25:480-493. [DOI: 10.1016/j.tim.2016.12.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/03/2016] [Accepted: 12/15/2016] [Indexed: 11/27/2022]
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38
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Uyeda A, Nakayama S, Kato Y, Watanabe H, Matsuura T. Construction of an in Vitro Gene Screening System of the E. coli EmrE Transporter Using Liposome Display. Anal Chem 2016; 88:12028-12035. [DOI: 10.1021/acs.analchem.6b02308] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Atsuko Uyeda
- Department of Biotechnology,
Graduate School of Engineering, Osaka University, 2-1 Yamadaoka,
Suita, Osaka 565-0871, Japan
| | - Shintaro Nakayama
- Department of Biotechnology,
Graduate School of Engineering, Osaka University, 2-1 Yamadaoka,
Suita, Osaka 565-0871, Japan
| | - Yasuhiko Kato
- Department of Biotechnology,
Graduate School of Engineering, Osaka University, 2-1 Yamadaoka,
Suita, Osaka 565-0871, Japan
| | - Hajime Watanabe
- Department of Biotechnology,
Graduate School of Engineering, Osaka University, 2-1 Yamadaoka,
Suita, Osaka 565-0871, Japan
| | - Tomoaki Matsuura
- Department of Biotechnology,
Graduate School of Engineering, Osaka University, 2-1 Yamadaoka,
Suita, Osaka 565-0871, Japan
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39
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Ohta N, Kato Y, Watanabe H, Mori H, Matsuura T. In vitro membrane protein synthesis inside Sec translocon-reconstituted cell-sized liposomes. Sci Rep 2016; 6:36466. [PMID: 27808179 PMCID: PMC5093552 DOI: 10.1038/srep36466] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 10/17/2016] [Indexed: 12/24/2022] Open
Abstract
Protein synthesis using an in vitro transcription-translation system (IVTT) inside cell-sized liposomes has become a valuable tool to study the properties of biological systems under cell-mimicking conditions. However, previous liposome systems lacked the machinery for membrane protein translocation. Here, we reconstituted the translocon consisting of SecYEG from Escherichia coli inside cell-sized liposomes. The cell-sized liposomes also carry the reconstituted IVTT, thereby providing a cell-mimicking environment for membrane protein synthesis. By using EmrE, a multidrug transporter from E. coli, as a model membrane protein, we found that both the amount and activity of EmrE synthesized inside the liposome is increased approximately three-fold by incorporating the Sec translocon. The topological change of EmrE induced by the translocon was also identified. The membrane integration of 6 out of 9 E. coli inner membrane proteins that was tested was increased by incorporation of the translocon. By introducing the Sec translocon, the membrane integration efficiency of the membrane protein of interest was increased, and enabled the integration of membrane proteins that otherwise cannot be inserted. In addition, this work represents an essential step toward the construction of an artificial cell through a bottom-up approach.
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Affiliation(s)
- Naoki Ohta
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, Japan
| | - Yasuhiko Kato
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, Japan
| | - Hajime Watanabe
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, Japan
| | - Hirotada Mori
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-tyou, Ikoma, Nara, Japan
| | - Tomoaki Matsuura
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, Japan
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40
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Lentini R, Yeh Martín N, Mansy SS. Communicating artificial cells. Curr Opin Chem Biol 2016; 34:53-61. [DOI: 10.1016/j.cbpa.2016.06.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/10/2016] [Accepted: 06/10/2016] [Indexed: 10/21/2022]
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41
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Sunami T, Ichihashi N, Nishikawa T, Kazuta Y, Yomo T. Effect of Liposome Size on Internal RNA Replication Coupled with Replicase Translation. Chembiochem 2016; 17:1282-9. [DOI: 10.1002/cbic.201500662] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Takeshi Sunami
- Institute for Academic Initiatives; Osaka University; 1-5 Yamadaoka Suita Osaka 565-0871 Japan
- Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency (JST); 1-5 Yamadaoka Suita Osaka 565-0871 Japan
| | - Norikazu Ichihashi
- Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency (JST); 1-5 Yamadaoka Suita Osaka 565-0871 Japan
- Department of Bioinformatics Engineering; Graduate School of Information Science and Technology; Osaka University; 1-5 Yamadaoka Suita Osaka 565-0871 Japan
| | - Takehiro Nishikawa
- Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency (JST); 1-5 Yamadaoka Suita Osaka 565-0871 Japan
| | - Yasuaki Kazuta
- Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency (JST); 1-5 Yamadaoka Suita Osaka 565-0871 Japan
| | - Tetsuya Yomo
- Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency (JST); 1-5 Yamadaoka Suita Osaka 565-0871 Japan
- Department of Bioinformatics Engineering; Graduate School of Information Science and Technology; Osaka University; 1-5 Yamadaoka Suita Osaka 565-0871 Japan
- Graduate School of Frontier Biosciences; Osaka University; 1-5 Yamadaoka Suita Osaka 565-0871 Japan
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42
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43
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High-Throughput Screening in Protein Engineering: Recent Advances and Future Perspectives. Int J Mol Sci 2015; 16:24918-45. [PMID: 26492240 PMCID: PMC4632782 DOI: 10.3390/ijms161024918] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/13/2015] [Accepted: 10/13/2015] [Indexed: 11/17/2022] Open
Abstract
Over the last three decades, protein engineering has established itself as an important tool for the development of enzymes and (therapeutic) proteins with improved characteristics. New mutagenesis techniques and computational design tools have greatly aided in the advancement of protein engineering. Yet, one of the pivotal components to further advance protein engineering strategies is the high-throughput screening of variants. Compartmentalization is one of the key features allowing miniaturization and acceleration of screening. This review focuses on novel screening technologies applied in protein engineering, highlighting flow cytometry- and microfluidics-based platforms.
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44
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Kapsner K, Simmel FC. Partitioning Variability of a Compartmentalized In Vitro Transcriptional Thresholding Circuit. ACS Synth Biol 2015; 4:1136-43. [PMID: 25974035 DOI: 10.1021/acssynbio.5b00051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Encapsulation of in vitro biochemical reaction circuits into small, cell-sized compartments can result in considerable variations in the dynamical properties of the circuits. As a model system, we here investigate a simple in vitro transcriptional reaction circuit, which generates an ultrasensitive fluorescence response when the concentration of an RNA transcript reaches a preset threshold. The reaction circuit is compartmentalized into spherical water-in-oil microemulsion droplets, and the reaction progress is monitored by fluorescence microscopy. A quantitative statistical analysis of thousands of individual droplets ranging in size from a few up to 20 μm reveals a strong variability in effective RNA production rates, which by computational modeling is traced back to a larger-than-Poisson variability in RNAP activities in the droplets. The noise level in terms of the noise strength (the Fano factor) is strongly dependent on the ratio between transcription templates and polymerases, and increases for higher template concentrations.
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Affiliation(s)
| | - Friedrich C. Simmel
- Physics
Department, TU München, 85748 Garching, Germany
- Nanosystems Initiative Munich, Schellingstrasse
4, 80539 München, Germany
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45
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Mayne R, Adamatzky A. On the Computing Potential of Intracellular Vesicles. PLoS One 2015; 10:e0139617. [PMID: 26431435 PMCID: PMC4592144 DOI: 10.1371/journal.pone.0139617] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 09/14/2015] [Indexed: 02/02/2023] Open
Abstract
Collision-based computing (CBC) is a form of unconventional computing in which travelling localisations represent data and conditional routing of signals determines the output state; collisions between localisations represent logical operations. We investigated patterns of Ca2+-containing vesicle distribution within a live organism, slime mould Physarum polycephalum, with confocal microscopy and observed them colliding regularly. Vesicles travel down cytoskeletal ‘circuitry’ and their collisions may result in reflection, fusion or annihilation. We demonstrate through experimental observations that naturally-occurring vesicle dynamics may be characterised as a computationally-universal set of Boolean logical operations and present a ‘vesicle modification’ of the archetypal CBC ‘billiard ball model’ of computation. We proceed to discuss the viability of intracellular vesicles as an unconventional computing substrate in which we delineate practical considerations for reliable vesicle ‘programming’ in both in vivo and in vitro vesicle computing architectures and present optimised designs for both single logical gates and combinatorial logic circuits based on cytoskeletal network conformations. The results presented here demonstrate the first characterisation of intracelluar phenomena as collision-based computing and hence the viability of biological substrates for computing.
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Affiliation(s)
- Richard Mayne
- Unconventional Computing Group, Faculty of the Environment and Technology, University of the West of England, Bristol, United Kingdom
- * E-mail:
| | - Andrew Adamatzky
- Unconventional Computing Group, Faculty of the Environment and Technology, University of the West of England, Bristol, United Kingdom
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46
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Brea RJ, Hardy MD, Devaraj NK. Towards self-assembled hybrid artificial cells: novel bottom-up approaches to functional synthetic membranes. Chemistry 2015; 21:12564-70. [PMID: 26149747 PMCID: PMC4617832 DOI: 10.1002/chem.201501229] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Indexed: 01/09/2023]
Abstract
There has been increasing interest in utilizing bottom-up approaches to develop synthetic cells. A popular methodology is the integration of functionalized synthetic membranes with biological systems, producing "hybrid" artificial cells. This Concept article covers recent advances and the current state-of-the-art of such hybrid systems. Specifically, we describe minimal supramolecular constructs that faithfully mimic the structure and/or function of living cells, often by controlling the assembly of highly ordered membrane architectures with defined functionality. These studies give us a deeper understanding of the nature of living systems, bring new insights into the origin of cellular life, and provide novel synthetic chassis for advancing synthetic biology.
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Affiliation(s)
- Roberto J Brea
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Building: Urey Hall 4120, La Jolla, CA 92093 (USA), Fax: (+1) 858-534-9503 Homepage: http://devarajgroup.ucsd.edu
| | - Michael D Hardy
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Building: Urey Hall 4120, La Jolla, CA 92093 (USA), Fax: (+1) 858-534-9503 Homepage: http://devarajgroup.ucsd.edu
| | - Neal K Devaraj
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Building: Urey Hall 4120, La Jolla, CA 92093 (USA), Fax: (+1) 858-534-9503 Homepage: http://devarajgroup.ucsd.edu.
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47
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48
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Awai T, Ichihashi N, Yomo T. Activities of 20 aminoacyl-tRNA synthetases expressed in a reconstituted translation system in Escherichia coli. Biochem Biophys Rep 2015; 3:140-143. [PMID: 29124177 PMCID: PMC5668874 DOI: 10.1016/j.bbrep.2015.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 08/06/2015] [Accepted: 08/06/2015] [Indexed: 01/18/2023] Open
Abstract
A significant challenge in the field of in vitro synthetic biology is the construction of a self-reproducing cell-free translation system, which reproduces its components, such as translation proteins, through translation and transcription by itself. As a first step for such construction, in this study we expressed and evaluated the activity of 20 aminoacyl-tRNA synthetases (aaRSs), a major component of a translation system, in a reconstituted translation system (PURE system). We found that 19 aaRS with the exception of phenylalanyl-tRNA synthetase (PheRS) are expressed as soluble proteins and their activities are comparable to those expressed in Escherichia coli . This study provides basic information on the properties of aaRSs expressed in the PURE system, which will be helpful for the future reconstitution of a self-reproducing translation system. We expressed 20 aminoacyl-tRNA synthetases in a reconstituted translation system. All aminoacyl-tRNA synthetases (aaRSs) are expressed as soluble proteins. All aaRSs with the exception of phenylalanyl-tRNA synthetase are active. Their activities are comparable to those expressed in E. coli.
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Affiliation(s)
- Takako Awai
- Exploratory Research for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.,Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, Japan
| | - Norikazu Ichihashi
- Exploratory Research for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.,Department of Bioinformatics Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tetsuya Yomo
- Exploratory Research for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.,Department of Bioinformatics Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.,Graduate School of Frontier Biosciences, Osaka University University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
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49
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Fujii S, Matsuura T, Yomo T. Membrane Curvature Affects the Formation of α-Hemolysin Nanopores. ACS Chem Biol 2015; 10:1694-701. [PMID: 25860290 DOI: 10.1021/acschembio.5b00107] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Membrane proteins perform their functions within or on the lipid membrane, and lipid compositions are known to affect membrane protein integration and activity. Recently, the geometric aspect of membrane curvature was shown to play an important role in membrane protein behavior. Certain membrane proteins are known to sense the curvature of the membrane and to preferentially bind to highly curved membranes. However, although numerous membrane proteins assemble to form homo- or heterocomplexes and perform their biological functions, the dependence of membrane protein assembly on membrane curvature remains elusive. In this study, we analyzed the effect of the membrane curvature on the nanopore formation of α-hemolysin (AH), which is a toxic membrane protein derived from Staphylococcus aureus. The AH protein binds to the membrane as a monomer, assembles to form a heptamer, and forms a nanopore. By simultaneously measuring the molecules bound to the membrane and the activities of the nanopore on the membrane, we determined the nanopore formation ratio of AH. We used various sizes of liposomes and analyzed the dependence on the membrane curvature by using flow cytometry. Combining the results for positive and negative curvature, we found that the nanopore formation ratio of AH was curvature sensitive and was higher in a flat membrane than in a curved membrane. Furthermore, the nanopore formation ratio was almost identical or relatively higher in membranes with negative curvature than those with positive curvature.
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Affiliation(s)
- Satoshi Fujii
- Japan Science and Technology (JST), ERATO, Yomo
Dynamical Micro-scale Reaction Environment Project, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tomoaki Matsuura
- Japan Science and Technology (JST), ERATO, Yomo
Dynamical Micro-scale Reaction Environment Project, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
- Graduate
School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tetsuya Yomo
- Japan Science and Technology (JST), ERATO, Yomo
Dynamical Micro-scale Reaction Environment Project, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
- Graduate
School of Information Science and Technology, Osaka University, 1-5
Yamadaoka, Suita, Osaka 565-0871, Japan
- Graduate
School of Frontier Biosciences, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
- Earth-Life
Science Institute, Tokyo Institute of Technology, Meguro, Tokyo, 152-8550, Japan
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50
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Tsuda S, Sakakura T, Fujii S, Suzuki H, Yomo T. Shape Transformations of Lipid Vesicles by Insertion of Bulky-Head Lipids. PLoS One 2015; 10:e0132963. [PMID: 26176953 PMCID: PMC4503622 DOI: 10.1371/journal.pone.0132963] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 06/20/2015] [Indexed: 11/26/2022] Open
Abstract
Lipid vesicles, in particular Giant Unilamellar Vesicles (GUVs), have been increasingly important as compartments of artificial cells to reconstruct living cell-like systems in a bottom-up fashion. Here, we report shape transformations of lipid vesicles induced by polyethylene glycol-lipid conjugate (PEG lipids). Statistical analysis of deformed vesicle shapes revealed that shapes vesicles tend to deform into depended on the concentration of the PEG lipids. When compared with theoretically simulated vesicle shapes, those shapes were found to be more energetically favorable, with lower membrane bending energies than other shapes. This result suggests that the vesicle shape transformations can be controlled by externally added membrane molecules, which can serve as a potential method to control the replications of artificial cells.
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Affiliation(s)
- Soichiro Tsuda
- Yomo Dynamical Micro-scale Reaction Environment Project, ERATO, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Tatsuya Sakakura
- Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Satoshi Fujii
- Yomo Dynamical Micro-scale Reaction Environment Project, ERATO, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hiroaki Suzuki
- Yomo Dynamical Micro-scale Reaction Environment Project, ERATO, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Tetsuya Yomo
- Yomo Dynamical Micro-scale Reaction Environment Project, ERATO, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Graduate School of Frontier Biosciences, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
- * E-mail:
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