1
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Huo S, Lyu Z, Wang X, Liu S, Chen X, Yang M, Liu Z, Yin X. Engineering mesoporous polydopamine-based potentiate STING pathway activation for advanced anti-biofilm therapy. Biomaterials 2024; 312:122739. [PMID: 39096840 DOI: 10.1016/j.biomaterials.2024.122739] [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: 03/13/2024] [Revised: 07/07/2024] [Accepted: 07/30/2024] [Indexed: 08/05/2024]
Abstract
The biofilm-induced "relatively immune-compromised zone" creates an immunosuppressive microenvironment that is a significant contributor to refractory infections in orthopedic endophytes. Consequently, the manipulation of immune cells to co-inhibit or co-activate signaling represents a crucial strategy for the management of biofilm. This study reports the incorporation of Mn2+ into mesoporous dopamine nanoparticles (Mnp) containing the stimulator of interferon genes (STING) pathway activator cGAMP (Mncp), and outer wrapping by M1-like macrophage cell membrane (m-Mncp). The cell membrane enhances the material's targeting ability for biofilm, allowing it to accumulate locally at the infectious focus. Furthermore, m-Mncp mechanically disrupts the biofilm through photothermal therapy and induces antigen exposure through photodynamic therapy-generated reactive oxygen species (ROS). Importantly, the modulation of immunosuppression and immune activation results in the augmentation of antigen-presenting cells (APCs) and the commencement of antigen presentation, thereby inducing biofilm-specific humoral immunity and memory responses. Additionally, this approach effectively suppresses the activation of myeloid-derived suppressor cells (MDSCs) while simultaneously boosting the activity of T cells. Our study showcases the efficacy of utilizing m-Mncp immunotherapy in conjunction with photothermal and photodynamic therapy to effectively mitigate residual and recurrent infections following the extraction of infected implants. As such, this research presents a viable alternative to traditional antibiotic treatments for biofilm that are challenging to manage.
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Affiliation(s)
- Shicheng Huo
- Department of Orthopedic Surgery, Spine Center, Changzheng Hospital, Navy Medical University, Shanghai, China
| | - Zhuocheng Lyu
- Department of Bone and Joint Surgery, Department of Orthopedics, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Xiaoyuan Wang
- Physical Examination Center, Xi'an International Medical Center Hospital, Xi'an, China
| | - Shichang Liu
- Department of Spine Surgery, Hong Hui Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Xuxu Chen
- Department of Sports Medicine, Hong Hui Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Ming Yang
- Department of Spine Surgery, Hong Hui Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Zhongkai Liu
- Department of Spine Surgery, Hong Hui Hospital, Xi'an Jiaotong University, Xi'an, China.
| | - Xinhua Yin
- Department of Spine Surgery, Hong Hui Hospital, Xi'an Jiaotong University, Xi'an, China.
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2
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Spencer RKW, Smirnova YG, Soleimani A, Müller M. Transient pores in hemifusion diaphragms. Biophys J 2024:S0006-3495(24)00392-8. [PMID: 38867448 DOI: 10.1016/j.bpj.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 05/07/2024] [Accepted: 06/07/2024] [Indexed: 06/14/2024] Open
Abstract
Exchange of material across two membranes, as in the case of synaptic neurotransmitter release from a vesicle, involves the formation and poration of a hemifusion diaphragm (HD). The nontrivial geometry of the HD leads to environment-dependent control, regarding the stability and dynamics of the pores required for this kind of exocytosis. This work combines particle simulations, field-based calculations, and phenomenological modeling to explore the factors influencing the stability, dynamics, and possible control mechanisms of pores in HDs. We find that pores preferentially form at the HD rim, and that their stability is sensitive to a number of factors, including the three line tensions, membrane tension, HD size, and the ability of lipids to "flip-flop" across leaflets. Along with a detailed analysis of these factors, we discuss ways that vesicles or cells may use them to open and close pores and thereby quickly and efficiently transport material.
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Affiliation(s)
- Russell K W Spencer
- Institute for Theoretical Physics, Georg-August University, Göttingen, Germany.
| | - Yuliya G Smirnova
- Institute for Theoretical Physics, Georg-August University, Göttingen, Germany; Technische Universität Dortmund, Dortmund, Germany
| | - Alireza Soleimani
- Institute for Theoretical Physics, Georg-August University, Göttingen, Germany
| | - Marcus Müller
- Institute for Theoretical Physics, Georg-August University, Göttingen, Germany.
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3
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Wilson S, Clarke CD, Carbajal MA, Buccafusca R, Fleck RA, Daskalakis V, Ruban AV. Hydrophobic Mismatch in the Thylakoid Membrane Regulates Photosynthetic Light Harvesting. J Am Chem Soc 2024; 146:14905-14914. [PMID: 38759103 PMCID: PMC11140739 DOI: 10.1021/jacs.4c05220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 05/19/2024]
Abstract
The ability to harvest light effectively in a changing environment is necessary to ensure efficient photosynthesis and crop growth. One mechanism, known as qE, protects photosystem II (PSII) and regulates electron transfer through the harmless dissipation of excess absorbed photons as heat. This process involves reversible clustering of the major light-harvesting complexes of PSII (LHCII) in the thylakoid membrane and relies upon the ΔpH gradient and the allosteric modulator protein PsbS. To date, the exact role of PsbS in the qE mechanism has remained elusive. Here, we show that PsbS induces hydrophobic mismatch in the thylakoid membrane through dynamic rearrangement of lipids around LHCII leading to observed membrane thinning. We found that upon illumination, the thylakoid membrane reversibly shrinks from around 4.3 to 3.2 nm, without PsbS, this response is eliminated. Furthermore, we show that the lipid digalactosyldiacylglycerol (DGDG) is repelled from the LHCII-PsbS complex due to an increase in both the pKa of lumenal residues and in the dipole moment of LHCII, which allows for further conformational change and clustering in the membrane. Our results suggest a mechanistic role for PsbS as a facilitator of a hydrophobic mismatch-mediated phase transition between LHCII-PsbS and its environment. This could act as the driving force to sort LHCII into photoprotective nanodomains in the thylakoid membrane. This work shows an example of the key role of the hydrophobic mismatch process in regulating membrane protein function in plants.
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Affiliation(s)
- Sam Wilson
- Department
of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Charlea D. Clarke
- Department
of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - M. Alejandra Carbajal
- Centre
for Ultrastructural Imaging, King’s
College London, London SE1 1UL, United Kingdom
| | - Roberto Buccafusca
- Department
of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Roland A. Fleck
- Centre
for Ultrastructural Imaging, King’s
College London, London SE1 1UL, United Kingdom
| | - Vangelis Daskalakis
- Department
of Chemical Engineering, School of Engineering, University of Patras, Patras 26504, Greece
| | - Alexander V. Ruban
- Department
of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
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4
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Fábián B, Javanainen M. Energetics of the Transmembrane Peptide Sorting by Hydrophobic Mismatch. J Phys Chem Lett 2024; 15:5344-5349. [PMID: 38738950 PMCID: PMC11129306 DOI: 10.1021/acs.jpclett.4c00651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/14/2024]
Abstract
Hydrophobic mismatch between a lipid membrane and embedded transmembrane peptides or proteins plays a role in their lateral localization and function. Earlier studies have resolved numerous mechanisms through which the peptides and membrane proteins adapt to mismatch, yet the energetics of lateral sorting due to hydrophobic mismatch have remained elusive due to the lack of suitable computational or experimental protocols. Here, we pioneer a molecular dynamics simulation approach to study the sorting of peptides along a membrane thickness gradient. Peptides of different lengths tilt and diffuse along the membrane to eliminate mismatch with a rate directly proportional to the magnitude of mismatch. We extract the 2-dimensional free energy profiles as a function of local thickness and peptide orientation, revealing the relative contributions of sorting and tilting, and suggesting their thermally accessible regimes. Our approach can readily be applied to study other membrane systems of biological interest where hydrophobic mismatch, or membrane thickness in general, plays a role.
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Affiliation(s)
- Balázs Fábián
- Department
of Theoretical Biophysics, MPI Biophysics, DE-60438 Frankfurt
am Main, Germany
| | - Matti Javanainen
- Institute
of Biotechnology, University of Helsinki, FI-00790 Helsinki, Finland
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5
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Lipowsky R. Multiscale remodeling of biomembranes and vesicles. Methods Enzymol 2024; 701:175-236. [PMID: 39025572 DOI: 10.1016/bs.mie.2024.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Biomembranes and vesicles cover a wide range of length scales. Indeed, small nanovesicles have a diameter of a few tens of nanometers whereas giant vesicles can have diameters up to hundreds of micrometers. The remodeling of giant vesicles on the micron scale can be observed by light microscopy and understood by the theory of curvature elasticity, which represents a top-down approach. The theory predicts the formation of multispherical shapes as recently observed experimentally. On the nanometer scale, much insight has been obtained via coarse-grained molecular dynamics simulations of nanovesicles, which provides a bottom-up approach based on the lipid numbers assembled in the two bilayer leaflets and the resulting leaflet tensions. The remodeling processes discussed here include the shape transformations of vesicles, their morphological responses to the adhesion of condensate droplets, the instabilities of lipid bilayers and nanovesicles, as well as the topological transformations of vesicles by membrane fission and fusion. The latter processes determine the complex topology of the endoplasmic reticulum.
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Affiliation(s)
- Reinhard Lipowsky
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, Potsdam, Germany.
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6
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Dahley C, Böckmann T, Ebert A, Goss KU. Predicting the intrinsic membrane permeability of Caco-2/MDCK cells by the solubility-diffusion model. Eur J Pharm Sci 2024; 195:106720. [PMID: 38311258 DOI: 10.1016/j.ejps.2024.106720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/17/2024] [Accepted: 02/01/2024] [Indexed: 02/09/2024]
Abstract
Membrane permeability is one of the main determinants for the absorption, distribution, metabolism and excretion of compounds and is therefore of crucial importance for successful drug development. Experiments with artificial phospholipid membranes have shown that the intrinsic membrane permeability (P0) of compounds is well-predicted by the solubility-diffusion model (SDM). However, using the solubility-diffusion model to predict the P0 of biological Caco-2 and MDCK cell membranes has proven unreliable so far. Recent publications revealed that many published P0 extracted from Caco-2 and MDCK experiments are incorrect. In this work, we therefore used a small self-generated set as well as a large revised set of experimental Caco-2 and MDCK data from literature to compare experimental and predicted P0. The P0 extracted from Caco-2 and MDCK experiments were systematically lower than the P0 predicted by the solubility-diffusion model. However, using the following correlation: log P0,Caco-2/MDCK = 0.84 log P0,SDM - 1.85, P0 of biological Caco-2 and MDCK cell membranes was well-predicted by the solubility-diffusion model.
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Affiliation(s)
- Carolin Dahley
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstraße 15, Leipzig 04318, Germany
| | - Tim Böckmann
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstraße 15, Leipzig 04318, Germany
| | - Andrea Ebert
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstraße 15, Leipzig 04318, Germany.
| | - Kai-Uwe Goss
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstraße 15, Leipzig 04318, Germany; Institute of Chemistry, University of Halle-Wittenberg, Kurt-Mothes-Straße 2, Halle 06120, Germany
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7
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Lujan P, Garcia-Cabau C, Wakana Y, Vera Lillo J, Rodilla-Ramírez C, Sugiura H, Malhotra V, Salvatella X, Garcia-Parajo MF, Campelo F. Sorting of secretory proteins at the trans-Golgi network by human TGN46. eLife 2024; 12:RP91708. [PMID: 38466628 DOI: 10.7554/elife.91708] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024] Open
Abstract
Secretory proteins are sorted at the trans-Golgi network (TGN) for export into specific transport carriers. However, the molecular players involved in this fundamental process remain largely elusive. Here, we identified the human transmembrane protein TGN46 as a receptor for the export of secretory cargo protein PAUF in CARTS - a class of protein kinase D-dependent TGN-to-plasma membrane carriers. We show that TGN46 is necessary for cargo sorting and loading into nascent carriers at the TGN. By combining quantitative fluorescence microscopy and mutagenesis approaches, we further discovered that the lumenal domain of TGN46 encodes for its cargo sorting function. In summary, our results define a cellular function of TGN46 in sorting secretory proteins for export from the TGN.
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Affiliation(s)
- Pablo Lujan
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Carla Garcia-Cabau
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Yuichi Wakana
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Javier Vera Lillo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Carmen Rodilla-Ramírez
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Hideaki Sugiura
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Vivek Malhotra
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Xavier Salvatella
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Maria F Garcia-Parajo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Felix Campelo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
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8
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Turbant F, Machiels Q, Waeytens J, Wien F, Arluison V. The Amyloid Assembly of the Bacterial Hfq Is Lipid-Driven and Lipid-Specific. Int J Mol Sci 2024; 25:1434. [PMID: 38338713 PMCID: PMC10855545 DOI: 10.3390/ijms25031434] [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: 12/27/2023] [Revised: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
Under specific conditions, some proteins can self-assemble into fibrillar structures called amyloids. Initially, these proteins were associated with neurodegenerative diseases in eucaryotes. Nevertheless, they have now been identified in the three domains of life. In bacteria, they are involved in diverse biological processes and are usually useful for the cell. For this reason, they are classified as "functional amyloids". In this work, we focus our analysis on a bacterial functional amyloid called Hfq. Hfq is a pleiotropic regulator that mediates several aspects of genetic expression, mainly via the use of small noncoding RNAs. Our previous work showed that Hfq amyloid-fibrils interact with membranes. This interaction influences Hfq amyloid structure formation and stability, but the specifics of the lipid on the dynamics of this process is unknown. Here, we show, using spectroscopic methods, how lipids specifically drive and modulate Hfq amyloid assembly or, conversely, its disassembly. The reported effects are discussed in light of the consequences for bacterial cell life.
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Affiliation(s)
- Florian Turbant
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, CEA Saclay, 91191 Gif-sur-Yvette, France;
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France;
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Quentin Machiels
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles, 1050 Bruxelles, Belgium; (Q.M.); (J.W.)
| | - Jehan Waeytens
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles, 1050 Bruxelles, Belgium; (Q.M.); (J.W.)
- Unit of Pharmacognosy, Bioanalysis and Drug Discovery, Université Libre de Bruxelles, 1050 Bruxelles, Belgium
| | - Frank Wien
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France;
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, CEA Saclay, 91191 Gif-sur-Yvette, France;
- SDV Department, Université Paris Cité, 75006 Paris, France
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9
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Renne MF, Ernst R. Membrane homeostasis beyond fluidity: control of membrane compressibility. Trends Biochem Sci 2023; 48:963-977. [PMID: 37652754 PMCID: PMC10580326 DOI: 10.1016/j.tibs.2023.08.004] [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: 05/03/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 09/02/2023]
Abstract
Biomembranes are complex materials composed of lipids and proteins that compartmentalize biochemistry. They are actively remodeled in response to physical and metabolic cues, as well as during cell differentiation and stress. The concept of homeoviscous adaptation has become a textbook example of membrane responsiveness. Here, we discuss limitations and common misconceptions revolving around it. By highlighting key moments in the life cycle of a transmembrane protein, we illustrate that membrane thickness and a finely regulated membrane compressibility are crucial to facilitate proper membrane protein insertion, function, sorting, and inheritance. We propose that the unfolded protein response (UPR) provides a mechanism for endoplasmic reticulum (ER) membrane homeostasis by sensing aberrant transverse membrane stiffening and triggering adaptive responses that re-establish membrane compressibility.
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Affiliation(s)
- Mike F Renne
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany; PZMS, Center for Molecular Signaling, Medical Faculty, Saarland University, Homburg, Germany.
| | - Robert Ernst
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany; PZMS, Center for Molecular Signaling, Medical Faculty, Saarland University, Homburg, Germany.
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10
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McClain SM, Milchberg MH, Rienstra CM, Murphy CJ. Biologically Representative Lipid-Coated Gold Nanoparticles and Phospholipid Vesicles for the Study of Alpha-Synuclein/Membrane Interactions. ACS NANO 2023; 17:20387-20401. [PMID: 37782491 DOI: 10.1021/acsnano.3c06606] [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] [Indexed: 10/03/2023]
Abstract
Alpha-synuclein is an intrinsically disordered protein whose formation of beta-sheet-rich protein aggregates in the brain is implicated in the development of Parkinson's disease. Due to its believed role in synaptic vesicle trafficking and neurotransmission, many studies have employed simple, synthetic model systems to investigate alpha-synuclein/membrane interactions in an attempt to gain a better understanding of the protein's native and pathogenic functions. Interestingly, these studies seem to suggest that alpha-synuclein interacts differently with rigid vesicle mimics in comparison to malleable vesicle mimics. However, the use of different mimic sizes and surface chemistries across existing studies makes it challenging to directly compare the effects of membrane mechanical properties on protein behavior observed thus far. In this work, we developed a synaptic vesicle mimic library comprising a range of both malleable and rigid synaptic vesicle mimics possessing the same size and biologically representative lipid surface chemistry. Limited proteolysis mass spectrometry experiments revealed distinct fragmentation patterns between rigid and malleable synaptic vesicle mimics. The N-terminal and C-terminal regions of alpha-synuclein were found to become less solvent-accessible upon binding to all synaptic vesicle mimics. Nevertheless, minor variations in digestion pattern were observed in the central region of the protein dependent upon mimic size, rigidity, and lipid composition. Higher binding affinities were observed for alpha-synuclein binding to rigid synaptic vesicle mimics compared to malleable synaptic vesicle mimics. Additionally, the binding affinity of alpha-synuclein toward small lipid vesicles and small lipid-coated gold nanoparticles without cholesterol was found to be lower than that of their respective malleable and rigid counterparts. Interestingly, the binding curves for the rigid synaptic vesicle mimics demonstrated a nontraditional peak and dip shape believed to arise from differences in alpha-synuclein orientation on the particle surface at different protein-to-particle incubation ratios.
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Affiliation(s)
- Sophia M McClain
- Department of Chemistry, University of Illinois Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Moses H Milchberg
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, Wisconsin 53706, United States
| | - Chad M Rienstra
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, Wisconsin 53706, United States
- National Magnetic Resonance Facility at Madison, University of Wisconsin-Madison, 433 Babcock Drive, Madison, Wisconsin 53706, United States
| | - Catherine J Murphy
- Department of Chemistry, University of Illinois Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
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11
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Li DH, Wilson S, Mastroianni G, Ruban AV. Altered lipid acyl chain length controls energy dissipation in light-harvesting complex II proteoliposomes by hydrophobic mismatch. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2023; 246:112758. [PMID: 37531665 DOI: 10.1016/j.jphotobiol.2023.112758] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 08/04/2023]
Abstract
In plants, the major light-harvesting antenna complex (LHCII) is vital for both light harvesting and photoprotection in photosystem II. Previously, we proposed that the thylakoid membrane itself could switch LHCII into the photoprotective state, qE, via a process known as hydrophobic mismatch. The decrease in the membrane thickness that followed the formation of ΔpH was a key fact that prompted this idea. To test this, we made proteoliposomes from lipids with altered acyl chain length (ACL). Here, we show that ACL regulates the average chlorophyll fluorescence lifetime of LHCII. For liposomes made of lipids with an ACL of 18 carbons, the lifetime was ∼2 ns, like that for the thylakoid membrane. Furthermore, LHCII appears to be quenched in proteoliposomes with an ACL both shorter and longer than 18 carbons. The proteoliposomes made of short ACL lipids display structural heterogeneity revealing two quenched conformations of LHCII, each having characteristic 77 K fluorescence spectra. One conformation spectrally resembles isolated LHCII aggregates, whilst the other resembles LHCII immobilized in polyacrylamide gels. Overall, the decrease in the ACL appears to produce quenched conformations of LHCII, which renders plausible the idea that the trigger of qE is the hydrophobic mismatch.
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Affiliation(s)
- Dan-Hong Li
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
| | - Sam Wilson
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
| | - Giulia Mastroianni
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
| | - Alexander V Ruban
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
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12
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Liu S, Sommese RF, Nedoma NL, Stevens LM, Dutra JK, Zhang L, Edmonds DJ, Wang Y, Garnsey M, Clasquin MF. Structural basis of lipid-droplet localization of 17-beta-hydroxysteroid dehydrogenase 13. Nat Commun 2023; 14:5158. [PMID: 37620305 PMCID: PMC10449848 DOI: 10.1038/s41467-023-40766-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 08/07/2023] [Indexed: 08/26/2023] Open
Abstract
Hydroxysteroid 17-beta-dehydrogenase 13 (HSD17B13) is a hepatic lipid droplet-associated enzyme that is upregulated in patients with non-alcoholic fatty liver disease. Recently, there have been several reports that predicted loss of function variants in HSD17B13 protect against the progression of steatosis to non-alcoholic steatohepatitis with fibrosis and hepatocellular carcinoma. Here we report crystal structures of full length HSD17B13 in complex with its NAD+ cofactor, and with lipid/detergent molecules and small molecule inhibitors from two distinct series in the ligand binding pocket. These structures provide insights into a mechanism for lipid droplet-associated proteins anchoring to membranes as well as a basis for HSD17B13 variants disrupting function. Two series of inhibitors interact with the active site residues and the bound cofactor similarly, yet they occupy different paths leading to the active site. These structures provide ideas for structure-based design of inhibitors that may be used in the treatment of liver disease.
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Affiliation(s)
- Shenping Liu
- Medicine Design, Pfizer Inc, Groton, CT, 06340, USA.
| | | | | | | | - Jason K Dutra
- Medicine Design, Pfizer Inc, Cambridge, MA, 02139, USA
| | - Liying Zhang
- Medicine Design, Pfizer Inc, Cambridge, MA, 02139, USA
- Discovery Chemistry, Merck Research Laboratories, Cambridge, MA, USA
| | - David J Edmonds
- Medicine Design, Pfizer Inc, Cambridge, MA, 02139, USA
- Medicinal Chemistry, Roche, Basel, Switzerland
| | - Yang Wang
- Medicine Design, Pfizer Inc, Cambridge, MA, 02139, USA
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13
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Jin Z, Vighi A, Dong Y, Bureau JA, Ignea C. Engineering membrane architecture for biotechnological applications. Biotechnol Adv 2023; 64:108118. [PMID: 36773706 DOI: 10.1016/j.biotechadv.2023.108118] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 02/02/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023]
Abstract
Cellular membranes, predominantly described as a dynamic bilayer, are composed of different lipids, transmembrane proteins, and carbohydrates. Most research on biological membranes focuses on the identification, characterization, and mechanistic aspects of their different components. These studies provide a fundamental understanding of membrane structure, function, and dynamics, establishing a basis for the development of membrane engineering strategies. To date, approaches in this field concentrate on membrane adaptation to harsh conditions during industrial fermentation, which can be caused by temperature, osmotic, or organic solvent stress. With advances in the field of metabolic engineering and synthetic biology, recent breakthroughs include proof of concept microbial production of essential medicines, such as cannabinoids and vinblastine. However, long pathways, low yields, and host adaptation continue to pose challenges to the efficient scale up production of many important compounds. The lipid bilayer is profoundly linked to the activity of heterologous membrane-bound enzymes and transport of metabolites. Therefore, strategies for improving enzyme performance, facilitating pathway reconstruction, and enabling storage of products to increase the yields directly involve cellular membranes. At the forefront of membrane engineering research are re-emerging approaches in lipid research and synthetic biology that manipulate membrane size and composition and target lipid profiles across species. This review summarizes engineering strategies applied to cellular membranes and discusses the challenges and future perspectives, particularly with regards to their applications in host engineering and bioproduction.
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Affiliation(s)
- Zimo Jin
- Department of Bioengineering, McGill University, Montreal, Quebec H3A 0E9, Canada
| | - Asia Vighi
- Department of Bioengineering, McGill University, Montreal, Quebec H3A 0E9, Canada
| | - Yueming Dong
- Department of Bioengineering, McGill University, Montreal, Quebec H3A 0E9, Canada
| | | | - Codruta Ignea
- Department of Bioengineering, McGill University, Montreal, Quebec H3A 0E9, Canada.
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14
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Kumagawa E, Yajima Y, Takahashi H. Calorimetric, volumetric and structural studies of the interaction between chlorogenic acid and dipalmitoylphosphatidylcholine bilayers. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184158. [PMID: 37094707 DOI: 10.1016/j.bbamem.2023.184158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/02/2023] [Accepted: 03/29/2023] [Indexed: 04/26/2023]
Abstract
Chlorogenic acid (CGA) is the main component of coffee and an antioxidant. CGA has been reported to bear various good health effects. At the same time, it has been found that the addition of CGA induces an undesirable deformation of red blood cells. This fact suggests that CGA may bind to the proteins or/and membrane lipids of red blood cells. This study aimed to examine how CGA binds the bilayers of phosphatidylcholine (PC), one of red blood cells' primary lipids. To this end, we investigated the effect of CGA on the phase behavior and the structure of dipalmitoyl-PC (DPPC) bilayers in the form of multi-lamellar vesicles. Calorimetry and dilatometry measurements showed that the DPPC chain melting transition cooperativity decreases as increasing CGA concentrations. In addition, X-ray diffraction results showed that the lamellar repeat periodicity becomes disordered, and the periodicity disappears completely at high CGA concentrations. Together with these findings, it can be inferred that the CGA molecules do not penetrate inside the DPPC bilayers but bind to their surface in a negatively charged form.
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Affiliation(s)
- Eri Kumagawa
- Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan
| | - Yoshiki Yajima
- Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan
| | - Hiroshi Takahashi
- Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan.
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15
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Liu Z, Yethiraj A, Cui Q. Sensitive and selective polymer condensation at membrane surface driven by positive co-operativity. Proc Natl Acad Sci U S A 2023; 120:e2212516120. [PMID: 37018196 PMCID: PMC10104518 DOI: 10.1073/pnas.2212516120] [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: 07/20/2022] [Accepted: 03/06/2023] [Indexed: 04/06/2023] Open
Abstract
Biomolecular phase separation has emerged as an essential mechanism for cellular organization. How cells respond to environmental stimuli in a robust and sensitive manner to build functional condensates at the proper time and location is only starting to be understood. Recently, lipid membranes have been recognized as an important regulatory center for biomolecular condensation. However, how the interplay between the phase behaviors of cellular membranes and surface biopolymers may contribute to the regulation of surface condensation remains to be elucidated. Using simulations and a mean-field theoretical model, we show that two key factors are the membrane's tendency to phase-separate and the surface polymer's ability to reorganize local membrane composition. Surface condensate forms with high sensitivity and selectivity in response to features of biopolymer when positive co-operativity is established between coupled growth of the condensate and local lipid domains. This effect relating the degree of membrane-surface polymer co-operativity and condensate property regulation is shown to be robust by different ways of tuning the co-operativity, such as varying membrane protein obstacle concentration, lipid composition, and the affinity between lipid and polymer. The general physical principle emerged from the current analysis may have implications in other biological processes and beyond.
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Affiliation(s)
- Zhuang Liu
- Department of Physics, Boston University, Boston, MA02215
| | - Arun Yethiraj
- Department of Chemistry, University of Wisconsin, Madison, WI53706
| | - Qiang Cui
- Department of Physics, Boston University, Boston, MA02215
- Department of Chemistry, Boston University, Boston, MA02215
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16
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Chen T, Ghosh A, Enderlein J. Cholesterol-Induced Nanoscale Variations in the Thickness of Phospholipid Membranes. NANO LETTERS 2023; 23:2421-2426. [PMID: 36706024 PMCID: PMC10037415 DOI: 10.1021/acs.nanolett.2c04635] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/26/2023] [Indexed: 06/18/2023]
Abstract
Graphene-induced energy transfer (GIET) is a recently developed fluorescence-spectroscopic technique that achieves subnanometric optical localization of fluorophores along the optical axis of a microscope. GIET is based on the near-field energy transfer from an optically excited fluorescent molecule to a single sheet of graphene. It has been successfully used for estimating interleaflet distances of single lipid bilayers and for investigating the membrane organization of living mitochondria. In this study, we use GIET to measure the cholesterol-induced subtle changes of membrane thickness at the nanoscale. We quantify membrane thickness variations in supported lipid bilayers (SLBs) as a function of lipid composition and increasing cholesterol content. Our findings demonstrate that GIET is an extremely sensitive tool for investigating nanometric structural changes in biomembranes.
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Affiliation(s)
- Tao Chen
- Third
Institute of Physics − Biophysics, Georg August University, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Arindam Ghosh
- Third
Institute of Physics − Biophysics, Georg August University, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Jörg Enderlein
- Third
Institute of Physics − Biophysics, Georg August University, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
- Cluster
of Excellence “Multiscale Bioimaging: from Molecular Machines
to Networks of Excitable Cells” (MBExC), Universitätsmedizin Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany
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17
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Simas RG, Pessoa Junior A, Long PF. Mechanistic aspects of IPTG (isopropylthio-β-galactoside) transport across the cytoplasmic membrane of Escherichia coli-a rate limiting step in the induction of recombinant protein expression. J Ind Microbiol Biotechnol 2023; 50:kuad034. [PMID: 37849239 PMCID: PMC10639102 DOI: 10.1093/jimb/kuad034] [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: 05/20/2023] [Accepted: 10/16/2023] [Indexed: 10/19/2023]
Abstract
Coupling transcription of a cloned gene to the lac operon with induction by isopropylthio-β-galactoside (IPTG) has been a favoured approach for recombinant protein expression using Escherichia coli as a heterologous host for more than six decades. Despite a wealth of experimental data gleaned over this period, a quantitative relationship between extracellular IPTG concentration and consequent levels of recombinant protein expression remains surprisingly elusive across a broad spectrum of experimental conditions. This is because gene expression under lac operon regulation is tightly correlated with intracellular IPTG concentration due to allosteric regulation of the lac repressor protein (lacY). An in-silico mathematical model established that uptake of IPTG across the cytoplasmic membrane of E. coli by simple diffusion was negligible. Conversely, lacY mediated active transport was a rapid process, taking only some seconds for internal and external IPTG concentrations to equalize. Optimizing kcat and KM parameters by targeted mutation of the galactoside binding site in lacY could be a future strategy to improve the performance of recombinant protein expression. For example, if kcat were reduced whilst KM was increased, active transport of IPTG across the cytoplasmic membrane would be reduced, thereby lessening the metabolic burden on the cell and expediating accumulation of recombinant protein. The computational model described herein is made freely available and is amenable to optimize recombinant protein expression in other heterologous hosts. ONE-SENTENCE SUMMARY A computational model made freely available to optimize recombinant protein expression in Escherichia coli other heterologous hosts.
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Affiliation(s)
- Rodrigo G Simas
- Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 580, B16, 05508-000 São Paulo, SP, Brazil
| | - Adalberto Pessoa Junior
- Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 580, B16, 05508-000 São Paulo, SP, Brazil
| | - Paul F Long
- Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 580, B16, 05508-000 São Paulo, SP, Brazil
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18
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Welsh JA, Arkesteijn GJA, Bremer M, Cimorelli M, Dignat-George F, Giebel B, Görgens A, Hendrix A, Kuiper M, Lacroix R, Lannigan J, van Leeuwen TG, Lozano-Andrés E, Rao S, Robert S, de Rond L, Tang VA, Tertel T, Yan X, Wauben MHM, Nolan JP, Jones JC, Nieuwland R, van der Pol E. A compendium of single extracellular vesicle flow cytometry. J Extracell Vesicles 2023; 12:e12299. [PMID: 36759917 PMCID: PMC9911638 DOI: 10.1002/jev2.12299] [Citation(s) in RCA: 40] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 11/29/2022] [Accepted: 12/17/2022] [Indexed: 02/11/2023] Open
Abstract
Flow cytometry (FCM) offers a multiparametric technology capable of characterizing single extracellular vesicles (EVs). However, most flow cytometers are designed to detect cells, which are larger than EVs. Whereas cells exceed the background noise, signals originating from EVs partly overlap with the background noise, thereby making EVs more difficult to detect than cells. This technical mismatch together with complexity of EV-containing fluids causes limitations and challenges with conducting, interpreting and reproducing EV FCM experiments. To address and overcome these challenges, researchers from the International Society for Extracellular Vesicles (ISEV), International Society for Advancement of Cytometry (ISAC), and the International Society on Thrombosis and Haemostasis (ISTH) joined forces and initiated the EV FCM working group. To improve the interpretation, reporting, and reproducibility of future EV FCM data, the EV FCM working group published an ISEV position manuscript outlining a framework of minimum information that should be reported about an FCM experiment on single EVs (MIFlowCyt-EV). However, the framework contains limited background information. Therefore, the goal of this compendium is to provide the background information necessary to design and conduct reproducible EV FCM experiments. This compendium contains background information on EVs, the interaction between light and EVs, FCM hardware, experimental design and preanalytical procedures, sample preparation, assay controls, instrument data acquisition and calibration, EV characterization, and data reporting. Although this compendium focuses on EVs, many concepts and explanations could also be applied to FCM detection of other particles within the EV size range, such as bacteria, lipoprotein particles, milk fat globules, and viruses.
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Affiliation(s)
- Joshua A Welsh
- Translational Nanobiology Section, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Ger J A Arkesteijn
- Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Michel Bremer
- Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Michael Cimorelli
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Experimental Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Department of Chemical Engineering, Drexel University, Philadelphia, Pennsylvania, USA
| | - Françoise Dignat-George
- Aix Marseille Univ, INSERM, INRAE, C2VN, UFR de Pharmacie, Marseille, France
- Hematology and Vascular Biology Department, CHU La Conception, Assistance Publique-Hôpitaux de Marseille, Marseille, France
| | - Bernd Giebel
- Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - André Görgens
- Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Clinical Research Center, Department for Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Evox Therapeutics Ltd, Oxford, UK
| | - An Hendrix
- Laboratory of Experimental Cancer Research, Department of Human Structure and Repair, Ghent University, Ghent, Belgium
| | - Martine Kuiper
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Experimental Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Biomedical Engineering & Physics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Dutch Metrology Institute, VSL, Delft, The Netherlands
| | - Romaric Lacroix
- Aix Marseille Univ, INSERM, INRAE, C2VN, UFR de Pharmacie, Marseille, France
- Hematology and Vascular Biology Department, CHU La Conception, Assistance Publique-Hôpitaux de Marseille, Marseille, France
| | - Joanne Lannigan
- Flow Cytometry Support Services, LLC, Arlington, Virginia, USA
| | - Ton G van Leeuwen
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Biomedical Engineering & Physics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis and Ischemic Syndromes, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Estefanía Lozano-Andrés
- Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Shoaib Rao
- Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Stéphane Robert
- Aix Marseille Univ, INSERM, INRAE, C2VN, UFR de Pharmacie, Marseille, France
- Hematology and Vascular Biology Department, CHU La Conception, Assistance Publique-Hôpitaux de Marseille, Marseille, France
| | - Leonie de Rond
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Experimental Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Biomedical Engineering & Physics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Vera A Tang
- Flow Cytometry & Virometry Core Facility, Faculty of Medicine, Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Tobias Tertel
- Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Xiaomei Yan
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, People's Republic of China
| | - Marca H M Wauben
- Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - John P Nolan
- Scintillon Institute, San Diego, California, USA
- Cellarcus Biosciences, San Diego, California, USA
| | - Jennifer C Jones
- Translational Nanobiology Section, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Rienk Nieuwland
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Experimental Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis and Ischemic Syndromes, Amsterdam, The Netherlands
| | - Edwin van der Pol
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Experimental Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Biomedical Engineering & Physics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis and Ischemic Syndromes, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
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19
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Regulation of membrane protein structure and function by their lipid nano-environment. Nat Rev Mol Cell Biol 2023; 24:107-122. [PMID: 36056103 PMCID: PMC9892264 DOI: 10.1038/s41580-022-00524-4] [Citation(s) in RCA: 129] [Impact Index Per Article: 129.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2022] [Indexed: 02/04/2023]
Abstract
Transmembrane proteins comprise ~30% of the mammalian proteome, mediating metabolism, signalling, transport and many other functions required for cellular life. The microenvironment of integral membrane proteins (IMPs) is intrinsically different from that of cytoplasmic proteins, with IMPs solvated by a compositionally and biophysically complex lipid matrix. These solvating lipids affect protein structure and function in a variety of ways, from stereospecific, high-affinity protein-lipid interactions to modulation by bulk membrane properties. Specific examples of functional modulation of IMPs by their solvating membranes have been reported for various transporters, channels and signal receptors; however, generalizable mechanistic principles governing IMP regulation by lipid environments are neither widely appreciated nor completely understood. Here, we review recent insights into the inter-relationships between complex lipidomes of mammalian membranes, the membrane physicochemical properties resulting from such lipid collectives, and the regulation of IMPs by either or both. The recent proliferation of high-resolution methods to study such lipid-protein interactions has led to generalizable insights, which we synthesize into a general framework termed the 'functional paralipidome' to understand the mutual regulation between membrane proteins and their surrounding lipid microenvironments.
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20
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Goangul MS, Stewart WC, Erenso D, Crogman HT. The radiation response measurement of a single and multiple cell ionization of neuroblastoma cells by infrared laser trap. JOURNAL OF RADIATION RESEARCH 2023; 64:113-125. [PMID: 36527720 PMCID: PMC9855329 DOI: 10.1093/jrr/rrac082] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 06/16/2022] [Indexed: 06/17/2023]
Abstract
Neuroblastoma (NB) is a common type of cancer found mostly in infants and arising from the immature neural crest cells of the sympathetic nervous system. Using laser trapping (LT) technique, the present work contributes to advancing radiotherapy (RT), a leading treatment method for cancer. A single, 2-cells, 3-cells, 4-cells, and 5-cells were trapped using the high-intensity gradient infrared laser at 1064 nm and allowed to become ionized. In this work, a systematic study of Threshold Ionization Energy (TIE) and Threshold Radiation Dose (TRD) versus mass for both single and multi-cell ionization using laser trapping (LT) techniques on NB is presented. The results show that TIE increased as the mass of cells increased, meanwhile TRD decreased with the increase of cell mass. We observed an inverse correlation between TRD and cell mass. We demonstrate how to compute the maximum radiation dosage for cell death using the LT technique. Results show a possible blueprint for computing the TRD in vivo. The use of multiple cell ionization to determine radiation dosage along with better data accuracy concerning the tumor size and density will have profound implications for radiation dosimetry. The diminution in TRD becomes more significant in multiple cell ionization as we see in TRD vs the number of cells entering the trap. This is due to the chain effect generated by radiation and the absorption by water molecules at 1064 nm. This result provides us with better insight into the optimization of the therapeutic ratio.
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Affiliation(s)
- Mulugeta S Goangul
- Department of Physics, Addis Ababa University, Addis Ababa 1000, Ethiopia
| | - William C Stewart
- Department of Biology, Middle Tennessee State University, Murfreesboro, Tennessee 37132, USA
| | - Daniel Erenso
- Department of Physics and Astronomy, Middle Tennessee State University, Murfreesboro, Tennessee 37132, USA
| | - Horace T Crogman
- Corresponding author. Department of Physics, California State University Dominguez Hills, Carson, California, 90747, USA. Tel: +1-310-243-2092; E-mail:
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21
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Marcos X, Sixto-López Y, Pérez-Casas S, Correa-Basurto J. Computational study of DMPC liposomes loaded with the N-(2-Hydroxyphenyl)-2-propylpentanamide (HO-AAVPA) and determination of its antiproliferative activity in vitro in NIH-3T3 cells. J Biomol Struct Dyn 2022; 40:11448-11459. [PMID: 34315332 DOI: 10.1080/07391102.2021.1955744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
N-(2-Hydroxyphenyl)-2-propylpentanamide (HO-AAVPA) is a valproic acid (VPA) derivative that has shown promising antiproliferative effects in different cancer cell lines, such as A204, HeLa, and MDA-MB-231. However, its low water solubility could reduce its therapeutic effectiveness. To solve this problem, in this work, we incorporated HO-AAVPA into dimyristoyl-phosphatidylcholine (DMPC) liposomes in the presence or absence of cholesterol (CHOL). Using differential scanning calorimetry (DSC), we found that the transition enthalpy (ΔHtr) of DMPC liposomes is reduced in the presence of CHOL and/or HO-AAVPA, indicating the favorable interactions between CHOL and/or HO-AAVPA and DMPC. Further, by molecular dynamics simulations it was possible to observed that HO-AAVPA migrates from the center of the bilayer toward the water and lipid interface of the DPMC bilayer systems exposing the amine group to water and the aliphatic chain toward the interior of the bilayer. As a consequence, we observed an ordering of the lipid bilayer. Moreover, CHOL harbors into the inner bilayer membrane, increasing the order parameter of the system. The liposomal solutions loaded with HO-AAVPA were tested in the NIH3T3 cell line, showing a reduction in cell proliferation compared to those cells presented without liposomes.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Xelhua Marcos
- Laboratorio de Biofísica y Biocatálisis, Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Yudibeth Sixto-López
- Laboratorio de Diseño y Desarrollo de Nuevos Fármacos e Innovación Biotecnológica (Laboratory for the Design and Development of New Drugs and Biotechnological Innovation) SEPI-ESM Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Silvia Pérez-Casas
- Laboratorio de Biofisicoquímica, Departamento de Fisicoquímica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - José Correa-Basurto
- Laboratorio de Diseño y Desarrollo de Nuevos Fármacos e Innovación Biotecnológica (Laboratory for the Design and Development of New Drugs and Biotechnological Innovation) SEPI-ESM Instituto Politécnico Nacional, Ciudad de México, Mexico
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22
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Joseph A, Wagner AM, Garay-Sarmiento M, Aleksanyan M, Haraszti T, Söder D, Georgiev VN, Dimova R, Percec V, Rodriguez-Emmenegger C. Zwitterionic Dendrimersomes: A Closer Xenobiotic Mimic of Cell Membranes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2206288. [PMID: 36134536 DOI: 10.1002/adma.202206288] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Building functional mimics of cell membranes is an important task toward the development of synthetic cells. So far, lipid and amphiphilic block copolymers are the most widely used amphiphiles with the bilayers by the former lacking stability while membranes by the latter are typically characterized by very slow dynamics. Herein, a new type of Janus dendrimer containing a zwitterionic phosphocholine hydrophilic headgroup (JDPC ) and a 3,5-substituted dihydrobenzoate-based hydrophobic dendron is introduced. JDPC self-assembles in water into zwitterionic dendrimersomes (z-DSs) that faithfully recapitulate the cell membrane in thickness, flexibility, and fluidity, while being resilient to harsh conditions and displaying faster pore closing dynamics in the event of membrane rupture. This enables the fabrication of hybrid DSs with components of natural membranes, including pore-forming peptides, structure-directing lipids, and glycans to create raft-like domains or onion vesicles. Moreover, z-DSs can be used to create active synthetic cells with life-like features that mimic vesicle fusion and motility as well as environmental sensing. Despite their fully synthetic nature, z-DSs are minimal cell mimics that can integrate and interact with living matter with the programmability to imitate life-like features and beyond.
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Affiliation(s)
- Anton Joseph
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstraße 50, 52074, Aachen, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| | - Anna M Wagner
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstraße 50, 52074, Aachen, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| | - Manuela Garay-Sarmiento
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstraße 50, 52074, Aachen, Germany
- Chair of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Mina Aleksanyan
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany
| | - Tamás Haraszti
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstraße 50, 52074, Aachen, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| | - Dominik Söder
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstraße 50, 52074, Aachen, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| | - Vasil N Georgiev
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany
| | - Rumiana Dimova
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany
| | - Virgil Percec
- Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104323, USA
| | - Cesar Rodriguez-Emmenegger
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstraße 50, 52074, Aachen, Germany
- Bioinspired Interactive Materials and Protocellular Systems, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Carrer de Baldiri Reixac 10-12, 08028, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08028, Barcelona, Spain
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23
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Abstract
Micromechanics techniques are playing an increasing role in characterization of biomembranes. The mechanical properties of membranes play an important role for a whole range of cellular processes. Lipid-protein biomembranes display lateral heterogeneity, domain formation, and morphological changes at mesoscopic and nanoscopic length scales. An attempt is made to introduce how membrane's material properties can be measured. Both fluctuation analysis and micro-pipette aspiration experiments have been used to quantify the micromechanics of membranes. The relationship between the structure and function of biomembranes is a critical concern in modern biology. This overview calls for a deeper understanding of how the cell complexity might be related to the mechanical properties of the lipid-protein membrane. Mechanical properties can influence cellular response to processes like adhesion, transport, differentiation, proliferation and migration.
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Jiang Y, Thienpont B, Sapuru V, Hite RK, Dittman JS, Sturgis JN, Scheuring S. Membrane-mediated protein interactions drive membrane protein organization. Nat Commun 2022; 13:7373. [PMID: 36450733 PMCID: PMC9712761 DOI: 10.1038/s41467-022-35202-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 11/22/2022] [Indexed: 12/02/2022] Open
Abstract
The plasma membrane's main constituents, i.e., phospholipids and membrane proteins, are known to be organized in lipid-protein functional domains and supercomplexes. No active membrane-intrinsic process is known to establish membrane organization. Thus, the interplay of thermal fluctuations and the biophysical determinants of membrane-mediated protein interactions must be considered to understand membrane protein organization. Here, we used high-speed atomic force microscopy and kinetic and membrane elastic theory to investigate the behavior of a model membrane protein in oligomerization and assembly in controlled lipid environments. We find that membrane hydrophobic mismatch modulates oligomerization and assembly energetics, and 2D organization. Our experimental and theoretical frameworks reveal how membrane organization can emerge from Brownian diffusion and a minimal set of physical properties of the membrane constituents.
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Affiliation(s)
- Yining Jiang
- Biochemistry & Structural Biology, Cell & Developmental Biology, and Molecular Biology (BCMB) Program, Weill Cornell Graduate School of Biomedical Sciences, 1300 York Avenue, New York, NY 10065 USA ,grid.5386.8000000041936877XWeill Cornell Medicine, Department of Anesthesiology, 1300 York Avenue, New York, NY 10065 USA
| | - Batiste Thienpont
- grid.5399.60000 0001 2176 4817Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM), Unité Mixte de Recherche (UMR) 7255, Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université, Marseille, France
| | - Vinay Sapuru
- grid.51462.340000 0001 2171 9952Structural Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065 USA ,Physiology, Biophysics, and Systems Biology (PBSB) Program, Weill Cornell Graduate School of Biomedical Sciences, 1300 York Avenue, New York, NY 10065 USA
| | - Richard K. Hite
- grid.51462.340000 0001 2171 9952Structural Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065 USA
| | - Jeremy S. Dittman
- grid.5386.8000000041936877XWeill Cornell Medicine, Department of Biochemistry, 1300 York Avenue, New York, NY 10065 USA
| | - James N. Sturgis
- grid.5399.60000 0001 2176 4817Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM), Unité Mixte de Recherche (UMR) 7255, Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université, Marseille, France
| | - Simon Scheuring
- grid.5386.8000000041936877XWeill Cornell Medicine, Department of Anesthesiology, 1300 York Avenue, New York, NY 10065 USA ,grid.5386.8000000041936877XWeill Cornell Medicine, Department of Physiology and Biophysics, 1300 York Avenue, New York, NY 10065 USA ,grid.5386.8000000041936877XKavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853 USA
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25
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Hellmann N, Schneider D. Hydrophobic mismatch and sequence specificity compete when transmembrane helix-helix interactions are measured with the TOXCAT assay. Front Chem 2022; 10:1049310. [DOI: 10.3389/fchem.2022.1049310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/16/2022] [Indexed: 11/29/2022] Open
Abstract
Genetic assays capable of measuring the propensity of transmembrane helices to oligomerize within the cytoplasmic membrane of the bacterium E. coli are frequently used when sequence-specificity in transmembrane helix-helix interactions is investigated. In the present study, dimerization of the well-investigated wild-type and G83I-mutated transmembrane helix of the human glycophorin A protein was studied. Gradual prolongation of the transmembrane helix at the C-terminus with Leu residues lead to pronounced changes in the dimerization propensity when measured with the TOXCAT assay. Thus, besides sequence specificity, hydrophobic mismatch between the hydrophobic core of a studied transmembrane helix and the E. coli membrane can impact the oligomerization propensity of a transmembrane helix. This suggests that the results of genetic assays aiming at determining interactions of heterologous transmembrane helices within the E. coli membrane do not necessarily solely reflect sequence specificity in transmembrane helix-helix interactions, but might be additionally modulated by topological and structural effects caused by hydrophobic mismatch.
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Human cone elongation responses can be explained by photoactivated cone opsin and membrane swelling and osmotic response to phosphate produced by RGS9-catalyzed GTPase. Proc Natl Acad Sci U S A 2022; 119:e2202485119. [PMID: 36122241 PMCID: PMC9522364 DOI: 10.1073/pnas.2202485119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Optical coherence tomography has established that human cone photoreceptor outer segments elongate in response to stimuli bleaching large fractions of their visual pigment. Elongation responses are completely described over their 200-fold bleaching range as the sum of two exponentially rising components differing 13-fold in time constants and 4-fold in light sensitivity. Bleaching measurements of individual cones with adaptive optics scanning laser ophthalmoscopy (SLO) suggest that component 2 arises from cone opsin and disk membrane swelling triggered by photoactivation. Application of a model of phototransduction suggests that component 1 corresponds to free phosphate generated by regulator of G-protein signaling 9 (RGS9)-catalyzed hydrolysis of guanosine triphosphate (GTP) in the α-subunit of G protein complexed with phosphodiesterase. Human cone outer segment (COS) length changes in response to stimuli bleaching up to 99% of L- and M-cone opsins were measured with high resolution, phase-resolved optical coherence tomography (OCT). Responses comprised a fast phase (∼5 ms), during which COSs shrink, and two slower phases (1.5 s), during which COSs elongate. The slower components saturated in amplitude (∼425 nm) and initial rate (∼3 nm ms−1) and are well described over the 200-fold bleaching range as the sum of two exponentially rising functions with time constants of 80 to 90 ms (component 1) and 1,000 to 1,250 ms (component 2). Measurements with adaptive optics reflection densitometry revealed component 2 to be linearly related to cone pigment bleaching, and the hypothesis is proposed that it arises from cone opsin and disk membrane swelling triggered by isomerization and rate-limited by chromophore hydrolysis and its reduction to membrane-localized all-trans retinol. The light sensitivity and kinetics of component 1 suggested that the underlying mechanism is an osmotic response to an amplified soluble by-product of phototransduction. The hypotheses that component 1 corresponds to G-protein subunits dissociating from the membrane, metabolites of cyclic guanosine monophosphate (cGMP) hydrolysis, or by-products of activated guanylate cyclase are rejected, while the hypothesis that it corresponds to phosphate produced by regulator of G-protein signaling 9 (RGS9)-catalyzed hydrolysis of guanosine triphosphate (GTP) in G protein–phosphodiesterase complexes was found to be consistent with the results. These results provide a basis for the assessment with optoretinography of phototransduction in individual cone photoreceptors in health and during disease progression and therapeutic interventions.
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Gu H, Kato T, Kumeta H, Kumaki Y, Tsukamoto T, Kikukawa T, Demura M, Ishida H, Vogel HJ, Aizawa T. Three-Dimensional Structure of the Antimicrobial Peptide Cecropin P1 in Dodecylphosphocholine Micelles and the Role of the C-Terminal Residues. ACS OMEGA 2022; 7:31924-31934. [PMID: 36120057 PMCID: PMC9475619 DOI: 10.1021/acsomega.2c02778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/23/2022] [Indexed: 05/31/2023]
Abstract
Cecropin P1 (CP1) isolated from a large roundworm Ascaris suum, which is found in pig intestines, has been extensively studied as a model antimicrobial peptide (AMP). However, despite being a model AMP, its antibacterial mechanism is not well understood, particularly the function of its C-terminus. By using an Escherichia coli overexpression system with calmodulin as a fusion partner, we succeeded in the mass expression of recombinant peptides, avoiding toxicity to the host and degradation of CP1. The structure of the recombinant 15N- and 13C-labeled CP1 and its C-terminus truncated analogue in dodecylphosphocholine (DPC) micelles was determined by NMR. In this membrane-mimetic environment, CP1 formed an α-helix for almost its entire length, except for a short region at the C-terminus, and there was no evidence of a hinge, which is considered important for the expression of activity in other cecropins. Several NMR analyses showed that the entire length of CP1 was protected from water by micelles. Since the loss of the C-terminus of the analogue had little effect on the NMR structure or its interaction with the micelle, we investigated another role of the C-terminus of CP1 in its antimicrobial activity. The results showed that the C-terminal region affected the DNA-binding capacity of CP1, and this mechanism of action was also newly suggested that it contributed to the antimicrobial activity of CP1.
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Affiliation(s)
- Hao Gu
- Graduate
School of Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Takasumi Kato
- Graduate
School of Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Hiroyuki Kumeta
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Yasuhiro Kumaki
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Takashi Tsukamoto
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Takashi Kikukawa
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Makoto Demura
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Hiroaki Ishida
- Department
of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Hans J. Vogel
- Department
of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Tomoyasu Aizawa
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
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Dahley C, Garessus EDG, Ebert A, Goss KU. Impact of cholesterol and sphingomyelin on intrinsic membrane permeability. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183953. [PMID: 35526600 DOI: 10.1016/j.bbamem.2022.183953] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/14/2022] [Accepted: 04/26/2022] [Indexed: 11/30/2022]
Abstract
Transwell experiments with Caco-2 or MDCK cells are the gold standard for determining the intestinal permeability of chemicals. The intrinsic membrane permeability (P0), that can be extracted from these experiments, might be comparable to P0 measured in black lipid membrane (BLM) experiments and P0 predicted by the solubility-diffusion model. Unfortunately, the overlap between experimental P0,Caco-2/MDCK and P0,BLM data is very small. So far, differences between both approaches have been attributed to the cholesterol and sphingomyelin content of cell membranes, but the database is too sparse to thoroughly test this theory. To create a diverse dataset, we measured P0,BLM of ten chemicals in BLM experiments using DPhPC and DPhPC/cholesterol/sphingomyelin membranes. The results were compared to predicted BLM data and experimental Caco-2/MDCK data obtained from literature. While P0,BLM of all chemicals was well predicted by the solubility-diffusion model, P0,Caco-2/MDCK was only predictable for rather hydrophilic compounds with logarithmic hexadecane/water partition coefficients below -0.5. The effect of cholesterol and sphingomyelin on P0,BLM was negligibly small.
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Affiliation(s)
- Carolin Dahley
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstraße 15, 04318 Leipzig, Germany.
| | - Estella Dora Germaine Garessus
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstraße 15, 04318 Leipzig, Germany
| | - Andrea Ebert
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstraße 15, 04318 Leipzig, Germany.
| | - Kai-Uwe Goss
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstraße 15, 04318 Leipzig, Germany; Institute of Chemistry, University of Halle-Wittenberg, Kurt-Mothes-Straße 2, 06120 Halle, Germany.
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29
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Hao B, Liu L, Liu N, Sun L, Fan F, Huang J. The Bombyx mori Nucleopolyhedrovirus GP64 Retains the Transmembrane Helix of Signal Peptide to Contribute to Secretion across the Cytomembrane. Microbiol Spectr 2022; 10:e0191322. [PMID: 35938817 PMCID: PMC9430547 DOI: 10.1128/spectrum.01913-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 07/14/2022] [Indexed: 11/20/2022] Open
Abstract
Bombyx mori nucleopolyhedrovirus (BmNPV) is the primary pathogen of silkworms that causes severe economic losses in sericulture. GP64 is the key membrane fusion protein that mediates budded virus (BV) fusion with the host cell membrane. Previously, we found that the n-region of the GP64 signal peptide (SP) is required for protein secretion and viral pathogenicity; however, our understanding of BmNPV GP64 remains limited. Here, we first reported that BmNPV GP64 retained its SP in the mature protein and virion in only host cells but did not retain in nonhost cells. Uncleaved SP mediates protein targeting to the cytomembrane or secretion in Bombyx mori cells. The exitance of the n-region extended the transmembrane helix length, which resulted in the cleavage site to be located in the helix structure and thus blocked cleavage from signal peptidase (SPase). Without the n-region, the protein fails to be transported to the cytomembrane, but this failure can be rescued by the cleavage site mutation of SP. Helix-breaking mutations in SP abolished protein targeting to the cytomembrane and secretion. Our results revealed a previously unrecognized mechanism by which SP of membrane fusion not only determines protein localization but also determines viral pathogenicity, which highlights the escape mechanism of SP from the cleavage by SPase. IMPORTANCE BmNPV is the primary pathogen of silkworms, which causes severe economic losses in sericulture. BmNPV and Autographa californica multiple nucleopolyhedrovirus (AcMNPV) are closely related group I alphabaculoviruses, but they exhibit nonoverlapping host specificity. Recent studies suppose that GP64 is a determinant of host range, while knowledge remains limited. In this study, we revealed that BmNPV GP64 retained its SP in host cells but not in nonhost cells, and the SP retention is required for GP64 secretion across the cytomembrane. This is the first report that a type I membrane fusion protein retained its SP in mature proteins and virions. Our results unveil the mechanism by which SP GP64 escapes cleavage and the role of SP in protein targeting. This study will help elucidate an important mechanistic understanding of BmNPV infection and host range specificity.
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Affiliation(s)
- Bifang Hao
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
- Key Laboratory of Genetic Improvement of Sericulture in the Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu, People’s Republic of China
| | - Lin Liu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
| | - Na Liu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
| | - Luping Sun
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
| | - Fengxiu Fan
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
| | - Jinshan Huang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
- Key Laboratory of Genetic Improvement of Sericulture in the Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu, People’s Republic of China
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30
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Herron JC, Hu S, Watanabe T, Nogueira AT, Liu B, Kern ME, Aaron J, Taylor A, Pablo M, Chew TL, Elston TC, Hahn KM. Actin nano-architecture of phagocytic podosomes. Nat Commun 2022; 13:4363. [PMID: 35896550 PMCID: PMC9329332 DOI: 10.1038/s41467-022-32038-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/13/2022] [Indexed: 11/09/2022] Open
Abstract
Podosomes are actin-enriched adhesion structures important for multiple cellular processes, including migration, bone remodeling, and phagocytosis. Here, we characterize the structure and organization of phagocytic podosomes using interferometric photoactivated localization microscopy, a super-resolution microscopy technique capable of 15-20 nm resolution, together with structured illumination microscopy and localization-based super-resolution microscopy. Phagocytic podosomes are observed during frustrated phagocytosis, a model in which cells attempt to engulf micropatterned IgG antibodies. For circular patterns, this results in regular arrays of podosomes with well-defined geometry. Using persistent homology, we develop a pipeline for semi-automatic identification and measurement of podosome features. These studies reveal an hourglass shape of the podosome actin core, a protruding knob at the bottom of the core, and two actin networks extending from the core. Additionally, the distributions of paxillin, talin, myosin II, α-actinin, cortactin, and microtubules relative to actin are characterized.
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Affiliation(s)
- J Cody Herron
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Computational Medicine Program, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Shiqiong Hu
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Takashi Watanabe
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Division of Gene Regulation, Cancer Center, Fujita Health University, Toyoake, Aichi, Japan
| | - Ana T Nogueira
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Bei Liu
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Megan E Kern
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jesse Aaron
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Aaron Taylor
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Michael Pablo
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Program in Molecular and Cellular Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Teng-Leong Chew
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Timothy C Elston
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Computational Medicine Program, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Klaus M Hahn
- Computational Medicine Program, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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31
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In vitro dose effect relationships of actinium-225- and lutetium-177-labeled PSMA-I&T. Eur J Nucl Med Mol Imaging 2022; 49:3627-3638. [PMID: 35556158 PMCID: PMC9399067 DOI: 10.1007/s00259-022-05821-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 04/25/2022] [Indexed: 12/18/2022]
Abstract
PURPOSE Targeting the prostate-specific membrane antigen (PSMA) using lutetium-177-labeled PSMA-specific tracers has become a very promising novel therapy option for prostate cancer (PCa). The efficacy of this therapy might be further improved by replacing the β-emitting lutetium-177 with the α-emitting actinium-225. Actinium-225 is thought to have a higher therapeutic efficacy due to the high linear energy transfer (LET) of the emitted α-particles, which can increase the amount and complexity of the therapy induced DNA double strand breaks (DSBs). Here we evaluated the relative biological effectiveness of [225Ac]Ac-PSMA-I&T and [177Lu]Lu-PSMA-I&T by assessing in vitro binding characteristics, dosimetry, and therapeutic efficacy. METHODS AND RESULTS The PSMA-expressing PCa cell line PC3-PIP was used for all in vitro assays. First, binding and displacement assays were performed, which revealed similar binding characteristics between [225Ac]Ac-PSMA-I&T and [177Lu]Lu-PSMA-I&T. Next, the assessment of the number of 53BP1 foci, a marker for the number of DNA double strand breaks (DSBs), showed that cells treated with [225Ac]Ac-PSMA-I&T had slower DSB repair kinetics compared to cells treated with [177Lu]Lu-PSMA-I&T. Additionally, clonogenic survival assays showed that specific targeting with [225Ac]Ac-PSMA-I&T and [177Lu]Lu-PSMA-I&T caused a dose-dependent decrease in survival. Lastly, after dosimetric assessment, the relative biological effectiveness (RBE) of [225Ac]Ac-PSMA-I&T was found to be 4.2 times higher compared to [177Lu]Lu-PSMA-I&T. CONCLUSION We found that labeling of PSMA-I&T with lutetium-177 or actinium-225 resulted in similar in vitro binding characteristics, indicating that the distinct biological effects observed in this study are not caused by a difference in uptake of the two tracers. The slower repair kinetics of [225Ac]Ac-PSMA-I&T compared to [177Lu]Lu-PSMA-I&T correlates to the assumption that irradiation with actinium-225 causes more complex, more difficult to repair DSBs compared to lutetium-177 irradiation. Furthermore, the higher RBE of [225Ac]Ac-PSMA-I&T compared to [177Lu]Lu-PSMA-I&T underlines the therapeutic potential for the treatment of PCa.
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32
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Hao B, Zhou W, Theg SM. Hydrophobic mismatch is a key factor in protein transport across lipid bilayer membranes via the Tat pathway. J Biol Chem 2022; 298:101991. [PMID: 35490783 PMCID: PMC9207671 DOI: 10.1016/j.jbc.2022.101991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 04/13/2022] [Accepted: 04/19/2022] [Indexed: 11/28/2022] Open
Abstract
The twin-arginine translocation (Tat) pathway transports folded proteins across membranes in bacteria, thylakoids, plant mitochondria, and archaea. In most species, the active Tat machinery consists of three independent subunits: TatA, TatB, and TatC. TatA and TatB possess short transmembrane alpha helices (TMHs), both of which are only 15 residues long in Escherichia coli. Such short TMHs cause a hydrophobic mismatch between Tat subunits and the membrane bilayer, although the functional significance of this mismatch is unclear. Here, we sought to address the functional importance of the hydrophobic mismatch in the Tat transport mechanism in E. coli. We conducted three different assays to evaluate the effect of TMH length mutants on Tat activity and observed that the TMHs of TatA and TatB appear to be evolutionarily tuned to 15 amino acids, with activity dropping off following any modification of this length. Surprisingly, TatA and TatB with as few as 11 residues in their TMHs can still insert into the membrane bilayer, albeit with a decline in membrane integrity. These findings support a model of Tat transport utilizing localized toroidal pores that form when the membrane bilayer is thinned to a critical threshold. In this context, we conclude that the 15-residue length of the TatA and TatB TMHs can be seen as a compromise between the need for some hydrophobic mismatch to allow the membrane to reversibly reach the threshold thinness required for toroidal pore formation and the permanently destabilizing effect of placing even shorter helices into these energy-transducing membranes.
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Affiliation(s)
- Binhan Hao
- Plant Biology Department, University of California, Davis, CA 95616
| | - Wenjie Zhou
- Plant Biology Department, University of California, Davis, CA 95616
| | - Steven M Theg
- Plant Biology Department, University of California, Davis, CA 95616.
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Karathanou K, Bondar AN. Algorithm to catalogue topologies of dynamic lipid hydrogen-bond networks. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183859. [PMID: 34999081 DOI: 10.1016/j.bbamem.2022.183859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 12/21/2021] [Accepted: 12/31/2021] [Indexed: 06/14/2023]
Abstract
Lipid membrane interfaces host reactions essential for the functioning of cells. The hydrogen-bonding environment at the membrane interface is particularly important for binding of proteins, drug molecules, and ions. We present here the implementation and applications of a depth-first search algorithm that analyzes dynamic lipid interaction networks. Lipid hydrogen-bond networks sampled transiently during simulations of lipid bilayers are clustered according to main types of topologies that characterize three-dimensional arrangements of lipids connected to each other via short water bridges. We characterize the dynamics of hydrogen-bonded lipid clusters in simulations of model POPE and POPE:POPG membranes that are often used for bacterial membrane proteins, in a model of the Escherichia coli membrane with six different lipid types, and in POPS membranes. We find that all lipids sample dynamic hydrogen-bonded networks with linear, star, or circular arrangements of the lipid headgroups, and larger networks with combinations of these three types of topologies. Overall, linear lipid-water bridges tend to be short. Water-mediated lipid clusters in all membranes with PE lipids tend to be somewhat small, with about four lipids in all membranes studied here. POPS membranes allow circular arrangements of three POPS lipids to be sampled frequently, and complex arrangements of linear, star, and circular paths may also be sampled. These findings suggest a molecular picture of the membrane interface whereby lipid molecules transiently connect in clusters with somewhat small spatial extension.
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Affiliation(s)
- Konstantina Karathanou
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, D-14195 Berlin, Germany
| | - Ana-Nicoleta Bondar
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, D-14195 Berlin, Germany; University of Bucharest, Faculty of Physics, Str. Atomiştilor 405, Bucharest-Măgurele 077125, Romania; Institute for Neuroscience and Medicine and Institute for Advanced Simulations (IAS-5/INM-9), Computational Biomedicine, Forschungszentrum Jülich, 52425 Jülich, Germany.
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34
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Boudreault F, Tan JJ, Grygorczyk R. Propidium uptake and ATP release in A549 cells share similar transport mechanisms. Biophys J 2022; 121:1593-1609. [PMID: 35398020 PMCID: PMC9117937 DOI: 10.1016/j.bpj.2022.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 03/03/2022] [Accepted: 04/04/2022] [Indexed: 11/02/2022] Open
Abstract
The lipid bilayer of eukaryotic cells' plasma membrane is almost impermeable to small ions and large polar molecules, but its miniscule basal permeability in intact cells is poorly characterized. This report describes the intrinsic membrane permeability of A549 cells toward the charged molecules propidium (Pr2+) and ATP4-. Under isotonic conditions, we detected with quantitative fluorescence microscopy, a continuous low-rate uptake of Pr (∼150 × 10-21 moles (zmol)/h/cell, [Pr]o = 150 μM, 32°C). It was stimulated transiently but strongly by 66% hypotonic cell swelling reaching an influx amplitude of ∼1500 (zmol/h)/cell. The progressive Pr uptake with increasing [Pr]o (30, 150, and 750 μM) suggested a permeation mechanism by simple diffusion. We quantified separately ATP release with custom wide-field-of-view chemiluminescence imaging. The strong proportionality between ATP efflux and Pr2+ influx during hypotonic challenge, and the absence of stimulation of transmembrane transport following 300% hypertonic shock, indicated that ATP and Pr travel the same conductive pathway. The fluorescence images revealed a homogeneously distributed intracellular uptake of Pr not consistent with high-conductance channels expressed at low density on the plasma membrane. We hypothesized that the pathway consists of transiently formed water pores evenly spread across the plasma membrane. The abolition of cell swelling-induced Pr uptake with 500 μM gadolinium, a known modulator of membrane fluidity, supported the involvement of water pores whose formation depends on the membrane fluidity. Our study suggests an alternative model of a direct permeation of ATP (and other molecules) through the phospholipid bilayer, which may have important physiological implications.
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Maltan L, Andova AM, Derler I. The Role of Lipids in CRAC Channel Function. Biomolecules 2022; 12:biom12030352. [PMID: 35327543 PMCID: PMC8944985 DOI: 10.3390/biom12030352] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/12/2022] [Accepted: 02/20/2022] [Indexed: 11/28/2022] Open
Abstract
The composition and dynamics of the lipid membrane define the physical properties of the bilayer and consequently affect the function of the incorporated membrane transporters, which also applies for the prominent Ca2+ release-activated Ca2+ ion channel (CRAC). This channel is activated by receptor-induced Ca2+ store depletion of the endoplasmic reticulum (ER) and consists of two transmembrane proteins, STIM1 and Orai1. STIM1 is anchored in the ER membrane and senses changes in the ER luminal Ca2+ concentration. Orai1 is the Ca2+-selective, pore-forming CRAC channel component located in the plasma membrane (PM). Ca2+ store-depletion of the ER triggers activation of STIM1 proteins, which subsequently leads to a conformational change and oligomerization of STIM1 and its coupling to as well as activation of Orai1 channels at the ER-PM contact sites. Although STIM1 and Orai1 are sufficient for CRAC channel activation, their efficient activation and deactivation is fine-tuned by a variety of lipids and lipid- and/or ER-PM junction-dependent accessory proteins. The underlying mechanisms for lipid-mediated CRAC channel modulation as well as the still open questions, are presented in this review.
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Bondar AN. Mechanisms of long-distance allosteric couplings in proton-binding membrane transporters. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2022; 128:199-239. [PMID: 35034719 DOI: 10.1016/bs.apcsb.2021.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Membrane transporters that use proton binding and proton transfer for function couple local protonation change with changes in protein conformation and water dynamics. Changes of protein conformation might be required to allow transient formation of hydrogen-bond networks that bridge proton donor and acceptor pairs separated by long distances. Inter-helical hydrogen-bond networks adjust rapidly to protonation change, and ensure rapid response of the protein structure and dynamics. Membrane transporters with known three-dimensional structures and proton-binding groups inform on general principles of protonation-coupled protein conformational dynamics. Inter-helical hydrogen bond motifs between proton-binding carboxylate groups and a polar sidechain are observed in unrelated membrane transporters, suggesting common principles of coupling protonation change with protein conformational dynamics.
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Affiliation(s)
- Ana-Nicoleta Bondar
- University of Bucharest, Faculty of Physics, Măgurele, Romania; Forschungszentrum Jülich, Institute of Computational Biomedicine, Jülich, Germany.
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Certain, but Not All, Tetraether Lipids from the Thermoacidophilic Archaeon Sulfolobus acidocaldarius Can Form Black Lipid Membranes with Remarkable Stability and Exhibiting Mthk Channel Activity with Unusually High Ca 2+ Sensitivity. Int J Mol Sci 2021; 22:ijms222312941. [PMID: 34884746 PMCID: PMC8657495 DOI: 10.3390/ijms222312941] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 11/25/2021] [Accepted: 11/27/2021] [Indexed: 11/19/2022] Open
Abstract
Bipolar tetraether lipids (BTL) have been long thought to play a critical role in allowing thermoacidophiles to thrive under extreme conditions. In the present study, we demonstrated that not all BTLs from the thermoacidophilic archaeon Sulfolobus acidocaldarius exhibit the same membrane behaviors. We found that free-standing planar membranes (i.e., black lipid membranes, BLM) made of the polar lipid fraction E (PLFE) isolated from S. acidocaldarius formed over a pinhole on a cellulose acetate partition in a dual-chamber Teflon device exhibited remarkable stability showing a virtually constant capacitance (~28 pF) for at least 11 days. PLFE contains exclusively tetraethers. The dominating hydrophobic core of PLFE lipids is glycerol dialky calditol tetraether (GDNT, ~90%), whereas glycerol dialkyl glycerol tetraether (GDGT) is a minor component (~10%). In sharp contrast, BLM made of BTL extracted from microvesicles (Sa-MVs) released from the same cells exhibited a capacitance between 36 and 39 pF lasting for only 8 h before membrane dielectric breakdown. Lipids in Sa-MVs are also exclusively tetraethers; however, the dominating lipid species in Sa-MVs is GDGT (>99%), not GDNT. The remarkable stability of BLMPLFE can be attributed to strong PLFE–PLFE and PLFE–substrate interactions. In addition, we compare voltage-dependent channel activity of calcium-gated potassium channels (MthK) in BLMPLFE to values recorded in BLMSa-MV. MthK is an ion channel isolated from a methanogenic that has been extensively characterized in diester lipid membranes and has been used as a model for calcium-gated potassium channels. We found that MthK can insert into BLMPLFE and exhibit channel activity, but not in BLMSa-MV. Additionally, the opening/closing of the MthK in BLMPLFE is detectable at calcium concentrations as low as 0.1 mM; conversely, in diester lipid membranes at such a low calcium concentration, no MthK channel activity is detectable. The differential effect of membrane stability and MthK channel activity between BLMPLFE and BLMSa-MV may be attributed to their lipid structural differences and thus their abilities to interact with the substrate and membrane protein. Since Sa-MVs that bud off from the plasma membrane are exclusively tetraether lipids but do not contain the main tetraether lipid component GDNT of the plasma membrane, domain segregation must occur in S. acidocaldarius. The implication of this study is that lipid domain formation is existent and functionally essential in all kinds of cells, but domain formation may be even more prevalent and pronounced in hyperthermophiles, as strong domain formation with distinct membrane behaviors is necessary to counteract randomization due to high growth temperatures while BTL in general make archaea cell membranes stable in high temperature and low pH environments whereas different BTL domains play different functional roles.
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Whitley P, Grau B, Gumbart JC, Martínez-Gil L, Mingarro I. Folding and Insertion of Transmembrane Helices at the ER. Int J Mol Sci 2021; 22:ijms222312778. [PMID: 34884581 PMCID: PMC8657811 DOI: 10.3390/ijms222312778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 01/16/2023] Open
Abstract
In eukaryotic cells, the endoplasmic reticulum (ER) is the entry point for newly synthesized proteins that are subsequently distributed to organelles of the endomembrane system. Some of these proteins are completely translocated into the lumen of the ER while others integrate stretches of amino acids into the greasy 30 Å wide interior of the ER membrane bilayer. It is generally accepted that to exist in this non-aqueous environment the majority of membrane integrated amino acids are primarily non-polar/hydrophobic and adopt an α-helical conformation. These stretches are typically around 20 amino acids long and are known as transmembrane (TM) helices. In this review, we will consider how transmembrane helices achieve membrane integration. We will address questions such as: Where do the stretches of amino acids fold into a helical conformation? What is/are the route/routes that these stretches take from synthesis at the ribosome to integration through the ER translocon? How do these stretches ‘know’ to integrate and in which orientation? How do marginally hydrophobic stretches of amino acids integrate and survive as transmembrane helices?
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Affiliation(s)
- Paul Whitley
- Department of Biology and Biochemistry, Centre for Regenerative Medicine, University of Bath, Bath BA2 7AY, UK;
| | - Brayan Grau
- Department of Biochemistry and Molecular Biology, Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, E-46100 Burjassot, Spain; (B.G.); (L.M.-G.)
| | - James C. Gumbart
- School of Physics, School of Chemistry and Biochemistry, Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Luis Martínez-Gil
- Department of Biochemistry and Molecular Biology, Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, E-46100 Burjassot, Spain; (B.G.); (L.M.-G.)
| | - Ismael Mingarro
- Department of Biochemistry and Molecular Biology, Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, E-46100 Burjassot, Spain; (B.G.); (L.M.-G.)
- Correspondence: ; Tel.: +34-963543796
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Wagner K, Smylla TK, Lampe M, Krieg J, Huber A. Phospholipase D and retromer promote recycling of TRPL ion channel via the endoplasmic reticulum. Traffic 2021; 23:42-62. [PMID: 34719094 DOI: 10.1111/tra.12824] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 10/20/2021] [Accepted: 10/26/2021] [Indexed: 12/27/2022]
Abstract
Plasma membrane protein trafficking is of fundamental importance for cell function and cell integrity of neurons and includes regulated protein recycling. In this work, we report a novel role of the endoplasmic reticulum (ER) for protein recycling as discovered in trafficking studies of the ion channel TRPL in photoreceptor cells of Drosophila. TRPL is located within the rhabdomeric membrane from where it is endocytosed upon light stimulation and stored in the cell body. Conventional immunohistochemistry as well as stimulated emission depletion super-resolution microscopy revealed TRPL storage at the ER after illumination, suggesting an unusual recycling route of TRPL. Our results also imply that both phospholipase D (PLD) and retromer complex are required for correct recycling of TRPL to the rhabdomeric membrane. Loss of PLD activity in PLD3.1 mutants results in enhanced degradation of TRPL. In the retromer mutant vps35MH20 , TRPL is trapped in a Rab5-positive compartment. Evidenced by epistatic analysis in the double mutant PLD3.1 vps35MH20 , PLD activity precedes retromer function. We propose a model in which PLD and retromer function play key roles in the transport of TRPL to an ER enriched compartment.
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Affiliation(s)
- Krystina Wagner
- Department of Biochemistry, University of Hohenheim, Institute of Biology, Stuttgart, Germany
| | - Thomas K Smylla
- Department of Biochemistry, University of Hohenheim, Institute of Biology, Stuttgart, Germany
| | - Marko Lampe
- European Molecular Biology Laboratory, Advanced Light Microscopy Core Facility, Heidelberg, Germany
| | - Jana Krieg
- Department of Biochemistry, University of Hohenheim, Institute of Biology, Stuttgart, Germany
| | - Armin Huber
- Department of Biochemistry, University of Hohenheim, Institute of Biology, Stuttgart, Germany
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Abstract
Lactococcus lactis strains residing in the microbial community of a complex dairy starter culture named “Ur” are hosts to prophages belonging to the family Siphoviridae. L. lactis strains (TIFN1 to TIFN7) showed detectable spontaneous phage production and release (109 to 1010 phage particles/ml) and up to 10-fold increases upon prophage induction, while in both cases we observed no obvious cell lysis typically described for the lytic life cycle of Siphoviridae phages. Intrigued by this phenomenon, we investigated the host-phage interaction using strain TIFN1 (harboring prophage proPhi1) as a representative. We confirmed that during the massive phage release, all bacterial cells remain viable. Further, by monitoring phage replication in vivo, using a green fluorescence protein reporter combined with flow cytometry, we demonstrated that the majority of the bacterial population (over 80%) is actively producing phage particles when induced with mitomycin C. The released tailless phage particles were found to be engulfed in lipid membranes, as evidenced by electron microscopy and lipid staining combined with chemical lipid analysis. Based on the collective observations, we propose a model of phage-host interaction in L. lactis TIFN1 where the phage particles are engulfed in membranes upon release, thereby leaving the producing host intact. Moreover, we discuss possible mechanisms of chronic, or nonlytic, release of LAB Siphoviridae phages and its impact on the bacterial host. IMPORTANCE In complex microbial consortia such as fermentation starters, bacteriophages can alter the dynamics and diversity of microbial communities. Bacteriophages infecting Lactococcus lactis are mostly studied for their detrimental impact on industrial dairy fermentation processes. In this study, we describe a novel form of phage-bacterium interaction in an L. lactis strain isolated from a complex dairy starter culture: when the prophages harbored in the L. lactis genome are activated, the phage particles are engulfed in lipid membranes upon release, leaving the producing host intact. Findings from this study provide additional insights into the diverse manners of phage-bacterium interactions and coevolution, which are essential for understanding the population dynamics in complex microbial communities like fermentation starters.
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Tran NH, Carter SD, De Mazière A, Ashkenazi A, Klumperman J, Walter P, Jensen GJ. The stress-sensing domain of activated IRE1α forms helical filaments in narrow ER membrane tubes. Science 2021; 374:52-57. [PMID: 34591618 PMCID: PMC9041316 DOI: 10.1126/science.abh2474] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The signaling network of the unfolded protein response (UPR) adjusts the protein-folding capacity of the endoplasmic reticulum (ER) according to need. The most conserved UPR sensor, IRE1α, spans the ER membrane and activates through oligomerization. IRE1α oligomers accumulate in dynamic foci. We determined the in situ structure of IRE1α foci by cryogenic correlated light and electron microscopy combined with electron cryo-tomography and complementary immuno–electron microscopy in mammalian cell lines. IRE1α foci localized to a network of narrow anastomosing ER tubes (diameter, ~28 nm) with complex branching. The lumen of the tubes contained protein filaments, which were likely composed of arrays of IRE1α lumenal domain dimers that were arranged in two intertwined, left-handed helices. This specialized ER subdomain may play a role in modulating IRE1α signaling.
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Affiliation(s)
- Ngoc-Han Tran
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Stephen D. Carter
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Ann De Mazière
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands
| | - Avi Ashkenazi
- Cancer Immunology, Genentech, Inc., South San Francisco, CA, USA
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands
| | - Peter Walter
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
- Corresponding author. (P.W.); (G.J.J.)
| | - Grant J. Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
- Corresponding author. (P.W.); (G.J.J.)
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Segawa K, Kikuchi A, Noji T, Sugiura Y, Hiraga K, Suzuki C, Haginoya K, Kobayashi Y, Matsunaga M, Ochiai Y, Yamada K, Nishimura T, Iwasawa S, Shoji W, Sugihara F, Nishino K, Kosako H, Ikawa M, Uchiyama Y, Suematsu M, Ishikita H, Kure S, Nagata S. A sublethal ATP11A mutation associated with neurological deterioration causes aberrant phosphatidylcholine flipping in plasma membranes. J Clin Invest 2021; 131:e148005. [PMID: 34403372 DOI: 10.1172/jci148005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 08/05/2021] [Indexed: 01/01/2023] Open
Abstract
ATP11A translocates phosphatidylserine (PtdSer), but not phosphatidylcholine (PtdCho), from the outer to the inner leaflet of plasma membranes, thereby maintaining the asymmetric distribution of PtdSer. Here, we detected a de novo heterozygous point mutation of ATP11A in a patient with developmental delays and neurological deterioration. Mice carrying the corresponding mutation died perinatally of neurological disorders. This mutation caused an amino acid substitution (Q84E) in the first transmembrane segment of ATP11A, and mutant ATP11A flipped PtdCho. Molecular dynamics simulations revealed that the mutation allowed PtdCho binding at the substrate entry site. Aberrant PtdCho flipping markedly decreased the concentration of PtdCho in the outer leaflet of plasma membranes, whereas sphingomyelin (SM) concentrations in the outer leaflet increased. This change in the distribution of phospholipids altered cell characteristics, including cell growth, cholesterol homeostasis, and sensitivity to sphingomyelinase. Matrix-assisted laser desorption ionization-imaging mass spectrometry (MALDI-IMS) showed a marked increase of SM levels in the brains of Q84E-knockin mouse embryos. These results provide insights into the physiological importance of the substrate specificity of plasma membrane flippases for the proper distribution of PtdCho and SM.
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Affiliation(s)
- Katsumori Segawa
- Laboratory of Biochemistry and Immunology, World Premier International Research Center, Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Atsuo Kikuchi
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Miyagi, Japan
| | - Tomoyasu Noji
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Yuki Sugiura
- Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan
| | - Keita Hiraga
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Chigure Suzuki
- Department of Cellular and Molecular Pharmacology and.,Department of Cellular and Neuropathology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Kazuhiro Haginoya
- Department of Pediatric Neurology, Takuto Rehabilitation Center for Children, Sendai, Miyagi, Japan.,Department of Pediatric Neurology, Miyagi Children's Hospital, Sendai, Miyagi, Japan
| | - Yasuko Kobayashi
- Department of Pediatric Neurology, Takuto Rehabilitation Center for Children, Sendai, Miyagi, Japan.,Department of Pediatrics, National Hospital Organization Sendai-Nishitaga Hospital, Sendai, Miyagi, Japan
| | - Mitsuhiro Matsunaga
- Laboratory of Biochemistry and Immunology, World Premier International Research Center, Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Yuki Ochiai
- Laboratory of Biochemistry and Immunology, World Premier International Research Center, Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Kyoko Yamada
- Laboratory of Biochemistry and Immunology, World Premier International Research Center, Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Takuo Nishimura
- Laboratory of Biochemistry and Immunology, World Premier International Research Center, Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Shinya Iwasawa
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Miyagi, Japan
| | - Wataru Shoji
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Fuminori Sugihara
- Central Instrumentation Laboratory, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Kohei Nishino
- Division of Cell Signaling, Fujii Memorial Institute of Medical Sciences, Tokushima University, Tokushima, Japan
| | - Hidetaka Kosako
- Division of Cell Signaling, Fujii Memorial Institute of Medical Sciences, Tokushima University, Tokushima, Japan
| | - Masahito Ikawa
- Department of Experimental Genome Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Yasuo Uchiyama
- Department of Cellular and Molecular Pharmacology and.,Department of Cellular and Neuropathology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Makoto Suematsu
- Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan
| | - Hiroshi Ishikita
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Shigeo Kure
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Miyagi, Japan.,Tohoku Medical Megabank Organization, Tohoku University, Sendai, Miyagi, Japan
| | - Shigekazu Nagata
- Laboratory of Biochemistry and Immunology, World Premier International Research Center, Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan.,Center for Infectious Disease Education and Research, Osaka University, Suita, Osaka, Japan
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Lujan P, Campelo F. Should I stay or should I go? Golgi membrane spatial organization for protein sorting and retention. Arch Biochem Biophys 2021; 707:108921. [PMID: 34038703 DOI: 10.1016/j.abb.2021.108921] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/12/2021] [Accepted: 05/03/2021] [Indexed: 12/23/2022]
Abstract
The Golgi complex is the membrane-bound organelle that lies at the center of the secretory pathway. Its main functions are to maintain cellular lipid homeostasis, to orchestrate protein processing and maturation, and to mediate protein sorting and export. These functions are not independent of one another, and they all require that the membranes of the Golgi complex have a well-defined biochemical composition. Importantly, a finely-regulated spatiotemporal organization of the Golgi membrane components is essential for the correct performance of the organelle. In here, we review our current mechanistic and molecular understanding of how Golgi membranes are spatially organized in the lateral and axial directions to fulfill their functions. In particular, we highlight the current evidence and proposed models of intra-Golgi transport, as well as the known mechanisms for the retention of Golgi residents and for the sorting and export of transmembrane cargo proteins. Despite the controversies, conflicting evidence, clashes between models, and technical limitations, the field has moved forward and we have gained extensive knowledge in this fascinating topic. However, there are still many important questions that remain to be completely answered. We hope that this review will help boost future investigations on these issues.
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Affiliation(s)
- Pablo Lujan
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860, Barcelona, Spain.
| | - Felix Campelo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860, Barcelona, Spain.
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Liaci AM, Steigenberger B, Telles de Souza PC, Tamara S, Gröllers-Mulderij M, Ogrissek P, Marrink SJ, Scheltema RA, Förster F. Structure of the human signal peptidase complex reveals the determinants for signal peptide cleavage. Mol Cell 2021; 81:3934-3948.e11. [PMID: 34388369 DOI: 10.1016/j.molcel.2021.07.031] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 06/02/2021] [Accepted: 07/26/2021] [Indexed: 12/18/2022]
Abstract
The signal peptidase complex (SPC) is an essential membrane complex in the endoplasmic reticulum (ER), where it removes signal peptides (SPs) from a large variety of secretory pre-proteins with exquisite specificity. Although the determinants of this process have been established empirically, the molecular details of SP recognition and removal remain elusive. Here, we show that the human SPC exists in two functional paralogs with distinct proteolytic subunits. We determined the atomic structures of both paralogs using electron cryo-microscopy and structural proteomics. The active site is formed by a catalytic triad and abuts the ER membrane, where a transmembrane window collectively formed by all subunits locally thins the bilayer. Molecular dynamics simulations indicate that this unique architecture generates specificity for SPs based on the length of their hydrophobic segments.
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Affiliation(s)
- A Manuel Liaci
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, the Netherlands
| | - Barbara Steigenberger
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands; Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, the Netherlands
| | - Paulo Cesar Telles de Souza
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, the Netherlands; Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS and University of Lyon, Lyon, France
| | - Sem Tamara
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands; Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, the Netherlands
| | - Mariska Gröllers-Mulderij
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, the Netherlands
| | - Patrick Ogrissek
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, the Netherlands; Institute of Chemistry and Metabolomics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, the Netherlands
| | - Richard A Scheltema
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands; Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, the Netherlands
| | - Friedrich Förster
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, the Netherlands.
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45
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Single-molecule fluorescence vistas of how lipids regulate membrane proteins. Biochem Soc Trans 2021; 49:1685-1694. [PMID: 34346484 DOI: 10.1042/bst20201074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 12/17/2022]
Abstract
The study of membrane proteins is undergoing a golden era, and we are gaining unprecedented knowledge on how this key group of proteins works. However, we still have only a basic understanding of how the chemical composition and the physical properties of lipid bilayers control the activity of membrane proteins. Single-molecule (SM) fluorescence methods can resolve sample heterogeneity, allowing to discriminate between the different molecular populations that biological systems often adopt. This short review highlights relevant examples of how SM fluorescence methodologies can illuminate the different ways in which lipids regulate the activity of membrane proteins. These studies are not limited to lipid molecules acting as ligands, but also consider how the physical properties of the bilayer can be determining factors on how membrane proteins function.
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Chen X, Lim X, Bouin A, Lautier T, Zhang C. High-level de novo biosynthesis of glycosylated zeaxanthin and astaxanthin in Escherichia coli. BIORESOUR BIOPROCESS 2021; 8:67. [PMID: 38650269 PMCID: PMC10992962 DOI: 10.1186/s40643-021-00415-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/05/2021] [Indexed: 11/10/2022] Open
Abstract
Because of wide applications in food, feed, pharmaceutical and cosmetic industries, the carotenoid market is growing rapidly. Most carotenoids are hydrophobic, which limits their bioavailability. Glycosylation is a natural route that substantially increases the water solubility, as well as the bioavailability, photostability and biological activities of carotenoids. Here, we report metabolic engineering efforts (e.g., promoter and RBS engineering, optimization of carbon sources and supplementation of bottleneck genes) to produce glycosylated carotenoids in Escherichia coli. By fine-tuning the carotenoid-biosynthetic genes (crtX, crtZ and crtY), our strain produced up to 47.2 mg/L (~ 11,670 ppm) of zeaxanthin glucosides, ~ 78% of the total carotenoids produced. In another construct with mevalonate, astaxanthin pathway and crtX genes, the strain produced a mixture of carotenoid glucosides including astaxanthin and adonixanthin glucosides with a total yield of 8.1 mg/L (1774 ppm). Our work demonstrated a proof-of-concept study for the microbial biosynthesis of glycosylated carotenoids.
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Affiliation(s)
- Xixian Chen
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Proteos level 4, Nanos, 138673, Singapore
| | - Xiaohui Lim
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Proteos level 4, Nanos, 138673, Singapore
| | - Aurélie Bouin
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Proteos level 4, Nanos, 138673, Singapore
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Thomas Lautier
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Proteos level 4, Nanos, 138673, Singapore
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Congqiang Zhang
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Proteos level 4, Nanos, 138673, Singapore.
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Cao L, Do T, Link AJ. Mechanisms of action of ribosomally synthesized and posttranslationally modified peptides (RiPPs). J Ind Microbiol Biotechnol 2021; 48:6121428. [PMID: 33928382 PMCID: PMC8183687 DOI: 10.1093/jimb/kuab005] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 01/22/2021] [Indexed: 12/19/2022]
Abstract
Natural products remain a critical source of medicines and drug leads. One of the most rapidly growing superclasses of natural products is RiPPs: ribosomally synthesized and posttranslationally modified peptides. RiPPs have rich and diverse bioactivities. This review highlights examples of the molecular mechanisms of action that underly those bioactivities. Particular emphasis is placed on RiPP/target interactions for which there is structural information. This detailed mechanism of action work is critical toward the development of RiPPs as therapeutics and can also be used to prioritize hits in RiPP genome mining studies.
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Affiliation(s)
- Li Cao
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Truc Do
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - A James Link
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.,Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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48
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Ligand binding at the protein-lipid interface: strategic considerations for drug design. Nat Rev Drug Discov 2021; 20:710-722. [PMID: 34257432 DOI: 10.1038/s41573-021-00240-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2021] [Indexed: 12/11/2022]
Abstract
Many drug targets are embedded within the phospholipid bilayer of cellular membranes, including G protein-coupled receptors, ion channels, transporters and membrane-bound enzymes. Increasing evidence from biophysical and structural studies suggests that many small-molecule drugs commonly associate with these targets at binding sites at the protein-phospholipid interface. Without a direct path from bulk solvent to a binding site, a drug must first partition in the phospholipid membrane before interacting with the protein target. This membrane access mechanism necessarily affects the interpretation of potency data, structure-activity relationships, pharmacokinetics and physicochemical properties for drugs that target these sites. With an increasing number of small-molecule intramembrane binding sites revealed through X-ray crystallography and cryogenic electron microscopy, we suggest that ligand-lipid interactions likely play a larger role in small-molecule drug action than commonly appreciated. This Perspective introduces key concepts and drug design considerations to aid discovery teams operating within this target space, and discusses challenges and future opportunities in the field.
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Unwin N. Protein-Lipid Interplay at the Neuromuscular Junction. Microscopy (Oxf) 2021; 71:i66-i71. [PMID: 34226930 PMCID: PMC8855523 DOI: 10.1093/jmicro/dfab023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/25/2021] [Accepted: 07/05/2021] [Indexed: 01/11/2023] Open
Abstract
Many new structures of membrane proteins have been determined over the last decade, yet the nature of protein–lipid interplay has received scant attention. The postsynaptic membrane of the neuromuscular junction and Torpedo electrocytes has a regular architecture, opening an opportunity to illuminate how proteins and lipids act together in a native membrane setting. Cryo electron microscopy (Cryo-EM) images show that cholesterol segregates preferentially around the constituent ion channel, the nicotinic acetylcholine receptor, interacting with specific sites in both leaflets of the bilayer. In addition to maintaining the transmembrane α-helical architecture, cholesterol forms microdomains – bridges of rigid sterol groups that link one channel to the next. This article discusses the whole protein–lipid organization of the cholinergic postsynaptic membrane, its physiological implications and how the observed details relate to our current concept of the membrane structure. I suggest that cooperative interactions, facilitated by the regular protein–lipid arrangement, help to spread channel activation into regions distant from the sites of neurotransmitter release, thereby enhancing the postsynaptic response.
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Affiliation(s)
- Nigel Unwin
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, CB2 0QH, Cambridge, UK
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50
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Parks SZ, Gao T, Jimenez Awuapura N, Ayathamattam J, Chabosseau PL, Kalvakolanu DV, Valdivia HH, Rutter GA, Leclerc I. The Ca 2+ -binding protein sorcin stimulates transcriptional activity of the unfolded protein response mediator ATF6. FEBS Lett 2021; 595:1782-1796. [PMID: 33960419 DOI: 10.1002/1873-3468.14101] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 12/13/2022]
Abstract
Sorcin is a calcium-binding protein involved in maintaining endoplasmic reticulum (ER) Ca2+ stores. We have previously shown that overexpressing sorcin under the rat insulin promoter was protective against high-fat diet-induced pancreatic beta-cell dysfunction in vivo. Activating transcription factor 6 (ATF6) is a key mediator of the unfolded protein response (UPR) that provides cellular protection during the progression of ER stress. Here, using nonexcitable HEK293 cells, we show that sorcin overexpression increased ATF6 signalling, whereas sorcin knock out caused a reduction in ATF6 transcriptional activity and increased ER stress. Altogether, our data suggest that sorcin downregulation during lipotoxic stress may prevent full ATF6 activation and a normal UPR during the progression of obesity and insulin resistance.
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Affiliation(s)
- Steven Z Parks
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion & Reproduction, Imperial College London, UK
| | - Tian Gao
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion & Reproduction, Imperial College London, UK
| | - Natalia Jimenez Awuapura
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion & Reproduction, Imperial College London, UK
| | - Joseph Ayathamattam
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion & Reproduction, Imperial College London, UK
| | - Pauline L Chabosseau
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion & Reproduction, Imperial College London, UK
| | - Dhananjaya V Kalvakolanu
- Departments of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Héctor H Valdivia
- Cardiovascular Research Center, University of Wisconsin-Madison, WI, USA
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion & Reproduction, Imperial College London, UK
| | - Isabelle Leclerc
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion & Reproduction, Imperial College London, UK
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