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Noguchi H. Curvature-sensing and generation by membrane proteins: a review. SOFT MATTER 2025; 21:3922-3940. [PMID: 40302616 DOI: 10.1039/d5sm00101c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2025]
Abstract
Membrane proteins are crucial in regulating biomembrane shapes and controlling the dynamic changes in membrane morphology during essential cellular processes. These proteins can localize to regions with their preferred curvatures (curvature sensing) and induce localized membrane curvature. Thus, this review describes the recent theoretical development in membrane remodeling performed by membrane proteins. The mean-field theories of protein binding and the resulting membrane deformations are reviewed. The effects of hydrophobic insertions on the area-difference elasticity energy and that of intrinsically disordered protein domains on the membrane bending energy are discussed. For the crescent-shaped proteins, such as Bin/Amphiphysin/Rvs superfamily proteins, anisotropic protein bending energy and orientation-dependent excluded volume significantly contribute to curvature sensing and generation. Moreover, simulation studies of membrane deformations caused by protein binding are reviewed, including domain formation, budding, and tubulation.
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Affiliation(s)
- Hiroshi Noguchi
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
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2
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Alsayyah C, Rodrigues E, Hach J, Renne MF, Ernst R. Reversible tuning of membrane sterol levels by cyclodextrin in a dialysis setting. Biophys J 2025; 124:1433-1445. [PMID: 40143542 DOI: 10.1016/j.bpj.2025.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2024] [Revised: 02/14/2025] [Accepted: 03/21/2025] [Indexed: 03/28/2025] Open
Abstract
Large unilamellar vesicles are popular membrane models for studying the impact of lipids and bilayer properties on the structure and function of transmembrane proteins. However, the functional reconstitution of transmembrane proteins in liposomes can be challenging, especially if the hydrophobic thickness of the protein does not match the thickness of the lipid bilayer. Such hydrophobic mismatch causes protein aggregation and low yields during the reconstitution procedure, which are exacerbated in sterol-rich membranes featuring low membrane compressibility. Here, we explore new approaches to reversibly tune the sterol content of (proteo)liposomes with methyl-β-cyclodextrin (mβCD) in a dialysis setting. Maintaining (proteo)liposomes in a confined compartment minimizes loss of material during cholesterol transfer and facilitates efficient removal of mβCD. We monitor the sterol concentration in the membrane with help of the solvatochromic probe C-Laurdan, which reports on lipid packing. Using Förster resonance energy transfer, we show that cholesterol delivery to proteoliposomes induces the oligomerization of a membrane property sensor, whereas a subsequent removal of cholesterol demonstrates full reversibility. We propose that tuning membrane compressibility by mβCD-meditated cholesterol delivery and removal in a dialysis setup provides a new handle to study the impact of sterols and membrane compressibility on membrane protein structure, function, and dynamics.
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Affiliation(s)
- Cynthia Alsayyah
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Saar, Germany; Preclinical Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, Homburg, Saar, Germany; Center for Biophysics (ZBP), Saarland University, Saarland, Germany
| | - Emmanuel Rodrigues
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Saar, Germany; Preclinical Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, Homburg, Saar, Germany; Center for Biophysics (ZBP), Saarland University, Saarland, Germany
| | - Julia Hach
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Saar, Germany; Preclinical Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, Homburg, Saar, Germany; Center for Biophysics (ZBP), Saarland University, Saarland, Germany
| | - Mike F Renne
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Saar, Germany; Preclinical Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, Homburg, Saar, Germany; Center for Biophysics (ZBP), Saarland University, Saarland, Germany
| | - Robert Ernst
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Saar, Germany; Preclinical Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, Homburg, Saar, Germany; Center for Biophysics (ZBP), Saarland University, Saarland, Germany.
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3
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Volgusheva AA, Hao J, He Y, Lovyagina ER, Loktyushkin AV, Parshina EY, Luneva OG, Baizhumanov AA, Khruschev SS, Maksimov GV, Rubin AB. Effect of the insecticide clothianidin on the photosynthetic electron transport chain in pea. Photochem Photobiol 2025; 101:580-591. [PMID: 39219414 DOI: 10.1111/php.14018] [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: 03/24/2024] [Revised: 07/09/2024] [Accepted: 08/17/2024] [Indexed: 09/04/2024]
Abstract
Clothianidin (CL) is a neonicotinoid insecticide widely used in crop protection against insect pests. However, its effects on photosynthesis remain largely unknown. Here, by investigating the influence of CL at the concentrations of 22 and 110 μg/L on the primary processes of photosynthesis, membrane fluidity and structural changes of pea chloroplasts, we located several primary binding sites of this pesticide. Similar dynamics were observed for both concentrations. However, statistically significant differences were only found at 110 μg/L for all methods used. The light saturated rate of linear electron flow decreased mainly due to the disturbance of electron flow on the acceptor side of photosystem II (PSII) associated with the appearance of QB-nonreducing centers and empty QB binding sites of PSII. The functioning of the donor side of PSII, the activity of photosystem I (PSI) and the maximum quantum yield of PSII photochemistry (Fv/Fm) were not found to be significantly altered. Increased membrane fluidity and structural alterations of the thylakoid membrane led to a decrease in the development of the proton gradient ΔрН and membrane energization processes.
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Affiliation(s)
- Alena A Volgusheva
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Jingrao Hao
- Faculty of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Yanlin He
- Faculty of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Elena R Lovyagina
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Aleksey V Loktyushkin
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Evgenia Yu Parshina
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Oksana G Luneva
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Adil A Baizhumanov
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Sergei S Khruschev
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Georgy V Maksimov
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Andrew B Rubin
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
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4
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Zheng S, Sarker P, Gursoy D, Wei T, Hsiao BS. Molecular Mechanisms of Perfluoroalkyl Substances Integration into Phospholipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2025; 41:9369-9376. [PMID: 40173325 DOI: 10.1021/acs.langmuir.5c00124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2025]
Abstract
Understanding the molecular interactions of per- and polyfluoroalkyl substances (PFAS) with phospholipids is crucial for elucidating their pathological mechanisms and developing PFAS remediation strategies. In this study, we employ atomistic molecular dynamics simulations to examine PFAS insertion into phospholipid bilayers, including anionic perfluorooctanesulfonic acid (PFOS), perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA), and perfluorododecanoic acid (PFDoA), as well as neutral polytetrafluoroethylene (PTFE). Our study shows that PFAS insertion into lipid bilayers is driven by the free energy gradient between bulk water and the lipid membrane. Positively charged trimethylammonium groups of phospholipids attract negatively charged PFAS, overcoming the surface hydration barrier. Hydrophobic interactions between PFAS fluoroalkyl tails and lipid chains generate a significant driving force for PFAS reorientation and insertion. The increase in electrostatic potential across the lipid surface aids anionic PFAS insertion, but their dehydration hinders further movement. PFAS insertion enhances membrane ordering and decreases lipid fluidity, potentially affecting cellular functions by modifying membrane rigidity. The extended chain length of PFAS facilitates its interactions with the lipid membrane, resulting in a more pronounced influence on altering its structural and dynamic properties.
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Affiliation(s)
- Size Zheng
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Pranab Sarker
- Department of Biomedical Engineering, University of South Carolina, Columbia, South Carolina 29208, United States
- Department of Chemical Engineering, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Deniz Gursoy
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Tao Wei
- Department of Biomedical Engineering, University of South Carolina, Columbia, South Carolina 29208, United States
- Department of Chemical Engineering, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Benjamin S Hsiao
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
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5
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Majdolhosseini M, Kleiven S, Villa A. Molecular dynamics study of stiffness and rupture of axonal membranes. Brain Res Bull 2025; 223:111266. [PMID: 39993508 DOI: 10.1016/j.brainresbull.2025.111266] [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: 02/19/2025] [Accepted: 02/21/2025] [Indexed: 02/26/2025]
Abstract
Diffuse axonal injury (DAI), characterized by widespread damage to axons throughout the brain, represents one of the most devastating and difficult-to-treat forms of traumatic brain injury. Different theories exist about the mechanism of DAI, among which one hypothesis states that membrane poration of the axons initiates DAI. To investigate the hypothesis, molecular models of axonal membranes, incorporating 25 different lipids distributed asymmetrically in the leaflets, were developed using a coarse-grain description and simulated using molecular dynamics techniques. Different protein concentrations were embedded inside the lipid bilayer to describe the different sub-cellular parts in myelinated and unmyelinated axons. The models were investigated in equilibration and under deformation to characterize the structural and mechanical properties of the membranes, and comparisons were made with other subcellular parts, particularly myelin. Employing a bottom-top approach, the results were coupled with a finite element model representing the axon at the cell level. The results indicate that pore formation in the node-of-Ranvier occurs at a lower rupture strain compared to other axolemma parts, whereas myelin poration exhibits the highest rupture strains among the investigated models. The observed rupture strain for the node-of-Ranvier aligns with experimental studies, indicating a threshold for injury at axonal strains exceeding 10-13 % depending on the strain rate. The results indicate that the hypothesis suggesting mechanoporation triggers axonal injury cannot be dismissed, as this phenomenon occurs within the threshold of axonal injury.
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Affiliation(s)
| | - Svein Kleiven
- Neuronic Engineering KTH Royal Institute of Technology, Stockholm 14152, Sweden
| | - Alessandra Villa
- PDC Center for High-Performance Computing KTH-Royal Institute of Technology, Stockholm 11428, Sweden.
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6
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DiPasquale M, Dziura M, Gbadamosi O, Castillo SR, Fahim A, Roberto J, Atkinson J, Boccalon N, Campana M, Pingali SV, Chandrasekera PC, Zolnierczuk PA, Nagao M, Kelley EG, Marquardt D. Vitamin E Acetate Causes Softening of Pulmonary Surfactant Membrane Models. Chem Res Toxicol 2025; 38:400-414. [PMID: 39970241 DOI: 10.1021/acs.chemrestox.4c00425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2025]
Abstract
The popularity of electronic cigarettes and vaping products has launched the outbreak of a condition affecting the respiratory system of users, known as electronic-cigarette/vaping-associated lung injury (EVALI). The build-up of vitamin E acetate (VEA), a diluent of some illicit vaping oils, in the bronchoalveolar lavage of patients with EVALI provided circumstantial evidence as a target for investigation. In this work, we provide a fundamental characterization of the interaction of VEA with lung cells and pulmonary surfactant (PS) models to explore the mechanisms by which vaping-related lung injuries may be present. We first confirm the localization and uptake of VEA in pulmonary epithelial cells. Further, as PS is vitally responsible for the biophysical functions of the lungs, we explore the effect of added VEA on three increasingly complex models of PS: dipalmitoylphosphatidylcholine (DPPC), a lipid-only synthetic PS, and the biologically derived extract Curosurf. Using high-resolution techniques of small-angle X-ray scattering, small-angle neutron scattering, neutron spin-echo spectroscopy, and neutron reflectometry, we compare the molecular-scale behaviors of these membranes to the bulk viscoelastic properties of surfactant monolayer films as studied by Langmuir monolayer techniques. While VEA does not obviously alter the structure or organization of PS membranes, a consistent softening of membrane systems─regardless of compositional complexity─provides a biophysical explanation for the respiratory distress associated with EVALI and yields a new perspective on the behavior of the PS system.
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Affiliation(s)
- Mitchell DiPasquale
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Maksymilian Dziura
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Omotayo Gbadamosi
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Stuart R Castillo
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Ambreen Fahim
- Canadian Centre for Alternatives to Animal Methods, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Justin Roberto
- Canadian Centre for Alternatives to Animal Methods, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Jeffrey Atkinson
- Department of Chemistry, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Natalie Boccalon
- Department of Chemistry, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Mario Campana
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, U.K
| | - Sai Venkatesh Pingali
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - P Charukeshi Chandrasekera
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Canadian Centre for Alternatives to Animal Methods, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Piotr A Zolnierczuk
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Michihiro Nagao
- National Institute of Standards and Technology, Center for Neutron Research, Gaithersburg, Maryland 20899, United States
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, United States
| | - Elizabeth G Kelley
- National Institute of Standards and Technology, Center for Neutron Research, Gaithersburg, Maryland 20899, United States
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Department of Physics, University of Windsor, Windsor, ON N9B 3P4, Canada
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7
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Kulkarni C, Gestsson HÓ, Cupellini L, Mennucci B, Olaya-Castro A. Theory of photosynthetic membrane influence on B800-B850 energy transfer in the LH2 complex. Biophys J 2025; 124:722-739. [PMID: 39849841 PMCID: PMC11897548 DOI: 10.1016/j.bpj.2025.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2024] [Revised: 12/06/2024] [Accepted: 01/17/2025] [Indexed: 01/25/2025] Open
Abstract
Photosynthetic organisms rely on a network of light-harvesting protein-pigment complexes to efficiently absorb sunlight and transfer excitation energy to reaction center proteins where charge separation occurs. In photosynthetic purple bacteria, these complexes are embedded within the cell membrane, with lipid composition affecting complex clustering, thereby impacting inter-complex energy transfer. However, the impact of the lipid bilayer on intra-complex excitation dynamics is less understood. Recent experiments have addressed this question by comparing photo-excitation dynamics in detergent-isolated light-harvesting complex 2 (LH2) to LH2 complexes embedded in membrane discs mimicking the biological environment, revealing differences in spectra and energy-transfer rates. In this paper, we use available quantum chemical and spectroscopy data to develop a complementary theoretical study on the excitonic structure and intra-complex energy-transfer kinetics of the LH2 of photosynthetic purple bacteria Rhodoblastus (Rbl.) acidophilus (formerly Rhodopseudomonas acidophila) in two different conditions: the LH2 in a membrane environment and detergent-isolated LH2. We find that dark excitonic states, crucial for B800-B850 energy transfer within LH2, are more delocalized in the membrane model. Using nonperturbative and generalized Förster calculations, we show that such increased quantum delocalization results in a 30% faster B800 to B850 transfer rate in the membrane model, in agreement with experimental results. We identify the dominant energy-transfer pathways in each environment and demonstrate how differences in the B800 to B850 transfer rate arise from changes in LH2's electronic properties when embedded in the membrane. Furthermore, by accounting for the quasi-static variations of electronic excitation energies in the LH2, we show that the broadening of the distribution of the B800-B850 transfer rates is affected by the lipid composition. We argue that such variation in broadening could be a signature of a speed-accuracy trade-off, commonly seen in biological process.
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Affiliation(s)
- Chawntell Kulkarni
- Department of Physics and Astronomy, University College London, London, United Kingdom.
| | | | - Lorenzo Cupellini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa, Italy
| | - Benedetta Mennucci
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa, Italy
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8
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Su J, Zhao L, Fu R, Tang Z. Linking Circadian Rhythms to Gut-Brain Axis Lipid Metabolism Associated With Endoplasmic Reticulum Stress in Alzheimer's Disease. CNS Neurosci Ther 2025; 31:e70329. [PMID: 40059063 PMCID: PMC11890981 DOI: 10.1111/cns.70329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2024] [Revised: 02/02/2025] [Accepted: 02/26/2025] [Indexed: 05/13/2025] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is characterized by a decline in cognitive, learning, and memory abilities. Neuroinflammation is associated with the spread of tau tangles in the neocortex of AD, leading to cognitive impairment. Therefore, clarifying the pathogenesis of Neuroinflammation and finding effective treatments are the crucial issues for the clinical management of AD. METHOD We systematically review the latest research on the pathogenesis and therapeutic strategies of AD in PubMed, Web of Science, and Elsevier SD. RESULT In this review, the mechanism of the effect of gut-brain axis lipid metabolism mediated by circadian rhythm on AD was discussed, and we also analysed the effects of inflammation and endoplasmic reticulum stress (ERS) induced by lipid abnormalities on intestinal mucosal barrier and neurodegeneration; furthermore, the importance of lipid homeostasis (phospholipids, fatty acids, sterol) in maintaining the functions of endoplasmic reticulum was emphasized. Meanwhile, as lipid composition affects protein conformation, the membrane phospholipids surrounding sarcoplasmic reticulum Ca2+-ATPase (SERCA) that influence SERCA to release Ca2+ mediating inflammation were also reviewed. CONCLUSION We interpreted the mechanism of action between lipid microdomains and ER membrane proteins, reviewed the role of the new pathway of circadian rhythm, lipid metabolism, intestinal mucosa, and brain signaling in the pathogenesis of AD, and proposed strategies to prevent AD by changing the dietary lipid measures.
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Affiliation(s)
- Jianhui Su
- School of Marine and BioengineeringYancheng Institute of TechnologyYanchengJiangsuChina
| | - Lanyang Zhao
- School of PharmacyNanjing University of Chinese MedicineNanjingChina
| | - Runze Fu
- School of Marine and BioengineeringYancheng Institute of TechnologyYanchengJiangsuChina
| | - Zhe Tang
- School of Chemistry & Chemical EngineeringYancheng Institute of TechnologyYanchengJiangsuChina
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9
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Duranti C, Iorio J, Manganelli V, Bagni G, Colasurdo R, Lottini T, Martinelli M, Capitani C, Boso G, D'Alessandro FN, Sorice M, Becchetti A, Misasi R, Garofalo T, Arcangeli A. Targeting the hERG1/β1 integrin complex in lipid rafts potentiates statins anti-cancer activity in pancreatic cancer. Cell Death Discov 2025; 11:39. [PMID: 39900574 PMCID: PMC11790905 DOI: 10.1038/s41420-025-02321-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2024] [Revised: 12/18/2024] [Accepted: 01/22/2025] [Indexed: 02/05/2025] Open
Abstract
Plasma membrane macromolecular complexes function as signaling hubs that regulate cell behavior, which is particularly relevant in cancer. Our study provides evidence that the complex formed by the hERG1 potassium channel and the β1 subunit of integrin receptors preferentially localizes in Lipid Rafts (LRs) in Pancreatic Ductal Adenocarcinoma (PDAC) cell lines and primary samples. The complex recruits the p85 subunit of phosphatidyl-inositol-3-kinase (PI3K), activating phosphoinositide metabolism and triggering an intracellular signaling pathway centered on Akt. This pathway ultimately affects cancer cell proliferation through cyclins and p21, and cell migration through the small GTPase Rac-1 and f-actin organization. The hERG1/β1 integrin complex in LRs can be dissociated and the downstream signaling pathway can be inhibited by either disrupting LRs through methyl-beta-cyclodextrin (MβCD) or inhibiting cholesterol synthesis by statins. Treatment with a single chain bispecific antibody-scDb-hERG1-β1-specifically targeting the complex significantly potentiates the effects of both MβCD and statins on intracellular signaling. Consequently, these treatments decrease PDAC cell proliferation and motility in vitro. From a pharmacological perspective, different statins produce anti-neoplastic effects in synergy with scDb-hERG1-β1. Such combination also enhances tumor sensitivity to chemotherapeutic drugs, such as gemcitabine and oxaliplatin. The efficacy of these combination treatments depends on the amount of the hERG1/β1 integrin complex present on the plasma membrane of cancer cells. Finally, the combined treatment with statins and scDb-hERG1-β1 significantly reduces tumor growth and improves survival in vivo, in a preclinical mouse model. These results suggest that the combination of scDb-hERG1-β1 and statins represent a potential novel strategy for treating PDAC patients.
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Affiliation(s)
- Claudia Duranti
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Jessica Iorio
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | | | - Giacomo Bagni
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Rossella Colasurdo
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Tiziano Lottini
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Michele Martinelli
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Chiara Capitani
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Giulia Boso
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Franco Nicolas D'Alessandro
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Maurizio Sorice
- Department of Experimental Medicine, "Sapienza" University, Rome, Italy
| | - Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Milan, Italy
| | - Roberta Misasi
- Department of Experimental Medicine, "Sapienza" University, Rome, Italy
| | - Tina Garofalo
- Department of Experimental Medicine, "Sapienza" University, Rome, Italy
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy.
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10
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Rodgers MJ, Staves MP. Mechanosensing and anesthesia of single internodal cells of Chara. PLANT SIGNALING & BEHAVIOR 2024; 19:2339574. [PMID: 38601988 PMCID: PMC11017945 DOI: 10.1080/15592324.2024.2339574] [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: 02/29/2024] [Accepted: 03/29/2024] [Indexed: 04/12/2024]
Abstract
The giant (2-3 × 10-2 m long) internodal cells of the aquatic plant, Chara, exhibit a rapid (>100 × 10-6 m s-1) cyclic cytoplasmic streaming which stops in response to mechanical stimuli. Since the streaming - and the stopping of streaming upon stimulation - is easily visible with a stereomicroscope, these single cells are ideal tools to investigate mechanosensing in plant cells, as well as the potential for these cells to be anesthetized. We found that dropping a steel ball (0.88 × 10-3 kg, 6 × 10-3 m in diameter) through a 4.6 cm long tube (delivering ca. 4 × 10-4 J) reliably induced mechanically-stimulated cessation of cytoplasmic streaming. To determine whether mechanically-induced cessation of cytoplasmic streaming in Chara was sensitive to anesthesia, we treated Chara internodal cells to volatilized chloroform in a 9.8 × 10-3 m3 chamber for 2 minutes. We found that low doses (15,000-25,000 ppm) of chloroform did not always anesthetize cells, whereas large doses (46,000 and higher) proved lethal. However, 31,000 ppm chloroform completely, and reversibly, anesthetized these cells in that they did not stop cytoplasmic streaming upon mechanostimulation, but after 24 hours the cells recovered their sensitivity to mechanostimulation. We believe this single-cell model will prove useful for elucidating the still obscure mode of action of volatile anesthetics.
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Affiliation(s)
- Manya J. Rodgers
- Department of Cell and Molecular Biology, Grand Valley State University, Allendale, MI, USA
| | - Mark P. Staves
- Department of Cell and Molecular Biology, Grand Valley State University, Allendale, MI, USA
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11
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Ljubič M, Perdih A, Borišek J. All-Atom Simulations Reveal the Effect of Membrane Composition on the Signaling of the NKG2A/CD94/HLA-E Immune Receptor Complex. J Chem Inf Model 2024; 64:9374-9387. [PMID: 39621690 DOI: 10.1021/acs.jcim.4c01357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2024]
Abstract
Understanding how membrane composition influences the dynamics and function of transmembrane proteins is crucial for the comprehensive elucidation of cellular signaling mechanisms and the development of targeted therapeutics. In this study, we employed all-atom molecular dynamics simulations to investigate the impact of different membrane compositions on the conformational dynamics of the NKG2A/CD94/HLA-E immune receptor complex, a key negative regulator of natural killer cell cytotoxic activity. Our results reveal significant variations in the behavior of the immune complex structure across five different membrane compositions, which include POPC, POPA, DPPC, and DLPC phospholipids, and a mixed POPC/cholesterol system. These variations are particularly evident in the intracellular domain of NKG2A, manifested as changes in mobility, tyrosine exposure, and interdomain communication. Additionally, we found that a large concentration of negative charge at the surface of the POPA-based membrane greatly increased the number of contacts with lipid molecules and significantly decreased the exposure of intracellular NKG2A ITIM regions to water molecules, thus likely halting the signal transduction process. Furthermore, the DPPC model with a membrane possessing a high transition temperature in a gel-like state became curved, affecting the exposure of one ITIM region. The decreased membrane thickness in the DPLC model caused a significant transmembrane domain tilt, altering the linker protrusion angle and potentially disrupting the hydrogen bonding network in the extracellular domain. Overall, our findings highlight the importance of considering membrane composition in the analysis of transmembrane protein dynamics and in the exploration of novel strategies for the external modulation of their signaling pathways.
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Affiliation(s)
- Martin Ljubič
- National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Andrej Perdih
- National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Jure Borišek
- National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
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12
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Muhammednazaar S, Yao J, Necelis MR, Park YC, Shen Z, Bridges MD, Guo R, Swope N, Rhee MS, Kim M, Kim KH, Hubbell WL, Fleming KG, Columbus L, Kang SG, Hong H. Lipid bilayer strengthens the cooperative network of membrane proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.30.542905. [PMID: 37398072 PMCID: PMC10312574 DOI: 10.1101/2023.05.30.542905] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Although membrane proteins fold and function in a lipid bilayer constituting cell membranes, their structure and functionality can be recapitulated in diverse amphiphilic assemblies whose compositions deviate from native membranes. It remains unclear how various hydrophobic environments can stabilize membrane proteins and whether lipids play any role therein. Here, using the evolutionary unrelated α-helical and β-barrel membrane proteins of Escherichia coli , we find that the hydrophobic thickness and the strength of amphiphile- amphiphile packing are critical environmental determinants of membrane protein stability. Lipid solvation enhances stability by facilitating residue burial in the protein interior and strengthens the cooperative network by promoting the propagation of local structural perturbations. This study demonstrates that lipids not only modulate membrane proteins' stability but also their response to external stimuli.
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13
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Drzymała-Czyż S, Walkowiak J, Colombo C, Alicandro G, Storrösten OT, Kolsgaard M, Bakkeheim E, Strandvik B. Fatty acid abnormalities in cystic fibrosis-the missing link for a cure? iScience 2024; 27:111153. [PMID: 39620135 PMCID: PMC11607544 DOI: 10.1016/j.isci.2024.111153] [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: 01/05/2025] Open
Abstract
The care for cystic fibrosis (CF) has dramatically changed with the development of modulators, correctors, and potentiators of the CFTR molecule, which lead to improved clinical status of most people with CF (pwCF). The modulators influence phospholipids and ceramides, but not linoleic acid (LA) deficiency, associated with more severe phenotypes of CF. The LA deficiency is associated with upregulation of its transfer to arachidonic acid (AA). The AA release from membranes is increased and associated with increase of pro-inflammatory prostanoids and the characteristic inflammation is present before birth and bacterial infections. Docosahexaenoic acid is often decreased, especially in associated liver disease Some endogenously synthesized fatty acids are increased. Cholesterol and ceramide metabolisms are disturbed. The lipid abnormalities are present at birth, and before feeding in transgenic pigs and ferrets. This review focus on the lipid abnormalities and their associations to clinical symptoms in CF, based on clinical studies and experimental research.
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Affiliation(s)
| | - Jarosław Walkowiak
- Department of Pediatric Gastroenterology and Metabolic Diseases, Institute of Pediatrics, Poznan University of Medical Sciences, Poznan, Poland
| | - Carla Colombo
- Cystic Fibrosis Centre, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, and Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Gianfranco Alicandro
- Cystic Fibrosis Centre, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, and Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Olav Trond Storrösten
- National Resource Centre for Cystic Fibrosis, Oslo University Hospital, Oslo, Norway
| | - Magnhild Kolsgaard
- National Resource Centre for Cystic Fibrosis, Oslo University Hospital, Oslo, Norway
| | - Egil Bakkeheim
- National Resource Centre for Cystic Fibrosis, Oslo University Hospital, Oslo, Norway
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14
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Matsuki Y, Iwamoto M, Maki T, Takashima M, Yoshida T, Oiki S. Programmable Lipid Bilayer Tension-Control Apparatus for Quantitative Mechanobiology. ACS NANO 2024; 18:30561-30573. [PMID: 39437160 PMCID: PMC11544928 DOI: 10.1021/acsnano.4c09017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2024] [Revised: 09/30/2024] [Accepted: 10/07/2024] [Indexed: 10/25/2024]
Abstract
The biological membrane is not just a platform for information processing but also a field of mechanics. The lipid bilayer that constitutes the membrane is an elastic body, generating stress upon deformation, while the membrane protein embedded therein deforms the bilayer through structural changes. Among membrane-protein interplays, various channel species act as tension-current converters for signal transduction, serving as elementary processes in mechanobiology. However, in situ studies in chaotically complex cell membranes are challenging, and characterizing the tension dependency of mechanosensitive channels remains semiquantitative owing to technical limitations. Here, we developed a programmable membrane tension-control apparatus on a lipid bilayer system. This synthetic membrane system [contact bubble bilayer (CBB)] uses pressure to drive bilayer tension changes via the Young-Laplace principle, whereas absolute bilayer tension is monitored in real-time through image analysis of the bubble geometry via the Young principle. Consequently, the mechanical nature of the system permits the implementation of closed-loop feedback control of bilayer tension (tension-clamp CBB), maintaining a constant tension for minutes and allowing stepwise tension changes within a hundred milliseconds in the tension range of 0.8 to 15 mN·m-1. We verified the system performance by examining the single-channel behavior of tension-dependent KcsA and TREK-1 potassium channels under scheduled tension time courses prescribed via visual interfaces. The result revealed steady-state activity and dynamic responses to the step tension changes, which are essential to the biophysical characterization of the channels. The apparatus explores a frontier for quantitative mechanobiology studies and promotes the development of a tension-operating experimental robot.
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Affiliation(s)
- Yuka Matsuki
- Department
of Anesthesiology and Reanimatology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
- Life
Science Innovation Center, University of
Fukui, Fukui 910-8507, Japan
| | - Masayuki Iwamoto
- Department
of Molecular Neuroscience, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
- Life
Science Innovation Center, University of
Fukui, Fukui 910-8507, Japan
| | - Takahisa Maki
- Department
of Molecular Neuroscience, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
- Life
Science Innovation Center, University of
Fukui, Fukui 910-8507, Japan
| | - Masako Takashima
- Department
of Molecular Neuroscience, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Toshiyuki Yoshida
- Department
of Information Science, Faculty of Engineering, University of Fukui, Fukui 910-8507, Japan
| | - Shigetoshi Oiki
- Biomedical
Imaging Research Center, University of Fukui, Fukui 910-1193, Japan
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15
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Jalali P, Nowroozi A, Moradi S, Shahlaei M. Exploration of lipid bilayer mechanical properties using molecular dynamics simulation. Arch Biochem Biophys 2024; 761:110151. [PMID: 39265694 DOI: 10.1016/j.abb.2024.110151] [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: 07/13/2024] [Revised: 08/22/2024] [Accepted: 09/09/2024] [Indexed: 09/14/2024]
Abstract
Important biological structures known for their exceptional mechanical qualities, lipid bilayers are essential to many cellular functions. Fluidity, elasticity, permeability, stiffness, tensile strength, compressibility, shear viscosity, line tension, and curvature elasticity are some of the fundamental characteristics affecting their behavior. The purpose of this review is to examine these characteristics in more detail by molecular dynamics simulation, elucidating their importance and the elements that lead to their appearance in lipid bilayers. Comprehending the mechanical characteristics of lipid bilayers is critical for creating medications, drug delivery systems, and biomaterials that interact with biological membranes because it allows one to understand how these materials respond to different stresses and deformations. The influence of mechanical characteristics on important lipid bilayer properties is examined in this review. The mechanical properties of lipid bilayers were clarified through the use of molecular dynamics simulation analysis techniques, including bilayer thickness, stress-strain analysis, lipid bilayer area compressibility, membrane bending rigidity, and time- or ensemble-averaged the area per lipid evaluation. We explain the significance of molecular dynamics simulation analysis methods, providing important new information about the stability and dynamic behavior of the bilayer. In the end, we hope to use molecular dynamics simulation to provide a comprehensive understanding of the mechanical properties and behavior of lipid bilayers, laying the groundwork for further studies and applications. Taken together, careful investigation of these mechanical aspects deepens our understanding of the adaptive capacities and functional roles of lipid bilayers in biological environments.
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Affiliation(s)
- Parvin Jalali
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Amin Nowroozi
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Sajad Moradi
- Nano Drug Delivery Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mohsen Shahlaei
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.
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16
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Poudel B, Vanegas JM. Structural Rearrangement of the AT1 Receptor Modulated by Membrane Thickness and Tension. J Phys Chem B 2024; 128:9470-9481. [PMID: 39298653 DOI: 10.1021/acs.jpcb.4c03325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2024]
Abstract
Membrane-embedded mechanosensitive (MS) proteins, including ion channels and G-protein coupled receptors (GPCRs), are essential for the transduction of external mechanical stimuli into biological signals. The angiotensin II type 1 (AT1) receptor plays many important roles in cardiovascular regulation and is associated with diseases such as hypertension and congestive heart failure. The membrane-mediated activation of the AT1 receptor is not well understood, despite this being one of the most widely studied GPCRs within the context of biased agonism. Here, we use extensive molecular dynamics (MD) simulations to characterize the effect of the local membrane environment on the activation of the AT1 receptor. We show that membrane thickness plays an important role in the stability of active and inactive states of the receptor, as well as the dynamic interchange between states. Furthermore, our simulation results show that membrane tension is effective in driving large-scale structural changes in the inactive state such as the outward movement of transmembrane helix 6 to stabilize intermediate active-like conformations. We conclude by comparing our simulation observations with AlphaFold 2 predictions, as a proxy to experimental structures, to provide a framework for how membrane mediated stimuli can facilitate activation of the AT1 receptor through the β-arrestin signaling pathway.
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Affiliation(s)
- Bharat Poudel
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Juan M Vanegas
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
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17
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Scott HL, Burns-Casamayor V, Dixson AC, Standaert RF, Stanley CB, Stingaciu LR, Carrillo JMY, Sumpter BG, Katsaras J, Qiang W, Heberle FA, Mertz B, Ashkar R, Barrera FN. Neutron spin echo shows pHLIP is capable of retarding membrane thickness fluctuations. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184349. [PMID: 38815687 PMCID: PMC11365786 DOI: 10.1016/j.bbamem.2024.184349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 04/03/2024] [Accepted: 05/21/2024] [Indexed: 06/01/2024]
Abstract
Cell membranes are responsible for a range of biological processes that require interactions between lipids and proteins. While the effects of lipids on proteins are becoming better understood, our knowledge of how protein conformational changes influence membrane dynamics remains rudimentary. Here, we performed experiments and computer simulations to study the dynamic response of a lipid membrane to changes in the conformational state of pH-low insertion peptide (pHLIP), which transitions from a surface-associated (SA) state at neutral or basic pH to a transmembrane (TM) α-helix under acidic conditions. Our results show that TM-pHLIP significantly slows down membrane thickness fluctuations due to an increase in effective membrane viscosity. Our findings suggest a possible membrane regulatory mechanism, where the TM helix affects lipid chain conformations, and subsequently alters membrane fluctuations and viscosity.
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Affiliation(s)
- Haden L Scott
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville 37996, United States of America
| | - Violeta Burns-Casamayor
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, United States of America
| | - Andrew C Dixson
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville 37996, United States of America
| | - Robert F Standaert
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville 37996, United States of America; C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, United States of America; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Christopher B Stanley
- Shull Wollan Center - a Joint Institute for Neutron Sciences, Oak Ridge, TN 37831, United States of America; Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Laura-Roxana Stingaciu
- Labs and Soft Matter Group, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America; JCNS1, FZJ outstation at SNS, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Jan-Michael Y Carrillo
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America; Center for Nanophase Materials Sciences, Oak Ridge, TN 37831, United States of America
| | - Bobby G Sumpter
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America; Center for Nanophase Materials Sciences, Oak Ridge, TN 37831, United States of America
| | - John Katsaras
- Shull Wollan Center - a Joint Institute for Neutron Sciences, Oak Ridge, TN 37831, United States of America; Labs and Soft Matter Group, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America; Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, United States of America
| | - Wei Qiang
- Department of Chemistry, the State University of New York, Binghamton, NY 13902, United States of America
| | - Frederick A Heberle
- Department of Chemistry, University of Tennessee, Knoxville, TN 37920, United States of America
| | - Blake Mertz
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, United States of America; West Virginia University Cancer Institute, Morgantown, WV 26506, United States of America
| | - Rana Ashkar
- Department of Physics, Virginia Tech, Blacksburg, VA 24061, United States of America; Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA 24061, United States of America.
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville 37996, United States of America.
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18
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Zhang C, Feng Y, Calderin JD, Balutowski A, Ahmed R, Knapp C, Fratti RA. Lysophospholipid headgroup size, and acyl chain length and saturation differentially affect vacuole acidification, Ca 2+ transport, and fusion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.27.615487. [PMID: 39386589 PMCID: PMC11463366 DOI: 10.1101/2024.09.27.615487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/12/2024]
Abstract
SNARE-mediated membrane fusion is regulated by the lipid composition of the engaged bilayers. Lipid composition impacts fusion through direct protein lipid interactions or through modulating the physical properties of membranes at the site of contact, including the induction of positive curvature by lysophospholipids (LPLs). The degree of positive curvature induced is due to the length and saturation of the single acyl chain in addition to the size of the head group. Here we examined how yeast vacuole fusion and ion transport were differentially affected by changes in lysolipid properties. We found that lysophosphatidylcholine (LPC) with acyl chains containing 14-18 carbons all inhibited fusion with IC 50 values ranging from ∼40-120 µM. The monounsaturation of LPC-18:1 had no effect when compared to its saturated counterpart LPC-18:0. On the other hand, head group size played a more significant role in blocking fusion as lysophosphatidic acid (LPA)-18:1 failed to fully inhibit fusion. We also show that both Ca 2+ uptake and SNARE-dependent Ca 2+ efflux was sensitive to changes in the acyl chain length and saturation of LPCs, while LPA only affected Ca 2+ efflux. Finally, we tested these LPLs on vacuole acidification by the V-ATPase. This showed that LPC-18:0 could fully inhibit acidification whereas other LPCs had moderate effects. Again, LPA had no effect. Together these data suggest that the effects of LPLs were due to a combination of head group size and acyl chain length leading to a range in degree of positive curvature.
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19
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Carlson RP, Beck AE, Benitez MG, Harcombe WR, Mahadevan R, Gedeon T. Cell Geometry and Membrane Protein Crowding Constrain Growth Rate, Overflow Metabolism, Respiration, and Maintenance Energy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.21.609071. [PMID: 39229203 PMCID: PMC11370460 DOI: 10.1101/2024.08.21.609071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
A metabolic theory is presented for predicting maximum growth rate, overflow metabolism, respiration efficiency, and maintenance energy flux based on the intersection of cell geometry, membrane protein crowding, and metabolism. The importance of cytosolic macromolecular crowding on phenotype has been established in the literature but the importance of surface area has been largely overlooked due to incomplete knowledge of membrane properties. We demonstrate that the capacity of the membrane to host proteins increases with growth rate offsetting decreases in surface area-to-volume ratios (SA:V). This increase in membrane protein is hypothesized to be essential to competitive Escherichia coli phenotypes. The presented membrane-centric theory uses biophysical properties and metabolic systems analysis to successfully predict the phenotypes of E. coli K-12 strains, MG1655 and NCM3722, which are genetically similar but have SA:V ratios that differ up to 30%, maximum growth rates on glucose media that differ by 40%, and overflow phenotypes that start at growth rates that differ by 80%. These analyses did not consider cytosolic macromolecular crowding, highlighting the distinct properties of the presented theory. Cell geometry and membrane protein crowding are significant biophysical constraints on phenotype and provide a theoretical framework for improved understanding and control of cell biology.
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Affiliation(s)
- Ross P. Carlson
- Department of Chemical and Biological Engineering, Center for Biofilm Engineering, Montana State University, Bozeman, MT USA
| | - Ashley E. Beck
- Department of Biological and Environmental Sciences, Carroll College, Helena, MT USA
| | | | - William R. Harcombe
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN USA
| | | | - Tomáš Gedeon
- Department of Mathematical Sciences, Montana State University, Bozeman, MT USA
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20
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Rogers J, Bajur AT, Salaita K, Spillane KM. Mechanical control of antigen detection and discrimination by T and B cell receptors. Biophys J 2024; 123:2234-2255. [PMID: 38794795 PMCID: PMC11331051 DOI: 10.1016/j.bpj.2024.05.020] [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: 02/14/2024] [Revised: 05/10/2024] [Accepted: 05/21/2024] [Indexed: 05/26/2024] Open
Abstract
The adaptive immune response is orchestrated by just two cell types, T cells and B cells. Both cells possess the remarkable ability to recognize virtually any antigen through their respective antigen receptors-the T cell receptor (TCR) and B cell receptor (BCR). Despite extensive investigations into the biochemical signaling events triggered by antigen recognition in these cells, our ability to predict or control the outcome of T and B cell activation remains elusive. This challenge is compounded by the sensitivity of T and B cells to the biophysical properties of antigens and the cells presenting them-a phenomenon we are just beginning to understand. Recent insights underscore the central role of mechanical forces in this process, governing the conformation, signaling activity, and spatial organization of TCRs and BCRs within the cell membrane, ultimately eliciting distinct cellular responses. Traditionally, T cells and B cells have been studied independently, with researchers working in parallel to decipher the mechanisms of activation. While these investigations have unveiled many overlaps in how these cell types sense and respond to antigens, notable differences exist. To fully grasp their biology and harness it for therapeutic purposes, these distinctions must be considered. This review compares and contrasts the TCR and BCR, placing emphasis on the role of mechanical force in regulating the activity of both receptors to shape cellular and humoral adaptive immune responses.
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Affiliation(s)
- Jhordan Rogers
- Department of Chemistry, Emory University, Atlanta, Georgia
| | - Anna T Bajur
- Department of Physics, King's College London, London, United Kingdom; Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, Georgia; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia.
| | - Katelyn M Spillane
- Department of Physics, King's College London, London, United Kingdom; Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom; Department of Life Sciences, Imperial College London, London, United Kingdom.
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21
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Kononova PA, Selyutina OY, Fomenko VV, Salakhutdinov NF, Polyakov NE. The mutual lipid-mediated effect of the transmembrane domain of SARS-CoV-2 E-protein and glycyrrhizin nicotinate derivatives on the localization in the lipid bilayer. Arch Biochem Biophys 2024; 758:110080. [PMID: 38960345 DOI: 10.1016/j.abb.2024.110080] [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: 03/13/2024] [Revised: 06/27/2024] [Accepted: 06/30/2024] [Indexed: 07/05/2024]
Abstract
Glycyrrhizinic acid (GA) is one of the active substances in licorice root. It exhibits antiviral activity against various enveloped viruses, for example, SARS-CoV-2. GA derivatives are promising biologically active compounds from perspective of developing broad-spectrum antiviral agents. Given that GA nicotinate derivatives (Glycyvir) demonstrate activity against various DNA- and RNA-viruses, a search for a possible mechanism of action of these compounds is required. In the present paper, the interaction of Glycyvir with the transmembrane domain of the SARS-CoV-2 E-protein (ETM) in a model lipid membrane was investigated by NMR spectroscopy and molecular dynamics simulation. The lipid-mediated influence on localization of the SARS-CoV-2 E-protein by Glycyvir was observed. The presence of Glycyvir leads to deeper immersion of the ETM in lipid bilayer. Taking into account that E-protein plays a significant role in virus production and takes part in virion assembly and budding, the data on the effect of potential antiviral agents on ETM localization and structure in the lipid environment may provide a basis for further studies of potential coronavirus E-protein inhibitors.
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Affiliation(s)
- Polina A Kononova
- V. V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya St., 630090, Novosibirsk, Russia
| | - Olga Yu Selyutina
- V. V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya St., 630090, Novosibirsk, Russia; Institute of Solid State Chemistry and Mechanochemistry, 18 Kutateladze St., 630128, Novosibirsk, Russia.
| | - Vladislav V Fomenko
- V. V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya St., 630090, Novosibirsk, Russia; N. N. Vorozhtsov Institute of Organic Chemistry, 9 Lavrentiev Ave, 630090, Novosibirsk, Russia
| | - Nariman F Salakhutdinov
- N. N. Vorozhtsov Institute of Organic Chemistry, 9 Lavrentiev Ave, 630090, Novosibirsk, Russia
| | - Nikolay E Polyakov
- V. V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya St., 630090, Novosibirsk, Russia; Institute of Solid State Chemistry and Mechanochemistry, 18 Kutateladze St., 630128, Novosibirsk, Russia
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22
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Aguilar-Pineda J, González-Melchor M. Influence of the Water Model on the Structure and Interactions of the GPR40 Protein with the Lipid Membrane and the Solvent: Rigid versus Flexible Water Models. J Chem Theory Comput 2024; 20:6369-6387. [PMID: 38991114 PMCID: PMC11270832 DOI: 10.1021/acs.jctc.4c00571] [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: 04/28/2024] [Revised: 06/07/2024] [Accepted: 06/21/2024] [Indexed: 07/13/2024]
Abstract
G protein-coupled receptors (GPCR) are responsible for modulating various physiological functions and are thus related to the pathophysiology of different diseases. Being potential therapeutic targets, multiple computational methodologies have been developed to analyze their behavior and interactions with other species. The solvent, on the other hand, has received much less attention. In this work, we analyzed the effect of four explicit water models on the structure and interactions of the GPR40 receptor in its apo form. We employed the rigid SPC/E and TIP4P models, and their flexible versions, the FBA/ϵ and TIP4P/ϵflex. We explored the structural changes and their correlation with some bulk dynamic properties of water. Our results showed an adverse effect on the conservation of the secondary structure of the receptor with all the models due to the breaking of the intramolecular hydrogen bond network, being more evident for the TIP4P models. Notably, all four models brought the receptor to states similar to the active one, modifying the intracellular part of the TM5 and TM6 domains in a "hinge" type movement, allowing the opening of the structure. Regarding the dynamic properties, the rigid models showed results comparable to those obtained in other studies on membrane systems. However, flexible models exhibit disparities in the molecular representation of systems. Surprisingly, the FBA/ϵ model improves the molecular picture of several properties, even though their agreement with bulk diffusion is poorer. These findings reinforce our idea that exploring other water models or improving the current ones, to better represent the membrane interface, can lead to a positive impact on the description of the signal transduction mechanisms and the search of new drugs by targeting these receptors.
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Affiliation(s)
- Jorge
Alberto Aguilar-Pineda
- Instituto de Física
“Luis Rivera Terrazas”, Benemérita Universidad
Autónoma de Puebla, Av San Claudio, Cd Universitaria, Apdo. Postal
J-48, Puebla 72570, México
| | - Minerva González-Melchor
- Instituto de Física
“Luis Rivera Terrazas”, Benemérita Universidad
Autónoma de Puebla, Av San Claudio, Cd Universitaria, Apdo. Postal
J-48, Puebla 72570, México
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23
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Srivatsav AT, Liang K, Jaworek MW, Dong W, Matsuo T, Grélard A, Peters J, Winter R, Duan M, Kapoor S. Residual Membrane Fluidity in Mycobacterial Cell Envelope Layers under Extreme Conditions Underlines Membrane-Centric Adaptation. J Phys Chem B 2024; 128:6838-6852. [PMID: 38960927 PMCID: PMC7617627 DOI: 10.1021/acs.jpcb.4c02469] [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] [Indexed: 07/05/2024]
Abstract
One of the routes for adaptation to extreme environments is via remodeling of cell membrane structure, composition, and biophysical properties rendering a functional membrane. Collective studies suggest some form of membrane feedback in mycobacterial species that harbor complex lipids within the outer and inner cell wall layers. Here, we study the homeostatic membrane landscape of mycobacteria in response to high hydrostatic pressure and temperature triggers using high pressure fluorescence, mass and infrared spectroscopies, NMR, SAXS, and molecular dynamics simulations. Our findings reveal that mycobacterial membrane possesses unique and lipid-specific pressure-induced signatures that attenuate progression to highly ordered phases. Both inner and outer membrane layers exhibit phase coexistence of nearly identical lipid phases keeping residual fluidity over a wide range of temperature and pressure, but with different sensitivities. Lipidomic analysis of bacteria grown under pressure revealed lipidome remodeling in terms of chain length, unsaturation, and specific long-chained characteristic mycobacterial lipids, rendering a fluid bacterial membrane. These findings could help understand how bacteria may adapt to a broad spectrum of harsh environments by modulating their lipidome to select lipids that enable the maintenance of a fluid functional cell envelope.
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Affiliation(s)
- Aswin T Srivatsav
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Kuan Liang
- Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Michel W Jaworek
- Department of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, Dortmund D-44227, Germany
| | - Wanqian Dong
- Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Tatsuhito Matsuo
- University of Grenoble Alpes, CNRS, LIPhy, Grenoble 38044, France
- Institut Laue Langevin, Grenoble F-38042, Cedex 9, France
- Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, 2-4 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Axelle Grélard
- Université de Bordeaux, CNRS, Bordeaux INP, Institut de Chimie & Biologie des Membranes & des Nano-objets, UMR5248, Institut Européen de Chimie et Biologie, Pessac F-33607, France
| | - Judith Peters
- University of Grenoble Alpes, CNRS, LIPhy, Grenoble 38044, France
- Institut Laue Langevin, Grenoble F-38042, Cedex 9, France
- Institut Universitaire de France (IUF), UFR de PhITEM, CS 10090, Grenoble 38044, France
| | - Roland Winter
- Department of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, Dortmund D-44227, Germany
| | - Mojie Duan
- Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8528, Japan
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24
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Dukic B, Ruppert Z, Tóth ME, Hunya Á, Czibula Á, Bíró P, Tiszlavicz Á, Péter M, Balogh G, Erdélyi M, Timinszky G, Vígh L, Gombos I, Török Z. Mild Hyperthermia-Induced Thermogenesis in the Endoplasmic Reticulum Defines Stress Response Mechanisms. Cells 2024; 13:1141. [PMID: 38994992 PMCID: PMC11240596 DOI: 10.3390/cells13131141] [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: 06/05/2024] [Revised: 06/24/2024] [Accepted: 06/27/2024] [Indexed: 07/13/2024] Open
Abstract
Previous studies reported that a mild, non-protein-denaturing, fever-like temperature increase induced the unfolded protein response (UPR) in mammalian cells. Our dSTORM super-resolution microscopy experiments revealed that the master regulator of the UPR, the IRE1 (inositol-requiring enzyme 1) protein, is clustered as a result of UPR activation in a human osteosarcoma cell line (U2OS) upon mild heat stress. Using ER thermo yellow, a temperature-sensitive fluorescent probe targeted to the endoplasmic reticulum (ER), we detected significant intracellular thermogenesis in mouse embryonic fibroblast (MEF) cells. Temperatures reached at least 8 °C higher than the external environment (40 °C), resulting in exceptionally high ER temperatures similar to those previously described for mitochondria. Mild heat-induced thermogenesis in the ER of MEF cells was likely due to the uncoupling of the Ca2+/ATPase (SERCA) pump. The high ER temperatures initiated a pronounced cytosolic heat-shock response in MEF cells, which was significantly lower in U2OS cells in which both the ER thermogenesis and SERCA pump uncoupling were absent. Our results suggest that depending on intrinsic cellular properties, mild hyperthermia-induced intracellular thermogenesis defines the cellular response mechanism and determines the outcome of hyperthermic stress.
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Affiliation(s)
- Barbara Dukic
- Laboratory of Molecular Stress Biology, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary; (B.D.); (L.V.); (I.G.)
- Doctoral School of Environmental Sciences, Faculty of Science and Informatics, University of Szeged, 6720 Szeged, Hungary
| | - Zsófia Ruppert
- Laboratory of Molecular Stress Biology, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary; (B.D.); (L.V.); (I.G.)
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, 6720 Szeged, Hungary
| | - Melinda E. Tóth
- Laboratory of Molecular Stress Biology, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary; (B.D.); (L.V.); (I.G.)
| | - Ákos Hunya
- Laboratory of Molecular Stress Biology, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary; (B.D.); (L.V.); (I.G.)
| | - Ágnes Czibula
- Laboratory of DNA Damage and Nuclear Dynamics, Institute of Genetics, HUN-REN Biological Research Centre, 6726 Szeged, Hungary
- Department of Immunology, University of Szeged, 6720 Szeged, Hungary
| | - Péter Bíró
- Department of Optics and Quantum Electronics, University of Szeged, 6720 Szeged, Hungary
| | - Ádám Tiszlavicz
- Laboratory of Molecular Stress Biology, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary; (B.D.); (L.V.); (I.G.)
| | - Mária Péter
- Laboratory of Molecular Stress Biology, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary; (B.D.); (L.V.); (I.G.)
| | - Gábor Balogh
- Laboratory of Molecular Stress Biology, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary; (B.D.); (L.V.); (I.G.)
| | - Miklós Erdélyi
- Department of Optics and Quantum Electronics, University of Szeged, 6720 Szeged, Hungary
| | - Gyula Timinszky
- Laboratory of DNA Damage and Nuclear Dynamics, Institute of Genetics, HUN-REN Biological Research Centre, 6726 Szeged, Hungary
| | - László Vígh
- Laboratory of Molecular Stress Biology, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary; (B.D.); (L.V.); (I.G.)
| | - Imre Gombos
- Laboratory of Molecular Stress Biology, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary; (B.D.); (L.V.); (I.G.)
| | - Zsolt Török
- Laboratory of Molecular Stress Biology, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary; (B.D.); (L.V.); (I.G.)
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25
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Zhong Z, Du G, Ma L, Wang Y, Jiang J. Self-Assembly of Lamellae-in-Lamellae by Double-Tail Cationic Surfactants. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2401210. [PMID: 38751126 PMCID: PMC11267300 DOI: 10.1002/advs.202401210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/25/2024] [Indexed: 07/25/2024]
Abstract
The molecular structures of surfactants play a pivotal role in influencing their self-assembly behaviors. In this work, using simulations and experiments, an unconventional hierarchically layered structure in the didodecyldimethylammonium bromide (DDAB)/water binary system: lamellae-in-lamellae is revealed, a new self-assembly structure in surfactant system. This self-assembly structure refers to a lamellar structure with a shorter periodic length (inner lamellae) embedded in a lamellar phase with a longer periodic length (outer lamellae). The normal vectors of these two lamellar regions orient perpendicularly. In addition, it is observed that this lamellar-in-lamellar phase disappears when the two tails of the cationic surfactants become longer. The formation of the lamellar-in-lamellar architecture arises from multiple interacting factors. The key element is that the short tails of the DDAB surfactants enhance hydrophilicity and rigidity, which facilitates the formation of the inner lamellae. Moreover, the lateral monolayer of the inner lamellae provides shielding from the water and prompts the formation of the outer lamellae. These findings indicate that molecular structures and flexibility can profoundly redirect the hierarchical self-assembly behaviors in amphiphilic systems. More broadly, this work presents a new strategy to deliberately program hierarchical nanomaterials by designing specific surfactant molecules to act as tunable scaffolds, reactors, and carriers.
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Affiliation(s)
- Zhixuan Zhong
- Beijing National Laboratory for Molecular SciencesState Key Laboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
- University of Chinese Academy of SciencesBeijing100049P. R. China
| | - Guanqun Du
- CAS Key Laboratory of ColloidInterface and Chemical ThermodynamicsCAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular ScienceInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
| | - Linbo Ma
- Beijing National Laboratory for Molecular SciencesState Key Laboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
- University of Chinese Academy of SciencesBeijing100049P. R. China
| | - Yilin Wang
- University of Chinese Academy of SciencesBeijing100049P. R. China
- CAS Key Laboratory of ColloidInterface and Chemical ThermodynamicsCAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular ScienceInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
| | - Jian Jiang
- Beijing National Laboratory for Molecular SciencesState Key Laboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
- University of Chinese Academy of SciencesBeijing100049P. R. China
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26
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Gudyka J, Ceja-Vega J, Krmic M, Porteus R, Lee S. The Role of Lipid Intrinsic Curvature in the Droplet Interface Bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:11428-11435. [PMID: 38764431 PMCID: PMC11155247 DOI: 10.1021/acs.langmuir.4c00270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/21/2024]
Abstract
Model bilayers are constructed from lipids having different intrinsic curvatures using the droplet interface bilayer (DIB) method, and their static physicochemical properties are determined. Geometrical and tensiometric measurements are used to derive the free energy of formation (ΔF) of a two-droplet DIB relative to a pair of isolated aqueous droplets, each decorated with a phospholipid monolayer. The lipid molecules employed have different headgroup sizes but identical hydrophobic tail structure, and each is characterized by an intrinsic curvature value (c0) that increases in absolute value with decreasing size of headgroup. Mixtures of lipids at different ratios were also investigated. The role of curvature stress on the values of ΔF of the respective lipid bilayers in these model membranes is discussed and is illuminated by the observation of a decrement in ΔF that scales as a near linear function of c02. Overall, the results reveal an association that should prove useful in studies of ion channels and other membrane proteins embedded in model droplet bilayer systems that will impact the understanding of protein function in cellular membranes composed of lipids of high and low curvature.
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Affiliation(s)
- Jamie Gudyka
- Department of Chemistry and
Biochemistry, Iona University, New Rochelle, New York 10801, United States
| | - Jasmin Ceja-Vega
- Department of Chemistry and
Biochemistry, Iona University, New Rochelle, New York 10801, United States
| | - Michael Krmic
- Department of Chemistry and
Biochemistry, Iona University, New Rochelle, New York 10801, United States
| | - Riley Porteus
- Department of Chemistry and
Biochemistry, Iona University, New Rochelle, New York 10801, United States
| | - Sunghee Lee
- Department of Chemistry and
Biochemistry, Iona University, New Rochelle, New York 10801, United States
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27
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Huster D, Maiti S, Herrmann A. Phospholipid Membranes as Chemically and Functionally Tunable Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2312898. [PMID: 38456771 DOI: 10.1002/adma.202312898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/12/2024] [Indexed: 03/09/2024]
Abstract
The sheet-like lipid bilayer is the fundamental structural component of all cell membranes. Its building blocks are phospholipids and cholesterol. Their amphiphilic structure spontaneously leads to the formation of a bilayer in aqueous environment. Lipids are not just structural elements. Individual lipid species, the lipid membrane structure, and lipid dynamics influence and regulate membrane protein function. An exciting field is emerging where the membrane-associated material properties of different bilayer systems are used in designing innovative solutions for widespread applications across various fields, such as the food industry, cosmetics, nano- and biomedicine, drug storage and delivery, biotechnology, nano- and biosensors, and computing. Here, the authors summarize what is known about how lipids determine the properties and functions of biological membranes and how this has been or can be translated into innovative applications. Based on recent progress in the understanding of membrane structure, dynamics, and physical properties, a perspective is provided on how membrane-controlled regulation of protein functions can extend current applications and even offer new applications.
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Affiliation(s)
- Daniel Huster
- Institute of Medical Physics and Biophysics, University of Leipzig, Härtelstr. 16/18, D-04107, Leipzig, Germany
| | - Sudipta Maiti
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, 400 005, India
| | - Andreas Herrmann
- Freie Universität Berlin, Department Chemistry and Biochemistry, SupraFAB, Altensteinstr. 23a, D-14195, Berlin, Germany
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28
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Beverley KM, Barbera N, Levitan I. Dual pattern of cholesterol-induced decoupling of residue-residue interactions of Kir2.2. J Struct Biol 2024; 216:108091. [PMID: 38641256 DOI: 10.1016/j.jsb.2024.108091] [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: 07/13/2023] [Revised: 03/28/2024] [Accepted: 04/09/2024] [Indexed: 04/21/2024]
Abstract
Cholesterol is a negative regulator of a variety of ion channels. We have previously shown that cholesterol suppresses Kir2.2 channels via residue-residue uncoupling on the inter-subunit interfaces within the close state of the channels (3JYC). In this study, we extend this analysis to the other known structure of Kir2.2 that is closer to the open state of Kir2.2 channels (3SPI) and provide additional analysis of the residue distances between the uncoupled residues and cholesterol binding domains in the two conformation states of the channels. We found that the general phenomenon of cholesterol binding leading to uncoupling between specific residues is conserved in both channel states but the specific pattern of the uncoupling residues is distinct between the two states and implies different mechanisms. Specifically, we found that cholesterol binding in the 3SPI state results in an uncoupling of residues in three distinct regions; the transmembrane domain, membrane-cytosolic interface, and the cytosolic domain, with the first two regions forming an envelope around PI(4,5)P2 and cholesterol binding sites and the distal region overlapping with the subunit-subunit interface characterized in our previous study of the disengaged state. We also found that this uncoupling is dependent upon the number of cholesterol molecules bound to the channel. We further generated a mutant channel Kir2.2P187V with a single point mutation in a residue proximal to the PI(4,5)P2 binding site, which is predicted to be uncoupled from other residues in its vicinity upon cholesterol binding and found that this mutation abrogates the sensitivity of Kir2.2 to cholesterol changes in the membrane. These findings suggest that cholesterol binding to this conformation state of Kir2.2 channels may destabilize the PI(4,5)P2 interactions with the channels while in the disengaged state the destabilization occurs where the subunits interact. These findings give insight into the structural mechanistic basis for the functional effects of cholesterol binding to the Kir2.2 channel.
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Affiliation(s)
- Katie M Beverley
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.
| | - Nicolas Barbera
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; Center for Public Health Genomics, Department of Biomedical Engineering, School of Engineering &Applied Science, University of Virginia, Charlottesville, VA 22904, USA
| | - Irena Levitan
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.
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29
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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] [Download PDF] [Figures] [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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30
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Liu TT, Huang SH, Chao L. Rapid Enrichment of a Native Multipass Transmembrane Protein via Cell Membrane Electrophoresis through Buffer pH and Ionic Strength Adjustment. J Am Chem Soc 2024; 146:11634-11647. [PMID: 38628144 PMCID: PMC11066866 DOI: 10.1021/jacs.3c13579] [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: 12/03/2023] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 05/02/2024]
Abstract
Supported membrane electrophoresis is a promising technique for collecting membrane proteins in native bilayer environments. However, the slow mobility of typical transmembrane proteins has impeded the technique's advancement. Here, we successfully applied cell membrane electrophoresis to rapidly enrich a 12-transmembrane helix protein, glucose transporter 1 with antibodies (GLUT1 complex), by tuning the buffer pH and ionic strength. The identified conditions allowed the separation of the GLUT1 complex and a lipid probe, Fast-DiO, within a native-like environment in a few minutes. A force model was developed to account for distinct electric and drag forces acting on the transmembrane and aqueous-exposed portion of a transmembrane protein as well as the electroosmotic force. This model not only elucidates the impact of size and charge properties of transmembrane proteins but also highlights the influence of pH and ionic strength on the driving forces and, consequently, electrophoretic mobility. Model predictions align well with experimentally measured electrophoretic mobilities of the GLUT1 complex and Fast-DiO at various pH and ionic strengths as well as with several lipid probes, lipid-anchored proteins, and reconstituted membrane proteins from previous studies. Force analyses revealed the substantial membrane drag of the GLUT1 complex, significantly slowing down electrophoretic mobility. Besides, the counterbalance of similar magnitudes of electroosmotic and electric forces results in a small net driving force and, consequently, reduced mobility under typical neutral pH conditions. Our results further highlight how the size and charge properties of transmembrane proteins influence the suitable range of operating conditions for effective movement, providing potential applications for concentrating and isolating membrane proteins within this platform.
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Affiliation(s)
- Tzu-Tzu Liu
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan
| | - Sin-Han Huang
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan
| | - Ling Chao
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan
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31
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Gudyka J, Ceja-Vega J, Ivanchenko K, Perla W, Poust C, Gamez Hernandez A, Clarke C, Silverberg S, Perez E, Lee S. Differential Effects of Soy Isoflavones on the Biophysical Properties of Model Membranes. J Phys Chem B 2024; 128:2412-2424. [PMID: 38417149 PMCID: PMC10945484 DOI: 10.1021/acs.jpcb.3c08390] [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: 12/24/2023] [Revised: 02/12/2024] [Accepted: 02/16/2024] [Indexed: 03/01/2024]
Abstract
The effects that the main soy isoflavones, genistein and daidzein, have upon the biophysical properties of a model lipid bilayer composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or DOPC with cholesterol (4 to 1 mol ratio) have been investigated by transbilayer water permeability, differential scanning calorimetry, and confocal Raman microspectroscopy. Genistein is found to increase water permeability, decrease phase transition temperature, reduce enthalpy of transition, and induce packing disorder in the DOPC membrane with an increasing concentration. On the contrary, daidzein decreases water permeability and shows negligible impact on thermodynamic parameters and packing disorder at comparable concentrations. For a cholesterol-containing DOPC bilayer, both genistein and daidzein exhibit an overall less pronounced effect on transbilayer water permeability. Their respective differential abilities to modify the physical and structural properties of biomembranes with varying lipid compositions signify a complex and sensitive nature to isoflavone interactions, which depends on the initial state of bilayer packing and the differences in the molecular structures of these soy isoflavones, and provide insights in understanding the interactions of these molecules with cellular membranes.
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Affiliation(s)
- Jamie Gudyka
- Department of Chemistry and
Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Jasmin Ceja-Vega
- Department of Chemistry and
Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Katherine Ivanchenko
- Department of Chemistry and
Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Wilber Perla
- Department of Chemistry and
Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Christopher Poust
- Department of Chemistry and
Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Alondra Gamez Hernandez
- Department of Chemistry and
Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Colleen Clarke
- Department of Chemistry and
Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Shakinah Silverberg
- Department of Chemistry and
Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Escarlin Perez
- Department of Chemistry and
Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Sunghee Lee
- Department of Chemistry and
Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
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32
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Ashrafuzzaman M, Koeppe RE, Andersen OS. Intrinsic Lipid Curvature and Bilayer Elasticity as Regulators of Channel Function: A Comparative Single-Molecule Study. Int J Mol Sci 2024; 25:2758. [PMID: 38474005 PMCID: PMC10931550 DOI: 10.3390/ijms25052758] [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: 01/06/2024] [Revised: 02/13/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Perturbations in bilayer material properties (thickness, lipid intrinsic curvature and elastic moduli) modulate the free energy difference between different membrane protein conformations, thereby leading to changes in the conformational preferences of bilayer-spanning proteins. To further explore the relative importance of curvature and elasticity in determining the changes in bilayer properties that underlie the modulation of channel function, we investigated how the micelle-forming amphiphiles Triton X-100, reduced Triton X-100 and the HII lipid phase promoter capsaicin modulate the function of alamethicin and gramicidin channels. Whether the amphiphile-induced changes in intrinsic curvature were negative or positive, amphiphile addition increased gramicidin channel appearance rates and lifetimes and stabilized the higher conductance states in alamethicin channels. When the intrinsic curvature was modulated by altering phospholipid head group interactions, however, maneuvers that promote a negative-going curvature stabilized the higher conductance states in alamethicin channels but destabilized gramicidin channels. Using gramicidin channels of different lengths to probe for changes in bilayer elasticity, we found that amphiphile adsorption increases bilayer elasticity, whereas altering head group interactions does not. We draw the following conclusions: first, confirming previous studies, both alamethicin and gramicidin channels are modulated by changes in lipid bilayer material properties, the changes occurring in parallel yet differing dependent on the property that is being changed; second, isolated, negative-going changes in curvature stabilize the higher current levels in alamethicin channels and destabilize gramicidin channels; third, increases in bilayer elasticity stabilize the higher current levels in alamethicin channels and stabilize gramicidin channels; and fourth, the energetic consequences of changes in elasticity tend to dominate over changes in curvature.
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Affiliation(s)
- Mohammad Ashrafuzzaman
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065, USA;
| | - Roger E. Koeppe
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA;
| | - Olaf S. Andersen
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065, USA;
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33
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Rostovtseva TK, Weinrich M, Jacobs D, Rosencrans WM, Bezrukov SM. Dimeric Tubulin Modifies Mechanical Properties of Lipid Bilayer, as Probed Using Gramicidin A Channel. Int J Mol Sci 2024; 25:2204. [PMID: 38396879 PMCID: PMC10889239 DOI: 10.3390/ijms25042204] [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: 12/07/2023] [Revised: 01/31/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024] Open
Abstract
Using the gramicidin A channel as a molecular probe, we show that tubulin binding to planar lipid membranes changes the channel kinetics-seen as an increase in the lifetime of the channel dimer-and thus points towards modification of the membrane's mechanical properties. The effect is more pronounced in the presence of non-lamellar lipids in the lipid mixture used for membrane formation. To interpret these findings, we propose that tubulin binding redistributes the lateral pressure of lipid packing along the membrane depth, making it closer to the profile expected for lamellar lipids. This redistribution happens because tubulin perturbs the lipid headgroup spacing to reach the membrane's hydrophobic core via its amphiphilic α-helical domain. Specifically, it increases the forces of repulsion between the lipid headgroups and reduces such forces in the hydrophobic region. We suggest that the effect is reciprocal, meaning that alterations in lipid bilayer mechanics caused by membrane remodeling during cell proliferation in disease and development may also modulate tubulin membrane binding, thus exerting regulatory functions. One of those functions includes the regulation of protein-protein interactions at the membrane surface, as exemplified by VDAC complexation with tubulin.
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Affiliation(s)
- Tatiana K. Rostovtseva
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA (S.M.B.)
| | - Michael Weinrich
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Daniel Jacobs
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA (S.M.B.)
| | - William M. Rosencrans
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA (S.M.B.)
- Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Sergey M. Bezrukov
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA (S.M.B.)
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Moura ACM, Asare IK, Cruz MF, Aguado AJF, Tuck KD, Campbell CC, Scheyer MW, Obaseki I, Alston S, Kravats AN, Sanders CR, Lorigan GA, Sahu ID. Studying Conformational Properties of Transmembrane Domain of KCNE3 in a Lipid Bilayer Membrane Using Molecular Dynamics Simulations. MEMBRANES 2024; 14:45. [PMID: 38392672 PMCID: PMC10890134 DOI: 10.3390/membranes14020045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 01/22/2024] [Accepted: 01/29/2024] [Indexed: 02/24/2024]
Abstract
KCNE3 is a single-pass integral membrane protein that regulates numerous voltage-gated potassium channel functions such as KCNQ1. Previous solution NMR studies suggested a moderate degree of curved α-helical structure in the transmembrane domain (TMD) of KCNE3 in lyso-myristoylphosphatidylcholine (LMPC) micelles and isotropic bicelles with the residues T71, S74 and G78 situated along the concave face of the curved helix. During the interaction of KCNE3 and KCNQ1, KCNE3 pushes its transmembrane domain against KCNQ1 to lock the voltage sensor in its depolarized conformation. A cryo-EM study of KCNE3 complexed with KCNQ1 in nanodiscs suggested a deviation of the KCNE3 structure from its independent structure in isotropic bicelles. Despite the biological significance of KCNE3 TMD, the conformational properties of KCNE3 are poorly understood. Here, all atom molecular dynamics (MD) simulations were utilized to investigate the conformational dynamics of the transmembrane domain of KCNE3 in a lipid bilayer containing a mixture of POPC and POPG lipids (3:1). Further, the effect of the interaction impairing mutations (V72A, I76A and F68A) on the conformational properties of the KCNE3 TMD in lipid bilayers was investigated. Our MD simulation results suggest that the KCNE3 TMD adopts a nearly linear α helical structural conformation in POPC-POPG lipid bilayers. Additionally, the results showed no significant change in the nearly linear α-helical conformation of KCNE3 TMD in the presence of interaction impairing mutations within the sampled time frame. The KCNE3 TMD is more stable with lower flexibility in comparison to the N-terminal and C-terminal of KCNE3 in lipid bilayers. The overall conformational flexibility of KCNE3 also varies in the presence of the interaction-impairing mutations. The MD simulation data further suggest that the membrane bilayer width is similar for wild-type KCNE3 and KCNE3 containing mutations. The Z-distance measurement data revealed that the TMD residue site A69 is close to the lipid bilayer center, and residue sites S57 and S82 are close to the surfaces of the lipid bilayer membrane for wild-type KCNE3 and KCNE3 containing interaction-impairing mutations. These results agree with earlier KCNE3 biophysical studies. The results of these MD simulations will provide complementary data to the experimental outcomes of KCNE3 to help understand its conformational dynamic properties in a more native lipid bilayer environment.
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Affiliation(s)
| | - Isaac K Asare
- Natural Science Division, Campbellsville University, Campbellsville, KY 42718, USA
| | - Mateo Fernandez Cruz
- Natural Science Division, Campbellsville University, Campbellsville, KY 42718, USA
| | | | - Kaeleigh Dyan Tuck
- Natural Science Division, Campbellsville University, Campbellsville, KY 42718, USA
| | - Conner C Campbell
- Natural Science Division, Campbellsville University, Campbellsville, KY 42718, USA
| | - Matthew W Scheyer
- Natural Science Division, Campbellsville University, Campbellsville, KY 42718, USA
| | - Ikponwmosa Obaseki
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Steve Alston
- Natural Science Division, Campbellsville University, Campbellsville, KY 42718, USA
| | - Andrea N Kravats
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Charles R Sanders
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Gary A Lorigan
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Indra D Sahu
- Natural Science Division, Campbellsville University, Campbellsville, KY 42718, USA
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
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Beck M, Covino R, Hänelt I, Müller-McNicoll M. Understanding the cell: Future views of structural biology. Cell 2024; 187:545-562. [PMID: 38306981 DOI: 10.1016/j.cell.2023.12.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/05/2023] [Accepted: 12/11/2023] [Indexed: 02/04/2024]
Abstract
Determining the structure and mechanisms of all individual functional modules of cells at high molecular detail has often been seen as equal to understanding how cells work. Recent technical advances have led to a flush of high-resolution structures of various macromolecular machines, but despite this wealth of detailed information, our understanding of cellular function remains incomplete. Here, we discuss present-day limitations of structural biology and highlight novel technologies that may enable us to analyze molecular functions directly inside cells. We predict that the progression toward structural cell biology will involve a shift toward conceptualizing a 4D virtual reality of cells using digital twins. These will capture cellular segments in a highly enriched molecular detail, include dynamic changes, and facilitate simulations of molecular processes, leading to novel and experimentally testable predictions. Transferring biological questions into algorithms that learn from the existing wealth of data and explore novel solutions may ultimately unveil how cells work.
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Affiliation(s)
- Martin Beck
- Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany; Goethe University Frankfurt, Frankfurt, Germany.
| | - Roberto Covino
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Straße 1, 60438 Frankfurt am Main, Germany.
| | - Inga Hänelt
- Goethe University Frankfurt, Frankfurt, Germany.
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36
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Drew D, Boudker O. Ion and lipid orchestration of secondary active transport. Nature 2024; 626:963-974. [PMID: 38418916 DOI: 10.1038/s41586-024-07062-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 01/12/2024] [Indexed: 03/02/2024]
Abstract
Transporting small molecules across cell membranes is an essential process in cell physiology. Many structurally diverse, secondary active transporters harness transmembrane electrochemical gradients of ions to power the uptake or efflux of nutrients, signalling molecules, drugs and other ions across cell membranes. Transporters reside in lipid bilayers on the interface between two aqueous compartments, where they are energized and regulated by symported, antiported and allosteric ions on both sides of the membrane and the membrane bilayer itself. Here we outline the mechanisms by which transporters couple ion and solute fluxes and discuss how structural and mechanistic variations enable them to meet specific physiological needs and adapt to environmental conditions. We then consider how general bilayer properties and specific lipid binding modulate transporter activity. Together, ion gradients and lipid properties ensure the effective transport, regulation and distribution of small molecules across cell membranes.
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Affiliation(s)
- David Drew
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
| | - Olga Boudker
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA.
- Howard Hughes Medical Institute, Weill Cornell Medicine, New York, NY, USA.
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37
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Kiani YS, Jabeen I. Challenges of Protein-Protein Docking of the Membrane Proteins. Methods Mol Biol 2024; 2780:203-255. [PMID: 38987471 DOI: 10.1007/978-1-0716-3985-6_12] [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: 07/12/2024]
Abstract
Despite the recent advances in the determination of high-resolution membrane protein (MP) structures, the structural and functional characterization of MPs remains extremely challenging, mainly due to the hydrophobic nature, low abundance, poor expression, purification, and crystallization difficulties associated with MPs. Whereby the major challenges/hurdles for MP structure determination are associated with the expression, purification, and crystallization procedures. Although there have been significant advances in the experimental determination of MP structures, only a limited number of MP structures (approximately less than 1% of all) are available in the Protein Data Bank (PDB). Therefore, the structures of a large number of MPs still remain unresolved, which leads to the availability of widely unplumbed structural and functional information related to MPs. As a result, recent developments in the drug discovery realm and the significant biological contemplation have led to the development of several novel, low-cost, and time-efficient computational methods that overcome the limitations of experimental approaches, supplement experiments, and provide alternatives for the characterization of MPs. Whereby the fine tuning and optimizations of these computational approaches remains an ongoing endeavor.Computational methods offer a potential way for the elucidation of structural features and the augmentation of currently available MP information. However, the use of computational modeling can be extremely challenging for MPs mainly due to insufficient knowledge of (or gaps in) atomic structures of MPs. Despite the availability of numerous in silico methods for 3D structure determination the applicability of these methods to MPs remains relatively low since all methods are not well-suited or adequate for MPs. However, sophisticated methods for MP structure predictions are constantly being developed and updated to integrate the modifications required for MPs. Currently, different computational methods for (1) MP structure prediction, (2) stability analysis of MPs through molecular dynamics simulations, (3) modeling of MP complexes through docking, (4) prediction of interactions between MPs, and (5) MP interactions with its soluble partner are extensively used. Towards this end, MP docking is widely used. It is notable that the MP docking methods yet few in number might show greater potential in terms of filling the knowledge gap. In this chapter, MP docking methods and associated challenges have been reviewed to improve the applicability, accuracy, and the ability to model macromolecular complexes.
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Affiliation(s)
- Yusra Sajid Kiani
- School of Interdisciplinary Engineering and Sciences (SINES), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Ishrat Jabeen
- School of Interdisciplinary Engineering and Sciences (SINES), National University of Sciences and Technology (NUST), Islamabad, Pakistan.
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38
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Blazhynska M, Gumbart JC, Chen H, Tajkhorshid E, Roux B, Chipot C. A Rigorous Framework for Calculating Protein-Protein Binding Affinities in Membranes. J Chem Theory Comput 2023; 19:9077-9092. [PMID: 38091976 PMCID: PMC11145395 DOI: 10.1021/acs.jctc.3c00941] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Calculating the binding free energy of integral transmembrane (TM) proteins is crucial for understanding the mechanisms by which they recognize one another and reversibly associate. The glycophorin A (GpA) homodimer, composed of two α-helical segments, has long served as a model system for studying TM protein reversible association. The present work establishes a methodological framework for calculating the binding affinity of the GpA homodimer in the heterogeneous environment of a membrane. Our investigation carefully considered a variety of protocols, including the appropriate choice of the force field, rigorous standardization reflecting the experimental conditions, sampling algorithm, anisotropic environment, and collective variables, to accurately describe GpA dimerization via molecular dynamics-based approaches. Specifically, two strategies were explored: (i) an unrestrained potential mean force (PMF) calculation, which merely enhances sampling along the separation of the two binding partners without any restraint, and (ii) a so-called "geometrical route", whereby the α-helices are progressively separated with imposed restraints on their orientational, positional, and conformational degrees of freedom to accelerate convergence. Our simulations reveal that the simplified, unrestrained PMF approach is inadequate for the description of GpA dimerization. Instead, the geometrical route, tailored specifically to GpA in a membrane environment, yields excellent agreement with experimental data within a reasonable computational time. A dimerization free energy of -10.7 kcal/mol is obtained, in fairly good agreement with available experimental data. The geometrical route further helps elucidate how environmental forces drive association before helical interactions stabilize it. Our simulations also brought to light a distinct, long-lived spatial arrangement that potentially serves as an intermediate state during dimer formation. The methodological advances in the generalized geometrical route provide a powerful tool for accurate and efficient binding-affinity calculations of intricate TM protein complexes in inhomogeneous environments.
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Affiliation(s)
- Marharyta Blazhynska
- Laboratoire International Associé Centre National de la Recherche Scientifique et University of Illinois at Urbana-Champaign, Unité Mixte de Recherche n°7019, Université de Lorraine, B.P. 70239, Vandœuvre-lès-Nancy cedex 54506, France
| | - James C Gumbart
- School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, Georgia 30332, United States
| | - Haochuan Chen
- Laboratoire International Associé Centre National de la Recherche Scientifique et University of Illinois at Urbana-Champaign, Unité Mixte de Recherche n°7019, Université de Lorraine, B.P. 70239, Vandœuvre-lès-Nancy cedex 54506, France
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, Illinois 61801, United States
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Benoît Roux
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 E. 57th Street W225, Chicago, Illinois 60637, United States
- Department of Chemistry, The University of Chicago, 5735 S. Ellis Avenue, Chicago, Illinois 60637, United States
| | - Christophe Chipot
- Laboratoire International Associé Centre National de la Recherche Scientifique et University of Illinois at Urbana-Champaign, Unité Mixte de Recherche n°7019, Université de Lorraine, B.P. 70239, Vandœuvre-lès-Nancy cedex 54506, France
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, Illinois 61801, United States
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 E. 57th Street W225, Chicago, Illinois 60637, United States
- Department of Chemistry, The University of Hawai'i at Ma̅noa, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
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39
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Krmic M, Perez E, Scollan P, Ivanchenko K, Gamez Hernandez A, Giancaspro J, Rosario J, Ceja-Vega J, Gudyka J, Porteus R, Lee S. Aspirin Interacts with Cholesterol-Containing Membranes in a pH-Dependent Manner. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:16444-16456. [PMID: 37939382 PMCID: PMC10666536 DOI: 10.1021/acs.langmuir.3c02242] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 11/10/2023]
Abstract
Aspirin has been used for broad therapeutic treatment, including secondary prevention of cardiovascular disease associated with increased cholesterol levels. Aspirin and other nonsteroidal anti-inflammatory drugs have been shown to interact with lipid membranes and change their biophysical properties. In this study, mixed lipid model bilayers made from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) or 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) comprising varying concentrations of cholesterol (10:1, 4:1, and 1:1 mole ratio of lipid:chol), prepared by the droplet interface bilayer method, were used to examine the effects of aspirin at various pH on transbilayer water permeability. The presence of aspirin increases the water permeability of POPC bilayers in a concentration-dependent manner, with a greater magnitude of increase at pH 3 compared to pH 7. In the presence of cholesterol, aspirin is similarly shown to increase water permeability; however, the extent of the increase depends on both the concentration of cholesterol and the pH, with the least pronounced enhancement in water permeability at high cholesterol levels at pH 7. A fusion of data from differential scanning calorimetry, confocal Raman microspectrophotometry, and interfacial tensiometric measurements demonstrates that aspirin can promote significant thermal, structural, and interfacial property perturbations in the mixed-lipid POPC or DOPC membranes containing cholesterol, indicating a disordering effect on the lipid membranes. Our findings suggest that aspirin fluidizes phosphocholine membranes in both cholesterol-free and cholesterol-enriched states and that the overall effect is greater when aspirin is in a neutral state. These results confer a deeper comprehension of the divergent effects of aspirin on biological membranes having heterogeneous compositions, under varying physiological pH and different cholesterol compositions, with implications for a better understanding of the gastrointestinal toxicity induced by the long term use of this important nonsteroidal anti-inflammatory molecule.
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Affiliation(s)
- Michael Krmic
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Escarlin Perez
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Patrick Scollan
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Katherine Ivanchenko
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Alondra Gamez Hernandez
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Joseph Giancaspro
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Juan Rosario
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Jasmin Ceja-Vega
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Jamie Gudyka
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Riley Porteus
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
| | - Sunghee Lee
- Department of Chemistry and Biochemistry, Iona University, 715 North Avenue, New Rochelle, New York 10801, United States
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40
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Xie H, Zhao Y, Zhao W, Chen Y, Liu M, Yang J. Solid-state NMR structure determination of a membrane protein in E. coli cellular inner membrane. SCIENCE ADVANCES 2023; 9:eadh4168. [PMID: 37910616 PMCID: PMC10619923 DOI: 10.1126/sciadv.adh4168] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 09/27/2023] [Indexed: 11/03/2023]
Abstract
Structure determination of membrane proteins in native cellular membranes is critical to precisely reveal their structures in physiological conditions. However, it remains challenging for solid-state nuclear magnetic resonance (ssNMR) due to the low sensitivity and high complexity of ssNMR spectra of cellular membranes. Here, we present the structure determination of aquaporin Z (AqpZ) by ssNMR in Escherichia coli inner membranes. To enhance the signal sensitivity of AqpZ, we optimized protein overexpression and removed outer membrane components. To suppress the interference of background proteins, we used a "dual-media" expression approach and antibiotic treatment. Using 1017 distance restraints obtained from two-dimensional 13C-13C spectra based on the complete chemical shift assignments, the 1.7-Å ssNMR structure of AqpZ is determined in E. coli inner membranes. This cellular ssNMR structure determination paves the way for analyzing the atomic structural details for membrane proteins in native cellular membranes.
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Affiliation(s)
- Huayong Xie
- National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Yongxiang Zhao
- National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Weijing Zhao
- National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Yanke Chen
- National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Maili Liu
- National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Jun Yang
- National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
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41
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Ghorbani M, Dehghan G, Allahverdi A. Concentration-dependent mechanism of the binding behavior of ibuprofen to the cell membrane: A molecular dynamic simulation study. J Mol Graph Model 2023; 124:108581. [PMID: 37536233 DOI: 10.1016/j.jmgm.2023.108581] [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: 05/08/2023] [Revised: 06/28/2023] [Accepted: 07/28/2023] [Indexed: 08/05/2023]
Abstract
Ibuprofen is a commonly used drug for treating headaches, pain, and fever. The lipid bilayer is the primary and most important interface for drugs to interact with biological systems. However, the molecular interactions between ibuprofen and the cell membrane are not well understood. Our findings suggest that the interactions between ibuprofen and the bilayer involve multiple steps and depend on the concentration of the drug. At low concentrations of ibuprofen, it can bind to the surface of the lipid bilayer. The electrostatic and vdW energies of IBU-lipid at 0 ns of the simulation were -22.5 ± 3.2 and -5.9 ± 1.2 kj.mol-1 Fig. 2. In the following, the vdW energy of the IBU-lipid was increased by around -134.6 ± 3.7 kj.mol-1 whereas the electrostatic energy of the IBU-lipid was significantly decreased. This binding is facilitated by electrostatic and vdW interactions between ibuprofen and the head group of lipids. In the second step, ibuprofen is inserted into the lipid bilayer and positioned at the interface between the bilayer and the aqueous phase. In high concentrations of ibuprofen, it moved to the central region of the lipid bilayer. At this concentration, the physical and structural properties of the cell membrane change significantly. Results from the radial distribution function analysis indicate that at low concentrations, ibuprofen molecules are situated close to the head groups of phosphate groups. However, at high concentrations of ibuprofen, these molecules move to the inner side of the lipid bilayer. In addition, our findings indicate that at low concentrations of ibuprofen, these molecules did not significantly alter the physical properties of the cell membrane. In contrast, at high concentrations of ibuprofen, the physical parameters of the hydrocarbon tails, such as thickness, fluidity, and order, changed dramatically. APL parameter for POPC membrane increased slightly to 0.60 and 0.63 nm2 in the presence of low and high concentrations of ibuprofen molecules. The three-step interaction between ibuprofen and the lipid bilayer involves several events, such as the movement of ibuprofen molecules towards the central region of the lipid bilayer and the deformation and alteration of the structural and stability properties of the cell membrane. These effects are observed only at high concentrations of ibuprofen. It appears that the side effects of ibuprofen overdose are related to changes in the properties of the cell membrane and, subsequently, the function of membrane-anchored target proteins.
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Affiliation(s)
| | | | - Abdollah Allahverdi
- Department of Biophysics, Faculty of Biological Sciences Tarbiat Modares University, Jalal Ale Ahmad Highway, P.O. Box: 14115-111, Tehran, Iran.
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42
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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: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [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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43
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Westerhoff HV. On paradoxes between optimal growth, metabolic control analysis, and flux balance analysis. Biosystems 2023; 233:104998. [PMID: 37591451 DOI: 10.1016/j.biosystems.2023.104998] [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: 05/01/2023] [Revised: 08/04/2023] [Accepted: 08/08/2023] [Indexed: 08/19/2023]
Abstract
In Microbiology it is often assumed that growth rate is maximal. This may be taken to suggest that the dependence of the growth rate on every enzyme activity is at the top of an inverse-parabolic function, i.e. that all flux control coefficients should equal zero. This might seem to imply that the sum of these flux control coefficients equals zero. According to the summation law of Metabolic Control Analysis (MCA) the sum of flux control coefficients should equal 1 however. And in Flux Balance Analysis (FBA) catabolism is often limited by a hard bound, causing catabolism to fully control the fluxes, again in apparent contrast with a flux control coefficient of zero. Here we resolve these paradoxes (apparent contradictions) in an analysis that uses the 'Edinburgh pathway', the 'Amsterdam pathway', as well as a generic metabolic network providing the building blocks or Gibbs energy for microbial growth. We review and show that (i) optimization depends on so-called enzyme control coefficients rather than the 'catalytic control coefficients' of MCA's summation law, (ii) when optimization occurs at fixed total protein, the former differ from the latter to the extent that they may all become equal to zero in the optimum state, (iii) in more realistic scenarios of optimization where catalytically inert biomass is compensating or maintenance metabolism is taken into consideration, the optimum enzyme concentrations should not be expected to equal those that maximize the specific growth rate, (iv) optimization may be in terms of yield rather than specific growth rate, which resolves the paradox because the sum of catalytic control coefficients on yield equals 0, (v) FBA effectively maximizes growth yield, and for yield the summation law states 0 rather than 1, thereby removing the paradox, (vi) furthermore, FBA then comes more often to a 'hard optimum' defined by a maximum catabolic flux and a catabolic-enzyme control coefficient of 1. The trade-off between maintenance metabolism and growth is highlighted as worthy of further analysis.
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Affiliation(s)
- Hans V Westerhoff
- Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, A-Life, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands; Synthetic Systems Biology and Nuclear Organization, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH, Amsterdam, the Netherlands; School of Biological Sciences, Medicine and Health, University of Manchester, Manchester, United Kingdom; Stellenbosch Institute for Advanced Study (STIAS), Wallenberg Research Centre at Stellenbosch University, Stellenbosch, 7600, South Africa.
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44
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Harris M, Dolan RF, Bryce JR, Ewusi JG, Cook GA. In Vitro Glycosylation of the Membrane Protein γ-Sarcoglycan in Nanodiscs. ACS OMEGA 2023; 8:40904-40910. [PMID: 37929139 PMCID: PMC10620887 DOI: 10.1021/acsomega.3c06135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 10/05/2023] [Indexed: 11/07/2023]
Abstract
Membrane glycoproteins are proteins that reside in the membranes of cells and are post-translationally modified to have sugars attached to their amino acid side chains. Studies of this subset of proteins in their native states are becoming more important since they have been linked to numerous human diseases. However, these proteins are difficult to study due to their hydrophobic nature and their propensity to aggregate. Using membrane mimetics allows us to solubilize these proteins, which, in turn, allows us to perform glycosylation in vitro to study the effects of the modification on protein structure, dynamics, and interactions. Here, the membrane glycoprotein γ-sarcoglycan was incorporated into nanodiscs composed of long-chain lipids and membrane scaffold proteins to perform N-linked glycosylation in which an enzyme attaches a sugar to the asparagine side chain within the glycosylation site. We previously performed glycosylation of membrane proteins in vitro when the protein had been solubilized using different detergents and short-chain lipids. This work demonstrates successful glycosylation of a full-length membrane protein in nanodiscs providing a more biologically relevant sample to study the effects of the modification.
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Affiliation(s)
- Michael
S. Harris
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Rachel F. Dolan
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - James R. Bryce
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Jonas G. Ewusi
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Gabriel A. Cook
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States
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45
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Ali O, Szabó A. Review of Eukaryote Cellular Membrane Lipid Composition, with Special Attention to the Fatty Acids. Int J Mol Sci 2023; 24:15693. [PMID: 37958678 PMCID: PMC10649022 DOI: 10.3390/ijms242115693] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023] Open
Abstract
Biological membranes, primarily composed of lipids, envelop each living cell. The intricate composition and organization of membrane lipids, including the variety of fatty acids they encompass, serve a dynamic role in sustaining cellular structural integrity and functionality. Typically, modifications in lipid composition coincide with consequential alterations in universally significant signaling pathways. Exploring the various fatty acids, which serve as the foundational building blocks of membrane lipids, provides crucial insights into the underlying mechanisms governing a myriad of cellular processes, such as membrane fluidity, protein trafficking, signal transduction, intercellular communication, and the etiology of certain metabolic disorders. Furthermore, comprehending how alterations in the lipid composition, especially concerning the fatty acid profile, either contribute to or prevent the onset of pathological conditions stands as a compelling area of research. Hence, this review aims to meticulously introduce the intricacies of membrane lipids and their constituent fatty acids in a healthy organism, thereby illuminating their remarkable diversity and profound influence on cellular function. Furthermore, this review aspires to highlight some potential therapeutic targets for various pathological conditions that may be ameliorated through dietary fatty acid supplements. The initial section of this review expounds on the eukaryotic biomembranes and their complex lipids. Subsequent sections provide insights into the synthesis, membrane incorporation, and distribution of fatty acids across various fractions of membrane lipids. The last section highlights the functional significance of membrane-associated fatty acids and their innate capacity to shape the various cellular physiological responses.
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Affiliation(s)
- Omeralfaroug Ali
- Agrobiotechnology and Precision Breeding for Food Security National Laboratory, Institute of Physiology and Animal Nutrition, Department of Animal Physiology and Health, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, 7400 Kaposvár, Hungary;
| | - András Szabó
- Agrobiotechnology and Precision Breeding for Food Security National Laboratory, Institute of Physiology and Animal Nutrition, Department of Animal Physiology and Health, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, 7400 Kaposvár, Hungary;
- HUN-REN-MATE Mycotoxins in the Food Chain Research Group, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, 7400 Kaposvár, Hungary
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46
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Panda A, Brown C, Gupta K. Studying Membrane Protein-Lipid Specificity through Direct Native Mass Spectrometric Analysis from Tunable Proteoliposomes. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:1917-1927. [PMID: 37432128 PMCID: PMC10932607 DOI: 10.1021/jasms.3c00110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
Native mass spectrometry (nMS) has emerged as a key analytical tool to study the organizational states of proteins and their complexes with both endogenous and exogenous ligands. Specifically, for membrane proteins, it provides a key analytical dimension to determine the identity of bound lipids and to decipher their effects on the observed structural assembly. We recently developed an approach to study membrane proteins directly from intact and tunable lipid membranes where both the biophysical properties of the membrane and its lipid compositions can be customized. Extending this, we use our liposome-nMS platform to decipher the lipid specificity of membrane proteins through their multiorganelle trafficking pathways. To demonstrate this, we used VAMP2 and reconstituted it in the endoplasmic reticulum (ER), Golgi, synaptic vesicle (SV), and plasma membrane (PM) mimicking liposomes. By directly studying VAMP2 from these customized liposomes, we show how the same transmembrane protein can bind to different sets of lipids in different organellar-mimicking membranes. Considering that the cellular trafficking pathway of most eukaryotic integral membrane proteins involves residence in multiple organellar membranes, this study highlights how the lipid-specificity of the same integral membrane protein may change depending on the membrane context. Further, leveraging the capability of the platform to study membrane proteins from liposomes with curated biophysical properties, we show how we can disentangle chemical versus biophysical properties, of individual lipids in regulating membrane protein assembly.
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Affiliation(s)
- Aniruddha Panda
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Caroline Brown
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Kallol Gupta
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
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47
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Romanauska A, Köhler A. Lipid saturation controls nuclear envelope function. Nat Cell Biol 2023; 25:1290-1302. [PMID: 37591950 PMCID: PMC10495262 DOI: 10.1038/s41556-023-01207-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/18/2023] [Indexed: 08/19/2023]
Abstract
The nuclear envelope (NE) is a spherical double membrane with elastic properties. How NE shape and elasticity are regulated by lipid chemistry is unknown. Here we discover lipid acyl chain unsaturation as essential for NE and nuclear pore complex (NPC) architecture and function. Increased lipid saturation rigidifies the NE and the endoplasmic reticulum into planar, polygonal membranes, which are fracture prone. These membranes exhibit a micron-scale segregation of lipids into ordered and disordered phases, excluding NPCs from the ordered phase. Balanced lipid saturation is required for NPC integrity, pore membrane curvature and nucleocytoplasmic transport. Oxygen deprivation amplifies the impact of saturated lipids, causing NE rigidification and rupture. Conversely, lipid droplets buffer saturated lipids to preserve NE architecture. Our study uncovers a fundamental link between lipid acyl chain structure and the integrity of the cell nucleus with implications for nuclear membrane malfunction in ischaemic tissues.
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Affiliation(s)
- Anete Romanauska
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Center for Molecular Biology, University of Vienna, Vienna, Austria
| | - Alwin Köhler
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria.
- Center for Molecular Biology, University of Vienna, Vienna, Austria.
- Center for Medical Biochemistry, Medical University of Vienna, Vienna, Austria.
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48
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Dobi D, Loberto N, Bassi R, Pistocchi A, Lunghi G, Tamanini A, Aureli M. Cross-talk between CFTR and sphingolipids in cystic fibrosis. FEBS Open Bio 2023; 13:1601-1614. [PMID: 37315117 PMCID: PMC10476574 DOI: 10.1002/2211-5463.13660] [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: 04/07/2023] [Revised: 06/06/2023] [Accepted: 06/12/2023] [Indexed: 06/16/2023] Open
Abstract
Cystic fibrosis (CF) is the most common inherited, life-limiting disorder in Caucasian populations. It is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR), which lead to an impairment of protein expression and/or function. CFTR is a chloride/bicarbonate channel expressed at the apical surface of epithelial cells of different organs. Nowadays, more than 2100 CFTR genetic variants have been described, but not all of them cause CF. However, around 80-85% of the patients worldwide are characterized by the presence, at least in one allele, of the mutation F508del. CFTR mutations cause aberrant hydration and secretion of mucus in hollow organs. In the lungs, this condition favors bacterial colonization, allowing the development of chronic infections that lead to the onset of the CF lung disease, which is the main cause of death in patients. In recent years, evidence has reported that CFTR loss of function is responsible for alterations in a particular class of bioactive lipids, called sphingolipids (SL). SL are ubiquitously present in eukaryotic cells and are mainly asymmetrically located within the external leaflet of the plasma membrane, where they organize specific platforms capable of segregating a selected number of proteins. CFTR is associated with these platforms that are fundamental for its functioning. Considering the importance of SL in CFTR homeostasis, we attempt here to provide a critical overview of the literature to determine the role of these lipids in channel stability and activity, and whether their modulation in CF could be a target for new therapeutic approaches.
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Affiliation(s)
- Dorina Dobi
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| | - Nicoletta Loberto
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| | - Rosaria Bassi
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| | - Anna Pistocchi
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| | - Giulia Lunghi
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| | - Anna Tamanini
- Section of Clinical Biochemistry, Department of Neurosciences, Biomedicine and MovementUniversity of VeronaItaly
| | - Massimo Aureli
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
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49
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Samolis PD, Sander MY, Hong MK, Erramilli S, Narayan O. Thermal transport across membranes and the Kapitza length from photothermal microscopy. J Biol Phys 2023; 49:365-381. [PMID: 37477759 PMCID: PMC10397174 DOI: 10.1007/s10867-023-09636-0] [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: 02/26/2023] [Accepted: 05/30/2023] [Indexed: 07/22/2023] Open
Abstract
An analytical model is presented for light scattering associated with heat transport near a cell membrane that divides a complex system into two topologically distinct half-spaces. Our analysis is motivated by experiments on vibrational photothermal microscopy which have not only demonstrated remarkably high contrast and resolution, but also are capable of providing label-free local information of heat transport in complex morphologies. In the first Born approximation, the derived Green's function leads to the reconstruction of a full 3D image with photothermal contrast obtained using both amplitude and phase detection of periodic excitations. We show that important fundamental parameters including the Kapitza length and Kapitza resistance can be derived from experiments. Our goal is to spur additional experimental studies with high-frequency modulation and heterodyne detection in order to make contact with recent theoretical molecular dynamics calculations of thermal transport properties in membrane systems.
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Affiliation(s)
- Panagis D Samolis
- Department of Electrical Engineering, Boston University, Boston, MA, 02215, USA
- The Photonics Center, Boston University, Boston, MA, 02215, USA
| | - Michelle Y Sander
- Department of Electrical Engineering, Boston University, Boston, MA, 02215, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA
- The Photonics Center, Boston University, Boston, MA, 02215, USA
| | - Mi K Hong
- Department of Physics, Boston University, Boston, MA, 02215, USA
| | - Shyamsunder Erramilli
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA.
- The Photonics Center, Boston University, Boston, MA, 02215, USA.
- Department of Physics, Boston University, Boston, MA, 02215, USA.
| | - Onuttom Narayan
- Department of Physics, University of California Santa Cruz, Santa Cruz, CA, USA.
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50
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Chai P, Lebedenko CG, Flynn RA. RNA Crossing Membranes: Systems and Mechanisms Contextualizing Extracellular RNA and Cell Surface GlycoRNAs. Annu Rev Genomics Hum Genet 2023; 24:85-107. [PMID: 37068783 DOI: 10.1146/annurev-genom-101722-101224] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
The subcellular localization of a biopolymer often informs its function. RNA is traditionally confined to the cytosolic and nuclear spaces, where it plays critical and conserved roles across nearly all biochemical processes. Our recent observation of cell surface glycoRNAs may further explain the extracellular role of RNA. While cellular membranes are efficient gatekeepers of charged polymers such as RNAs, a large body of research has demonstrated the accumulation of specific RNA species outside of the cell, termed extracellular RNAs (exRNAs). Across various species and forms of life, protein pores have evolved to transport RNA across membranes, thus providing a mechanistic path for exRNAs to achieve their extracellular topology. Here, we review types of exRNAs and the pores capable of RNA transport to provide a logical and testable path toward understanding the biogenesis and regulation of cell surface glycoRNAs.
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Affiliation(s)
- Peiyuan Chai
- Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Boston, Massachusetts, USA;
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Charlotta G Lebedenko
- Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Boston, Massachusetts, USA;
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Ryan A Flynn
- Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Boston, Massachusetts, USA;
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts, USA
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