1
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Zhang BC, Laursen MF, Hu L, Hazrati H, Narita R, Jensen LS, Hansen AS, Huang J, Zhang Y, Ding X, Muyesier M, Nilsson E, Banasik A, Zeiler C, Mogensen TH, Etzerodt A, Agger R, Johannsen M, Kofod-Olsen E, Paludan SR, Jakobsen MR. Cholesterol-binding motifs in STING that control endoplasmic reticulum retention mediate anti-tumoral activity of cholesterol-lowering compounds. Nat Commun 2024; 15:2760. [PMID: 38553448 PMCID: PMC10980718 DOI: 10.1038/s41467-024-47046-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 03/18/2024] [Indexed: 04/02/2024] Open
Abstract
The cGAS-STING pathway plays a crucial role in anti-tumoral responses by activating inflammation and reprogramming the tumour microenvironment. Upon activation, STING traffics from the endoplasmic reticulum (ER) to Golgi, allowing signalling complex assembly and induction of interferon and inflammatory cytokines. Here we report that cGAMP stimulation leads to a transient decline in ER cholesterol levels, mediated by Sterol O-Acyltransferase 1-dependent cholesterol esterification. This facilitates ER membrane curvature and STING trafficking to Golgi. Notably, we identify two cholesterol-binding motifs in STING and confirm their contribution to ER-retention of STING. Consequently, depletion of intracellular cholesterol levels enhances STING pathway activation upon cGAMP stimulation. In a preclinical tumour model, intratumorally administered cholesterol depletion therapy potentiated STING-dependent anti-tumoral responses, which, in combination with anti-PD-1 antibodies, promoted tumour remission. Collectively, we demonstrate that ER cholesterol sets a threshold for STING signalling through cholesterol-binding motifs in STING and we propose that this could be exploited for cancer immunotherapy.
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Affiliation(s)
- Bao-Cun Zhang
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark.
| | - Marlene F Laursen
- Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark
| | - Lili Hu
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Hossein Hazrati
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark
- Department of Forensic Medicine, Aarhus University, DK-8200, Aarhus N, Denmark
| | - Ryo Narita
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Lea S Jensen
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Aida S Hansen
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Jinrong Huang
- Department of Biology, University of Copenhagen, DK-2100, Copenhagen Ø, Denmark
| | - Yan Zhang
- Department of Engineering, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Xiangning Ding
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark
| | | | - Emil Nilsson
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Agnieszka Banasik
- Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark
| | - Christina Zeiler
- Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark
| | - Trine H Mogensen
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark
- Department of Infectious Diseases, Aarhus University Hospital, DK-8200, Aarhus N, Denmark
| | - Anders Etzerodt
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Ralf Agger
- Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark
| | - Mogens Johannsen
- Department of Forensic Medicine, Aarhus University, DK-8200, Aarhus N, Denmark
| | - Emil Kofod-Olsen
- Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark
| | - Søren R Paludan
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark.
| | - Martin R Jakobsen
- Department of Biomedicine, Aarhus University, DK-8000, Aarhus C, Denmark.
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2
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Veldsink AC, Gallardo P, Lusk CP, Veenhoff LM. Changing the guard-nuclear pore complex quality control. FEBS Lett 2023; 597:2739-2749. [PMID: 37715940 DOI: 10.1002/1873-3468.14739] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/31/2023] [Accepted: 08/31/2023] [Indexed: 09/18/2023]
Abstract
The integrity of the nuclear envelope depends on the function of nuclear pore complexes (NPCs), transport channels that control macromolecular traffic between the nucleus and cytosol. The central importance of NPCs suggests the existence of quality control (QC) mechanisms that oversee their assembly and function. In this perspective, we emphasize the challenges associated with NPC assembly and the need for QC mechanisms that operate at various stages of an NPC's life. This includes cytosolic preassembly QC that helps enforce key nucleoporin-nucleoporin interactions and their ultimate stoichiometry in the NPC in addition to mechanisms that monitor aberrant fusion of the inner and outer nuclear membranes. Furthermore, we discuss whether and how these QC mechanisms may operate to sense faulty mature NPCs to facilitate their repair or removal. The so far uncovered mechanisms for NPC QC provide fertile ground for future research that not only benefits a better understanding of the vital role that NPCs play in cellular physiology but also how loss of NPC function and/or these QC mechanisms might be an input to aging and disease.
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Affiliation(s)
- Annemiek C Veldsink
- European Research Institute for the Biology of Ageing, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, Groningen, 9713 AV, The Netherlands
| | - Paola Gallardo
- European Research Institute for the Biology of Ageing, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, Groningen, 9713 AV, The Netherlands
| | - C Patrick Lusk
- Department of Cell Biology, Yale School of Medicine, CT, New Haven, USA
| | - Liesbeth M Veenhoff
- European Research Institute for the Biology of Ageing, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, Groningen, 9713 AV, The Netherlands
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3
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Amm I, Weberruss M, Hellwig A, Schwarz J, Tatarek-Nossol M, Lüchtenborg C, Kallas M, Brügger B, Hurt E, Antonin W. Distinct domains in Ndc1 mediate its interaction with the Nup84 complex and the nuclear membrane. J Cell Biol 2023; 222:e202210059. [PMID: 37154843 PMCID: PMC10165475 DOI: 10.1083/jcb.202210059] [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: 10/13/2022] [Revised: 01/31/2023] [Accepted: 03/17/2023] [Indexed: 05/10/2023] Open
Abstract
Nuclear pore complexes (NPCs) are embedded in the nuclear envelope and built from ∼30 different nucleoporins (Nups) in multiple copies, few are integral membrane proteins. One of these transmembrane nucleoporins, Ndc1, is thought to function in NPC assembly at the fused inner and outer nuclear membranes. Here, we show a direct interaction of Ndc1's transmembrane domain with Nup120 and Nup133, members of the pore membrane coating Y-complex. We identify an amphipathic helix in Ndc1's C-terminal domain binding highly curved liposomes. Upon overexpression, this amphipathic motif is toxic and dramatically alters the intracellular membrane organization in yeast. Ndc1's amphipathic motif functionally interacts with related motifs in the C-terminus of the nucleoporins Nup53 and Nup59, important for pore membrane binding and interconnecting NPC modules. The essential function of Ndc1 can be suppressed by deleting the amphipathic helix from Nup53. Our data indicate that nuclear membrane and presumably NPC biogenesis depends on a balanced ratio between amphipathic motifs in diverse nucleoporins.
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Affiliation(s)
- Ingo Amm
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Heidelberg, Germany
| | - Marion Weberruss
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany
| | - Andrea Hellwig
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Johannes Schwarz
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Heidelberg, Germany
| | - Marianna Tatarek-Nossol
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany
| | - Christian Lüchtenborg
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Heidelberg, Germany
| | - Martina Kallas
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Heidelberg, Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Heidelberg, Germany
| | - Ed Hurt
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Heidelberg, Germany
| | - Wolfram Antonin
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany
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4
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Melero A, Boulanger J, Kukulski W, Miller EA. Ultrastructure of COPII vesicle formation in yeast characterized by correlative light and electron microscopy. Mol Biol Cell 2022; 33:ar122. [PMID: 36001360 PMCID: PMC9634970 DOI: 10.1091/mbc.e22-03-0103] [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] [Indexed: 01/18/2023] Open
Abstract
Traffic of proteins out of the endoplasmic reticulum (ER) is driven by the COPII coat, a layered protein scaffold that mediates the capture of cargo proteins and the remodeling of the ER membrane into spherical vesicular carriers. Although the components of this machinery have been genetically defined, and the mechanisms of coat assembly extensively explored in vitro, understanding the physical mechanisms of membrane remodeling in cells remains a challenge. Here we use correlative light and electron microscopy (CLEM) to visualize the nanoscale ultrastructure of membrane remodeling at ER exit sites (ERES) in yeast cells. Using various COPII mutants, we have determined the broad contribution that each layer of the coat makes to membrane remodeling. Our data suggest that inner coat components define the radius of curvature, whereas outer coat components facilitate membrane fission. The organization of the coat in conjunction with membrane biophysical properties determines the ultrastructure of vesicles and thus the efficiency of protein transport.
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Affiliation(s)
- Alejandro Melero
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
- *Address correspondence to: Elizabeth A. Miller (); Alejandro Melero ()
| | - Jerome Boulanger
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Wanda Kukulski
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Elizabeth A. Miller
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
- *Address correspondence to: Elizabeth A. Miller (); Alejandro Melero ()
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5
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Zhang L, Wang Y, Dong Y, Pant A, Liu Y, Masserman L, Xu Y, McLaughlin RN, Bai J. The endophilin curvature-sensitive motif requires electrostatic guidance to recycle synaptic vesicles in vivo. Dev Cell 2022; 57:750-766.e5. [PMID: 35303431 PMCID: PMC8969179 DOI: 10.1016/j.devcel.2022.02.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/21/2022] [Accepted: 02/22/2022] [Indexed: 12/29/2022]
Abstract
Curvature-sensing mechanisms assist proteins in executing particular actions on various membrane organelles. Here, we investigate the functional specificity of curvature-sensing amphipathic motifs in Caenorhabditis elegans through the study of endophilin, an endocytic protein for synaptic vesicle recycling. We generate chimeric endophilin proteins by replacing the endophilin amphipathic motif H0 with other curvature-sensing amphipathic motifs. We find that the role of amphipathic motifs cannot simply be extrapolated from the identity of their parental proteins. For example, the amphipathic motif of the nuclear pore complex protein NUP133 functionally replaces the synaptic role of endophilin H0. Interestingly, non-functional endophilin chimeras have similar defects-producing fewer synaptic vesicles but more endosomes-and this indicates that the curvature-sensing motifs in these chimeras have a common deficiency for reforming synaptic vesicles. Finally, we convert non-functional endophilin chimeras into functional proteins by changing the cationic property of amphipathic motifs, successfully reprogramming the functional specificity of curvature-sensing motifs in vivo.
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Affiliation(s)
- Lin Zhang
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Yu Wang
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, P.R. China; Fudan University, Shanghai 200433, P.R. China
| | - Yongming Dong
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Aaradhya Pant
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Yan Liu
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Laura Masserman
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Ye Xu
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | | | - Jihong Bai
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
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6
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Hamed M, Antonin W. Dunking into the Lipid Bilayer: How Direct Membrane Binding of Nucleoporins Can Contribute to Nuclear Pore Complex Structure and Assembly. Cells 2021; 10:3601. [PMID: 34944108 PMCID: PMC8700311 DOI: 10.3390/cells10123601] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/17/2021] [Accepted: 12/18/2021] [Indexed: 02/07/2023] Open
Abstract
Nuclear pore complexes (NPCs) mediate the selective and highly efficient transport between the cytoplasm and the nucleus. They are embedded in the two membrane structure of the nuclear envelope at sites where these two membranes are fused to pores. A few transmembrane proteins are an integral part of NPCs and thought to anchor these complexes in the nuclear envelope. In addition, a number of nucleoporins without membrane spanning domains interact with the pore membrane. Here we review our current knowledge of how these proteins interact with the membrane and how this interaction can contribute to NPC assembly, stability and function as well as shaping of the pore membrane.
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Affiliation(s)
| | - Wolfram Antonin
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, 52074 Aachen, Germany;
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7
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Zhang W, Watanabe R, Konishi HA, Fujiwara T, Yoshimura SH, Kumeta M. Redox-Sensitive Cysteines Confer Proximal Control of the Molecular Crowding Barrier in the Nuclear Pore. Cell Rep 2020; 33:108484. [PMID: 33326779 DOI: 10.1016/j.celrep.2020.108484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 09/01/2020] [Accepted: 11/13/2020] [Indexed: 10/22/2022] Open
Abstract
The nuclear pore complex forms a highly crowded selective barrier with intrinsically disordered regions at the nuclear membrane to coordinate nucleocytoplasmic molecular communications. Although oxidative stress is known to alter the barrier function, the molecular mechanism underlying this adaptive control of the nuclear pore complex remains unknown. Here we uncover a systematic control of the crowding barrier within the nuclear pore in response to various redox environments. Direct measurements of the crowding states using a crowding-sensitive FRET (Förster resonance energy transfer) probe reveal specific roles of the nuclear pore subunits that adjust the degree of crowding in response to different redox conditions, by adaptively forming or disrupting redox-sensitive disulfide bonds. Relationships between crowding control and the barrier function of the nuclear pore are investigated by single-molecular fluorescence measurements of nuclear transport. Based on these findings, we propose a proximal control model of molecular crowding in vivo that is dynamically regulated at the molecular level.
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Affiliation(s)
- Wanzhen Zhang
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Ryuji Watanabe
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Hide A Konishi
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan; Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Takahiro Fujiwara
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto 606-8501, Japan
| | - Shige H Yoshimura
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Masahiro Kumeta
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan.
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8
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Bhatt VS, Ashley R, Sundborger-Lunna A. Amphipathic Motifs Regulate N-BAR Protein Endophilin B1 Auto-inhibition and Drive Membrane Remodeling. Structure 2020; 29:61-69.e3. [PMID: 33086035 DOI: 10.1016/j.str.2020.09.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/13/2020] [Accepted: 09/25/2020] [Indexed: 02/02/2023]
Abstract
Membrane remodeling is a common theme in a variety of cellular processes. Here, we investigated membrane remodeling N-BAR protein endophilin B1, a critical player in diverse intracellular trafficking events, including mitochondrial and Golgi fission, and apoptosis. We find that endophilin B1 assembles into helical scaffolds on membranes, and that both membrane binding and assembly are driven by interactions between N-terminal helix H0 and the lipid bilayer. Furthermore, we find that endophilin B1 membrane remodeling is auto-inhibited and identify direct SH3 domain-H0 interactions as the underlying mechanism. Our results indicate that lipid composition plays a role in dictating endophilin B1 activity. Taken together, this study provides insight into a poorly understood N-BAR protein family member and highlights molecular mechanisms that may be general for the regulation of membrane remodeling. Our work suggests that interplay between membrane lipids and membrane interacting proteins facilitates spatial and temporal coordination of membrane remodeling.
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Affiliation(s)
- Veer S Bhatt
- The Hormel Institute, University of Minnesota, 801 16(th) Avenue NE, Austin, MN 55912, USA
| | - Robert Ashley
- The Hormel Institute, University of Minnesota, 801 16(th) Avenue NE, Austin, MN 55912, USA
| | - Anna Sundborger-Lunna
- The Hormel Institute, University of Minnesota, 801 16(th) Avenue NE, Austin, MN 55912, USA.
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9
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Ganesan S, Tavassoli M, Shabits BN, Zaremberg V. Tubular ER Associates With Diacylglycerol-Rich Structures During Lipid Droplet Consumption. Front Cell Dev Biol 2020; 8:700. [PMID: 32850820 PMCID: PMC7403446 DOI: 10.3389/fcell.2020.00700] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 07/09/2020] [Indexed: 11/13/2022] Open
Abstract
Growth resumption from stationary phase in Saccharomyces cerevisiae, is characterized by lipid droplet (LD) consumption and channeling of lipid precursors toward synthesis of membranes. We have previously determined that triacylglycerol lipolysis contributes to a pool of diacylglycerol (DAG) associated with the yeast vacuole that is enriched in structures that are in close proximity to LDs. In this study we have monitored these structures using a DAG sensor fused to GFP during isolation of LDs. A unique fraction containing the DAG sensor, with low presence of LDs, was identified. Membranes enriched in the DAG probe were obtained by immunoaffinity purification using a GFP nanobody, and the associated proteome was investigated by mass spectrometry. It was determined this LD-associated fraction was enriched in proteins known to shape the tubular endoplasmic reticulum (ER) like Yop1, Sey1, Rtn1, and Rtn2. Consistently, cells lacking three of these proteins (rtn1Δ rtn2Δ yop1Δ) exhibited delayed LD consumption, larger LDs and abnormal LD distribution. In addition, the triple mutant displayed aberrant localization of the DAG sensor after 5 h of growth resumption from stationary phase. Manipulation of DAG levels by overexpression of the DAG kinase Dgk1, impacted localization of the DAG probe and affected fitness of the triple mutant. Altogether these results link LD consumption to tubular ER expansion as a gateway of lipid precursors that otherwise accumulate in vacuolar associated membranes or other internal compartments. Furthermore, conversion of DAG to phosphatidic acid (PA) in the absence of a functional tubular ER was toxic to cells, suggesting the ratio of PA to DAG is critical to allow growth progression.
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Affiliation(s)
| | - Marjan Tavassoli
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Brittney N Shabits
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Vanina Zaremberg
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
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10
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van Hilten N, Stroh KS, Risselada HJ. Membrane Thinning Induces Sorting of Lipids and the Amphipathic Lipid Packing Sensor (ALPS) Protein Motif. Front Physiol 2020; 11:250. [PMID: 32372966 PMCID: PMC7177014 DOI: 10.3389/fphys.2020.00250] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 03/05/2020] [Indexed: 12/16/2022] Open
Abstract
Heterogeneities (e.g., membrane proteins and lipid domains) and deformations (e.g., highly curved membrane regions) in biological lipid membranes cause lipid packing defects that may trigger functional sorting of lipids and membrane-associated proteins. To study these phenomena in a controlled and efficient way within molecular simulations, we developed an external field protocol that artificially enhances packing defects in lipid membranes by enforcing local thinning of a flat membrane region. For varying lipid compositions, we observed strong thinning-induced depletion or enrichment, depending on the lipid's intrinsic shape and its effect on a membrane's elastic modulus. In particular, polyunsaturated and lysolipids are strongly attracted to regions high in packing defects, whereas phosphatidylethanolamine (PE) lipids and cholesterol are strongly repelled from it. Our results indicate that externally imposed changes in membrane thickness, area, and curvature are underpinned by shared membrane elastic principles. The observed sorting toward the thinner membrane region is in line with the sorting expected for a positively curved membrane region. Furthermore, we have demonstrated that the amphipathic lipid packing sensor (ALPS) protein motif, a known curvature and packing defect sensor, is effectively attracted to thinner membrane regions. By extracting the force that drives amphipathic molecules toward the thinner region, our thinning protocol can directly quantify and score the lipid packing sensing of different amphipathic molecules. In this way, our protocol paves the way toward high-throughput exploration of potential defect- and curvature-sensing motifs, making it a valuable addition to the molecular simulation toolbox.
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Affiliation(s)
- Niek van Hilten
- Leiden Institute of Chemistry, Leiden University, Leiden, Netherlands
| | - Kai Steffen Stroh
- Institute for Theoretical Physics, Georg August University Göttingen, Göttingen, Germany
| | - Herre Jelger Risselada
- Leiden Institute of Chemistry, Leiden University, Leiden, Netherlands.,Institute for Theoretical Physics, Georg August University Göttingen, Göttingen, Germany
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11
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Ceramide Domains in Health and Disease: A Biophysical Perspective. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1159:79-108. [DOI: 10.1007/978-3-030-21162-2_6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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12
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Le Roux AL, Quiroga X, Walani N, Arroyo M, Roca-Cusachs P. The plasma membrane as a mechanochemical transducer. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180221. [PMID: 31431176 PMCID: PMC6627014 DOI: 10.1098/rstb.2018.0221] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2019] [Indexed: 12/20/2022] Open
Abstract
Cells are constantly submitted to external mechanical stresses, which they must withstand and respond to. By forming a physical boundary between cells and their environment that is also a biochemical platform, the plasma membrane (PM) is a key interface mediating both cellular response to mechanical stimuli, and subsequent biochemical responses. Here, we review the role of the PM as a mechanosensing structure. We first analyse how the PM responds to mechanical stresses, and then discuss how this mechanical response triggers downstream biochemical responses. The molecular players involved in PM mechanochemical transduction include sensors of membrane unfolding, membrane tension, membrane curvature or membrane domain rearrangement. These sensors trigger signalling cascades fundamental both in healthy scenarios and in diseases such as cancer, which cells harness to maintain integrity, keep or restore homeostasis and adapt to their external environment. This article is part of a discussion meeting issue 'Forces in cancer: interdisciplinary approaches in tumour mechanobiology'.
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Affiliation(s)
- Anabel-Lise Le Roux
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
| | - Xarxa Quiroga
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
| | - Nikhil Walani
- LaCàN, Universitat Politècnica de Catalunya-BarcelonaTech, Spain
| | - Marino Arroyo
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
- LaCàN, Universitat Politècnica de Catalunya-BarcelonaTech, Spain
| | - Pere Roca-Cusachs
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
- Department of Biomedical Sciences, Universitat de Barcelona, Barcelona 08036, Spain
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13
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Hammond K, Lewis H, Faruqui N, Russell C, Hoogenboom BW, Ryadnov MG. Helminth Defense Molecules as Design Templates for Membrane Active Antibiotics. ACS Infect Dis 2019; 5:1471-1479. [PMID: 31117348 DOI: 10.1021/acsinfecdis.9b00157] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A design template for membrane active antibiotics against microbial and tumor cells is described. The template is an amino acid sequence that combines the properties of helminth defense molecules, which are not cytolytic, with the properties of host-defense peptides, which disrupt microbial membranes. Like helminth defense molecules, the template folds into an amphipathic helix in both mammalian host and microbial phospholipid membranes. Unlike these molecules, the template exhibits antimicrobial and anticancer properties that are comparable to those of antimicrobial and anticancer antibiotics. The selective antibiotic activity of the template builds upon a functional synergy between three distinctive faces of the helix, which is in contrast to two faces of membrane-disrupting amphipathic structures. This synergy enables the template to adapt pore formation mechanisms according to the nature of the target membrane, inducing the lysis of microbial and tumor cells.
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Affiliation(s)
- Katharine Hammond
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
- Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
- London Centre for Nanotechnology, University College London, Gordon Street, London WC1H 0AH, United Kingdom
| | - Helen Lewis
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
| | - Nilofar Faruqui
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
| | - Craig Russell
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
| | - Bart W. Hoogenboom
- Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
- London Centre for Nanotechnology, University College London, Gordon Street, London WC1H 0AH, United Kingdom
| | - Maxim G. Ryadnov
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
- Department of Physics, King’s College London, Strand Lane, London WC2R, United Kingdom
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14
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Bilir Ş, Kojidani T, Mori C, Osakada H, Kobayashi S, Koujin T, Hiraoka Y, Haraguchi T. Roles of Nup133, Nup153 and membrane fenestrations in assembly of the nuclear pore complex at the end of mitosis. Genes Cells 2019; 24:338-353. [PMID: 30821042 DOI: 10.1111/gtc.12677] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 02/15/2019] [Accepted: 02/24/2019] [Indexed: 12/25/2022]
Abstract
Reassembly of the nuclear pore complex (NPC) at the end of mitosis is an important event for eukaryotic nuclear function. In this study, we examined the dynamic behaviors of the endoplasmic reticulum (ER) by "Live CLEM" imaging. In metaphase, numerous fenestrations on the ER membrane were observed around chromosomes. In telophase, these fenestrations became filled at the region attached to chromosomes, whereas they remained open at the region unattached to chromosomes, suggesting that NPC assembly takes place at fenestrations on the membrane. To determine the roles of nucleoporins in postmitotic NPC formation, we used artificial beads conjugated with anti-GFP antibody, which captures GFP-fused proteins on the beads when incorporated into cells. Live CLEM imaging of telophase cells containing Nup133-coated beads or Nup153-coated beads showed that Nup133 and Nup153, as the sole effector molecules, assembled the NPC-like structure on the membrane fenestrations. Indirect immunofluorescence staining of the Nup133-coated beads showed that Nup133 effectively assembled Nup107 and ELYS, whereas minimal assembly of Nup98 and Nup62 was observed; the Nup153-coated bead effectively assembled Nup98, Nup62 and Pom121, but assembled neither Nup107 nor ELYS. Our results suggest that Nup133 and Nup153 play different roles in assembling the NPC on membrane fenestrations.
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Affiliation(s)
- Şükriye Bilir
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology (NICT), Kobe, Japan
| | - Tomoko Kojidani
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology (NICT), Kobe, Japan.,Japan Women's University, Tokyo, Japan
| | - Chie Mori
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology (NICT), Kobe, Japan
| | - Hiroko Osakada
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology (NICT), Kobe, Japan
| | - Shouhei Kobayashi
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology (NICT), Kobe, Japan
| | - Takako Koujin
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology (NICT), Kobe, Japan
| | - Yasushi Hiraoka
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology (NICT), Kobe, Japan
| | - Tokuko Haraguchi
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology (NICT), Kobe, Japan
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15
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Monje-Galvan V, Warburton L, Klauda JB. Setting Up All-Atom Molecular Dynamics Simulations to Study the Interactions of Peripheral Membrane Proteins with Model Lipid Bilayers. Methods Mol Biol 2019; 1949:325-339. [PMID: 30790265 DOI: 10.1007/978-1-4939-9136-5_22] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
All-atom molecular dynamics (MD) simulations enable the study of biological systems at atomic detail, complement the understanding gained from experiment, and can also motivate experimental techniques to further examine a given biological process. This method is based on statistical mechanics; it predicts the trajectory of atoms over time by solving Newton's Laws of motion taking into account all forces. Here, we describe the use of this methodology to study the interaction between peripheral membrane proteins and a lipid bilayer. Specifically, we provide step-by-step instructions to set up MD simulations to study the binding and interaction of the amphipathic helix of Osh4, a lipid transport protein, and Thanatin, an antimicrobial peptide (AMP), with model lipid bilayers using both fully detailed lipid tails and the highly mobile membrane-mimetic (HMMM) method to enhance conformational sampling.
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Affiliation(s)
- Viviana Monje-Galvan
- Department of Chemistry, The University of Chicago, Chicago, IL, USA. .,Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD, USA.
| | - Linnea Warburton
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD, USA
| | - Jeffery B Klauda
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD, USA.,Biophysics Program, University of Maryland, College Park, MD, USA
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16
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Monje-Galvan V, Klauda JB. Preferred Binding Mechanism of Osh4’s Amphipathic Lipid-Packing Sensor Motif, Insights from Molecular Dynamics. J Phys Chem B 2018; 122:9713-9723. [DOI: 10.1021/acs.jpcb.8b07067] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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17
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Čopič A, Antoine-Bally S, Giménez-Andrés M, La Torre Garay C, Antonny B, Manni MM, Pagnotta S, Guihot J, Jackson CL. A giant amphipathic helix from a perilipin that is adapted for coating lipid droplets. Nat Commun 2018; 9:1332. [PMID: 29626194 PMCID: PMC5889406 DOI: 10.1038/s41467-018-03717-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 03/05/2018] [Indexed: 11/21/2022] Open
Abstract
How proteins are targeted to lipid droplets (LDs) and distinguish the LD surface from the surfaces of other organelles is poorly understood, but many contain predicted amphipathic helices (AHs) that are involved in targeting. We have focused on human perilipin 4 (Plin4), which contains an AH that is exceptional in terms of length and repetitiveness. Using model cellular systems, we show that AH length, hydrophobicity, and charge are important for AH targeting to LDs and that these properties can compensate for one another, albeit at a loss of targeting specificity. Using synthetic lipids, we show that purified Plin4 AH binds poorly to lipid bilayers but strongly interacts with pure triglycerides, acting as a coat and forming small oil droplets. Because Plin4 overexpression alleviates LD instability under conditions where their coverage by phospholipids is limiting, we propose that the Plin4 AH replaces the LD lipid monolayer, for example during LD growth. Lipid droplets are cellular organelles important for cellular homeostasis and their disruption has been implicated in many diseases. Here the authors use a large amphipathic helix from perilipin 4 to uncover parameters important for specific lipid droplet targeting and stabilization of the oil core.
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Affiliation(s)
- Alenka Čopič
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France.
| | - Sandra Antoine-Bally
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France
| | - Manuel Giménez-Andrés
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France.,Université Paris-Sud, Université Paris-Saclay, 91405, Orsay, France
| | - César La Torre Garay
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France
| | - Bruno Antonny
- Université Côte d'Azur, CNRS, IPMC, 06560, Valbonne, France
| | - Marco M Manni
- Université Côte d'Azur, CNRS, IPMC, 06560, Valbonne, France
| | | | - Jeanne Guihot
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France
| | - Catherine L Jackson
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France
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18
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Prévost C, Sharp ME, Kory N, Lin Q, Voth GA, Farese RV, Walther TC. Mechanism and Determinants of Amphipathic Helix-Containing Protein Targeting to Lipid Droplets. Dev Cell 2018; 44:73-86.e4. [PMID: 29316443 DOI: 10.1016/j.devcel.2017.12.011] [Citation(s) in RCA: 144] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 11/02/2017] [Accepted: 12/07/2017] [Indexed: 11/30/2022]
Abstract
Cytosolic lipid droplets (LDs) are the main storage organelles for metabolic energy in most cells. They are unusual organelles that are bounded by a phospholipid monolayer and specific surface proteins, including key enzymes of lipid and energy metabolism. Proteins targeting LDs from the cytoplasm often contain amphipathic helices, but how they bind to LDs is not well understood. Combining computer simulations with experimental studies in vitro and in cells, we uncover a general mechanism for targeting of cytosolic proteins to LDs: large hydrophobic residues of amphipathic helices detect and bind to large, persistent membrane packing defects that are unique to the LD surface. Surprisingly, amphipathic helices with large hydrophobic residues from many different proteins are capable of binding to LDs. This suggests that LD protein composition is additionally determined by mechanisms that selectively prevent proteins from binding LDs, such as macromolecular crowding at the LD surface.
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Affiliation(s)
- Coline Prévost
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02124, USA
| | - Morris E Sharp
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA
| | - Nora Kory
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02124, USA
| | - Qingqing Lin
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02124, USA
| | - Gregory A Voth
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA.
| | - Robert V Farese
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02124, USA.
| | - Tobias C Walther
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02124, USA; Howard Hughes Medical Institute, Boston, MA 02115, USA.
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19
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Obado SO, Field MC, Rout MP. Comparative interactomics provides evidence for functional specialization of the nuclear pore complex. Nucleus 2017; 8:340-352. [PMID: 28463551 DOI: 10.1080/19491034.2017.1313936] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
The core architecture of the eukaryotic cell was established well over one billion years ago, and is largely retained in all extant lineages. However, eukaryotic cells also possess lineage-specific features, frequently keyed to specific functional requirements. One quintessential core eukaryotic structure is the nuclear pore complex (NPC), responsible for regulating exchange of macromolecules between the nucleus and cytoplasm as well as acting as a nuclear organizational hub. NPC architecture has been best documented in one eukaryotic supergroup, the Opisthokonts (e.g. Saccharomyces cerevisiae and Homo sapiens), which although compositionally similar, have significant variations in certain NPC subcomplex structures. The variation of NPC structure across other taxa in the eukaryotic kingdom however, remains poorly understood. We explored trypanosomes, highly divergent organisms, and mapped and assigned their NPC proteins to specific substructures to reveal their NPC architecture. We showed that the NPC central structural scaffold is conserved, likely across all eukaryotes, but more peripheral elements can exhibit very significant lineage-specific losses, duplications or other alterations in their components. Amazingly, trypanosomes lack the major components of the mRNA export platform that are asymmetrically localized within yeast and vertebrate NPCs. Concomitant with this, the trypanosome NPC is ALMOST completely symmetric with the nuclear basket being the only major source of asymmetry. We suggest these features point toward a stepwise evolution of the NPC in which a coating scaffold first stabilized the pore after which selective gating emerged and expanded, leading to the addition of peripheral remodeling machineries on the nucleoplasmic and cytoplasmic sides of the pore.
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Affiliation(s)
| | - Mark C Field
- b Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences , University of Dundee , Dundee , UK
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20
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Beck M, Hurt E. The nuclear pore complex: understanding its function through structural insight. Nat Rev Mol Cell Biol 2016; 18:73-89. [PMID: 27999437 DOI: 10.1038/nrm.2016.147] [Citation(s) in RCA: 414] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nuclear pore complexes (NPCs) fuse the inner and outer nuclear membranes to form channels across the nuclear envelope. They are large macromolecular assemblies with a complex composition and diverse functions. Apart from facilitating nucleocytoplasmic transport, NPCs are involved in chromatin organization, the regulation of gene expression and DNA repair. Understanding the molecular mechanisms underlying these functions has been hampered by a lack of structural knowledge about the NPC. The recent convergence of crystallographic and biochemical in vitro analysis of nucleoporins (NUPs), the components of the NPC, with cryo-electron microscopic imaging of the entire NPC in situ has provided first pseudo-atomic view of its central core and revealed that an unexpected network of short linear motifs is an important spatial organization principle. These breakthroughs have transformed the way we understand NPC structure, and they provide an important base for functional investigations, including the elucidation of the molecular mechanisms underlying clinically manifested mutations of the nucleocytoplasmic transport system.
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Affiliation(s)
- Martin Beck
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstrasse 1, Heidelberg D-69117, Germany
| | - Ed Hurt
- Biochemistry Center of Heidelberg University, INF328, Heidelberg D-69120, Germany
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21
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Khan HM, He T, Fuglebakk E, Grauffel C, Yang B, Roberts MF, Gershenson A, Reuter N. A Role for Weak Electrostatic Interactions in Peripheral Membrane Protein Binding. Biophys J 2016; 110:1367-78. [PMID: 27028646 PMCID: PMC4816757 DOI: 10.1016/j.bpj.2016.02.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 01/08/2016] [Accepted: 02/02/2016] [Indexed: 12/01/2022] Open
Abstract
Bacillus thuringiensis phosphatidylinositol-specific phospholipase C (BtPI-PLC) is a secreted virulence factor that binds specifically to phosphatidylcholine (PC) bilayers containing negatively charged phospholipids. BtPI-PLC carries a negative net charge and its interfacial binding site has no obvious cluster of basic residues. Continuum electrostatic calculations show that, as expected, nonspecific electrostatic interactions between BtPI-PLC and membranes vary as a function of the fraction of anionic lipids present in the bilayers. Yet they are strikingly weak, with a calculated ΔGel below 1 kcal/mol, largely due to a single lysine (K44). When K44 is mutated to alanine, the equilibrium dissociation constant for small unilamellar vesicles increases more than 50 times (∼2.4 kcal/mol), suggesting that interactions between K44 and lipids are not merely electrostatic. Comparisons of molecular-dynamics simulations performed using different lipid compositions reveal that the bilayer composition does not affect either hydrogen bonds or hydrophobic contacts between the protein interfacial binding site and bilayers. However, the occupancies of cation-π interactions between PC choline headgroups and protein tyrosines vary as a function of PC content. The overall contribution of basic residues to binding affinity is also context dependent and cannot be approximated by a rule-of-thumb value because these residues can contribute to both nonspecific electrostatic and short-range protein-lipid interactions. Additionally, statistics on the distribution of basic amino acids in a data set of membrane-binding domains reveal that weak electrostatics, as observed for BtPI-PLC, might be a less unusual mechanism for peripheral membrane binding than is generally thought.
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Affiliation(s)
- Hanif M Khan
- Department of Molecular Biology, University of Bergen, Bergen, Norway; Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
| | - Tao He
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts
| | - Edvin Fuglebakk
- Department of Molecular Biology, University of Bergen, Bergen, Norway; Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
| | - Cédric Grauffel
- Department of Molecular Biology, University of Bergen, Bergen, Norway; Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
| | - Boqian Yang
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts; Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts
| | - Mary F Roberts
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts
| | - Anne Gershenson
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts
| | - Nathalie Reuter
- Department of Molecular Biology, University of Bergen, Bergen, Norway; Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway.
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22
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Chen Z, Zhu C, Kuo CJ, Robustelli J, Baumgart T. The N-Terminal Amphipathic Helix of Endophilin Does Not Contribute to Its Molecular Curvature Generation Capacity. J Am Chem Soc 2016; 138:14616-14622. [PMID: 27755867 PMCID: PMC5562367 DOI: 10.1021/jacs.6b06820] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-BAR proteins such as endophilin are thought to bend lipid membranes via scaffolding (the molding of membranes through the crescent protein shape) and membrane insertion (also called wedging) of amphipathic helices. However, the contributions from these distinct mechanisms to membrane curvature generation and sensing have remained controversial. Here we quantitatively demonstrate that the amphipathic N-terminal H0 helix of endophilin is important for recruiting this protein to the membrane, but does not contribute significantly to its intrinsic membrane curvature generation capacity. These observations elevate the importance of the scaffolding mechanism, rather than H0 insertion, for the membrane curvature generation by N-BAR domains. Furthermore, consistent with the thermodynamically required coupling between curvature generation and sensing, we observed that the H0-truncated N-BAR domain is capable of sensing membrane curvature. Overall, our contribution clarifies an important mechanistic controversy in the function of N-BAR domain proteins.
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Affiliation(s)
- Zhiming Chen
- Department of Chemistry, University of Pennsylvania, Philadelphia, USA
| | - Chen Zhu
- Department of Chemistry, University of Pennsylvania, Philadelphia, USA
| | - Curtis J. Kuo
- Department of Chemistry, University of Pennsylvania, Philadelphia, USA
| | - Jaclyn Robustelli
- Department of Chemistry, University of Pennsylvania, Philadelphia, USA
| | - Tobias Baumgart
- Department of Chemistry, University of Pennsylvania, Philadelphia, USA
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23
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Magdeleine M, Gautier R, Gounon P, Barelli H, Vanni S, Antonny B. A filter at the entrance of the Golgi that selects vesicles according to size and bulk lipid composition. eLife 2016; 5. [PMID: 27458799 PMCID: PMC4961469 DOI: 10.7554/elife.16988] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 07/12/2016] [Indexed: 12/22/2022] Open
Abstract
When small phosphatidylcholine liposomes are added to perforated cells, they bind preferentially to the Golgi suggesting an exceptional avidity of this organelle for curved membranes without stereospecific interactions. We show that the cis golgin GMAP-210 accounts for this property. First, the liposome tethering properties of the Golgi resembles that of the amphipathic lipid-packing sensor (ALPS) motif of GMAP-210: both preferred small (radius < 40 nm) liposomes made of monounsaturated but not saturated lipids. Second, reducing GMAP-210 levels or redirecting its ALPS motif to mitochondria decreased liposome capture by the Golgi. Extensive mutagenesis analysis suggests that GMAP-210 tethers authentic transport vesicles via the same mechanism whereby the ALPS motif senses lipid-packing defects at the vesicle surface through its regularly spaced hydrophobic residues. We conclude that the Golgi uses GMAP-210 as a filter to select transport vesicles according to their size and bulk lipid composition. DOI:http://dx.doi.org/10.7554/eLife.16988.001
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Affiliation(s)
- Maud Magdeleine
- CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur, Valbonne, France
| | - Romain Gautier
- CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur, Valbonne, France
| | - Pierre Gounon
- Centre Commun de Microscopie Appliquée, Université Côte d'Azur, Nice, France
| | - Hélène Barelli
- CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur, Valbonne, France
| | - Stefano Vanni
- CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur, Valbonne, France
| | - Bruno Antonny
- CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur, Valbonne, France
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