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Lee C, Lepore D, Lee SH, Kim TG, Buwa N, Lee J, Munson M, Yoon TY. Exocyst stimulates multiple steps of exocytic SNARE complex assembly and vesicle fusion. Nat Struct Mol Biol 2024:10.1038/s41594-024-01388-2. [PMID: 39242980 DOI: 10.1038/s41594-024-01388-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 08/13/2024] [Indexed: 09/09/2024]
Abstract
Exocyst is a large multisubunit tethering complex essential for targeting and fusion of secretory vesicles in eukaryotic cells. Although the assembled exocyst complex has been proposed to tether vesicles to the plasma membrane and activate soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) for membrane fusion, the key biochemical steps that exocyst stimulates in SNARE-mediated fusion are undetermined. Here we use a combination of single-molecule and bulk fluorescence assays to investigate the roles of purified octameric yeast exocyst complexes in a reconstituted yeast exocytic SNARE assembly and vesicle fusion system. Exocyst had stimulatory roles in multiple distinct steps ranging from SNARE protein activation to binary and ternary complex assembly. Importantly, exocyst had a downstream role in driving membrane fusion and full content mixing of vesicle lumens. Our data suggest that exocyst provides extensive chaperoning functions across the entire process of SNARE complex assembly and fusion, thereby governing exocytosis at multiple steps.
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Affiliation(s)
- Chanwoo Lee
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
| | - Dante Lepore
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Seung-Hak Lee
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
| | - Tae Gyun Kim
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
| | - Natasha Buwa
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Jongchan Lee
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
| | - Mary Munson
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA, USA.
| | - Tae-Young Yoon
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, South Korea.
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2
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Tavakoli A, Hu S, Ebrahim S, Kachar B. Hemifusomes and Interacting Proteolipid Nanodroplets: Formation of a Novel Cellular Organelle Complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.28.610112. [PMID: 39253452 PMCID: PMC11383319 DOI: 10.1101/2024.08.28.610112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/11/2024]
Abstract
Within cells, vesicle fusion, scission, and the formation of intraluminal vesicles are critical processes that facilitate traffic, degradation, and recycling of cellular components, and maintenance of cellular homeostasis. Despite significant advancements in elucidating the molecular mechanisms that drive these dynamic processes, the direct in situ visualization of membrane remodeling intermediates remains challenging. Here, through the application of cryo-electron tomography in mammalian cells, we have identified a previously undescribed vesicular organelle complex with unique membrane topology: heterotypic hemifused vesicles that share extended hemifusion diaphragms (HDs) with a 42 nm proteolipid nanodroplet (PND) at their rim. We have termed these organelle complexes "hemifusomes". The HDs of hemifusomes exhibit a range of sizes and curvatures, including the formation of lens-shaped compartments encapsulated within the membrane bilayer. The morphological diversity of the lens-shaped vesicle aligns with a step-wise process of their intraluminal budding, ultimately leading to their scission and the generation of intraluminal vesicles. We propose that hemifusomes function as versatile platforms for protein and lipid sorting and as central hubs for the biogenesis of intraluminal vesicles and the formation of multivesicular bodies.
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3
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Shvarev D, König C, Susan N, Langemeyer L, Walter S, Perz A, Fröhlich F, Ungermann C, Moeller A. Structure of the endosomal CORVET tethering complex. Nat Commun 2024; 15:5227. [PMID: 38898033 PMCID: PMC11187117 DOI: 10.1038/s41467-024-49137-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 05/24/2024] [Indexed: 06/21/2024] Open
Abstract
Cells depend on their endolysosomal system for nutrient uptake and downregulation of plasma membrane proteins. These processes rely on endosomal maturation, which requires multiple membrane fusion steps. Early endosome fusion is promoted by the Rab5 GTPase and its effector, the hexameric CORVET tethering complex, which is homologous to the lysosomal HOPS. How these related complexes recognize their specific target membranes remains entirely elusive. Here, we solve the structure of CORVET by cryo-electron microscopy and revealed its minimal requirements for membrane tethering. As expected, the core of CORVET and HOPS resembles each other. However, the function-defining subunits show marked structural differences. Notably, we discover that unlike HOPS, CORVET depends not only on Rab5 but also on phosphatidylinositol-3-phosphate (PI3P) and membrane lipid packing defects for tethering, implying that an organelle-specific membrane code enables fusion. Our data suggest that both shape and membrane interactions of CORVET and HOPS are conserved in metazoans, thus providing a paradigm how tethering complexes function.
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Affiliation(s)
- Dmitry Shvarev
- Department of Biology/Chemistry, Structural Biology Section, Osnabrück University, 49076, Osnabrück, Germany
| | - Caroline König
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, 49076, Osnabrück, Germany
| | - Nicole Susan
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, 49076, Osnabrück, Germany
| | - Lars Langemeyer
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, 49076, Osnabrück, Germany
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, 49076, Osnabrück, Germany
| | - Stefan Walter
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, 49076, Osnabrück, Germany
| | - Angela Perz
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, 49076, Osnabrück, Germany
| | - Florian Fröhlich
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, 49076, Osnabrück, Germany
- Department of Biology/Chemistry, Bioanalytical Chemistry Section, Osnabrück University, 49076, Osnabrück, Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, 49076, Osnabrück, Germany.
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, 49076, Osnabrück, Germany.
| | - Arne Moeller
- Department of Biology/Chemistry, Structural Biology Section, Osnabrück University, 49076, Osnabrück, Germany.
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, 49076, Osnabrück, Germany.
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4
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Duan M, Plemel RL, Takenaka T, Lin A, Delgado BM, Nattermann U, Nickerson DP, Mima J, Miller EA, Merz AJ. SNARE chaperone Sly1 directly mediates close-range vesicle tethering. J Cell Biol 2024; 223:e202001032. [PMID: 38478018 PMCID: PMC10943277 DOI: 10.1083/jcb.202001032] [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: 01/16/2020] [Revised: 12/20/2023] [Accepted: 02/22/2024] [Indexed: 03/17/2024] Open
Abstract
The essential Golgi protein Sly1 is a member of the Sec1/mammalian Unc-18 (SM) family of SNARE chaperones. Sly1 was originally identified through remarkable gain-of-function alleles that bypass requirements for diverse vesicle tethering factors. Employing genetic analyses and chemically defined reconstitutions of ER-Golgi fusion, we discovered that a loop conserved among Sly1 family members is not only autoinhibitory but also acts as a positive effector. An amphipathic lipid packing sensor (ALPS)-like helix within the loop directly binds high-curvature membranes. Membrane binding is required for relief of Sly1 autoinhibition and also allows Sly1 to directly tether incoming vesicles to the Qa-SNARE on the target organelle. The SLY1-20 mutation bypasses requirements for diverse tethering factors but loses this ability if the tethering activity is impaired. We propose that long-range tethers, including Golgins and multisubunit tethering complexes, hand off vesicles to Sly1, which then tethers at close range to initiate trans-SNARE complex assembly and fusion in the early secretory pathway.
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Affiliation(s)
- Mengtong Duan
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Rachael L. Plemel
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | | | - Ariel Lin
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Department of Biology, California State University, San Bernardino, CA, USA
| | | | - Una Nattermann
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Biophysics, Structure, and Design Graduate Program, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | | | - Joji Mima
- Institute for Protein Research, Osaka University, Osaka, Japan
| | | | - Alexey J. Merz
- Department of Biochemistry, University of Washington, Seattle, WA, USA
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Orr A, Wickner W. Sec18 binds the tethering/SM complex HOPS to engage the Qc-SNARE for membrane fusion. Mol Biol Cell 2024; 35:ar71. [PMID: 38536444 PMCID: PMC11151092 DOI: 10.1091/mbc.e24-02-0060] [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: 02/06/2024] [Revised: 03/18/2024] [Accepted: 03/22/2024] [Indexed: 04/18/2024] Open
Abstract
Membrane fusion is regulated by Rab GTPases, their tethering effectors such as HOPS, SNARE proteins on each fusion partner, SM proteins to catalyze SNARE assembly, Sec17 (SNAP), and Sec18 (NSF). Though concentrated HOPS can support fusion without Sec18, we now report that fusion falls off sharply at lower HOPS levels, where direct Sec18 binding to HOPS restores fusion. This Sec18-dependent fusion needs adenine nucleotide but neither ATP hydrolysis nor Sec17. Sec18 enhances HOPS recognition of the Qc-SNARE. With high levels of HOPS, Qc has a Km for fusion of a few nM. Either lower HOPS levels, or substitution of a synthetic tether for HOPS, strikingly increases the Km for Qc to several hundred nM. With dilute HOPS, Sec18 returns the Km for Qc to low nM. In contrast, HOPS concentration and Sec18 have no effect on Qb-SNARE recognition. Just as Qc is required for fusion but not for the initial assembly of SNAREs in trans, impaired Qc recognition by limiting HOPS without Sec18 still allows substantial trans-SNARE assembly. Thus, in addition to the known Sec18 functions of disassembling SNARE complexes, oligomerizing Sec17 for membrane association, and allowing Sec17 to drive fusion without complete SNARE zippering, we report a fourth Sec18 function, the Sec17-independent binding of Sec18 to HOPS to enhance functional Qc-SNARE engagement.
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Affiliation(s)
- Amy Orr
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755-3844
| | - William Wickner
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755-3844
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6
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van der Beek J, de Heus C, Sanza P, Liv N, Klumperman J. Loss of the HOPS complex disrupts early-to-late endosome transition, impairs endosomal recycling and induces accumulation of amphisomes. Mol Biol Cell 2024; 35:ar40. [PMID: 38198575 PMCID: PMC10916860 DOI: 10.1091/mbc.e23-08-0328] [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: 08/29/2023] [Revised: 12/22/2023] [Accepted: 01/05/2024] [Indexed: 01/12/2024] Open
Abstract
The multisubunit HOPS tethering complex is a well-established regulator of lysosome fusion with late endosomes and autophagosomes. However, the role of the HOPS complex in other stages of endo-lysosomal trafficking is not well understood. To address this, we made HeLa cells knocked out for the HOPS-specific subunits Vps39 or Vps41, or the HOPS-CORVET-core subunits Vps18 or Vps11. In all four knockout cells, we found that endocytosed cargos were trapped in enlarged endosomes that clustered in the perinuclear area. By correlative light-electron microscopy, these endosomes showed a complex ultrastructure and hybrid molecular composition, displaying markers for early (Rab5, PtdIns3P, EEA1) as well as late (Rab7, CD63, LAMP1) endosomes. These "HOPS bodies" were not acidified, contained enzymatically inactive cathepsins and accumulated endocytosed cargo and cation-independent mannose-6-phosphate receptor (CI-MPR). Consequently, CI-MPR was depleted from the TGN, and secretion of lysosomal enzymes to the extracellular space was enhanced. Strikingly, HOPS bodies also contained the autophagy proteins p62 and LC3, defining them as amphisomes. Together, these findings show that depletion of the lysosomal HOPS complex has a profound impact on the functional organization of the entire endosomal system and suggest the existence of a HOPS-independent mechanism for amphisome formation.
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Affiliation(s)
- Jan van der Beek
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Cecilia de Heus
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Paolo Sanza
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Nalan Liv
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Judith Klumperman
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
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7
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Hanley SE, Willis SD, Doyle SJ, Strich R, Cooper KF. Ksp1 is an autophagic receptor protein for the Snx4-assisted autophagy of Ssn2/Med13. Autophagy 2024; 20:397-415. [PMID: 37733395 PMCID: PMC10813586 DOI: 10.1080/15548627.2023.2259708] [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: 01/31/2023] [Accepted: 09/11/2023] [Indexed: 09/22/2023] Open
Abstract
Ksp1 is a casein II-like kinase whose activity prevents aberrant macroautophagy/autophagy induction in nutrient-rich conditions in yeast. Here, we describe a kinase-independent role of Ksp1 as a novel autophagic receptor protein for Ssn2/Med13, a known cargo of Snx4-assisted autophagy of transcription factors. In this pathway, a subset of conserved transcriptional regulators, Ssn2/Med13, Rim15, and Msn2, are selectively targeted for vacuolar proteolysis following nitrogen starvation, assisted by the sorting nexin heterodimer Snx4-Atg20. Here we show that phagophores also engulf Ksp1 alongside its cargo for vacuolar proteolysis. Ksp1 directly associates with Atg8 following nitrogen starvation at the interface of an Atg8-family interacting motif (AIM)/LC3-interacting region (LIR) in Ksp1 and the LIR/AIM docking site (LDS) in Atg8. Mutating the LDS site prevents the autophagic degradation of Ksp1. However, deletion of the C terminal canonical AIM still permitted Ssn2/Med13 proteolysis, suggesting that additional non-canonical AIMs may mediate the Ksp1-Atg8 interaction. Ksp1 is recruited to the perivacuolar phagophore assembly site by Atg29, a member of the trimeric scaffold complex. This interaction is independent of Atg8 and Snx4, suggesting that Ksp1 is recruited early to phagophores, with Snx4 delivering Ssn2/Med13 thereafter. Finally, normal cell survival following prolonged nitrogen starvation requires Ksp1. Together, these studies define a kinase-independent role for Ksp1 as an autophagic receptor protein mediating Ssn2/Med13 degradation. They also suggest that phagophores built by the trimeric scaffold complex are capable of receptor-mediated autophagy. These results demonstrate the dual functionality of Ksp1, whose kinase activity prevents autophagy while it plays a scaffolding role supporting autophagic degradation.Abbreviations: 3-AT: 3-aminotriazole; 17C: Atg17-Atg31-Atg29 trimeric scaffold complex; AIM: Atg8-family interacting motif; ATG: autophagy related; CKM: CDK8 kinase module; Cvt: cytoplasm-to-vacuole targeting; IDR: intrinsically disordered region; LIR: LC3-interacting region; LDS: LIR/AIM docking site; MoRF: molecular recognition feature; NPC: nuclear pore complex; PAS: phagophore assembly site; PKA: protein kinase A; RBP: RNA-binding protein; UPS: ubiquitin-proteasome system. SAA-TF: Snx4-assisted autophagy of transcription factors; Y2H: yeast two-hybrid.
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Affiliation(s)
- Sara E. Hanley
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering & Sciences, Rowan University, Stratford, NJ, USA
| | - Stephen D. Willis
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering & Sciences, Rowan University, Stratford, NJ, USA
| | - Steven J. Doyle
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering & Sciences, Rowan University, Stratford, NJ, USA
- School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
| | - Randy Strich
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering & Sciences, Rowan University, Stratford, NJ, USA
| | - Katrina F. Cooper
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering & Sciences, Rowan University, Stratford, NJ, USA
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8
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Jahn R, Cafiso DC, Tamm LK. Mechanisms of SNARE proteins in membrane fusion. Nat Rev Mol Cell Biol 2024; 25:101-118. [PMID: 37848589 DOI: 10.1038/s41580-023-00668-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2023] [Indexed: 10/19/2023]
Abstract
Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are a family of small conserved eukaryotic proteins that mediate membrane fusion between organelles and with the plasma membrane. SNAREs are directly or indirectly anchored to membranes. Prior to fusion, complementary SNAREs assemble between membranes with the aid of accessory proteins that provide a scaffold to initiate SNARE zippering, pulling the membranes together and mediating fusion. Recent advances have enabled the construction of detailed models describing bilayer transitions and energy barriers along the fusion pathway and have elucidated the structures of SNAREs complexed in various states with regulatory proteins. In this Review, we discuss how these advances are yielding an increasingly detailed picture of the SNARE-mediated fusion pathway, leading from first contact between the membranes via metastable non-bilayer intermediates towards the opening and expansion of a fusion pore. We describe how SNARE proteins assemble into complexes, how this assembly is regulated by accessory proteins and how SNARE complexes overcome the free energy barriers that prevent spontaneous membrane fusion.
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Affiliation(s)
- Reinhard Jahn
- Laboratory of Neurobiology, Max-Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
| | - David C Cafiso
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - Lukas K Tamm
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
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9
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Kraft C, Reggiori F. Phagophore closure, autophagosome maturation and autophagosome fusion during macroautophagy in the yeast Saccharomyces cerevisiae. FEBS Lett 2024; 598:73-83. [PMID: 37585559 DOI: 10.1002/1873-3468.14720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/07/2023] [Accepted: 08/07/2023] [Indexed: 08/18/2023]
Abstract
Macroautophagy, hereafter referred to as autophagy, is a complex process in which multiple membrane-remodeling events lead to the formation of a cisterna known as the phagophore, which then expands and closes into a double-membrane vesicle termed the autophagosome. During the past decade, enormous progress has been made in understanding the molecular function of the autophagy-related proteins and their role in generating these phagophores. In this Review, we discuss the current understanding of three membrane remodeling steps in autophagy that remain to be largely characterized; namely, the closure of phagophores, the maturation of the resulting autophagosomes into fusion-competent vesicles, and their fusion with vacuoles/lysosomes. Our review will mainly focus on the yeast Saccharomyces cerevisiae, which has been the leading model system for the study of molecular events in autophagy and has led to the discovery of the major mechanistic concepts, which have been found to be mostly conserved in higher eukaryotes.
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Affiliation(s)
- Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Germany
| | - Fulvio Reggiori
- Department of Biomedicine, Aarhus University, Denmark
- Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Denmark
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10
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Shao Q, Wijaya CS, Wang S, Meng X, Yuan C, Ma C, Xu S. The SNARE complex formed by RIC-4/SEC-22/SYX-2 promotes C. elegans epidermal wound healing. Cell Rep 2023; 42:113349. [PMID: 37910502 DOI: 10.1016/j.celrep.2023.113349] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/18/2023] [Accepted: 10/10/2023] [Indexed: 11/03/2023] Open
Abstract
Maintaining cellular viability relies on the integrity of the plasma membrane, which must be repaired upon damage. Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-mediated membrane fusion is a crucial mechanism involved in membrane repair. In C. elegans epidermal cell hyp 7, syntaxin-2 (SYX-2) facilitates large membrane wound repair; however, the underlying molecular mechanism remains unclear. Here, we found that SNAP-25 protein RIC-4 and synaptobrevin protein SEC-22 are required for SYX-2 recruitment at the wound site. They interact to form a SNARE complex to promote membrane repair in vivo and fusion in vitro. Moreover, we found that SEC-22 localized in multiple intracellular compartments, including endosomes and the trans-Golgi network, which recruited to the wounds. Furthermore, inhibition of RAB-5 disrupted SEC-22 localization and prevented its interaction with SYX-2. Our findings suggest that RAB-5 facilitates the formation of the RIC-4/SEC-22/SYX-2 SNARE complex and provides valuable insights into the molecular mechanism of how cells repair large membrane wounds.
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Affiliation(s)
- Qingfang Shao
- International Biomedicine-X Research Center of the Second Affiliated Hospital, Zhejiang University School of Medicine and the Zhejiang University-University of Edinburgh Institute, 718 East Haizhou Road, Haining, Zhejiang 314400, China; Center for Stem Cell and Regenerative Medicine and Department of Burn and Wound Repair of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Chandra Sugiarto Wijaya
- International Biomedicine-X Research Center of the Second Affiliated Hospital, Zhejiang University School of Medicine and the Zhejiang University-University of Edinburgh Institute, 718 East Haizhou Road, Haining, Zhejiang 314400, China; School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Shen Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xinan Meng
- International Biomedicine-X Research Center of the Second Affiliated Hospital, Zhejiang University School of Medicine and the Zhejiang University-University of Edinburgh Institute, 718 East Haizhou Road, Haining, Zhejiang 314400, China; School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Cheng Yuan
- International Biomedicine-X Research Center of the Second Affiliated Hospital, Zhejiang University School of Medicine and the Zhejiang University-University of Edinburgh Institute, 718 East Haizhou Road, Haining, Zhejiang 314400, China
| | - Cong Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Suhong Xu
- International Biomedicine-X Research Center of the Second Affiliated Hospital, Zhejiang University School of Medicine and the Zhejiang University-University of Edinburgh Institute, 718 East Haizhou Road, Haining, Zhejiang 314400, China; Center for Stem Cell and Regenerative Medicine and Department of Burn and Wound Repair of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China; School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.
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11
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Bianco V, D'Agostino M, Pirone D, Giugliano G, Mosca N, Di Summa M, Scerra G, Memmolo P, Miccio L, Russo T, Stella E, Ferraro P. Label-Free Intracellular Multi-Specificity in Yeast Cells by Phase-Contrast Tomographic Flow Cytometry. SMALL METHODS 2023; 7:e2300447. [PMID: 37670547 DOI: 10.1002/smtd.202300447] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 08/14/2023] [Indexed: 09/07/2023]
Abstract
In-flow phase-contrast tomography provides a 3D refractive index of label-free cells in cytometry systems. Its major limitation, as with any quantitative phase imaging approach, is the lack of specificity compared to fluorescence microscopy, thus restraining its huge potentialities in single-cell analysis and diagnostics. Remarkable results in introducing specificity are obtained through artificial intelligence (AI), but only for adherent cells. However, accessing the 3D fluorescence ground truth and obtaining accurate voxel-level co-registration of image pairs for AI training is not viable for high-throughput cytometry. The recent statistical inference approach is a significant step forward for label-free specificity but remains limited to cells' nuclei. Here, a generalized computational strategy based on a self-consistent statistical inference to achieve intracellular multi-specificity is shown. Various subcellular compartments (i.e., nuclei, cytoplasmic vacuoles, the peri-vacuolar membrane area, cytoplasm, vacuole-nucleus contact site) can be identified and characterized quantitatively at different phases of the cells life cycle by using yeast cells as a biological model. Moreover, for the first time, virtual reality is introduced for handling the information content of multi-specificity in single cells. Full fruition is proofed for exploring and interacting with 3D quantitative biophysical parameters of the identified compartments on demand, thus opening the route to a metaverse for 3D microscopy.
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Affiliation(s)
- Vittorio Bianco
- CNR-ISASI, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Via Campi Flegrei 34, Pozzuoli, Napoli, 80078, Italy
| | - Massimo D'Agostino
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Via S. Pansini 5, Naples, 80131, Italy
| | - Daniele Pirone
- CNR-ISASI, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Via Campi Flegrei 34, Pozzuoli, Napoli, 80078, Italy
| | - Giusy Giugliano
- CNR-ISASI, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Via Campi Flegrei 34, Pozzuoli, Napoli, 80078, Italy
| | - Nicola Mosca
- Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing, National Research Council of Italy, Via Amendola 122/D-O, Bari, 70125, Italy
| | - Maria Di Summa
- Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing, National Research Council of Italy, Via Amendola 122/D-O, Bari, 70125, Italy
| | - Gianluca Scerra
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Via S. Pansini 5, Naples, 80131, Italy
| | - Pasquale Memmolo
- CNR-ISASI, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Via Campi Flegrei 34, Pozzuoli, Napoli, 80078, Italy
| | - Lisa Miccio
- CNR-ISASI, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Via Campi Flegrei 34, Pozzuoli, Napoli, 80078, Italy
| | - Tommaso Russo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Via S. Pansini 5, Naples, 80131, Italy
| | - Ettore Stella
- Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing, National Research Council of Italy, Via Amendola 122/D-O, Bari, 70125, Italy
| | - Pietro Ferraro
- CNR-ISASI, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Via Campi Flegrei 34, Pozzuoli, Napoli, 80078, Italy
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12
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Terawaki S, Vasilev F, Moriwaki T, Otomo T. HOPS, CORVET and newly-identified Hybrid tethering complexes contribute differentially towards multiple modes of endocytosis. Sci Rep 2023; 13:18734. [PMID: 37907479 PMCID: PMC10618185 DOI: 10.1038/s41598-023-45418-3] [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: 08/18/2023] [Accepted: 10/19/2023] [Indexed: 11/02/2023] Open
Abstract
Vesicular transport driven by membrane trafficking systems conserved in eukaryotes is critical to cellular functionality and homeostasis. It is known that homotypic fusion and vacuole protein sorting (HOPS) and class C core endosomal vacuole tethering (CORVET) interact with Rab-GTPases and SNARE proteins to regulate vesicle transport, fusion, and maturation in autophagy and endocytosis pathways. In this study, we identified two novel "Hybrid" tethering complexes in mammalian cells in which one of the subunits of HOPS or CORVET is replaced with the subunit from the other. Substrates taken up by receptor-mediated endocytosis or pinocytosis were transported by distinctive pathways, and the newly identified hybrid complexes contributed to pinocytosis in the presence of HOPS, whereas receptor-mediated endocytosis was exclusively dependent on HOPS. Our study provides new insights into the molecular mechanisms of the endocytic pathway and the function of the vacuolar protein sorting-associated (VPS) protein family.
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Affiliation(s)
- Seigo Terawaki
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan
| | - Filipp Vasilev
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan
| | - Takahito Moriwaki
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan
| | - Takanobu Otomo
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
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13
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Zhang S, Tong M, Zheng D, Huang H, Li L, Ungermann C, Pan Y, Luo H, Lei M, Tang Z, Fu W, Chen S, Liu X, Zhong Q. C9orf72-catalyzed GTP loading of Rab39A enables HOPS-mediated membrane tethering and fusion in mammalian autophagy. Nat Commun 2023; 14:6360. [PMID: 37821429 PMCID: PMC10567733 DOI: 10.1038/s41467-023-42003-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 09/25/2023] [Indexed: 10/13/2023] Open
Abstract
The multi-subunit homotypic fusion and vacuole protein sorting (HOPS) membrane-tethering complex is required for autophagosome-lysosome fusion in mammals, yet reconstituting the mammalian HOPS complex remains a challenge. Here we propose a "hook-up" model for mammalian HOPS complex assembly, which requires two HOPS sub-complexes docking on membranes via membrane-associated Rabs. We identify Rab39A as a key small GTPase that recruits HOPS onto autophagic vesicles. Proper pairing with Rab2 and Rab39A enables HOPS complex assembly between proteoliposomes for its tethering function, facilitating efficient membrane fusion. GTP loading of Rab39A is important for the recruitment of HOPS to autophagic membranes. Activation of Rab39A is catalyzed by C9orf72, a guanine exchange factor associated with amyotrophic lateral sclerosis and familial frontotemporal dementia. Constitutive activation of Rab39A can rescue autophagy defects caused by C9orf72 depletion. These results therefore reveal a crucial role for the C9orf72-Rab39A-HOPS axis in autophagosome-lysosome fusion.
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Affiliation(s)
- Shen Zhang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mindan Tong
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Denghao Zheng
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Huiying Huang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Linsen Li
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Christian Ungermann
- Osnabrück University, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany
- Center of Cellular Nanoanalytic Osnabrück (CellNanOs), Osnabrück University, Osnabrück, Germany
| | - Yi Pan
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hanyan Luo
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ming Lei
- State Key Laboratory of Oncogenes and Related Genes, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200011, Shanghai, China
- Shanghai Institute of Precision Medicine, 200125, Shanghai, China
| | - Zaiming Tang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wan Fu
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - She Chen
- National Institute of Biological Sciences, 102206, Beijing, China
| | - Xiaoxia Liu
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Qing Zhong
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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14
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Stanton AE, Hughson FM. The machinery of vesicle fusion. Curr Opin Cell Biol 2023; 83:102191. [PMID: 37421936 PMCID: PMC10529041 DOI: 10.1016/j.ceb.2023.102191] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/01/2023] [Accepted: 06/07/2023] [Indexed: 07/10/2023]
Abstract
The compartmentalization of eukaryotic cells is reliant on the fidelity of vesicle-mediated intracellular transport. Vesicles deliver their cargo via membrane fusion, a process requiring membrane tethers, Sec1/Munc18 (SM) proteins, and SNAREs. These components function in concert to ensure that membrane fusion is efficient and accurate, but the mechanisms underlying their cooperative action are still in many respects mysterious. In this brief review, we highlight recent progress toward a more integrative understanding of the vesicle fusion machinery. We focus particular attention on cryo-electron microscopy structures of intact multisubunit tethers in complex with SNAREs or SM proteins, as well as a structure of an SM protein bound to multiple SNAREs. The insights gained from this work emphasize the advantages of studying the fusion machinery intact and in context.
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Affiliation(s)
- Abigail E Stanton
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Frederick M Hughson
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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15
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Álvarez D, Sapia J, Vanni S. Computational modeling of membrane trafficking processes: From large molecular assemblies to chemical specificity. Curr Opin Cell Biol 2023; 83:102205. [PMID: 37451175 DOI: 10.1016/j.ceb.2023.102205] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/16/2023] [Accepted: 06/16/2023] [Indexed: 07/18/2023]
Abstract
In the last decade, molecular dynamics (MD) simulations have become an essential tool to investigate the molecular properties of membrane trafficking processes, often in conjunction with experimental approaches. The combination of MD simulations with recent developments in structural biology, such as cryo-electron microscopy and artificial intelligence-based structure determination, opens new, exciting possibilities for future investigations. However, the full potential of MD simulations to provide a molecular view of the complex and dynamic processes involving membrane trafficking can only be realized if certain limitations are addressed, and especially those concerning the quality of coarse-grain models, which, despite recent successes in describing large-scale systems, still suffer from far-from-ideal chemical accuracy. In this review, we will highlight recent success stories of MD simulations in the investigation of membrane trafficking processes, their implications for future research, and the challenges that lie ahead in this specific research domain.
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Affiliation(s)
- Daniel Álvarez
- Department of Biology, University of Fribourg, Switzerland; Departamento de Química Física y Analítica, Universidad de Oviedo, Spain
| | - Jennifer Sapia
- Department of Biology, University of Fribourg, Switzerland
| | - Stefano Vanni
- Department of Biology, University of Fribourg, Switzerland; Université Côte d'Azur, Inserm, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France.
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16
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Empereur-mot C, Pedersen KB, Capelli R, Crippa M, Caruso C, Perrone M, Souza PCT, Marrink SJ, Pavan GM. Automatic Optimization of Lipid Models in the Martini Force Field Using SwarmCG. J Chem Inf Model 2023; 63:3827-3838. [PMID: 37279107 PMCID: PMC10302490 DOI: 10.1021/acs.jcim.3c00530] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Indexed: 06/08/2023]
Abstract
After two decades of continued development of the Martini coarse-grained force field (CG FF), further refinment of the already rather accurate Martini lipid models has become a demanding task that could benefit from integrative data-driven methods. Automatic approaches are increasingly used in the development of accurate molecular models, but they typically make use of specifically designed interaction potentials that transfer poorly to molecular systems or conditions different than those used for model calibration. As a proof of concept, here, we employ SwarmCG, an automatic multiobjective optimization approach facilitating the development of lipid force fields, to refine specifically the bonded interaction parameters in building blocks of lipid models within the framework of the general Martini CG FF. As targets of the optimization procedure, we employ both experimental observables (top-down references: area per lipid and bilayer thickness) and all-atom molecular dynamics simulations (bottom-up reference), which respectively inform on the supra-molecular structure of the lipid bilayer systems and on their submolecular dynamics. In our training sets, we simulate at different temperatures in the liquid and gel phases up to 11 homogeneous lamellar bilayers composed of phosphatidylcholine lipids spanning various tail lengths and degrees of (un)saturation. We explore different CG representations of the molecules and evaluate improvements a posteriori using additional simulation temperatures and a portion of the phase diagram of a DOPC/DPPC mixture. Successfully optimizing up to ∼80 model parameters within still limited computational budgets, we show that this protocol allows the obtainment of improved transferable Martini lipid models. In particular, the results of this study demonstrate how a fine-tuning of the representation and parameters of the models may improve their accuracy and how automatic approaches, such as SwarmCG, may be very useful to this end.
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Affiliation(s)
- Charly Empereur-mot
- Department
of Innovative Technologies, University of
Applied Sciences and Arts of Southern Switzerland, Polo Universitario
Lugano, Campus Est, Via
la Santa 1, 6962 Lugano-Viganello, Switzerland
| | - Kasper B. Pedersen
- Department
of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Riccardo Capelli
- Department
of Biosciences, Università degli
Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Martina Crippa
- Politecnico
di Torino, Department of Applied
Science and Technology, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Cristina Caruso
- Politecnico
di Torino, Department of Applied
Science and Technology, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Mattia Perrone
- Politecnico
di Torino, Department of Applied
Science and Technology, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Paulo C. T. Souza
- Molecular
Microbiology and Structural Biochemistry (MMSB, UMR 5086), CNRS & University of Lyon, 7 Passage du Vercors, 69007 Lyon, France
| | - Siewert J. Marrink
- Molecular
Dynamics, Groningen Biomolecular Sciences and Biotechnology Institute
(GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Giovanni M. Pavan
- Department
of Innovative Technologies, University of
Applied Sciences and Arts of Southern Switzerland, Polo Universitario
Lugano, Campus Est, Via
la Santa 1, 6962 Lugano-Viganello, Switzerland
- Politecnico
di Torino, Department of Applied
Science and Technology, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
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17
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Beaven AH, Sapp K, Sodt AJ. Simulated dynamic cholesterol redistribution favors membrane fusion pore constriction. Biophys J 2023; 122:2162-2175. [PMID: 36588341 PMCID: PMC10257089 DOI: 10.1016/j.bpj.2022.12.024] [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: 02/08/2022] [Revised: 06/17/2022] [Accepted: 12/16/2022] [Indexed: 01/01/2023] Open
Abstract
Endo- and exocytosis proceed through a highly strained membrane fusion pore topology regardless of the aiding protein machinery. The membrane's lipid components bias fusion pores toward expansion or closure, modifying the necessary work done by proteins. Cholesterol, a key component of plasma membranes, promotes both inverted lipid phases with concave leaflets (i.e., negative total curvature, which thins the leaflet) and flat bilayer phases with thick, ordered hydrophobic interiors. We demonstrate by theory and simulation that both leaflets of nascent catenoidal fusion pores have negative total curvature. Furthermore, the hydrophobic core of bilayers with strong negative Gaussian curvature is thinned. Therefore, it is an open question whether cholesterol will be enriched in these regions because of the negative total curvature or depleted because of the membrane thinning. Here, we compare all-atom molecular dynamics simulations (built using a procedure to create specific fusion pore geometries) and theory to understand the underlying reasons for lipid redistribution on fusion pores. Our all-atom molecular dynamics simulations resolve this question by showing that cholesterol is strongly excluded from the thinned neck of fusion and fission pores, revealing that thickness (and/or lipid order) influences cholesterol distributions more than curvature. The results imply that cholesterol exclusion can drive fusion pore closure by creating a small, cholesterol-depleted zone in the neck. This model agrees with literature evidence that membrane reshaping is connected to cholesterol-dependent lateral phase separation.
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Affiliation(s)
- Andrew H Beaven
- Unit on Membrane Chemical Physics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Postdoctoral Research Associate Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, Maryland
| | - Kayla Sapp
- Unit on Membrane Chemical Physics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Alexander J Sodt
- Unit on Membrane Chemical Physics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland.
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18
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Canepa E, Bochicchio D, Brosio G, Silva PHJ, Stellacci F, Dante S, Rossi G, Relini A. Cholesterol-Containing Liposomes Decorated With Au Nanoparticles as Minimal Tunable Fusion Machinery. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2207125. [PMID: 36899445 DOI: 10.1002/smll.202207125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/30/2023] [Indexed: 06/08/2023]
Abstract
Membrane fusion is essential for the basal functionality of eukaryotic cells. In physiological conditions, fusion events are regulated by a wide range of specialized proteins, operating with finely tuned local lipid composition and ionic environment. Fusogenic proteins, assisted by membrane cholesterol and calcium ions, provide the mechanical energy necessary to achieve vesicle fusion in neuromediator release. Similar cooperative effects must be explored when considering synthetic approaches for controlled membrane fusion. We show that liposomes decorated with amphiphilic Au nanoparticles (AuLips) can act as minimal tunable fusion machinery. AuLips fusion is triggered by divalent ions, while the number of fusion events dramatically changes with, and can be finely tuned by, the liposome cholesterol content. We combine quartz-crystal-microbalance with dissipation monitoring (QCM-D), fluorescence assays, and small-angle X-ray scattering (SAXS) with molecular dynamics (MD) at coarse-grained (CG) resolution, revealing new mechanistic details on the fusogenic activity of amphiphilic Au nanoparticles (AuNPs) and demonstrating the ability of these synthetic nanomaterials to induce fusion regardless of the divalent ion used (Ca2+ or Mg2+ ). The results provide a novel contribution to developing new artificial fusogenic agents for next-generation biomedical applications that require tight control of the rate of fusion events (e.g., targeted drug delivery).
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Affiliation(s)
- Ester Canepa
- Department of Physics, University of Genoa, Genoa, 16146, Italy
- Institute of Materials Science & Engineering, EPFL, Lausanne, 1015, Switzerland
| | | | - Giorgia Brosio
- Department of Physics, University of Genoa, Genoa, 16146, Italy
| | | | - Francesco Stellacci
- Materials Characterization Facility, Istituto Italiano di Tecnologia, Genoa, 16163, Italy
| | - Silvia Dante
- Institute of Materials Science & Engineering, EPFL, Lausanne, 1015, Switzerland
| | - Giulia Rossi
- Department of Physics, University of Genoa, Genoa, 16146, Italy
| | - Annalisa Relini
- Department of Physics, University of Genoa, Genoa, 16146, Italy
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19
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Abstract
Cargo delivery from one compartment to the next relies on the fusion of vesicles with different cellular organelles in a process that requires the concerted action of tethering factors. Although all tethers act to bridge vesicle membranes to mediate fusion, they form very diverse groups as they differ in composition, and in their overall architecture and size, as well as their protein interactome. However, their conserved function relies on a common design. Recent data on class C Vps complexes indicates that tethers play a significant role in membrane fusion beyond vesicle capturing. Furthermore, these studies provide additional mechanistic insights into membrane fusion events and reveal that tethers should be considered as key players of the fusion machinery. Moreover, the discovery of the novel tether FERARI complex has changed our understanding of cargo transport in the endosomal system as it has been shown to mediate 'kiss-and-run' vesicle-target membrane interactions. In this Cell Science at a Glance and the accompanying poster, we compare the structure of the coiled-coil and the multisubunit CATCHR and class C Vps tether families on the basis of their functional analogy. We discuss the mechanism of membrane fusion, and summarize how tethers capture vesicles, mediate membrane fusion at different cellular compartments and regulate cargo traffic.
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Affiliation(s)
| | - Anne Spang
- Biozentrum, University of Basel, 4056 Basel, Switzerland
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20
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Sánchez-Martín P, Kriegenburg F, Alves L, Adam J, Elsaesser J, Babic R, Mancilla H, Licheva M, Tascher G, Münch C, Eimer S, Kraft C. ULK1-mediated phosphorylation regulates the conserved role of YKT6 in autophagy. J Cell Sci 2023; 136:jcs260546. [PMID: 36644903 PMCID: PMC10022743 DOI: 10.1242/jcs.260546] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 01/06/2023] [Indexed: 01/17/2023] Open
Abstract
Autophagy is a catabolic process during which cytosolic material is enwrapped in a newly formed double-membrane structure called the autophagosome, and subsequently targeted for degradation in the lytic compartment of the cell. The fusion of autophagosomes with the lytic compartment is a tightly regulated step and involves membrane-bound SNARE proteins. These play a crucial role as they promote lipid mixing and fusion of the opposing membranes. Among the SNARE proteins implicated in autophagy, the essential SNARE protein YKT6 is the only SNARE protein that is evolutionarily conserved from yeast to humans. Here, we show that alterations in YKT6 function, in both mammalian cells and nematodes, produce early and late autophagy defects that result in reduced survival. Moreover, mammalian autophagosomal YKT6 is phospho-regulated by the ULK1 kinase, preventing premature bundling with the lysosomal SNARE proteins and thereby inhibiting autophagosome-lysosome fusion. Together, our findings reveal that timely regulation of the YKT6 phosphorylation status is crucial throughout autophagy progression and cell survival.
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Affiliation(s)
- Pablo Sánchez-Martín
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Franziska Kriegenburg
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Ludovico Alves
- Department of Structural Cell Biology, Institute for Cell Biology and Neuroscience, Goethe University Frankfurt, 60438 Frankfurt, Germany
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, 60590 Frankfurt, Germany
| | - Julius Adam
- Department of Structural Cell Biology, Institute for Cell Biology and Neuroscience, Goethe University Frankfurt, 60438 Frankfurt, Germany
| | - Jana Elsaesser
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Riccardo Babic
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Hector Mancilla
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Mariya Licheva
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Georg Tascher
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, 60590 Frankfurt, Germany
| | - Christian Münch
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, 60590 Frankfurt, Germany
| | - Stefan Eimer
- Department of Structural Cell Biology, Institute for Cell Biology and Neuroscience, Goethe University Frankfurt, 60438 Frankfurt, Germany
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
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21
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Kümmel D, Herrmann E, Langemeyer L, Ungermann C. Molecular insights into endolysosomal microcompartment formation and maintenance. Biol Chem 2022; 404:441-454. [PMID: 36503831 DOI: 10.1515/hsz-2022-0294] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 11/22/2022] [Indexed: 12/14/2022]
Abstract
Abstract
The endolysosomal system of eukaryotic cells has a key role in the homeostasis of the plasma membrane, in signaling and nutrient uptake, and is abused by viruses and pathogens for entry. Endocytosis of plasma membrane proteins results in vesicles, which fuse with the early endosome. If destined for lysosomal degradation, these proteins are packaged into intraluminal vesicles, converting an early endosome to a late endosome, which finally fuses with the lysosome. Each of these organelles has a unique membrane surface composition, which can form segmented membrane microcompartments by membrane contact sites or fission proteins. Furthermore, these organelles are in continuous exchange due to fission and fusion events. The underlying machinery, which maintains organelle identity along the pathway, is regulated by signaling processes. Here, we will focus on the Rab5 and Rab7 GTPases of early and late endosomes. As molecular switches, Rabs depend on activating guanine nucleotide exchange factors (GEFs). Over the last years, we characterized the Rab7 GEF, the Mon1-Ccz1 (MC1) complex, and key Rab7 effectors, the HOPS complex and retromer. Structural and functional analyses of these complexes lead to a molecular understanding of their function in the context of organelle biogenesis.
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Affiliation(s)
- Daniel Kümmel
- Institute of Biochemistry, University of Münster , Corrensstraße 36 , D-48149 Münster , Germany
| | - Eric Herrmann
- Institute of Biochemistry, University of Münster , Corrensstraße 36 , D-48149 Münster , Germany
| | - Lars Langemeyer
- Department of Biology/Chemistry, Biochemistry section , Osnabrück University , Barbarastraße 13 , D-49076 Osnabrück , Germany
- Center of Cellular Nanoanalytics (CellNanOs) , Osnabrück University , Barbarastraße 11 , D-49076 Osnabrück , Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry section , Osnabrück University , Barbarastraße 13 , D-49076 Osnabrück , Germany
- Center of Cellular Nanoanalytics (CellNanOs) , Osnabrück University , Barbarastraße 11 , D-49076 Osnabrück , Germany
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22
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Xu N, Liu Z, Lv Y, Liu S, Yang S, Zhang W. Improved Coarse-Grained Model for Nanoparticles Based on the Martini Force Field and Its Application in Molecular Dynamics Simulation on Gel Ink. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:14172-14184. [PMID: 36367785 DOI: 10.1021/acs.langmuir.2c02185] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Research on the dispersion and stability of nanoparticles in liquid media is one of the key subjects for nanomaterial utilization. In consideration of the preponderance of coarse-grained (CG) molecular dynamics (MD) simulation in following and understanding the structure and dynamics on the nanoscale, an improved CG model for nanoparticles based on the Martini force field is established to facilitate the more extensive applications of this simulation method and further studies on complex nanoparticle liquid systems. Gel ink is selected as the liquid system for nanoparticles to validate the improved CG model on the one hand and introduce the CGMD simulation method into the studies of this system on the other. The calculation shows that the improved model can provide relatively precise results and has good computational stability. The effect mechanisms of the thickener and disperser on the carbon black nanoparticle are similar, namely the result of a delicate balance between the interaction of the thickener/disperser with the carbon black nanoparticle and the interaction of the thickener and disperser with each other. Furthermore, the phase assimilating effect of disperser molecules is key for separating the agglomerated carbon black nanoparticles; thereafter, the space steric hindrance effect and the electrostatic hindrance effect play main roles in maintaining the dispersion of carbon black nanoparticles.
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Affiliation(s)
- Na Xu
- College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan, Shanxi030024, China
- Shanxi coking coal in Yuncheng salt Refco Group Ltd., Yuncheng, Shanxi044000, China
| | - Zilu Liu
- College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan, Shanxi030024, China
| | - Yaodong Lv
- College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan, Shanxi030024, China
| | - Shoujun Liu
- College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan, Shanxi030024, China
| | - Song Yang
- College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan, Shanxi030024, China
| | - Wei Zhang
- College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan, Shanxi030024, China
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23
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Scerra G, De Pasquale V, Scarcella M, Caporaso MG, Pavone LM, D'Agostino M. Lysosomal positioning diseases: beyond substrate storage. Open Biol 2022; 12:220155. [PMID: 36285443 PMCID: PMC9597170 DOI: 10.1098/rsob.220155] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Lysosomal storage diseases (LSDs) comprise a group of inherited monogenic disorders characterized by lysosomal dysfunctions due to undegraded substrate accumulation. They are caused by a deficiency in specific lysosomal hydrolases involved in cellular catabolism, or non-enzymatic proteins essential for normal lysosomal functions. In LSDs, the lack of degradation of the accumulated substrate and its lysosomal storage impairs lysosome functions resulting in the perturbation of cellular homeostasis and, in turn, the damage of multiple organ systems. A substantial number of studies on the pathogenesis of LSDs has highlighted how the accumulation of lysosomal substrates is only the first event of a cascade of processes including the accumulation of secondary metabolites and the impairment of cellular trafficking, cell signalling, autophagic flux, mitochondria functionality and calcium homeostasis, that significantly contribute to the onset and progression of these diseases. Emerging studies on lysosomal biology have described the fundamental roles of these organelles in a variety of physiological functions and pathological conditions beyond their canonical activity in cellular waste clearance. Here, we discuss recent advances in the knowledge of cellular and molecular mechanisms linking lysosomal positioning and trafficking to LSDs.
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Affiliation(s)
- Gianluca Scerra
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via Sergio Pansini 5, 80131 Naples, Italy
| | - Valeria De Pasquale
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via Federico Delpino 1, 80137 Naples, Italy
| | - Melania Scarcella
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via Sergio Pansini 5, 80131 Naples, Italy
| | - Maria Gabriella Caporaso
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via Sergio Pansini 5, 80131 Naples, Italy
| | - Luigi Michele Pavone
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via Sergio Pansini 5, 80131 Naples, Italy
| | - Massimo D'Agostino
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via Sergio Pansini 5, 80131 Naples, Italy
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24
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Aniento F, Sánchez de Medina Hernández V, Dagdas Y, Rojas-Pierce M, Russinova E. Molecular mechanisms of endomembrane trafficking in plants. THE PLANT CELL 2022; 34:146-173. [PMID: 34550393 PMCID: PMC8773984 DOI: 10.1093/plcell/koab235] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/12/2021] [Indexed: 05/10/2023]
Abstract
Endomembrane trafficking is essential for all eukaryotic cells. The best-characterized membrane trafficking organelles include the endoplasmic reticulum (ER), Golgi apparatus, early and recycling endosomes, multivesicular body, or late endosome, lysosome/vacuole, and plasma membrane. Although historically plants have given rise to cell biology, our understanding of membrane trafficking has mainly been shaped by the much more studied mammalian and yeast models. Whereas organelles and major protein families that regulate endomembrane trafficking are largely conserved across all eukaryotes, exciting variations are emerging from advances in plant cell biology research. In this review, we summarize the current state of knowledge on plant endomembrane trafficking, with a focus on four distinct trafficking pathways: ER-to-Golgi transport, endocytosis, trans-Golgi network-to-vacuole transport, and autophagy. We acknowledge the conservation and commonalities in the trafficking machinery across species, with emphasis on diversity and plant-specific features. Understanding the function of organelles and the trafficking machinery currently nonexistent in well-known model organisms will provide great opportunities to acquire new insights into the fundamental cellular process of membrane trafficking.
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Affiliation(s)
| | - Víctor Sánchez de Medina Hernández
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, 1030 Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, A-1030, Vienna, Austria
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25
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Empereur-Mot C, Capelli R, Perrone M, Caruso C, Doni G, Pavan GM. Automatic multi-objective optimization of coarse-grained lipid force fields using SwarmCG. J Chem Phys 2022; 156:024801. [PMID: 35032979 DOI: 10.1063/5.0079044] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The development of coarse-grained (CG) molecular models typically requires a time-consuming iterative tuning of parameters in order to have the approximated CG models behave correctly and consistently with, e.g., available higher-resolution simulation data and/or experimental observables. Automatic data-driven approaches are increasingly used to develop accurate models for molecular dynamics simulations. However, the parameters obtained via such automatic methods often make use of specifically designed interaction potentials and are typically poorly transferable to molecular systems or conditions other than those used for training them. Using a multi-objective approach in combination with an automatic optimization engine (SwarmCG), here, we show that it is possible to optimize CG models that are also transferable, obtaining optimized CG force fields (FFs). As a proof of concept, here, we use lipids for which we can avail reference experimental data (area per lipid and bilayer thickness) and reliable atomistic simulations to guide the optimization. Once the resolution of the CG models (mapping) is set as an input, SwarmCG optimizes the parameters of the CG lipid models iteratively and simultaneously against higher-resolution simulations (bottom-up) and experimental data (top-down references). Including different types of lipid bilayers in the training set in a parallel optimization guarantees the transferability of the optimized lipid FF parameters. We demonstrate that SwarmCG can reach satisfactory agreement with experimental data for different resolution CG FFs. We also obtain stimulating insights into the precision-resolution balance of the FFs. The approach is general and can be effectively used to develop new FFs and to improve the existing ones.
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Affiliation(s)
- Charly Empereur-Mot
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Polo Universitario Lugano, Campus Est, Via la Santa 1, 6962 Lugano-Viganello, Switzerland
| | - Riccardo Capelli
- Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi 24, Torino 10129, Italy
| | - Mattia Perrone
- Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi 24, Torino 10129, Italy
| | - Cristina Caruso
- Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi 24, Torino 10129, Italy
| | - Giovanni Doni
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Polo Universitario Lugano, Campus Est, Via la Santa 1, 6962 Lugano-Viganello, Switzerland
| | - Giovanni M Pavan
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Polo Universitario Lugano, Campus Est, Via la Santa 1, 6962 Lugano-Viganello, Switzerland
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26
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van der Beek J, de Heus C, Liv N, Klumperman J. Quantitative correlative microscopy reveals the ultrastructural distribution of endogenous endosomal proteins. J Cell Biol 2022; 221:212877. [PMID: 34817533 PMCID: PMC8624803 DOI: 10.1083/jcb.202106044] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 10/22/2021] [Accepted: 11/01/2021] [Indexed: 02/07/2023] Open
Abstract
The key endosomal regulators Rab5, EEA1, and APPL1 are frequently applied in fluorescence microscopy to mark early endosomes, whereas Rab7 is used as a marker for late endosomes and lysosomes. However, endogenous levels of these proteins localize poorly in immuno-EM, and systematic studies on their native ultrastructural distributions are lacking. To address this gap, we here present a quantitative, on-section correlative light and electron microscopy (CLEM) approach. Using the sensitivity of fluorescence microscopy, we label hundreds of organelles that are subsequently visualized by EM and classified by ultrastructure. We show that Rab5 predominantly marks small, endocytic vesicles and early endosomes. EEA1 colocalizes with Rab5 on early endosomes, but unexpectedly also labels Rab5-negative late endosomes, which are positive for PI(3)P but lack Rab7. APPL1 is restricted to small Rab5-positive, tubulo-vesicular profiles. Rab7 primarily labels late endosomes and lysosomes. These data increase our understanding of the structural-functional organization of the endosomal system and introduce quantitative CLEM as a sensitive alternative for immuno-EM.
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Affiliation(s)
- Jan van der Beek
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, Utrecht, the Netherlands
| | - Cecilia de Heus
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, Utrecht, the Netherlands
| | - Nalan Liv
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, Utrecht, the Netherlands
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, Utrecht, the Netherlands
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27
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Scerra G, Caporaso MG, Renna M, D’Agostino M. Protocol for labeling and fixation of intact lysosomes with esterified amino acid analogs to assess lysosomal expansion in living eukaryotic cells. STAR Protoc 2021; 2:100916. [PMID: 34755119 PMCID: PMC8564676 DOI: 10.1016/j.xpro.2021.100916] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The lysosomal compartment is a key hub for cell metabolism, and morphological alterations have been described in several pathological conditions. Here, we describe the use of amino acid analogs modified by the presence of a methyl ester group that accumulates within lysosomes. This generates an intraluminal osmotic effect able to trigger a rapid and selective expansion of the lysosomal compartment within 2 h of treatment. We also present protocols to preserve lysosomal morphology, which yields a more accurate size measurement. For complete details on the use and execution of this protocol, please refer to Scerra et al. (2021). Methyl-group-modified amino acid analogs (LEU-ME) can localize to lysosomes LEU-ME triggers a rapid expansion of the lysosomal compartment Fixation procedure is a key step for preserving lysosomal morphology Quantification and analysis of lysosomal dimensions
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Affiliation(s)
- Gianluca Scerra
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples ‘‘Federico II’’, 80131 Naples, Italy
| | - Maria Gabriella Caporaso
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples ‘‘Federico II’’, 80131 Naples, Italy
| | - Maurizio Renna
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples ‘‘Federico II’’, 80131 Naples, Italy
| | - Massimo D’Agostino
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples ‘‘Federico II’’, 80131 Naples, Italy
- Corresponding author
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28
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Yu X, Sha L, Liu Q, Zhao Y, Fang H, Cao Y, Zhao J. Recent advances in cell membrane camouflage-based biosensing application. Biosens Bioelectron 2021; 194:113623. [PMID: 34530371 DOI: 10.1016/j.bios.2021.113623] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 01/04/2023]
Abstract
Cell membrane, a semi-permeable membrane composed of phospholipid bilayers, is a natural barrier to prevent extracellular substances from freely entering the cell. Cell membrane with selective permeability and fluidity ensures the relative stability of the intracellular environment and enables various biochemical reactions to smoothly operate in an orderly manner. Inspired by the natural composition and transport process, various cell membranes and synthetic bionic films as the mimics of cell membranes have emerged as appealing camouflage materials for biosensing applications. The membranes are devoted to surface modification and substance delivery, and realize the detection or in situ analysis of multiple biomarkers, such as glucose, nucleic acids, virus, and circulating tumor cells. In this review, we summarize the recent advances in cell membrane camouflage-based biosensing applications, mainly focusing on the use of the membranes extracted from natural cells (e.g., blood cells and cancer cells) as well as biomimetic membranes. Materials and surfaces camouflaged with cell membranes are shown to have superior stability and biocompatibility as well as intrinsic properties of original cells, which greatly facilitate their use in biosensing. In specific, camouflage with blood cell membranes bestows low immunogenicity and prolonged blood circulation time, camouflage with cancer cell membranes provides homologous targeting ability, and camouflage with biomimetic membranes endows considerable plasticity for functionalization. Further research is expected to focus on the deeper understanding of cell-specific properties of membranes and the exploration of hybrid membranes, which might provide new development opportunities for cell membrane camouflage-based biosensing application.
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Affiliation(s)
- Xiaomeng Yu
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong, 226011, PR China; Center for Molecular Recognition and Biosensing, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai, 200444, PR China
| | - Lingjun Sha
- Center for Molecular Recognition and Biosensing, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai, 200444, PR China
| | - Qi Liu
- Center for Molecular Recognition and Biosensing, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai, 200444, PR China
| | - Yingyan Zhao
- Center for Molecular Recognition and Biosensing, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai, 200444, PR China
| | - Huan Fang
- Center for Molecular Recognition and Biosensing, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai, 200444, PR China
| | - Ya Cao
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong, 226011, PR China; Center for Molecular Recognition and Biosensing, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai, 200444, PR China.
| | - Jing Zhao
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong, 226011, PR China; Center for Molecular Recognition and Biosensing, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai, 200444, PR China.
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29
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Hanley SE, Willis SD, Cooper KF. Snx4-assisted vacuolar targeting of transcription factors defines a new autophagy pathway for controlling ATG expression. Autophagy 2021; 17:3547-3565. [PMID: 33678121 PMCID: PMC8632336 DOI: 10.1080/15548627.2021.1877934] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 01/14/2021] [Indexed: 12/18/2022] Open
Abstract
Autophagy, in part, is controlled by the repression and activation of autophagy-related (ATG) genes. Here, we describe a new selective autophagy pathway that targets functional transcriptional regulators to control their activity. This pathway is activated in response to nitrogen starvation and recycles transcriptional activators (Msn2 and Rim15) and a repressor (Ssn2/Med13) of ATG expression. Further analysis of Ssn2/Med13 vacuolar proteolysis revealed that this pathway utilizes the core autophagic machinery. However, it is independent of known nucleophagy mechanisms, receptor proteins, and the scaffold protein Atg11. Instead, Ssn2/Med13 exits the nucleus through the nuclear pore complex (NPC) and associates with the cytoplasmic nucleoporin Gle1, a member of the RNA remodeling complex. Dbp5 and Nup159, that act in concert with Gle1, are also required for Ssn2/Med13 clearance. Ssn2/Med13 is retrieved from the nuclear periphery and degraded by Atg17-initiated phagophores anchored to the vacuole. Efficient transfer to phagophores depends on the sorting nexin heterodimer Snx4/Atg24-Atg20, which binds to Atg17, and relocates to the perinucleus following nitrogen starvation. To conclude, this pathway defines a previously undescribed autophagy mechanism that targets select transcriptional regulators for rapid vacuolar proteolysis, utilizing the RNA remodeling complex, the sorting nexin heterodimer Snx4-Atg20, Atg17, and the core autophagic machinery. It is physiologically relevant as this Snx4-assisted vacuolar targeting pathway permits cells to fine-tune the autophagic response by controlling the turnover of both positive and negative regulators of ATG transcription.Abbreviations: AIM: Atg8 interacting motif; ATG: autophagy-related; CKM: CDK8 kinase module; IDR: intrinsically disordered region; IP6: phosphoinositide inositol hexaphosphate; NPC: nuclear pore complex; PAS: phagophore assembly site; UPS: ubiquitin-proteasomal system.
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Affiliation(s)
- Sara E. Hanley
- Department of Molecular Biology, Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
| | - Stephen D. Willis
- Department of Molecular Biology, Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
| | - Katrina F. Cooper
- Department of Molecular Biology, Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
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30
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Hu W, Zhang Y, Fei P, Zhang T, Yao D, Gao Y, Liu J, Chen H, Lu Q, Mudianto T, Zhang X, Xiao C, Ye Y, Sun Q, Zhang J, Xie Q, Wang PH, Wang J, Li Z, Lou J, Chen W. Mechanical activation of spike fosters SARS-CoV-2 viral infection. Cell Res 2021; 31:1047-1060. [PMID: 34465913 PMCID: PMC8406658 DOI: 10.1038/s41422-021-00558-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 08/06/2021] [Indexed: 02/07/2023] Open
Abstract
The outbreak of SARS-CoV-2 (SARS2) has caused a global COVID-19 pandemic. The spike protein of SARS2 (SARS2-S) recognizes host receptors, including ACE2, to initiate viral entry in a complex biomechanical environment. Here, we reveal that tensile force, generated by bending of the host cell membrane, strengthens spike recognition of ACE2 and accelerates the detachment of spike's S1 subunit from the S2 subunit to rapidly prime the viral fusion machinery. Mechanistically, such mechano-activation is fulfilled by force-induced opening and rotation of spike's receptor-binding domain to prolong the bond lifetime of spike/ACE2 binding, up to 4 times longer than that of SARS-S binding with ACE2 under 10 pN force application, and subsequently by force-accelerated S1/S2 detachment which is up to ~103 times faster than that in the no-force condition. Interestingly, the SARS2-S D614G mutant, a more infectious variant, shows 3-time stronger force-dependent ACE2 binding and 35-time faster force-induced S1/S2 detachment. We also reveal that an anti-S1/S2 non-RBD-blocking antibody that was derived from convalescent COVID-19 patients with potent neutralizing capability can reduce S1/S2 detachment by 3 × 106 times under force. Our study sheds light on the mechano-chemistry of spike activation and on developing a non-RBD-blocking but S1/S2-locking therapeutic strategy to prevent SARS2 invasion.
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Affiliation(s)
- Wei Hu
- grid.13402.340000 0004 1759 700XDepartment of Cardiology of the Second Affiliated Hospital and Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang China
| | - Yong Zhang
- grid.9227.e0000000119573309Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Panyu Fei
- grid.13402.340000 0004 1759 700XDepartment of Cardiology of the Second Affiliated Hospital and Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang China ,grid.13402.340000 0004 1759 700XSchool of Mechanical Engineering, Zhejiang University, Hangzhou, Zhejiang China
| | - Tongtong Zhang
- grid.13402.340000 0004 1759 700XDepartment of Cardiology of the Second Affiliated Hospital and Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang China ,grid.13402.340000 0004 1759 700XDepartment of Hepatobiliary and Pancreatic Surgery, The Center for Integrated Oncology and Precision Medicine, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang China
| | - Danmei Yao
- grid.13402.340000 0004 1759 700XDepartment of Cardiology of the Second Affiliated Hospital and Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang China
| | - Yufei Gao
- grid.13402.340000 0004 1759 700XDepartment of Cardiology of the Second Affiliated Hospital and Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang China ,grid.13402.340000 0004 1759 700XSchool of Mechanical Engineering, Zhejiang University, Hangzhou, Zhejiang China
| | - Jia Liu
- grid.240324.30000 0001 2109 4251Department of Pathology, New York University Grossman School of Medicine, New York, NY USA ,grid.137628.90000 0004 1936 8753The Laura and Isaac Perlmutter Cancer Center, New York University Langone Health, New York, NY USA
| | - Hui Chen
- grid.9227.e0000000119573309Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Qiao Lu
- grid.240324.30000 0001 2109 4251Department of Pathology, New York University Grossman School of Medicine, New York, NY USA ,grid.137628.90000 0004 1936 8753The Laura and Isaac Perlmutter Cancer Center, New York University Langone Health, New York, NY USA
| | - Tenny Mudianto
- grid.240324.30000 0001 2109 4251Department of Pathology, New York University Grossman School of Medicine, New York, NY USA
| | - Xinrui Zhang
- grid.13402.340000 0004 1759 700XDepartment of Cardiology of the Second Affiliated Hospital and Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang China
| | - Chuxuan Xiao
- grid.13402.340000 0004 1759 700XCollaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the MOE Frontier Science Center for Brain Science & Brain-machine Integration, State Key Laboratory for Modern Optical Instrumentation Key Laboratory for Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, Zhejiang China
| | - Yang Ye
- grid.9227.e0000000119573309Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Qiming Sun
- grid.13402.340000 0004 1759 700XDepartment of Cardiology of the Second Affiliated Hospital and Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang China
| | - Jing Zhang
- grid.27255.370000 0004 1761 1174Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, Shandong China
| | - Qi Xie
- grid.494629.40000 0004 8008 9315Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, Hangzhou, Zhejiang China
| | - Pei-Hui Wang
- grid.27255.370000 0004 1761 1174Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, Shandong China
| | - Jun Wang
- grid.240324.30000 0001 2109 4251Department of Pathology, New York University Grossman School of Medicine, New York, NY USA ,grid.137628.90000 0004 1936 8753The Laura and Isaac Perlmutter Cancer Center, New York University Langone Health, New York, NY USA
| | - Zhenhai Li
- grid.39436.3b0000 0001 2323 5732Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai Institute of Applied Mathematics and Mechanics, School of Mechanics and Engineering Science, Shanghai University, Shanghai, China
| | - Jizhong Lou
- grid.9227.e0000000119573309Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China ,grid.508040.9Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, Guangdong China
| | - Wei Chen
- grid.13402.340000 0004 1759 700XDepartment of Cardiology of the Second Affiliated Hospital and Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang China ,grid.13402.340000 0004 1759 700XCollaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the MOE Frontier Science Center for Brain Science & Brain-machine Integration, State Key Laboratory for Modern Optical Instrumentation Key Laboratory for Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, Zhejiang China ,grid.13402.340000 0004 1759 700XZhejiang Laboratory for Systems and Precision Medicine, Zhejiang University Medical Center, Hangzhou, Zhejiang China
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31
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Wu Z, Dharan N, McDargh ZA, Thiyagarajan S, O'Shaughnessy B, Karatekin E. The neuronal calcium sensor Synaptotagmin-1 and SNARE proteins cooperate to dilate fusion pores. eLife 2021; 10:68215. [PMID: 34190041 PMCID: PMC8294851 DOI: 10.7554/elife.68215] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/29/2021] [Indexed: 02/07/2023] Open
Abstract
All membrane fusion reactions proceed through an initial fusion pore, including calcium-triggered release of neurotransmitters and hormones. Expansion of this small pore to release cargo is energetically costly and regulated by cells, but the mechanisms are poorly understood. Here, we show that the neuronal/exocytic calcium sensor Synaptotagmin-1 (Syt1) promotes expansion of fusion pores induced by SNARE proteins. Pore dilation relied on calcium-induced insertion of the tandem C2 domain hydrophobic loops of Syt1 into the membrane, previously shown to reorient the C2 domain. Mathematical modelling suggests that C2B reorientation rotates a bound SNARE complex so that it exerts force on the membranes in a mechanical lever action that increases the height of the fusion pore, provoking pore dilation to offset the bending energy penalty. We conclude that Syt1 exerts novel non-local calcium-dependent mechanical forces on fusion pores that dilate pores and assist neurotransmitter and hormone release.
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Affiliation(s)
- Zhenyong Wu
- Department of Cellular and Molecular Physiology, Yale University, New Haven, United States.,Nanobiology Institute, Yale University, West Haven, United States
| | - Nadiv Dharan
- Department of Chemical Engineering, Columbia University, New York, United States
| | - Zachary A McDargh
- Department of Chemical Engineering, Columbia University, New York, United States
| | - Sathish Thiyagarajan
- Department of Chemical Engineering, Columbia University, New York, United States
| | - Ben O'Shaughnessy
- Department of Chemical Engineering, Columbia University, New York, United States
| | - Erdem Karatekin
- Department of Cellular and Molecular Physiology, Yale University, New Haven, United States.,Nanobiology Institute, Yale University, West Haven, United States.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, United States.,Saints-Pères Paris Institute for the Neurosciences (SPPIN), Université de Paris, Centre National de la Recherche Scientifique (CNRS) UMR 8003, Paris, France
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32
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33
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Davis LJ, Bright NA, Edgar JR, Parkinson MDJ, Wartosch L, Mantell J, Peden AA, Luzio JP. Organelle tethering, pore formation and SNARE compensation in the late endocytic pathway. J Cell Sci 2021; 134:268392. [PMID: 34042162 PMCID: PMC8186482 DOI: 10.1242/jcs.255463] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 04/14/2021] [Indexed: 11/24/2022] Open
Abstract
To provide insights into the kiss-and-run and full fusion events resulting in endocytic delivery to lysosomes, we investigated conditions causing increased tethering and pore formation between late endocytic organelles in HeLa cells. Knockout of the soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) VAMP7 and VAMP8 showed, by electron microscopy, the accumulation of tethered lysosome-associated membrane protein (LAMP)-carrier vesicles around multivesicular bodies, as well as the appearance of ‘hourglass’ profiles of late endocytic organelles attached by filamentous tethers, but did not prevent endocytic delivery to lysosomal hydrolases. Subsequent depletion of the SNARE YKT6 reduced this delivery, consistent with it compensating for the absence of VAMP7 and VAMP8. We also investigated filamentous tethering between multivesicular bodies and enlarged endolysosomes following depletion of charged multi-vesicular body protein 6 (CHMP6), and provide the first evidence that pore formation commences at the edge of tether arrays, with pore expansion required for full membrane fusion. Summary: Endocytic delivery to lysosomes by kiss and run/membrane fusion entails pore formation commencing at the edge of tether arrays, and demonstrates SNARE redundancy and compensation.
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Affiliation(s)
- Luther J Davis
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Nicholas A Bright
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - James R Edgar
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Michael D J Parkinson
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Lena Wartosch
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Judith Mantell
- School of Biochemistry, University of Bristol, Medical Sciences Building, University Walk, Bristol BS81TD, UK.,Wolfson Bioimaging Facility, University of Bristol, Medical Sciences Building, University Walk, Bristol BS81TD, UK
| | - Andrew A Peden
- Department of Biomedical Science & Centre for Membrane Interactions and Dynamics (CMIAD), The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - J Paul Luzio
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
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34
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Souza PCT, Alessandri R, Barnoud J, Thallmair S, Faustino I, Grünewald F, Patmanidis I, Abdizadeh H, Bruininks BMH, Wassenaar TA, Kroon PC, Melcr J, Nieto V, Corradi V, Khan HM, Domański J, Javanainen M, Martinez-Seara H, Reuter N, Best RB, Vattulainen I, Monticelli L, Periole X, Tieleman DP, de Vries AH, Marrink SJ. Martini 3: a general purpose force field for coarse-grained molecular dynamics. Nat Methods 2021; 18:382-388. [PMID: 33782607 DOI: 10.1038/s41592-021-01098-3] [Citation(s) in RCA: 479] [Impact Index Per Article: 159.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 02/22/2021] [Indexed: 01/31/2023]
Abstract
The coarse-grained Martini force field is widely used in biomolecular simulations. Here we present the refined model, Martini 3 ( http://cgmartini.nl ), with an improved interaction balance, new bead types and expanded ability to include specific interactions representing, for example, hydrogen bonding and electronic polarizability. The updated model allows more accurate predictions of molecular packing and interactions in general, which is exemplified with a vast and diverse set of applications, ranging from oil/water partitioning and miscibility data to complex molecular systems, involving protein-protein and protein-lipid interactions and material science applications as ionic liquids and aedamers.
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Affiliation(s)
- Paulo C T Souza
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands. .,Molecular Microbiology and Structural Biochemistry, UMR 5086 CNRS and University of Lyon, Lyon, France.
| | - Riccardo Alessandri
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands
| | - Jonathan Barnoud
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands.,Intangible Realities Laboratory, University of Bristol, School of Chemistry, Bristol, UK
| | - Sebastian Thallmair
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands.,Frankfurt Institute for Advanced Studies, Frankfurt am Main, Germany
| | - Ignacio Faustino
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands
| | - Fabian Grünewald
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands
| | - Ilias Patmanidis
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands
| | - Haleh Abdizadeh
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands
| | - Bart M H Bruininks
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands
| | - Tsjerk A Wassenaar
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands
| | - Peter C Kroon
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands
| | - Josef Melcr
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands
| | - Vincent Nieto
- Molecular Microbiology and Structural Biochemistry, UMR 5086 CNRS and University of Lyon, Lyon, France
| | - Valentina Corradi
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Hanif M Khan
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.,Department of Chemistry and Computational Biology Unit, University of Bergen, Bergen, Norway
| | - Jan Domański
- Department of Biochemistry, University of Oxford, Oxford, UK.,Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Matti Javanainen
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic.,Computational Physics Laboratory, Tampere University, Tampere, Finland
| | - Hector Martinez-Seara
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Nathalie Reuter
- Department of Chemistry and Computational Biology Unit, University of Bergen, Bergen, Norway
| | - Robert B Best
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ilpo Vattulainen
- Computational Physics Laboratory, Tampere University, Tampere, Finland.,Department of Physics, University of Helsinki, Helsinki, Finland
| | - Luca Monticelli
- Molecular Microbiology and Structural Biochemistry, UMR 5086 CNRS and University of Lyon, Lyon, France
| | - Xavier Periole
- Department of Chemistry, Aarhus University, Aarhus C, Denmark
| | - D Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Alex H de Vries
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands
| | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Material, University of Groningen, Groningen, the Netherlands.
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35
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Xia Q, Huang X, Huang J, Zheng Y, March ME, Li J, Wei Y. The Role of Autophagy in Skeletal Muscle Diseases. Front Physiol 2021; 12:638983. [PMID: 33841177 PMCID: PMC8027491 DOI: 10.3389/fphys.2021.638983] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 02/22/2021] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle is the most abundant type of tissue in human body, being involved in diverse activities and maintaining a finely tuned metabolic balance. Autophagy, characterized by the autophagosome–lysosome system with the involvement of evolutionarily conserved autophagy-related genes, is an important catabolic process and plays an essential role in energy generation and consumption, as well as substance turnover processes in skeletal muscles. Autophagy in skeletal muscles is finely tuned under the tight regulation of diverse signaling pathways, and the autophagy pathway has cross-talk with other pathways to form feedback loops under physiological conditions and metabolic stress. Altered autophagy activity characterized by either increased formation of autophagosomes or inhibition of lysosome-autophagosome fusion can lead to pathological cascades, and mutations in autophagy genes and deregulation of autophagy pathways have been identified as one of the major causes for a variety of skeleton muscle disorders. The advancement of multi-omics techniques enables further understanding of the molecular and biochemical mechanisms underlying the role of autophagy in skeletal muscle disorders, which may yield novel therapeutic targets for these disorders.
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Affiliation(s)
- Qianghua Xia
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Xubo Huang
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Jieru Huang
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Yongfeng Zheng
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Michael E March
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Jin Li
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Yongjie Wei
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
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36
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Risselada HJ, Grubmüller H. How proteins open fusion pores: insights from molecular simulations. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:279-293. [PMID: 33340336 PMCID: PMC8071795 DOI: 10.1007/s00249-020-01484-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/16/2020] [Accepted: 11/24/2020] [Indexed: 02/06/2023]
Abstract
Fusion proteins can play a versatile and involved role during all stages of the fusion reaction. Their roles go far beyond forcing the opposing membranes into close proximity to drive stalk formation and fusion. Molecular simulations have played a central role in providing a molecular understanding of how fusion proteins actively overcome the free energy barriers of the fusion reaction up to the expansion of the fusion pore. Unexpectedly, molecular simulations have revealed a preference of the biological fusion reaction to proceed through asymmetric pathways resulting in the formation of, e.g., a stalk-hole complex, rim-pore, or vertex pore. Force-field based molecular simulations are now able to directly resolve the minimum free-energy path in protein-mediated fusion as well as quantifying the free energies of formed reaction intermediates. Ongoing developments in Graphics Processing Units (GPUs), free energy calculations, and coarse-grained force-fields will soon gain additional insights into the diverse roles of fusion proteins.
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Affiliation(s)
- H. Jelger Risselada
- Department of Theoretical Physics, Georg-August University of Göttingen, Göttingen, Germany
- Leiden University, Leiden Institute of Chemistry (LIC), Leiden, The Netherlands
| | - Helmut Grubmüller
- Max Planck Institute for Biophysical Chemistry, Theoretical and Computational Biophysics Department, Göttingen, Germany
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37
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Chen F, Chen H, Chen Y, Wei W, Sun Y, Zhang L, Cui L, Wang Y. Dysfunction of the SNARE complex in neurological and psychiatric disorders. Pharmacol Res 2021; 165:105469. [PMID: 33524541 DOI: 10.1016/j.phrs.2021.105469] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/30/2020] [Accepted: 01/24/2021] [Indexed: 02/07/2023]
Abstract
The communication between neurons constitutes the basis of all neural activities, and synaptic vesicle exocytosis is the fundamental biological event that mediates most communication between neurons in the central nervous system. The SNARE complex is the core component of the protein machinery that facilitates the fusion of synaptic vesicles with presynaptic terminals and thereby the release of neurotransmitters. In synapses, each release event is dependent on the assembly of the SNARE complex. In recent years, basic research on the SNARE complex has provided a clearer understanding of the mechanism underlying the formation of the SNARE complex and its role in vesicle formation. Emerging evidence indicates that abnormal expression or dysfunction of the SNARE complex in synapse physiology might contribute to abnormal neurotransmission and ultimately to synaptic dysfunction. Clinical research using postmortem tissues suggests that SNARE complex dysfunction is correlated with various neurological diseases, and some basic research has also confirmed the important role of the SNARE complex in the pathology of these diseases. Genetic and pharmacogenetic studies suggest that the SNARE complex and individual proteins might represent important molecular targets in neurological disease. In this review, we summarize the recent progress toward understanding the SNARE complex in regulating membrane fusion events and provide an update of the recent discoveries from clinical and basic research on the SNARE complex in neurodegenerative, neuropsychiatric, and neurodevelopmental diseases.
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Affiliation(s)
- Feng Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Huiyi Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Yanting Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Wenyan Wei
- Department of Gerontology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Yuanhong Sun
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Lu Zhang
- The First Clinical College, Guangdong Medical University, Zhanjiang, China
| | - Lili Cui
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China.
| | - Yan Wang
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China; Key Laboratory of Biomedical Information Engineering of Ministry of Education, Biomedical Informatics & Genomics Center, School of Life Science and Technology, Xi'an Jiao tong University, Xi'an, China.
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38
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Actin Polymerization and ESCRT Trigger Recruitment of the Fusogens Syntaxin-2 and EFF-1 to Promote Membrane Repair in C. elegans. Dev Cell 2020; 54:624-638.e5. [DOI: 10.1016/j.devcel.2020.06.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 05/08/2020] [Accepted: 06/19/2020] [Indexed: 12/20/2022]
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39
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Endter LJ, Smirnova Y, Risselada HJ. Density Field Thermodynamic Integration (DFTI): A "Soft" Approach to Calculate the Free Energy of Surfactant Self-Assemblies. J Phys Chem B 2020; 124:6775-6785. [PMID: 32631061 DOI: 10.1021/acs.jpcb.0c03982] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thermodynamic integration is one of the most established methods to quantify excess free energies between different metastable states. Excess intermolecular interactions in surfactant assemblies are on the scale of the energy of thermal fluctuations. Therefore, these materials can be deformed and topologically altered via relatively small mechanical stresses. It is thus intuitive to design reaction paths and associated order parameters that exploit the "soft" nature of these materials to mechanically rather than alchemically morph surfactant assemblies from state to state. Here, we propose a novel method coined "density field thermodynamic integration" (DFTI) that adopts the universality and transferability of alchemical methods while simultaneously exploiting the soft excess interactions between surfactant molecules. DFTI was designed for a rapid quantification of the free energy differences between different metastable structures in soft fluid materials. The DFTI method uses an external field coupled to the local density to mechanically morph the system between metastable states of interest. Here, we explored the capability of the DFTI method to swiftly and accurately calculate free energy differences between states. To this aim, we studied two different coarse-grained lipidic surfactant systems: (i) a fusion stalk and (ii) a worm-like micelle. Our results illustrate that DFTI can provide an efficient, versatile, and rather reliable method to calculate the free energy differences between surfactant assemblies.
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Affiliation(s)
- Laura Josefine Endter
- Institute for Theoretical Physics, Georg-August University, 37077 Göttingen, Germany
| | - Yuliya Smirnova
- Institute for Theoretical Physics, Georg-August University, 37077 Göttingen, Germany
| | - Herre Jelger Risselada
- Institute for Theoretical Physics, Georg-August University, 37077 Göttingen, Germany.,Leiden Institute of Chemistry (LIC), University of Leiden, 2311 Leiden,The Netherlands.,Chemical Deptartment, Leibniz Institute of Surface Modifications, 04318 Leipzig, Germany
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40
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SNAREs, tethers and SM proteins: how to overcome the final barriers to membrane fusion? Biochem J 2020; 477:243-258. [PMID: 31951000 DOI: 10.1042/bcj20190050] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 12/04/2019] [Accepted: 12/16/2019] [Indexed: 12/18/2022]
Abstract
Physiological membrane vesicles are built to separate reaction spaces in a stable manner, even when they accidentally collide or are kept in apposition by spatial constraints in the cell. This requires a natural resistance to fusion and mixing of their content, which originates from substantial energetic barriers to membrane fusion [1]. To facilitate intracellular membrane fusion reactions in a controlled manner, proteinaceous fusion machineries have evolved. An important open question is whether protein fusion machineries actively pull the fusion reaction over the present free energy barriers, or whether they rather catalyze fusion by lowering those barriers. At first sight, fusion proteins such as SNARE complexes and viral fusion proteins appear to act as nano-machines, which mechanically transduce force to the membranes and thereby overcome the free energy barriers [2,3]. Whether fusion proteins additionally alter the free energy landscape of the fusion reaction via catalytic roles is less obvious. This is a question that we shall discuss in this review, with particular focus on the influence of the eukaryotic SNARE-dependent fusion machinery on the final step of the reaction, the formation and expansion of the fusion pore.
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41
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Travis SM, DAmico K, Yu IM, McMahon C, Hamid S, Ramirez-Arellano G, Jeffrey PD, Hughson FM. Structural basis for the binding of SNAREs to the multisubunit tethering complex Dsl1. J Biol Chem 2020; 295:10125-10135. [PMID: 32409579 DOI: 10.1074/jbc.ra120.013654] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/01/2020] [Indexed: 01/02/2023] Open
Abstract
Multisubunit-tethering complexes (MTCs) are large (250 to >750 kDa), conserved macromolecular machines that are essential for soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-mediated membrane fusion in all eukaryotes. MTCs are thought to organize membrane trafficking by mediating the initial long-range interaction between a vesicle and its target membrane and promoting the formation of membrane-bridging SNARE complexes. Previously, we reported the structure of the yeast Dsl1 complex, the simplest known MTC, which is essential for coat protein I (COPI) mediated transport from the Golgi to the endoplasmic reticulum (ER). This structure suggests how the Dsl1 complex might tether a vesicle to its target membrane by binding at one end to the COPI coat and at the other to ER-associated SNAREs. Here, we used X-ray crystallography to investigate these Dsl1-SNARE interactions in greater detail. The Dsl1 complex comprises three subunits that together form a two-legged structure with a central hinge. We found that distal regions of each leg bind N-terminal Habc domains of the ER SNAREs Sec20 (a Qb-SNARE) and Use1 (a Qc-SNARE). The observed binding modes appear to anchor the Dsl1 complex to the ER target membrane while simultaneously ensuring that both SNAREs are in open conformations, with their SNARE motifs available for assembly. The proximity of the two SNARE motifs, and therefore their ability to enter the same SNARE complex, will depend on the relative orientation of the two Dsl1 legs. These results underscore the critical roles of SNARE N-terminal domains in mediating interactions with other elements of the vesicle docking and fusion machinery.
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Affiliation(s)
- Sophie M Travis
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Kevin DAmico
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - I-Mei Yu
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Conor McMahon
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Safraz Hamid
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | | | - Philip D Jeffrey
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Frederick M Hughson
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
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42
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Shen Q, Shi Y, Liu J, Su H, Huang J, Zhang Y, Peng C, Zhou T, Sun Q, Wan W, Liu W. Acetylation of STX17 (syntaxin 17) controls autophagosome maturation. Autophagy 2020; 17:1157-1169. [PMID: 32264736 PMCID: PMC8143222 DOI: 10.1080/15548627.2020.1752471] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The fusion of autophagosomes and endosomes/lysosomes, also called autophagosome maturation, ensures the degradation of autophagic cargoes. It is an important regulatory step of the macroautophagy/autophagy process. STX17 is the key autophagosomal SNARE protein that mediates autophagosome maturation. Here, we report that the acetylation of STX17 regulates its SNARE activity and autophagic degradation. The histone acetyltransferase CREBBP/CBP and the deacetylase HDAC2 specifically regulate the acetylation of STX17. In response to cell starvation and MTORC1 inhibition, the inactivation of CREBBP leads to the deacetylation of STX17 at its SNARE domain. This deacetylation promotes the interaction between STX17 and SNAP29 and the formation of the STX17-SNAP29-VAMP8 SNARE complex with no effect on the recruitment of STX17 to autophagosomal membranes. Deacetylation of STX17 also enhances the interaction between STX17 and the tethering complex HOPS, thereby further promoting autophagosome-lysosome fusion. Our study suggests a mechanism by which acetylation regulates the late-stage of autophagy, and possibly other STX17-related intracellular membrane fusion events.Abbreviations: ACTB: actin beta; CREBBP/CBP: CREB binding protein; Ctrl: control; GFP: green fluorescent protein; GST: glutathione S-transferase; HDAC: histone deacetylase; HOPS: homotypic fusion and protein sorting complex; KO: knockout; LAMP1/2: lysosomal associated membrane protein 1/2; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MEFs: mouse embryonic fibroblasts; MS: mass spectrometry; MTORC1: mechanistic target of rapamycin kinase complex 1; NAM: nicotinamide; PtdIns3K: phosphatidylinositol 3-kinase; RFP: red fluorescent protein; SNAP29: synaptosome associated protein 29; SNARE: soluble N-ethylamide-sensitive factor attachment protein receptor; SQSTM1/p62: sequestosome 1; STX17: syntaxin 17; TSA: trichostatin A; TSC1/2: TSC complex subunit 1/2; VAMP8: vesicle associated membrane protein 8; WT: wild type.
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Affiliation(s)
- Qiuhong Shen
- Department of Biochemistry and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yin Shi
- Department of Biochemistry and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jiaqi Liu
- Department of Biochemistry and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hua Su
- Department of Biochemistry and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jingtao Huang
- Department of Biochemistry and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yi Zhang
- Department of Biochemistry and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chao Peng
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Tianhua Zhou
- Department of Biochemistry and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qiming Sun
- Department of Biochemistry and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei Wan
- Department of Biochemistry and Department of Thoracic Surgery of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei Liu
- Department of Biochemistry and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University School of Medicine, Joint Institute of Genetics and Genomics Medicine between Zhejiang University and University of Toronto, Hangzhou, China
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43
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Influenza hemagglutinin drives viral entry via two sequential intramembrane mechanisms. Proc Natl Acad Sci U S A 2020; 117:7200-7207. [PMID: 32188780 DOI: 10.1073/pnas.1914188117] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Enveloped viruses enter cells via a process of membrane fusion between the viral envelope and a cellular membrane. For influenza virus, mutational data have shown that the membrane-inserted portions of the hemagglutinin protein play a critical role in achieving fusion. In contrast to the relatively well-understood ectodomain, a predictive mechanistic understanding of the intramembrane mechanisms by which influenza hemagglutinin drives fusion has been elusive. We used molecular dynamics simulations of fusion between a full-length hemagglutinin proteoliposome and a lipid bilayer to analyze these mechanisms. In our simulations, hemagglutinin first acts within the membrane to increase lipid tail protrusion and promote stalk formation and then acts to engage the distal leaflets of each membrane and promote stalk widening, curvature, and eventual fusion. These two sequential mechanisms, one occurring before stalk formation and one after, are consistent with our experimental measurements of single-virus fusion kinetics to liposomes of different sizes. The resulting model also helps explain and integrate previous mutational and biophysical data, particularly the mutational sensitivity of the fusion peptide N terminus and the length sensitivity of the transmembrane domain. We hypothesize that entry by other enveloped viruses may also use sequential processes of acyl tail exposure, followed by membrane curvature and distal leaflet engagement.
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44
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Abstract
Biological transmission of vesicular content occurs by opening of a fusion pore. Recent experimental observations have illustrated that fusion pores between vesicles that are docked by an extended flat contact zone are located at the edge (vertex) of this zone. We modeled this experimentally observed scenario by coarse-grained molecular simulations and elastic theory. This revealed that fusion pores experience a direct attraction toward the vertex. The size adopted by the resulting vertex pore strongly depends on the apparent contact angle between the adhered vesicles even in the absence of membrane surface tension. Larger contact angles substantially increase the equilibrium size of the vertex pore. Because the cellular membrane fusion machinery actively docks membranes, it facilitates a collective expansion of the contact zone and increases the contact angle. In this way, the fusion machinery can drive expansion of the fusion pore by free energy equivalents of multiple tens of kBT from a distance and not only through the fusion proteins that reside within the fusion pore.
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Affiliation(s)
- Edgar M Blokhuis
- Leiden Institute of Chemistry (LIC) , Leiden University , 2333 CD Leiden , The Netherlands
| | - Massimo D'Agostino
- Department of Molecular Medicine and Medical Biotechnology , University of Naples Federico II , 80138 Naples , Italy
| | - Andreas Mayer
- Département de Biochimie , Université de Lausanne , CH-1015 Epalinges , Switzerland
| | - H Jelger Risselada
- Leiden Institute of Chemistry (LIC) , Leiden University , 2333 CD Leiden , The Netherlands
- Department of Theoretical Physics , Georg-August University of Goettingen , 37077 Goettingen , Germany
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45
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Song H, Orr AS, Lee M, Harner ME, Wickner WT. HOPS recognizes each SNARE, assembling ternary trans-complexes for rapid fusion upon engagement with the 4th SNARE. eLife 2020; 9:53559. [PMID: 31961324 PMCID: PMC6994237 DOI: 10.7554/elife.53559] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 01/19/2020] [Indexed: 01/23/2023] Open
Abstract
Yeast vacuole fusion requires R-SNARE, Q-SNAREs, and HOPS. A HOPS SM-family subunit binds the R- and Qa-SNAREs. We now report that HOPS binds each of the four SNAREs. HOPS catalyzes fusion when the Q-SNAREs are not pre-assembled, ushering them into a functional complex. Co-incubation of HOPS, proteoliposomes bearing R-SNARE, and proteoliposomes with any two Q-SNAREs yields a rapid-fusion complex with 3 SNAREs in a trans-assembly. The missing Q-SNARE then induces sudden fusion. HOPS can 'template' SNARE complex assembly through SM recognition of R- and Qa-SNAREs. Though the Qa-SNARE is essential for spontaneous SNARE assembly, HOPS also assembles a rapid-fusion complex between R- and QbQc-SNARE proteoliposomes in the absence of Qa-SNARE, awaiting Qa for fusion. HOPS-dependent fusion is saturable at low concentrations of each Q-SNARE, showing binding site functionality. HOPS thus tethers membranes and recognizes each SNARE, assembling R+Qa or R+QbQc rapid fusion intermediates.
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Affiliation(s)
- Hongki Song
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - Amy S Orr
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - Miriam Lee
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - Max E Harner
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - William T Wickner
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, United States
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Sec17 (α-SNAP) and Sec18 (NSF) restrict membrane fusion to R-SNAREs, Q-SNAREs, and SM proteins from identical compartments. Proc Natl Acad Sci U S A 2019; 116:23573-23581. [PMID: 31685636 DOI: 10.1073/pnas.1913985116] [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: 01/06/2023] Open
Abstract
Membrane fusion at each organelle requires conserved proteins: Rab-GTPases, effector tethering complexes, Sec1/Munc18 (SM)-family SNARE chaperones, SNAREs of the R, Qa, Qb, and Qc families, and the Sec17/α-SNAP and ATP-dependent Sec18/NSF SNARE chaperone system. The basis of organelle-specific fusion, which is essential for accurate protein compartmentation, has been elusive. Rab family GTPases, SM proteins, and R- and Q-SNAREs may contribute to this specificity. We now report that the fusion supported by SNAREs alone is both inefficient and promiscuous with respect to organelle identity and to stimulation by SM family proteins or complexes. SNARE-only fusion is abolished by the disassembly chaperones Sec17 and Sec18. Efficient fusion in the presence of Sec17 and Sec18 requires a tripartite match between the organellar identities of the R-SNARE, the Q-SNAREs, and the SM protein or complex. The functions of Sec17 and Sec18 are not simply negative regulation; they stimulate fusion with either vacuolar SNAREs and their SM protein complex HOPS or endoplasmic reticulum/cis-Golgi SNAREs and their SM protein Sly1. The fusion complex of each organelle is assembled from its own functionally matching pieces to engage Sec17/Sec18 for fusion stimulation rather than inhibition.
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Delgado Cruz M, Kim K. The inner workings of intracellular heterotypic and homotypic membrane fusion mechanisms. J Biosci 2019. [DOI: 10.1007/s12038-019-9913-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Pavlova EV, Shatunov A, Wartosch L, Moskvina AI, Nikolaeva LE, Bright NA, Tylee KL, Church HJ, Ballabio A, Luzio JP, Cox TM. The lysosomal disease caused by mutant VPS33A. Hum Mol Genet 2019; 28:2514-2530. [PMID: 31070736 PMCID: PMC6644154 DOI: 10.1093/hmg/ddz077] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/04/2019] [Accepted: 04/05/2019] [Indexed: 12/14/2022] Open
Abstract
A rare lysosomal disease resembling a mucopolysaccharidosis with unusual systemic features, including renal disease and platelet dysfunction, caused by the defect in a conserved region of the VPS33A gene on human chromosome 12q24.31, occurs in Yakuts-a nomadic Turkic ethnic group of Southern Siberia. VPS33A is a core component of the class C core vacuole/endosome tethering (CORVET) and the homotypic fusion and protein sorting (HOPS) complexes, which have essential functions in the endocytic pathway. Here we show that cultured fibroblasts from patients with this disorder have morphological changes: vacuolation with disordered endosomal/lysosomal compartments and-common to sphingolipid diseases-abnormal endocytic trafficking of lactosylceramide. Urine glycosaminoglycan studies revealed a pathological excess of sialylated conjugates as well as dermatan and heparan sulphate. Lipidomic screening showed elevated β-D-galactosylsphingosine with unimpaired activity of cognate lysosomal hydrolases. The 3D crystal structure of human VPS33A predicts that replacement of arginine 498 by tryptophan will de-stabilize VPS33A folding. We observed that the missense mutation reduced the abundance of full-length VPS33A and other components of the HOPS and CORVET complexes. Treatment of HeLa cells stably expressing the mutant VPS33A with a proteasome inhibitor rescued the mutant protein from degradation. We propose that the disease is due to diminished intracellular abundance of intact VPS33A. Exposure of patient-derived fibroblasts to the clinically approved proteasome inhibitor, bortezomib, or inhibition of glucosylceramide synthesis with eliglustat, partially corrected the impaired lactosylceramide trafficking defect and immediately suggest therapeutic avenues to explore in this fatal orphan disease.
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Affiliation(s)
- Elena V Pavlova
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Aleksey Shatunov
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, UK
| | - Lena Wartosch
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, Wellcome Trust/MRC Building, University of Cambridge, Cambridge, UK
| | - Alena I Moskvina
- Paediatric Centre, National Medical Centre of the Republic of Sakha, Yakutsk, Russia
| | - Lena E Nikolaeva
- Paediatric Centre, National Medical Centre of the Republic of Sakha, Yakutsk, Russia
| | - Nicholas A Bright
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, Wellcome Trust/MRC Building, University of Cambridge, Cambridge, UK
| | - Karen L Tylee
- Willink Biochemical Genetics Unit, Genomic Diagnostics Laboratory, Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
| | - Heather J Church
- Willink Biochemical Genetics Unit, Genomic Diagnostics Laboratory, Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - J Paul Luzio
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, Wellcome Trust/MRC Building, University of Cambridge, Cambridge, UK
| | - Timothy M Cox
- Department of Medicine, University of Cambridge, Cambridge, UK
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Yang X, Liao CY, Tang J, Bassham DC. Overexpression of trans-Golgi network t-SNAREs rescues vacuolar trafficking and TGN morphology defects in a putative tethering factor mutant. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 99:703-716. [PMID: 31009161 DOI: 10.1111/tpj.14353] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 03/25/2019] [Accepted: 04/17/2019] [Indexed: 06/09/2023]
Abstract
The trans-Golgi network (TGN) is a major site for sorting of cargo to either the vacuole or apoplast. The TGN-localized coiled-coil protein TNO1 is a putative tethering factor that interacts with the TGN t-SNARE SYP41 and is required for correct localization of the SYP61 t-SNARE. An Arabidopsis thaliana tno1 mutant is hypersensitive to salt stress and partially mislocalizes vacuolar proteins to the apoplast, indicating a role in vacuolar trafficking. Here, we show that overexpression of SYP41 or SYP61 significantly increases SYP41-SYP61 complex formation in a tno1 mutant, and rescues the salt sensitivity and defective vacuolar trafficking of the tno1 mutant. The TGN is disrupted and vesicle budding from Golgi cisternae is reduced in the tno1 mutant, and these defects are also rescued by overexpression of SYP41 or SYP61. Our results suggest that the trafficking and Golgi morphology defects caused by loss of TNO1 can be rescued by increasing SYP41-SYP61 t-SNARE complex formation, implicating TNO1 as a tethering factor mediating efficient vesicle fusion at the TGN.
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Affiliation(s)
- Xiaochen Yang
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, 50011, USA
| | - Ching-Yi Liao
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, 50011, USA
| | - Jie Tang
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, 50011, USA
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, 50011, USA
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He D, Xia B, Zhou Q, Wang L, Huang X. Rare earth elements regulate the endocytosis and DNA methylation in root cells of Arabidopsis thaliana. CHEMOSPHERE 2019; 227:522-532. [PMID: 31004819 DOI: 10.1016/j.chemosphere.2019.04.076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 03/30/2019] [Accepted: 04/10/2019] [Indexed: 06/09/2023]
Abstract
With increasing application of rare earth elements (REEs), the resulting environmental safety has attracted extensive attention. When REEs act on plant leaves, REEs can initiate endocytosis in leaf cells, causing more REEs enter plant cells and then severe damage to plants. But when REEs directly act on plant roots, whether and how REEs affect the endocytosis in root cells remain unknown. Here, we characterized effects of lanthanum [La(III)], a REE with high accumulation in environment, on the endocytosis in root cells of Arabidopsis thaliana, and revealed effect mechanism from the perspective of DNA methylation. We found that La(III) enhanced the endocytosis in root cells and the extent of enhancement depended on the dose and time of La(III) exposure: 160 μM > 80 μM >30 μM (12 h); 80 μM > 30 μM >160 μM (24 h); 24 h > 12 h. La(III)-enhanced endocytosis in root cells resulted from DNA methylation, which was closely related to the expression level of genes encoding DNA methylases/demethylases: CMT3, DRM2 and DNMT2 for 12 h, MET1, CMT1, CMT2, CMT3, DRM2, DNMT2, ROS1, DME, DML2, DML5a, and DML5b for 24 h. Conversely, enhanced endocytosis also promoted the expression level of genes encoding DNA methylases/demethylases. Our findings provide references for understanding the mechanisms by which REEs impact plants.
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Affiliation(s)
- Ding He
- State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Binxin Xia
- State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Qing Zhou
- State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Lihong Wang
- State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China.
| | - Xiaohua Huang
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, China.
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