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D'Agostino M, Risselada HJ, Lürick A, Ungermann C, Mayer A. A tethering complex drives the terminal stage of SNARE-dependent membrane fusion. Nature 2017; 551:634-638. [PMID: 29088698 DOI: 10.1038/nature24469] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 10/03/2017] [Indexed: 11/09/2022]
Abstract
Membrane fusion in eukaryotic cells mediates the biogenesis of organelles, vesicular traffic between them, and exo- and endocytosis of important signalling molecules, such as hormones and neurotransmitters. Distinct tasks in intracellular membrane fusion have been assigned to conserved protein systems. Tethering proteins mediate the initial recognition and attachment of membranes, whereas SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) protein complexes are considered as the core fusion engine. SNARE complexes provide mechanical energy to distort membranes and drive them through a hemifusion intermediate towards the formation of a fusion pore. This last step is highly energy-demanding. Here we combine the in vivo and in vitro fusion of yeast vacuoles with molecular simulations to show that tethering proteins are critical for overcoming the final energy barrier to fusion pore formation. SNAREs alone drive vacuoles only into the hemifused state. Tethering proteins greatly increase the volume of SNARE complexes and deform the site of hemifusion, which lowers the energy barrier for pore opening and provides the driving force. Thereby, tethering proteins assume a crucial mechanical role in the terminal stage of membrane fusion that is likely to be conserved at multiple steps of vesicular traffic. We therefore propose that SNAREs and tethering proteins should be considered as a single, non-dissociable device that drives fusion. The core fusion machinery may then be larger and more complex than previously thought.
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Affiliation(s)
- Massimo D'Agostino
- Département de Biochimie, Université de Lausanne, Chemin des Boveresses 155, CH-1066 Epalinges, Switzerland
| | - Herre Jelger Risselada
- Georg-August University, Department of Theoretical Physics, Göttingen, Friedrich-Hund-Platz 1, D-37077 Göttingen, Germany.,Leibniz Institute of Surface Modification, Chemical Department, Permoserstrasse 15, D-04318, Leipzig, Germany
| | - Anna Lürick
- University of Osnabrück, Department of Biology/Chemistry, Barbarastrasse 13, D-49076 Osnabrück, Germany
| | - Christian Ungermann
- University of Osnabrück, Department of Biology/Chemistry, Barbarastrasse 13, D-49076 Osnabrück, Germany
| | - Andreas Mayer
- Département de Biochimie, Université de Lausanne, Chemin des Boveresses 155, CH-1066 Epalinges, Switzerland
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Lürick A, Gao J, Kuhlee A, Yavavli E, Langemeyer L, Perz A, Raunser S, Ungermann C. Multivalent Rab interactions determine tether-mediated membrane fusion. Mol Biol Cell 2016; 28:322-332. [PMID: 27852901 PMCID: PMC5231900 DOI: 10.1091/mbc.e16-11-0764] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 12/22/2022] Open
Abstract
Membrane fusion at endomembranes requires cross-talk between Rab GTPases and tethers to drive SNARE-mediated lipid bilayer mixing. Several tethers have multiple Rab-binding sites with largely untested function. Here we dissected the lysosomal HOPS complex as a tethering complex with just two binding sites for the Rab7-like Ypt7 protein to determine their relevance for fusion. Using tethering and fusion assays combined with HOPS mutants, we show that HOPS-dependent fusion requires both Rab-binding sites, with Vps39 being the stronger Ypt7 interactor than Vps41. The intrinsic amphipathic lipid packaging sensor (ALPS) motif within HOPS Vps41, a target of the vacuolar kinase Yck3, is dispensable for tethering and fusion but can affect tethering if phosphorylated. In combination, our data demonstrate that a multivalent tethering complex uses its two Rab bindings to determine the place of SNARE assembly and thus fusion at endomembranes.
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Affiliation(s)
- Anna Lürick
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Jieqiong Gao
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Anne Kuhlee
- Department of Physical Biochemistry, Max-Planck Institute of Molecular Physiology; 44227 Dortmund, Germany
| | - Erdal Yavavli
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Lars Langemeyer
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Angela Perz
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Stefan Raunser
- Department of Physical Biochemistry, Max-Planck Institute of Molecular Physiology; 44227 Dortmund, Germany
| | - Christian Ungermann
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
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Lürick A, Kuhlee A, Bröcker C, Kümmel D, Raunser S, Ungermann C. The Habc domain of the SNARE Vam3 interacts with the HOPS tethering complex to facilitate vacuole fusion. J Biol Chem 2015; 290:5405-13. [PMID: 25564619 DOI: 10.1074/jbc.m114.631465] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Membrane fusion at vacuoles requires a consecutive action of the HOPS tethering complex, which is recruited by the Rab GTPase Ypt7, and vacuolar SNAREs to drive membrane fusion. It is assumed that the Sec1/Munc18-like Vps33 within the HOPS complex is largely responsible for SNARE chaperoning. Here, we present direct evidence for HOPS binding to SNAREs and the Habc domain of the Vam3 SNARE protein, which may explain its function during fusion. We show that HOPS interacts strongly with the Vam3 Habc domain, assembled Q-SNAREs, and the R-SNARE Ykt6, but not the Q-SNARE Vti1 or the Vam3 SNARE domain. Electron microscopy combined with Nanogold labeling reveals that the binding sites for vacuolar SNAREs and the Habc domain are located in the large head of the HOPS complex, where Vps16 and Vps33 have been identified before. Competition experiments suggest that HOPS bound to the Habc domain can still interact with assembled Q-SNAREs, whereas Q-SNARE binding prevents recognition of the Habc domain. In agreement, membranes carrying Vam3ΔHabc fuse poorly unless an excess of HOPS is provided. These data suggest that the Habc domain of Vam3 facilitates the assembly of the HOPS/SNARE machinery at fusion sites and thus supports efficient membrane fusion.
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Affiliation(s)
- Anna Lürick
- From the Department of Biology/Chemistry, Biochemistry Section and
| | - Anne Kuhlee
- the Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Cornelia Bröcker
- From the Department of Biology/Chemistry, Biochemistry Section and
| | - Daniel Kümmel
- the Department of Biology/Chemistry, Structural Biology, University of Osnabrück, 49076 Osnabrück, Germany and
| | - Stefan Raunser
- the Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
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Behrmann H, Lürick A, Kuhlee A, Balderhaar HK, Bröcker C, Kümmel D, Engelbrecht-Vandré S, Gohlke U, Raunser S, Heinemann U, Ungermann C. Structural identification of the Vps18 β-propeller reveals a critical role in the HOPS complex stability and function. J Biol Chem 2014; 289:33503-12. [PMID: 25324549 DOI: 10.1074/jbc.m114.602714] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Membrane fusion at the vacuole, the lysosome equivalent in yeast, requires the HOPS tethering complex, which is recruited by the Rab7 GTPase Ypt7. HOPS provides a template for the assembly of SNAREs and thus likely confers fusion at a distinct position on vacuoles. Five of the six subunits in HOPS have a similar domain prediction with strong similarity to COPII subunits and nuclear porins. Here, we show that Vps18 indeed has a seven-bladed β-propeller as its N-terminal domain by revealing its structure at 2.14 Å. The Vps18 N-terminal domain can interact with the N-terminal part of Vps11 and also binds to lipids. Although deletion of the Vps18 N-terminal domain does not preclude HOPS assembly, as revealed by negative stain electron microscopy, the complex is instable and cannot support membrane fusion in vitro. We thus conclude that the β-propeller of Vps18 is required for HOPS stability and function and that it can serve as a starting point for further structural analyses of the HOPS tethering complex.
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Affiliation(s)
- Heide Behrmann
- From the Max-Delbrück Center for Molecular Medicine, Macromolecular Structure and Interaction Group, Robert-Rössle-Strasse 10, 13125 Berlin, Germany, Freie Universität Berlin, Chemistry and Biochemistry Institute, Takustrasse 6, 14195 Berlin, Germany
| | - Anna Lürick
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Anne Kuhlee
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany, and
| | - Henning Kleine Balderhaar
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Cornelia Bröcker
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Daniel Kümmel
- Department of Biology/Chemistry, Structural Biology Section, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Siegfried Engelbrecht-Vandré
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Ulrich Gohlke
- From the Max-Delbrück Center for Molecular Medicine, Macromolecular Structure and Interaction Group, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany, and
| | - Udo Heinemann
- From the Max-Delbrück Center for Molecular Medicine, Macromolecular Structure and Interaction Group, Robert-Rössle-Strasse 10, 13125 Berlin, Germany, Freie Universität Berlin, Chemistry and Biochemistry Institute, Takustrasse 6, 14195 Berlin, Germany,
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany,
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