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Meca J, Massoni-Laporte A, Martinez D, Sartorel E, Loquet A, Habenstein B, McCusker D. Avidity-driven polarity establishment via multivalent lipid-GTPase module interactions. EMBO J 2018; 38:embj.201899652. [PMID: 30559330 DOI: 10.15252/embj.201899652] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 10/26/2018] [Accepted: 11/02/2018] [Indexed: 12/17/2022] Open
Abstract
While Rho GTPases are indispensible regulators of cellular polarity, the mechanisms underlying their anisotropic activation at membranes have been elusive. Using the budding yeast Cdc42 GTPase module, which includes a guanine nucleotide exchange factor (GEF) Cdc24 and the scaffold Bem1, we find that avidity generated via multivalent anionic lipid interactions is a critical mechanistic constituent of polarity establishment. We identify basic cluster (BC) motifs in Bem1 that drive the interaction of the scaffold-GEF complex with anionic lipids at the cell pole. This interaction appears to influence lipid acyl chain ordering, thus regulating membrane rigidity and feedback between Cdc42 and the membrane environment. Sequential mutation of the Bem1 BC motifs, PX domain, and the PH domain of Cdc24 lead to a progressive loss of cellular polarity stemming from defective Cdc42 nanoclustering on the plasma membrane and perturbed signaling. Our work demonstrates the importance of avidity via multivalent anionic lipid interactions in the spatial control of GTPase activation.
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Divakara MB, Martinez D, Ravi A, Bhavana V, Ramana V, Habenstein B, Loquet A, Santosh MS. Molecular mechanisms for the destabilization of model membranes by islet amyloid polypeptide. Biophys Chem 2018; 245:34-40. [PMID: 30576976 DOI: 10.1016/j.bpc.2018.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/29/2018] [Accepted: 12/10/2018] [Indexed: 12/30/2022]
Abstract
Misfolding of human islet amyloid polypeptide (hIAPP) into insoluble aggregates is associated with Type 2 diabetes. It has been suggested that hIAPP toxicity may be due to its accumulation in pancreatic islets, causing membrane disruption and cell permeabilization, however the molecular basis underlying its lipid association are still unclear. Here, we combine solid-state NMR, fluorescence and bright field microscopy to investigate hIAPP - lipid membrane interactions. Real-time microscopy highlights a time-dependent penetration of hIAPP oligomers toward the most buried layers of the lipid vesicles until the membrane disrupts. Deuterium NMR was conducted on liposomes at different hIAPP concentration to probe lipid internal order and thermotropism. The gel-to-fluid phase transition of the lipids is decreased by the presence of hIAPP, and site-specific analysis of the order parameter showed a significant increase of lipid order for the first eight positions of the acyl chain, suggesting a partial insertion of the peptide inside the bilayer. These results offer experimental insight into the membrane destabilization of hIAPP on model membrane vesicles.
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Tolchard J, Pandey MK, Berbon M, Noubhani A, Saupe SJ, Nishiyama Y, Habenstein B, Loquet A. Detection of side-chain proton resonances of fully protonated biosolids in nano-litre volumes by magic angle spinning solid-state NMR. JOURNAL OF BIOMOLECULAR NMR 2018; 70:177-185. [PMID: 29502224 DOI: 10.1007/s10858-018-0168-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 02/16/2018] [Indexed: 06/08/2023]
Abstract
We present a new solid-state NMR proton-detected three-dimensional experiment dedicated to the observation of protein proton side chain resonances in nano-liter volumes. The experiment takes advantage of very fast magic angle spinning and double quantum 13C-13C transfer to establish efficient (H)CCH correlations detected on side chain protons. Our approach is demonstrated on the HET-s prion domain in its functional amyloid fibrillar form, fully protonated, with a sample amount of less than 500 µg using a MAS frequency of 70 kHz. The majority of aliphatic and aromatic side chain protons (70%) are observable, in addition to Hα resonances, in a single experiment providing a complementary approach to the established proton-detected amide-based multidimensional solid-state NMR experiments for the study and resonance assignment of biosolid samples, in particular for aromatic side chain resonances.
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Martinez D, Legrand A, Gronnier J, Decossas M, Gouguet P, Lambert O, Berbon M, Verron L, Grélard A, Germain V, Loquet A, Mongrand S, Habenstein B. Coiled-coil oligomerization controls localization of the plasma membrane REMORINs. J Struct Biol 2018; 206:12-19. [PMID: 29481850 DOI: 10.1016/j.jsb.2018.02.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 01/25/2018] [Accepted: 02/12/2018] [Indexed: 12/20/2022]
Abstract
REMORINs are nanodomain-organized proteins located in the plasma membrane and involved in cellular responses in plants. The dynamic assembly of the membrane nanodomains represents an essential tool of the versatile membrane barriers to control and modulate cellular functions. Nevertheless, the assembly mechanisms and protein organization strategies of nanodomains are poorly understood and many structural aspects are difficult to visualize. Using an ensemble of biophysical approaches, including solid-state nuclear magnetic resonance, cryo-electron microscopy and in vivo confocal imaging, we provide first insights on the role and the structural mechanisms of REMORIN trimerization. Our results suggest that the formation of REMORIN coiled-coil trimers is essential for membrane recruitment and promotes REMORIN assembly in vitro into long filaments by trimer-trimer interactions that might participate in nanoclustering into membrane domains in vivo.
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Martinez D, Decossas M, Kowal J, Frey L, Stahlberg H, Dufourc EJ, Riek R, Habenstein B, Bibow S, Loquet A. Cover Feature: Lipid Internal Dynamics Probed in Nanodiscs (ChemPhysChem 19/2017). Chemphyschem 2017. [DOI: 10.1002/cphc.201701006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Martinez D, Decossas M, Kowal J, Frey L, Stahlberg H, Dufourc EJ, Riek R, Habenstein B, Bibow S, Loquet A. Lipid Internal Dynamics Probed in Nanodiscs. Chemphyschem 2017; 18:2651-2657. [PMID: 28573816 PMCID: PMC5697661 DOI: 10.1002/cphc.201700450] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Indexed: 11/29/2022]
Abstract
Nanodiscs offer a very promising tool to incorporate membrane proteins into native-like lipid bilayers and an alternative to liposomes to maintain protein functions and protein-lipid interactions in a soluble nanoscale object. The activity of the incorporated membrane protein appears to be correlated to its dynamics in the lipid bilayer and by protein-lipid interactions. These two parameters depend on the lipid internal dynamics surrounded by the lipid-encircling discoidal scaffold protein that might differ from more unrestricted lipid bilayers observed in vesicles or cellular extracts. A solid-state NMR spectroscopy investigation of lipid internal dynamics and thermotropism in nanodiscs is reported. The gel-to-fluid phase transition is almost abolished for nanodiscs, which maintain lipid fluid properties for a large temperature range. The addition of cholesterol allows fine-tuning of the internal bilayer dynamics by increasing chain ordering. Increased site-specific order parameters along the acyl chain reflect a higher internal ordering in nanodiscs compared with liposomes at room temperature; this is induced by the scaffold protein, which restricts lipid diffusion in the nanodisc area.
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Loquet A, Tolchard J, Berbon M, Martinez D, Habenstein B. Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy. J Vis Exp 2017:55779. [PMID: 28994783 PMCID: PMC5752270 DOI: 10.3791/55779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Supramolecular protein assemblies play fundamental roles in biological processes ranging from host-pathogen interaction, viral infection to the propagation of neurodegenerative disorders. Such assemblies consist in multiple protein subunits organized in a non-covalent way to form large macromolecular objects that can execute a variety of cellular functions or cause detrimental consequences. Atomic insights into the assembly mechanisms and the functioning of those macromolecular assemblies remain often scarce since their inherent insolubility and non-crystallinity often drastically reduces the quality of the data obtained from most techniques used in structural biology, such as X-ray crystallography and solution Nuclear Magnetic Resonance (NMR). We here present magic-angle spinning solid-state NMR spectroscopy (SSNMR) as a powerful method to investigate structures of macromolecular assemblies at atomic resolution. SSNMR can reveal atomic details on the assembled complex without size and solubility limitations. The protocol presented here describes the essential steps from the production of 13C/15N isotope-labeled macromolecular protein assemblies to the acquisition of standard SSNMR spectra and their analysis and interpretation. As an example, we show the pipeline of a SSNMR structural analysis of a filamentous protein assembly.
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Gronnier J, Crowet JM, Habenstein B, Nasir MN, Bayle V, Hosy E, Platre MP, Gouguet P, Raffaele S, Martinez D, Grelard A, Loquet A, Simon-Plas F, Gerbeau-Pissot P, Der C, Bayer EM, Jaillais Y, Deleu M, Germain V, Lins L, Mongrand S. Structural basis for plant plasma membrane protein dynamics and organization into functional nanodomains. eLife 2017; 6:e26404. [PMID: 28758890 PMCID: PMC5536944 DOI: 10.7554/elife.26404] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 07/13/2017] [Indexed: 12/31/2022] Open
Abstract
Plasma Membrane is the primary structure for adjusting to ever changing conditions. PM sub-compartmentalization in domains is thought to orchestrate signaling. Yet, mechanisms governing membrane organization are mostly uncharacterized. The plant-specific REMORINs are proteins regulating hormonal crosstalk and host invasion. REMs are the best-characterized nanodomain markers via an uncharacterized moiety called REMORIN C-terminal Anchor. By coupling biophysical methods, super-resolution microscopy and physiology, we decipher an original mechanism regulating the dynamic and organization of nanodomains. We showed that targeting of REMORIN is independent of the COP-II-dependent secretory pathway and mediated by PI4P and sterol. REM-CA is an unconventional lipid-binding motif that confers nanodomain organization. Analyses of REM-CA mutants by single particle tracking demonstrate that mobility and supramolecular organization are critical for immunity. This study provides a unique mechanistic insight into how the tight control of spatial segregation is critical in the definition of PM domain necessary to support biological function.
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Xiang S, Kulminskaya N, Habenstein B, Biernat J, Tepper K, Paulat M, Griesinger C, Becker S, Lange A, Mandelkow E, Linser R. A Two-Component Adhesive: Tau Fibrils Arise from a Combination of a Well-Defined Motif and Conformationally Flexible Interactions. J Am Chem Soc 2017; 139:2639-2646. [PMID: 28124562 DOI: 10.1021/jacs.6b09619] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Fibrillar aggregates of Aβ and Tau in the brain are the major hallmarks of Alzheimer's disease. Most Tau fibers have a twisted appearance, but the twist can be variable and even absent. This ambiguity, which has also been associated with different phenotypes of tauopathies, has led to controversial assumptions about fibril constitution, and it is unclear to-date what the molecular causes of this polymorphism are. To tackle this question, we used solid-state NMR strategies providing assignments of non-seeded three-repeat-domain Tau3RD with an inherent heterogeneity. This is in contrast to the general approach to characterize the most homogeneous preparations by construct truncation or intricate seeding protocols. Here, carbon and nitrogen chemical-shift conservation between fibrils revealed invariable secondary-structure properties, however, with inter-monomer interactions variable among samples. Residues with variable amide shifts are localized mostly to N- and C-terminal regions within the rigid beta structure in the repeat region of Tau3RD. By contrast, the hexapeptide motif in repeat R3, a crucial motif for fibril formation, shows strikingly low variability of all NMR parameters: Starting as a nucleation site for monomer-monomer contacts, this six-residue sequence element also turns into a well-defined structural element upon fibril formation. Given the absence of external causes in vitro, the interplay of structurally differently conserved elements in this protein likely reflects an intrinsic property of Tau fibrils.
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Habenstein B, Loquet A. Erratum to: Bacterial Filamentous Appendages Investigated by Solid-State NMR Spectroscopy. Methods Mol Biol 2017; 1615:E1. [PMID: 29446058 DOI: 10.1007/978-1-4939-7033-9_37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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Stanek J, Andreas LB, Jaudzems K, Cala D, Lalli D, Bertarello A, Schubeis T, Akopjana I, Kotelovica S, Tars K, Pica A, Leone S, Picone D, Xu ZQ, Dixon NE, Martinez D, Berbon M, Mammeri NE, Noubhani A, Saupe S, Habenstein B, Loquet A, Pintacuda G. Frontispiz: Zuordnung der Rückgrat- und Seitenketten-Protonen in vollständig protonierten Proteinen durch Festkörper-NMR-Spektroskopie: Mikrokristalle, Sedimente und Amyloidfibrillen. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201685061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Stanek J, Andreas LB, Jaudzems K, Cala D, Lalli D, Bertarello A, Schubeis T, Akopjana I, Kotelovica S, Tars K, Pica A, Leone S, Picone D, Xu ZQ, Dixon NE, Martinez D, Berbon M, El Mammeri N, Noubhani A, Saupe S, Habenstein B, Loquet A, Pintacuda G. Frontispiece: NMR Spectroscopic Assignment of Backbone and Side-Chain Protons in Fully Protonated Proteins: Microcrystals, Sedimented Assemblies, and Amyloid Fibrils. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/anie.201685061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Stanek J, Andreas LB, Jaudzems K, Cala D, Lalli D, Bertarello A, Schubeis T, Akopjana I, Kotelovica S, Tars K, Pica A, Leone S, Picone D, Xu ZQ, Dixon NE, Martinez D, Berbon M, Mammeri NE, Noubhani A, Saupe S, Habenstein B, Loquet A, Pintacuda G. Zuordnung der Rückgrat- und Seitenketten-Protonen in vollständig protonierten Proteinen durch Festkörper-NMR-Spektroskopie: Mikrokristalle, Sedimente und Amyloidfibrillen. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201607084] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Stanek J, Andreas LB, Jaudzems K, Cala D, Lalli D, Bertarello A, Schubeis T, Akopjana I, Kotelovica S, Tars K, Pica A, Leone S, Picone D, Xu ZQ, Dixon NE, Martinez D, Berbon M, El Mammeri N, Noubhani A, Saupe S, Habenstein B, Loquet A, Pintacuda G. NMR Spectroscopic Assignment of Backbone and Side-Chain Protons in Fully Protonated Proteins: Microcrystals, Sedimented Assemblies, and Amyloid Fibrils. Angew Chem Int Ed Engl 2016; 55:15504-15509. [DOI: 10.1002/anie.201607084] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/05/2016] [Indexed: 12/20/2022]
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Kamgar-Parsi K, Tolchard J, Habenstein B, Loquet A, Naito A, Ramamoorthy A. Structural Biology of Calcitonin: From Aqueous Therapeutic Properties to Amyloid Aggregation. Isr J Chem 2016. [DOI: 10.1002/ijch.201600096] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Habenstein B, Loquet A. Solid-state NMR: An emerging technique in structural biology of self-assemblies. Biophys Chem 2016; 210:14-26. [DOI: 10.1016/j.bpc.2015.07.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Accepted: 07/08/2015] [Indexed: 12/13/2022]
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Habenstein B, Loquet A, Hwang S, Giller K, Vasa SK, Becker S, Habeck M, Lange A. Hybrid Structure of the Type 1 Pilus of Uropathogenic Escherichia coli. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Habenstein B, Loquet A, Hwang S, Giller K, Vasa SK, Becker S, Habeck M, Lange A. Hybrid Structure of the Type 1 Pilus of Uropathogenic Escherichia coli. Angew Chem Int Ed Engl 2015; 54:11691-5. [PMID: 26267365 DOI: 10.1002/anie.201505065] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 07/16/2015] [Indexed: 12/21/2022]
Abstract
Type 1 pili are filamentous protein assemblies on the surface of Gram-negative bacteria that mediate adhesion to host cells during the infection process. The molecular structure of type 1 pili remains elusive on the atomic scale owing to their insolubility and noncrystallinity. Herein we describe an approach for hybrid-structure determination that is based on data from solution-state NMR spectroscopy on the soluble subunit and solid-state NMR spectroscopy and STEM data on the assembled pilus. Our approach is based on iterative modeling driven by structural information extracted from different sources and provides a general tool to access pseudo atomic structures of protein assemblies with complex subunit folds. By using this methodology, we determined the local conformation of the FimA pilus subunit in the context of the assembled type 1 pilus, determined the exact helical pilus architecture, and elucidated the intermolecular interfaces contributing to pilus assembly and stability with atomic detail.
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Fasshuber HK, Lakomek NA, Habenstein B, Loquet A, Shi C, Giller K, Wolff S, Becker S, Lange A. Structural heterogeneity in microcrystalline ubiquitin studied by solid-state NMR. Protein Sci 2015; 24:592-8. [PMID: 25644665 DOI: 10.1002/pro.2654] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 01/07/2023]
Abstract
By applying [1-(13) C]- and [2-(13) C]-glucose labeling schemes to the folded globular protein ubiquitin, a strong reduction of spectral crowding and increase in resolution in solid-state NMR (ssNMR) spectra could be achieved. This allowed spectral resonance assignment in a straightforward manner and the collection of a wealth of long-range distance information. A high precision solid-state NMR structure of microcrystalline ubiquitin was calculated with a backbone rmsd of 1.57 to the X-ray structure and 1.32 Å to the solution NMR structure. Interestingly, we can resolve structural heterogeneity as the presence of three slightly different conformations. Structural heterogeneity is most significant for the loop region β1-β2 but also for β-strands β1, β2, β3, and β5 as well as for the loop connecting α1 and β3. This structural polymorphism observed in the solid-state NMR spectra coincides with regions that showed dynamics in solution NMR experiments on different timescales.
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Daskalov A, Habenstein B, Martinez D, Debets AJM, Sabaté R, Loquet A, Saupe SJ. Signal transduction by a fungal NOD-like receptor based on propagation of a prion amyloid fold. PLoS Biol 2015; 13:e1002059. [PMID: 25671553 PMCID: PMC4344463 DOI: 10.1371/journal.pbio.1002059] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 12/29/2014] [Indexed: 01/09/2023] Open
Abstract
In the fungus Podospora anserina, the [Het-s] prion induces programmed cell death by activating the HET-S pore-forming protein. The HET-s β-solenoid prion fold serves as a template for converting the HET-S prion-forming domain into the same fold. This conversion, in turn, activates the HET-S pore-forming domain. The gene immediately adjacent to het-S encodes NWD2, a Nod-like receptor (NLR) with an N-terminal motif similar to the elementary repeat unit of the β-solenoid fold. NLRs are immune receptors controlling cell death and host defense processes in animals, plants and fungi. We have proposed that, analogously to [Het-s], NWD2 can activate the HET-S pore-forming protein by converting its prion-forming region into the β-solenoid fold. Here, we analyze the ability of NWD2 to induce formation of the β-solenoid prion fold. We show that artificial NWD2 variants induce formation of the [Het-s] prion, specifically in presence of their cognate ligands. The N-terminal motif is responsible for this prion induction, and mutations predicted to affect the β-solenoid fold abolish templating activity. In vitro, the N-terminal motif assembles into infectious prion amyloids that display a structure resembling the β-solenoid fold. In vivo, the assembled form of the NWD2 N-terminal region activates the HET-S pore-forming protein. This study documenting the role of the β-solenoid fold in fungal NLR function further highlights the general importance of amyloid and prion-like signaling in immunity-related cell fate pathways. The fungus Podospora anserina uses a prion amyloid fold as a signal transduction device between a Nod-like receptor and a downstream cell death execution protein. Although amyloids are best known as protein aggregates that are responsible for fatal neurodegenerative diseases, amyloid structures can also fulfill functional roles in cells. In particular, the controlled formation of amyloid structures appears to be involved in different signaling processes in the context of programmed cell death and host defense. The [Het-s] prion of the filamentous fungus Podospora anserina is a model system in which the 3-D structure of the prion form has been solved. The [Het-s] prion works as an activation switch for a second protein termed HET-S. HET-S is a pore-forming protein that is activated when the [Het-s] prion causes its C-terminal domain to adopt an amyloid-like fold. The protein encoded by the gene adjacent to het-S is a Nod-like receptor (NLR) called NWD2. NLRs are immune receptors that control host defense and cell death processes in plants, animals, and fungi. We show that NWD2 can template the formation of the [Het-s] prion fold in a ligand-controlled manner. NWD2 has an N-terminal motif homologous to the HET-S/s prion-forming region; we find that this region is both necessary and sufficient for its prion-inducing activity, and our functional and structural approaches reveal that the N-terminal region of NWD2 adopts a fold closely related to that of the HET-S/s prion. This study illustrates how the controlled formation of a prion amyloid fold can be used in a signaling process whereby a Nod-like receptor protein activates a downstream cell death execution domain.
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Luckgei N, Schütz AK, Habenstein B, Bousset L, Sourigues Y, Melki R, Meier BH, Böckmann A. Solid-state NMR sequential assignments of the amyloid core of Sup35pNM. BIOMOLECULAR NMR ASSIGNMENTS 2014; 8:365-370. [PMID: 23934139 DOI: 10.1007/s12104-013-9518-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 08/01/2013] [Indexed: 06/02/2023]
Abstract
Sup35pNM represents the N-terminal and middle (M) domains of the yeast Saccharomyces cerevisiae prion Sup35p. This fragment is commonly used for structural and functional studies of Sup35p. We here present a solid-state NMR study of fibrils formed by this fragment and show that sequential assignments can be obtained for the rigid and well-ordered parts of the protein using 3D spectroscopy. We describe in detail the sequential assignment of the 22 residues yielding strong, narrow signals with chemical shifts that correspond mostly to β-sheet secondary-structured amino acids that form the fibril core.
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Gath J, Bousset L, Habenstein B, Melki R, Meier BH, Böckmann A. Yet another polymorph of α-synuclein: solid-state sequential assignments. BIOMOLECULAR NMR ASSIGNMENTS 2014; 8:395-404. [PMID: 24114178 DOI: 10.1007/s12104-013-9526-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Accepted: 09/27/2013] [Indexed: 06/02/2023]
Abstract
Parkinson's disease is a neurological human proteinopathy, which is caused by the accumulation of protein aggregates of high molecular mass. α-Synuclein is a major component of these fibrillar, β-sheet rich, insoluble assemblies and is deposited in the form of amyloids. Structural characterization of amyloids is possible by solid-state NMR, although no atomic-resolution structure is available as of today. α-Synuclein, as many other pathology-related fibril-forming proteins, can form a number of different polymorphs that are sometimes tricky to obtain in pure form. Here, we describe the chemical shifts and secondary structure analysis of a polymorph that also adopts mainly β-sheet conformation, with a fibrillar core ranging from residues 38 to 94. In addition, residues 15-20 from the N-terminus found to be part of a rigid ordered β-sheet. The chemical shifts differ substantially from the polymorph we previously assigned.
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Schütz AK, Habenstein B, Luckgei N, Bousset L, Sourigues Y, Nielsen AB, Melki R, Böckmann A, Meier BH. Solid-state NMR sequential assignments of the amyloid core of full-length Sup35p. BIOMOLECULAR NMR ASSIGNMENTS 2014; 8:349-356. [PMID: 23943018 DOI: 10.1007/s12104-013-9515-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 08/01/2013] [Indexed: 06/02/2023]
Abstract
Sup35p is a yeast prion and is responsible for the [PSI(+)] trait in Saccharomyces cerevisiae. With 685 amino acids, full-length soluble and fibrillar Sup35p are challenging targets for structural biology as they cannot be investigated by X-ray crystallography or NMR in solution. We present solid-state NMR studies of fibrils formed by the full-length Sup35 protein. We detect an ordered and rigid core of the protein that gives rise to narrow and strong peaks, while large parts of the protein show either static disorder or dynamics on time scales which interfere with dipolar polarization transfer or shorten the coherence lifetime. Thus, only a small subset of resonances is observed in 3D spectra. Here we describe in detail the sequential assignments of the 22 residues for which resonances are observed in 3D spectra: their chemical shifts mostly corresponding to β-sheet secondary structure. We suspect that these residues form the amyloid core of the fibril.
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Chevelkov V, Habenstein B, Loquet A, Giller K, Becker S, Lange A. Proton-detected MAS NMR experiments based on dipolar transfers for backbone assignment of highly deuterated proteins. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 242:180-188. [PMID: 24667274 DOI: 10.1016/j.jmr.2014.02.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 02/19/2014] [Accepted: 02/24/2014] [Indexed: 06/03/2023]
Abstract
Proton-detected solid-state NMR was applied to a highly deuterated insoluble, non-crystalline biological assembly, the Salmonella typhimurium type iii secretion system (T3SS) needle. Spectra of very high resolution and sensitivity were obtained at a low protonation level of 10-20% at exchangeable amide positions. We developed efficient experimental protocols for resonance assignment tailored for this system and the employed experimental conditions. Using exclusively dipolar-based interspin magnetization transfers, we recorded two sets of 3D spectra allowing for an almost complete backbone resonance assignment of the needle subunit PrgI. The additional information provided by the well-resolved proton dimension revealed the presence of two sets of resonances in the N-terminal helix of PrgI, while in previous studies employing (13)C detection only a single set of resonances was observed.
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Shi C, Fasshuber HK, Chevelkov V, Xiang S, Habenstein B, Vasa SK, Becker S, Lange A. BSH-CP based 3D solid-state NMR experiments for protein resonance assignment. JOURNAL OF BIOMOLECULAR NMR 2014; 59:15-22. [PMID: 24584701 DOI: 10.1007/s10858-014-9820-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 01/20/2014] [Indexed: 05/10/2023]
Abstract
We have recently presented band-selective homonuclear cross-polarization (BSH-CP) as an efficient method for CO-CA transfer in deuterated as well as protonated solid proteins. Here we show how the BSH-CP CO-CA transfer block can be incorporated in a set of three-dimensional (3D) solid-state NMR (ssNMR) pulse schemes tailored for resonance assignment of proteins at high static magnetic fields and moderate magic-angle spinning rates. Due to the achieved excellent transfer efficiency of 33 % for BSH-CP, a complete set of 3D spectra needed for unambiguous resonance assignment could be rapidly recorded within 1 week for the model protein ubiquitin. Thus we expect that BSH-CP could replace the typically used CO-CA transfer schemes in well-established 3D ssNMR approaches for resonance assignment of solid biomolecules.
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