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Klein MA, Wild K, Kišonaitė M, Sinning I. Methionine aminopeptidase 2 and its autoproteolysis product have different binding sites on the ribosome. Nat Commun 2024; 15:716. [PMID: 38267453 PMCID: PMC10808355 DOI: 10.1038/s41467-024-44862-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 01/04/2024] [Indexed: 01/26/2024] Open
Abstract
Excision of the initiator methionine is among the first co-translational processes that occur at the ribosome. While this crucial step in protein maturation is executed by two types of methionine aminopeptidases in eukaryotes (MAP1 and MAP2), additional roles in disease and translational regulation have drawn more attention to MAP2. Here, we report several cryo-EM structures of human and fungal MAP2 at the 80S ribosome. Irrespective of nascent chains, MAP2 can occupy the tunnel exit. On nascent chain displaying ribosomes, the MAP2-80S interaction is highly dynamic and the MAP2-specific N-terminal extension engages in stabilizing interactions with the long rRNA expansion segment ES27L. Loss of this extension by autoproteolytic cleavage impedes interactions at the tunnel, while promoting MAP2 to enter the ribosomal A-site, where it engages with crucial functional centers of translation. These findings reveal that proteolytic remodeling of MAP2 severely affects ribosome binding, and set the stage for targeted functional studies.
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Affiliation(s)
- Marius A Klein
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Miglė Kišonaitė
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany.
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2
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McDowell MA, Heimes M, Enkavi G, Farkas Á, Saar D, Wild K, Schwappach B, Vattulainen I, Sinning I. The GET insertase exhibits conformational plasticity and induces membrane thinning. Nat Commun 2023; 14:7355. [PMID: 37963916 PMCID: PMC10646013 DOI: 10.1038/s41467-023-42867-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 10/24/2023] [Indexed: 11/16/2023] Open
Abstract
The eukaryotic guided entry of tail-anchored proteins (GET) pathway mediates the biogenesis of tail-anchored (TA) membrane proteins at the endoplasmic reticulum. In the cytosol, the Get3 chaperone captures the TA protein substrate and delivers it to the Get1/Get2 membrane protein complex (GET insertase), which then inserts the substrate via a membrane-embedded hydrophilic groove. Here, we present structures, atomistic simulations and functional data of human and Chaetomium thermophilum Get1/Get2/Get3. The core fold of the GET insertase is conserved throughout eukaryotes, whilst thinning of the lipid bilayer occurs in the vicinity of the hydrophilic groove to presumably lower the energetic barrier of membrane insertion. We show that the gating interaction between Get2 helix α3' and Get3 drives conformational changes in both Get3 and the Get1/Get2 membrane heterotetramer. Thus, we provide a framework to understand the conformational plasticity of the GET insertase and how it remodels its membrane environment to promote substrate insertion.
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Affiliation(s)
- Melanie A McDowell
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany.
- Max Planck Institute of Biophysics, Max-von-Laue Strasse 3, 60438, Frankfurt am Main, Germany.
| | - Michael Heimes
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Giray Enkavi
- Department of Physics, University of Helsinki, P. O. Box 64, FI-00014, Helsinki, Finland
| | - Ákos Farkas
- Department of Molecular Biology, University Medical Center Göttingen, 37073, Göttingen, Germany
| | - Daniel Saar
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Blanche Schwappach
- Department of Molecular Biology, University Medical Center Göttingen, 37073, Göttingen, Germany
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, P. O. Box 64, FI-00014, Helsinki, Finland
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany.
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3
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Kišonaitė M, Wild K, Lapouge K, Gesé GV, Kellner N, Hurt E, Sinning I. Structural inventory of cotranslational protein folding by the eukaryotic RAC complex. Nat Struct Mol Biol 2023; 30:670-677. [PMID: 37081320 DOI: 10.1038/s41594-023-00973-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 03/20/2023] [Indexed: 04/22/2023]
Abstract
The challenge of nascent chain folding at the ribosome is met by the conserved ribosome-associated complex (RAC), which forms a chaperone triad with the Hsp70 protein Ssb in fungi, and consists of the non-canonical Hsp70 Ssz1 and the J domain protein Zuotin (Zuo1). Here we determine cryo-EM structures of Chaetomium thermophilum RAC bound to 80S ribosomes. RAC adopts two distinct conformations accommodating continuous ribosomal rotation by a flexible lever arm. It is held together by a tight interaction between the Ssz1 substrate-binding domain and the Zuo1 N terminus, and additional contacts between the Ssz1 nucleotide-binding domain and Zuo1 J- and Zuo1 homology domains, which form a rigid unit. The Zuo1 HPD motif conserved in J-proteins is masked in a non-canonical interaction by the Ssz1 nucleotide-binding domain, and allows the positioning of Ssb for activation by Zuo1. Overall, we provide the basis for understanding how RAC cooperates with Ssb in a dynamic nascent chain interaction and protein folding.
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Affiliation(s)
- Miglė Kišonaitė
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Karine Lapouge
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | | | - Nikola Kellner
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Ed Hurt
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany.
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4
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Soni K, Sivadas A, Horvath A, Dobrev N, Hayashi R, Kiss L, Simon B, Wild K, Sinning I, Fischer T. Mechanistic insights into RNA surveillance by the canonical poly(A) polymerase Pla1 of the MTREC complex. Nat Commun 2023; 14:772. [PMID: 36774373 PMCID: PMC9922296 DOI: 10.1038/s41467-023-36402-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 01/31/2023] [Indexed: 02/13/2023] Open
Abstract
The S. pombe orthologue of the human PAXT connection, Mtl1-Red1 Core (MTREC), is an eleven-subunit complex that targets cryptic unstable transcripts (CUTs) to the nuclear RNA exosome for degradation. It encompasses the canonical poly(A) polymerase Pla1, responsible for polyadenylation of nascent RNA transcripts as part of the cleavage and polyadenylation factor (CPF/CPSF). In this study we identify and characterise the interaction between Pla1 and the MTREC complex core component Red1 and analyse the functional relevance of this interaction in vivo. Our crystal structure of the Pla1-Red1 complex shows that a 58-residue fragment in Red1 binds to the RNA recognition motif domain of Pla1 and tethers it to the MTREC complex. Structure-based Pla1-Red1 interaction mutations show that Pla1, as part of MTREC complex, hyper-adenylates CUTs for their efficient degradation. Interestingly, the Red1-Pla1 interaction is also required for the efficient assembly of the fission yeast facultative heterochromatic islands. Together, our data suggest a complex interplay between the RNA surveillance and 3'-end processing machineries.
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Affiliation(s)
- Komal Soni
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Anusree Sivadas
- The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Attila Horvath
- The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Nikolay Dobrev
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Rippei Hayashi
- The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Leo Kiss
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Bernd Simon
- European Molecular Biology Laboratory (EMBL), Meyerhofstr, 1, D-69117, Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120, Heidelberg, Germany.
| | - Tamás Fischer
- The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia.
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5
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Kišonaitė M, Wild K, Lapouge K, Ruppert T, Sinning I. High-resolution structures of a thermophilic eukaryotic 80S ribosome reveal atomistic details of translocation. Nat Commun 2022; 13:476. [PMID: 35079002 PMCID: PMC8789840 DOI: 10.1038/s41467-022-27967-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 01/02/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractRibosomes are complex and highly conserved ribonucleoprotein assemblies catalyzing protein biosynthesis in every organism. Here we present high-resolution cryo-EM structures of the 80S ribosome from a thermophilic fungus in two rotational states, which due to increased 80S stability provide a number of mechanistic details of eukaryotic translation. We identify a universally conserved ‘nested base-triple knot’ in the 26S rRNA at the polypeptide tunnel exit with a bulged-out nucleotide that likely serves as an adaptable element for nascent chain containment and handover. We visualize the structure and dynamics of the ribosome protective factor Stm1 upon ribosomal 40S head swiveling. We describe the structural impact of a unique and essential m1acp3 Ψ 18S rRNA hyper-modification embracing the anticodon wobble-position for eukaryotic tRNA and mRNA translocation. We complete the eEF2-GTPase switch cycle describing the GDP-bound post-hydrolysis state. Taken together, our data and their integration into the structural landscape of 80S ribosomes furthers our understanding of protein biogenesis.
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Soni K, Kempf G, Manalastas-Cantos K, Hendricks A, Flemming D, Guizetti J, Simon B, Frischknecht F, Svergun DI, Wild K, Sinning I. Structural analysis of the SRP Alu domain from Plasmodium falciparum reveals a non-canonical open conformation. Commun Biol 2021; 4:600. [PMID: 34017052 PMCID: PMC8137916 DOI: 10.1038/s42003-021-02132-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 11/25/2020] [Accepted: 04/22/2021] [Indexed: 12/25/2022] Open
Abstract
The eukaryotic signal recognition particle (SRP) contains an Alu domain, which docks into the factor binding site of translating ribosomes and confers translation retardation. The canonical Alu domain consists of the SRP9/14 protein heterodimer and a tRNA-like folded Alu RNA that adopts a strictly 'closed' conformation involving a loop-loop pseudoknot. Here, we study the structure of the Alu domain from Plasmodium falciparum (PfAlu), a divergent apicomplexan protozoan that causes human malaria. Using NMR, SAXS and cryo-EM analyses, we show that, in contrast to its prokaryotic and eukaryotic counterparts, the PfAlu domain adopts an 'open' Y-shaped conformation. We show that cytoplasmic P. falciparum ribosomes are non-discriminative and recognize both the open PfAlu and closed human Alu domains with nanomolar affinity. In contrast, human ribosomes do not provide high affinity binding sites for either of the Alu domains. Our analyses extend the structural database of Alu domains to the protozoan species and reveal species-specific differences in the recognition of SRP Alu domains by ribosomes.
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Affiliation(s)
- Komal Soni
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Georg Kempf
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | | | - Astrid Hendricks
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Dirk Flemming
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Julien Guizetti
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Bernd Simon
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany.
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7
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Chiapparino A, Grbavac A, Jonker HR, Hackmann Y, Mortensen S, Zatorska E, Schott A, Stier G, Saxena K, Wild K, Schwalbe H, Strahl S, Sinning I. Functional implications of MIR domains in protein O-mannosylation. eLife 2020; 9:61189. [PMID: 33357379 PMCID: PMC7759382 DOI: 10.7554/elife.61189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022] Open
Abstract
Protein O-mannosyltransferases (PMTs) represent a conserved family of multispanning endoplasmic reticulum membrane proteins involved in glycosylation of S/T-rich protein substrates and unfolded proteins. PMTs work as dimers and contain a luminal MIR domain with a β-trefoil fold, which is susceptive for missense mutations causing α-dystroglycanopathies in humans. Here, we analyze PMT-MIR domains by an integrated structural biology approach using X-ray crystallography and NMR spectroscopy and evaluate their role in PMT function in vivo. We determine Pmt2- and Pmt3-MIR domain structures and identify two conserved mannose-binding sites, which are consistent with general β-trefoil carbohydrate-binding sites (α, β), and also a unique PMT2-subfamily exposed FKR motif. We show that conserved residues in site α influence enzyme processivity of the Pmt1-Pmt2 heterodimer in vivo. Integration of the data into the context of a Pmt1-Pmt2 structure and comparison with homologous β-trefoil – carbohydrate complexes allows for a functional description of MIR domains in protein O-mannosylation.
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Affiliation(s)
| | - Antonija Grbavac
- Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Hendrik Ra Jonker
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University, Frankfurt am Main, Germany
| | - Yvonne Hackmann
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Sofia Mortensen
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Ewa Zatorska
- Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Andrea Schott
- Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Gunter Stier
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Krishna Saxena
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University, Frankfurt am Main, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University, Frankfurt am Main, Germany
| | - Sabine Strahl
- Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
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8
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Juaire KD, Lapouge K, Becker MMM, Kotova I, Michelhans M, Carapito R, Wild K, Bahram S, Sinning I. Structural and Functional Impact of SRP54 Mutations Causing Severe Congenital Neutropenia. Structure 2020; 29:15-28.e7. [PMID: 33053321 DOI: 10.1016/j.str.2020.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/22/2020] [Accepted: 09/23/2020] [Indexed: 01/12/2023]
Abstract
The SRP54 GTPase is a key component of co-translational protein targeting by the signal recognition particle (SRP). Point mutations in SRP54 have been recently shown to lead to a form of severe congenital neutropenia displaying symptoms overlapping with those of Shwachman-Diamond syndrome. The phenotype includes severe neutropenia, exocrine pancreatic deficiency, and neurodevelopmental as well as skeletal disorders. Using a combination of X-ray crystallography, hydrogen-deuterium exchange coupled to mass spectrometry and complementary biochemical and biophysical methods, we reveal extensive structural defects in three disease-causing SRP54 variants resulting in critical protein destabilization. GTP binding is mostly abolished as a consequence of an altered GTPase core. The mutations located in conserved sequence fingerprints of SRP54 eliminate targeting complex formation with the SRP receptor as demonstrated in yeast and human cells. These specific defects critically influence the entire SRP pathway, thereby causing this life-threatening disease.
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Affiliation(s)
- Keven D Juaire
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
| | - Karine Lapouge
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
| | - Matthias M M Becker
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
| | - Irina Kotova
- BIOMICA SAS, 4 rue Boussingault, 67000 Strasbourg, France
| | - Michelle Michelhans
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
| | - Raphael Carapito
- Laboratoire d'ImmunoRhumatologie Moléculaire, plateforme GENOMAX, INSERM UMR_S 1109, Faculté de Médecine, Fédération Hospitalo-Universitaire OMICARE, Fédération de Médecine Translationnelle de Strasbourg (FMTS), LabEx TRANSPLANTEX, Université de Strasbourg, 4 rue Kirschleger, 67085 Strasbourg, France
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
| | - Seiamak Bahram
- Laboratoire d'ImmunoRhumatologie Moléculaire, plateforme GENOMAX, INSERM UMR_S 1109, Faculté de Médecine, Fédération Hospitalo-Universitaire OMICARE, Fédération de Médecine Translationnelle de Strasbourg (FMTS), LabEx TRANSPLANTEX, Université de Strasbourg, 4 rue Kirschleger, 67085 Strasbourg, France
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
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9
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Wild K, Aleksić M, Lapouge K, Juaire KD, Flemming D, Pfeffer S, Sinning I. MetAP-like Ebp1 occupies the human ribosomal tunnel exit and recruits flexible rRNA expansion segments. Nat Commun 2020; 11:776. [PMID: 32034140 PMCID: PMC7005732 DOI: 10.1038/s41467-020-14603-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [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: 09/18/2019] [Accepted: 01/20/2020] [Indexed: 12/13/2022] Open
Abstract
Human Ebp1 is a member of the proliferation-associated 2G4 (PA2G4) family and plays an important role in cancer regulation. Ebp1 shares the methionine aminopeptidase (MetAP) fold and binds to mature 80S ribosomes for translational control. Here, we present a cryo-EM single particle analysis reconstruction of Ebp1 bound to non-translating human 80S ribosomes at a resolution range from 3.3 to ~8 Å. Ebp1 blocks the tunnel exit with major interactions to the general uL23/uL29 docking site for nascent chain-associated factors complemented by eukaryote-specific eL19 and rRNA helix H59. H59 is defined as dynamic adaptor undergoing significant remodeling upon Ebp1 binding. Ebp1 recruits rRNA expansion segment ES27L to the tunnel exit via specific interactions with rRNA consensus sequences. The Ebp1-ribosome complex serves as a template for MetAP binding and provides insights into the structural principles for spatial coordination of co-translational events and molecular triage at the ribosomal tunnel exit. The ErbB3 receptor binding protein Ebp1 binds to ribosomes and is linked to translational control. Here, the authors present the cryo-EM structure of human Ebp1 bound to a non-translating 80S ribosome and find that Ebp1 blocks the tunnel exit and recruits the rRNA expansion segment ES27L to the tunnel exit.
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Affiliation(s)
- Klemens Wild
- Biochemiezentrum der Universität Heidelberg (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Milan Aleksić
- Zentrum für Molekulare Biologie der Universität Heidelberg, INF282, D-69120, Heidelberg, Germany
| | - Karine Lapouge
- Biochemiezentrum der Universität Heidelberg (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Keven D Juaire
- Biochemiezentrum der Universität Heidelberg (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Dirk Flemming
- Biochemiezentrum der Universität Heidelberg (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Stefan Pfeffer
- Zentrum für Molekulare Biologie der Universität Heidelberg, INF282, D-69120, Heidelberg, Germany.
| | - Irmgard Sinning
- Biochemiezentrum der Universität Heidelberg (BZH), INF 328, D-69120, Heidelberg, Germany.
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10
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Wild K, Juaire KD, Soni K, Shanmuganathan V, Hendricks A, Segnitz B, Beckmann R, Sinning I. Reconstitution of the human SRP system and quantitative and systematic analysis of its ribosome interactions. Nucleic Acids Res 2019; 47:3184-3196. [PMID: 30649417 PMCID: PMC6451106 DOI: 10.1093/nar/gky1324] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [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: 10/10/2018] [Revised: 12/20/2018] [Accepted: 01/02/2019] [Indexed: 12/22/2022] Open
Abstract
Co-translational protein targeting to membranes depends on the regulated interaction of two ribonucleoprotein particles (RNPs): the ribosome and the signal recognition particle (SRP). Human SRP is composed of an SRP RNA and six proteins with the SRP GTPase SRP54 forming the targeting complex with the heterodimeric SRP receptor (SRαβ) at the endoplasmic reticulum membrane. While detailed structural and functional data are available especially for the bacterial homologs, the analysis of human SRP was impeded by the unavailability of recombinant SRP. Here, we describe the large-scale production of all human SRP components and the reconstitution of homogeneous SRP and SR complexes. Binding to human ribosomes is determined by microscale thermophoresis for individual components, assembly intermediates and entire SRP, and binding affinities are correlated with structural information available for all ribosomal contacts. We show that SRP RNA does not bind to the ribosome, while SRP binds with nanomolar affinity involving a two-step mechanism of the key-player SRP54. Ultrasensitive binding of SRP68/72 indicates avidity by multiple binding sites that are dominated by the C-terminus of SRP72. Our data extend the experimental basis to understand the mechanistic principles of co-translational targeting in mammals and may guide analyses of complex RNP–RNP interactions in general.
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Affiliation(s)
- Klemens Wild
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Keven D Juaire
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Komal Soni
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Vivekanandan Shanmuganathan
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Feodor-Lynen-Str. 25, D-81377 Munich, Germany
| | - Astrid Hendricks
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Bernd Segnitz
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Roland Beckmann
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Feodor-Lynen-Str. 25, D-81377 Munich, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
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11
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Wild K, Becker MM, Kempf G, Sinning I. Structure, dynamics and interactions of large SRP variants. Biol Chem 2019; 401:63-80. [DOI: 10.1515/hsz-2019-0282] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/09/2019] [Indexed: 12/11/2022]
Abstract
Abstract
Co-translational protein targeting to membranes relies on the signal recognition particle (SRP) system consisting of a cytosolic ribonucleoprotein complex and its membrane-associated receptor. SRP recognizes N-terminal cleavable signals or signal anchor sequences, retards translation, and delivers ribosome-nascent chain complexes (RNCs) to vacant translocation channels in the target membrane. While our mechanistic understanding is well advanced for the small bacterial systems it lags behind for the large bacterial, archaeal and eukaryotic SRP variants including an Alu and an S domain. Here we describe recent advances on structural and functional insights in domain architecture, particle dynamics and interplay with RNCs and translocon and GTP-dependent regulation of co-translational protein targeting stimulated by SRP RNA.
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Affiliation(s)
- Klemens Wild
- Heidelberg University Biochemistry Center (BZH) , INF 328 , D-69120 Heidelberg , Germany
| | - Matthias M.M. Becker
- Heidelberg University Biochemistry Center (BZH) , INF 328 , D-69120 Heidelberg , Germany
| | - Georg Kempf
- Heidelberg University Biochemistry Center (BZH) , INF 328 , D-69120 Heidelberg , Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH) , INF 328 , D-69120 Heidelberg , Germany
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12
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August A, Schmidt N, Klingler J, Baumkötter F, Lechner M, Klement J, Eggert S, Vargas C, Wild K, Keller S, Kins S. Copper and zinc ions govern the trans‐directed dimerization of APP family members in multiple ways. J Neurochem 2019; 151:626-641. [DOI: 10.1111/jnc.14716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 04/29/2019] [Accepted: 04/29/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Alexander August
- Division of Human Biology and Human GeneticsTechnische Universität Kaiserslautern (TUK) Kaiserslautern Germany
| | - Nadine Schmidt
- Division of Human Biology and Human GeneticsTechnische Universität Kaiserslautern (TUK) Kaiserslautern Germany
| | - Johannes Klingler
- Molecular Biophysics Technische Universität Kaiserslautern (TUK) Kaiserslautern Germany
| | - Frederik Baumkötter
- Division of Human Biology and Human GeneticsTechnische Universität Kaiserslautern (TUK) Kaiserslautern Germany
| | - Marius Lechner
- Division of Human Biology and Human GeneticsTechnische Universität Kaiserslautern (TUK) Kaiserslautern Germany
| | - Jessica Klement
- Molecular Biophysics Technische Universität Kaiserslautern (TUK) Kaiserslautern Germany
| | - Simone Eggert
- Division of Human Biology and Human GeneticsTechnische Universität Kaiserslautern (TUK) Kaiserslautern Germany
| | - Carolyn Vargas
- Molecular Biophysics Technische Universität Kaiserslautern (TUK) Kaiserslautern Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH) University of Heidelberg Heidelberg Germany
| | - Sandro Keller
- Molecular Biophysics Technische Universität Kaiserslautern (TUK) Kaiserslautern Germany
| | - Stefan Kins
- Division of Human Biology and Human GeneticsTechnische Universität Kaiserslautern (TUK) Kaiserslautern Germany
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13
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Dodge H, Wild K, Silbert LC, Kaye JA, Asgari M, Croff R, Goodrich E. VIDEO CHAT AS A TOOL TO ENHANCE COGNITIVE RESERVE: INTRODUCTION OF A MULTI-CENTER RANDOMIZED CONTROLLED TRIAL. Innov Aging 2018. [DOI: 10.1093/geroni/igy023.3109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- H Dodge
- Oregon Health & Science University and University of Michigan, PORTLAND, Oregon, United States
| | - K Wild
- Layton Aging and Alzheimer’s Disease Center, OHSU, Portland, OR, USA
| | - L C Silbert
- Layton Aging and Alzheimer’s Disease Center, OHSU; Portland VA Medical Center Portland, OR. USA
| | - J A Kaye
- Layton Aging and Alzheimer’s Disease Center, OHSU; Portland VA Medical Center Portland, OR. USA
| | - M Asgari
- Center for Spoken Language and Understanding, OHSU, Portland, OR, USA
| | - R Croff
- Layton Aging and Alzheimer’s Disease Center, OHSU, Portland, OR
| | - E Goodrich
- Layton Aging and Alzheimer’s Disease Center, OHSU, Portland, OR
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14
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Wild K, Mattek N, Sharma N, Riley T, Kaye J. DO SUBTLE BEHAVIORAL CHANGES PREDICT INCREASED CARE NEEDS? FINDINGS FROM AN IN-HOME MONITORING TECHNOLOGY PLATFORM. Innov Aging 2018. [DOI: 10.1093/geroni/igy031.3445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- K Wild
- Oregon Health & Science University
| | - N Mattek
- Oregon Health & Science University
| | - N Sharma
- Oregon Health & Science University
| | - T Riley
- Oregon Health & Science University
| | - J Kaye
- Oregon Center for Aging & Technology (ORCATECH)
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15
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Calviño FR, Kornprobst M, Schermann G, Birkle F, Wild K, Fischer T, Hurt E, Ahmed YL, Sinning I. Structural basis for 5'-ETS recognition by Utp4 at the early stages of ribosome biogenesis. PLoS One 2017; 12:e0178752. [PMID: 28575120 PMCID: PMC5456268 DOI: 10.1371/journal.pone.0178752] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 05/18/2017] [Indexed: 11/18/2022] Open
Abstract
Eukaryotic ribosome biogenesis begins with the co-transcriptional assembly of the 90S pre-ribosome. The ‘U three protein’ (UTP) complexes and snoRNP particles arrange around the nascent pre-ribosomal RNA chaperoning its folding and further maturation. The earliest event in this hierarchical process is the binding of the UTP-A complex to the 5'-end of the pre-ribosomal RNA (5'-ETS). This oligomeric complex predominantly consists of β-propeller and α-solenoidal proteins. Here we present the structure of the Utp4 subunit from the thermophilic fungus Chaetomium thermophilum at 2.15 Å resolution and analyze its function by UV RNA-crosslinking (CRAC) and in context of a recent cryo-EM structure of the 90S pre-ribosome. Utp4 consists of two orthogonal and highly basic β-propellers that perfectly fit the EM-data. The Utp4 structure highlights an unusual Velcro-closure of its C-terminal β-propeller as relevant for protein integrity and potentially Utp8 recognition in the context of the pre-ribosome. We provide a first model of the 5'-ETS RNA from the internally hidden 5'-end up to the region that hybridizes to the 3'-hinge sequence of U3 snoRNA and validate a specific Utp4/5'-ETS interaction by CRAC analysis.
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Affiliation(s)
- Fabiola R. Calviño
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Markus Kornprobst
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Géza Schermann
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Fabienne Birkle
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Tamas Fischer
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Ed Hurt
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Yasar Luqman Ahmed
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
- * E-mail: (IS); (YLA)
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
- * E-mail: (IS); (YLA)
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16
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Feilen LP, Haubrich K, Strecker P, Probst S, Eggert S, Stier G, Sinning I, Konietzko U, Kins S, Simon B, Wild K. Fe65-PTB2 Dimerization Mimics Fe65-APP Interaction. Front Mol Neurosci 2017; 10:140. [PMID: 28553201 PMCID: PMC5425604 DOI: 10.3389/fnmol.2017.00140] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/25/2017] [Indexed: 01/21/2023] Open
Abstract
Physiological function and pathology of the Alzheimer’s disease causing amyloid precursor protein (APP) are correlated with its cytosolic adaptor Fe65 encompassing a WW and two phosphotyrosine-binding domains (PTBs). The C-terminal Fe65-PTB2 binds a large portion of the APP intracellular domain (AICD) including the GYENPTY internalization sequence fingerprint. AICD binding to Fe65-PTB2 opens an intra-molecular interaction causing a structural change and altering Fe65 activity. Here we show that in the absence of the AICD, Fe65-PTB2 forms a homodimer in solution and determine its crystal structure at 2.6 Å resolution. Dimerization involves the unwinding of a C-terminal α-helix that mimics binding of the AICD internalization sequence, thus shielding the hydrophobic binding pocket. Specific dimer formation is validated by nuclear magnetic resonance (NMR) techniques and cell-based analyses reveal that Fe65-PTB2 together with the WW domain are necessary and sufficient for dimerization. Together, our data demonstrate that Fe65 dimerizes via its APP interaction site, suggesting that besides intra- also intermolecular interactions between Fe65 molecules contribute to homeostatic regulation of APP mediated signaling.
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Affiliation(s)
- Lukas P Feilen
- Heidelberg University Biochemistry Center (BZH), University of HeidelbergHeidelberg, Germany
| | - Kevin Haubrich
- Heidelberg University Biochemistry Center (BZH), University of HeidelbergHeidelberg, Germany.,European Molecular Biology Laboratory (EMBL), Structural and Computational BiologyHeidelberg, Germany
| | - Paul Strecker
- Division of Human Biology and Human Genetics, University of KaiserslauternKaiserslautern, Germany
| | - Sabine Probst
- Institute for Regenerative Medicine (IREM), University of ZurichZurich, Switzerland
| | - Simone Eggert
- Division of Human Biology and Human Genetics, University of KaiserslauternKaiserslautern, Germany
| | - Gunter Stier
- Heidelberg University Biochemistry Center (BZH), University of HeidelbergHeidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), University of HeidelbergHeidelberg, Germany
| | - Uwe Konietzko
- Institute for Regenerative Medicine (IREM), University of ZurichZurich, Switzerland
| | - Stefan Kins
- Division of Human Biology and Human Genetics, University of KaiserslauternKaiserslautern, Germany
| | - Bernd Simon
- European Molecular Biology Laboratory (EMBL), Structural and Computational BiologyHeidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), University of HeidelbergHeidelberg, Germany
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17
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Wild K, August A, Pietrzik CU, Kins S. Structure and Synaptic Function of Metal Binding to the Amyloid Precursor Protein and its Proteolytic Fragments. Front Mol Neurosci 2017; 10:21. [PMID: 28197076 PMCID: PMC5281630 DOI: 10.3389/fnmol.2017.00021] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/16/2017] [Indexed: 12/19/2022] Open
Abstract
Alzheimer’s disease (AD) is ultimately linked to the amyloid precursor protein (APP). However, current research reveals an important synaptic function of APP and APP-like proteins (APLP1 and 2). In this context various neurotrophic and neuroprotective functions have been reported for the APP proteolytic fragments sAPPα, sAPPβ and the monomeric amyloid-beta peptide (Aβ). APP is a metalloprotein and binds copper and zinc ions. Synaptic activity correlates with a release of these ions into the synaptic cleft and dysregulation of their homeostasis is linked to different neurodegenerative diseases. Metal binding to APP or its fragments affects its structure and its proteolytic cleavage and therefore its physiological function at the synapse. Here, we summarize the current data supporting this hypothesis and provide a model of how these different mechanisms might be intertwined with each other.
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Affiliation(s)
- Klemens Wild
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg Heidelberg, Germany
| | - Alexander August
- Division of Human Biology and Human Genetics, Technical University of Kaiserslautern Kaiserslautern, Germany
| | - Claus U Pietrzik
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University Mainz Mainz, Germany
| | - Stefan Kins
- Division of Human Biology and Human Genetics, Technical University of Kaiserslautern Kaiserslautern, Germany
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18
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Becker MMM, Lapouge K, Segnitz B, Wild K, Sinning I. Structures of human SRP72 complexes provide insights into SRP RNA remodeling and ribosome interaction. Nucleic Acids Res 2016; 45:470-481. [PMID: 27899666 PMCID: PMC5224484 DOI: 10.1093/nar/gkw1124] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [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: 09/23/2016] [Revised: 10/21/2016] [Accepted: 10/28/2016] [Indexed: 12/30/2022] Open
Abstract
Co-translational protein targeting and membrane protein insertion is a fundamental process and depends on the signal recognition particle (SRP). In mammals, SRP is composed of the SRP RNA crucial for SRP assembly and function and six proteins. The two largest proteins SRP68 and SRP72 form a heterodimer and bind to a regulatory site of the SRP RNA. Despite their essential roles in the SRP pathway, structural information has been available only for the SRP68 RNA-binding domain (RBD). Here we present the crystal structures of the SRP68 protein-binding domain (PBD) in complex with SRP72-PBD and of the SRP72-RBD bound to the SRP S domain (SRP RNA, SRP19 and SRP68) detailing all interactions of SRP72 within SRP. The SRP72-PBD is a tetratricopeptide repeat, which binds an extended linear motif of SRP68 with high affinity. The SRP72-RBD is a flexible peptide crawling along the 5e- and 5f-loops of SRP RNA. A conserved tryptophan inserts into the 5e-loop forming a novel type of RNA kink-turn stabilized by a potassium ion, which we define as K+-turn. In addition, SRP72-RBD remodels the 5f-loop involved in ribosome binding and visualizes SRP RNA plasticity. Docking of the S domain structure into cryo-electron microscopy density maps reveals multiple contact sites between SRP68/72 and the ribosome, and explains the role of SRP72 in the SRP pathway.
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Affiliation(s)
- Matthias M M Becker
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
| | - Karine Lapouge
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
| | - Bernd Segnitz
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
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19
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Wild K, Bange G, Motiejunas D, Kribelbauer J, Hendricks A, Segnitz B, Wade RC, Sinning I. Structural Basis for Conserved Regulation and Adaptation of the Signal Recognition Particle Targeting Complex. J Mol Biol 2016; 428:2880-97. [PMID: 27241309 DOI: 10.1016/j.jmb.2016.05.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 05/13/2016] [Accepted: 05/18/2016] [Indexed: 12/25/2022]
Abstract
The signal recognition particle (SRP) is a ribonucleoprotein complex with a key role in targeting and insertion of membrane proteins. The two SRP GTPases, SRP54 (Ffh in bacteria) and FtsY (SRα in eukaryotes), form the core of the targeting complex (TC) regulating the SRP cycle. The architecture of the TC and its stimulation by RNA has been described for the bacterial SRP system while this information is lacking for other domains of life. Here, we present the crystal structures of the GTPase heterodimers of archaeal (Sulfolobus solfataricus), eukaryotic (Homo sapiens), and chloroplast (Arabidopsis thaliana) SRP systems. The comprehensive structural comparison combined with Brownian dynamics simulations of TC formation allows for the description of the general blueprint and of specific adaptations of the quasi-symmetric heterodimer. Our work defines conserved external nucleotide-binding sites for SRP GTPase activation by RNA. Structural analyses of the GDP-bound, post-hydrolysis states reveal a conserved, magnesium-sensitive switch within the I-box. Overall, we provide a general model for SRP cycle regulation by RNA.
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Affiliation(s)
- Klemens Wild
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Gert Bange
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Domantas Motiejunas
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg, Germany
| | - Judith Kribelbauer
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Astrid Hendricks
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Bernd Segnitz
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Rebecca C Wade
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg, Germany; Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, INF 282, 69120 Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany.
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20
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Horn A, Hennig J, Ahmed YL, Stier G, Wild K, Sattler M, Sinning I. Structural basis for cpSRP43 chromodomain selectivity and dynamics in Alb3 insertase interaction. Nat Commun 2015; 6:8875. [PMID: 26568381 PMCID: PMC4660199 DOI: 10.1038/ncomms9875] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [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: 07/03/2015] [Accepted: 10/12/2015] [Indexed: 01/21/2023] Open
Abstract
Canonical membrane protein biogenesis requires co-translational delivery of ribosome-associated proteins to the Sec translocase and depends on the signal recognition particle (SRP) and its receptor (SR). In contrast, high-throughput delivery of abundant light-harvesting chlorophyll a,b-binding proteins (LHCPs) in chloroplasts to the Alb3 insertase occurs post-translationally via a soluble transit complex including the cpSRP43/cpSRP54 heterodimer (cpSRP). Here we describe the molecular mechanisms of tethering cpSRP to the Alb3 insertase by specific interaction of cpSRP43 chromodomain 3 with a linear motif in the Alb3 C-terminal tail. Combining NMR spectroscopy, X-ray crystallography and biochemical analyses, we dissect the structural basis for selectivity of chromodomains 2 and 3 for their respective ligands cpSRP54 and Alb3, respectively. Negative cooperativity in ligand binding can be explained by dynamics in the chromodomain interface. Our study provides a model for membrane recruitment of the transit complex and may serve as a prototype for a functional gain by the tandem arrangement of chromodomains. The chloroplast signal recognition particle delivers LHCPs to the thylakoid membrane by interaction of cpSRP43 with the Alb3 insertase. Here the authors decipher the specific recognition of the Alb3 C-terminal tail within the interface of two communicating chromodomains by structural biochemistry.
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Affiliation(s)
- Annemarie Horn
- Heidelberg University Biochemistry Center (BZH), INF 328, Heidelberg D-69120, Germany
| | - Janosch Hennig
- Center for Integrated Protein Science Munich at Biomolecular NMR Spectroscopy, Department Chemie, Technische Universität München, Lichtenbergstrasse 4, Garching DE-85747, Germany.,Institute of Structural Biology, Helmholtz Center Munich, Ingolstädter Landstrasse 1, Neuherberg D-85764, Germany
| | - Yasar L Ahmed
- Heidelberg University Biochemistry Center (BZH), INF 328, Heidelberg D-69120, Germany
| | - Gunter Stier
- Heidelberg University Biochemistry Center (BZH), INF 328, Heidelberg D-69120, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), INF 328, Heidelberg D-69120, Germany
| | - Michael Sattler
- Center for Integrated Protein Science Munich at Biomolecular NMR Spectroscopy, Department Chemie, Technische Universität München, Lichtenbergstrasse 4, Garching DE-85747, Germany.,Institute of Structural Biology, Helmholtz Center Munich, Ingolstädter Landstrasse 1, Neuherberg D-85764, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), INF 328, Heidelberg D-69120, Germany
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21
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Abstract
More than one third of the cellular proteome is destined for incorporation into cell membranes or export from the cell. In all domains of life, the signal recognition particle (SRP) delivers these proteins to the membrane and protein traffic falls apart without SRP logistics. With the aid of a topogenic transport signal, SRP retrieves its cargo right at the ribosome, from where they are sorted to the translocation channel. Mammalian SRP is a ribonucleoprotein complex consisting of an SRP RNA of 300 nucleotides and 6 proteins bound to it. Assembly occurs in a hierarchical manner mainly in the nucleolus and only SRP54, which recognizes the signal sequence and regulates the targeting process, is added as the last component in the cytosol. Here we present an update on recent insights in the structure, function and dynamics of SRP RNA in SRP assembly with focus on the S domain, and present SRP as an example for the complex biogenesis of a rather small ribonucleoprotein particle.
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Affiliation(s)
- Klemens Wild
- a Heidelberg University Biochemistry Center (BZH) ; Heidelberg , Germany
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22
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Wild K, Kempf G, Grotwinkel JT, Segnitz B, Sinning I. When RNP meets RNP: the signal recognition particle and the ribosome. Acta Crystallogr A Found Adv 2015. [DOI: 10.1107/s2053273315099490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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23
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Kharde S, Calviño FR, Gumiero A, Wild K, Sinning I. The structure of Rpf2-Rrs1 explains its role in ribosome biogenesis. Nucleic Acids Res 2015; 43:7083-95. [PMID: 26117542 PMCID: PMC4538828 DOI: 10.1093/nar/gkv640] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [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: 04/24/2015] [Accepted: 06/07/2015] [Indexed: 12/02/2022] Open
Abstract
The assembly of eukaryotic ribosomes is a hierarchical process involving about 200 biogenesis factors and a series of remodeling steps. The 5S RNP consisting of the 5S rRNA, RpL5 and RpL11 is recruited at an early stage, but has to rearrange during maturation of the pre-60S ribosomal subunit. Rpf2 and Rrs1 have been implicated in 5S RNP biogenesis, but their precise role was unclear. Here, we present the crystal structure of the Rpf2–Rrs1 complex from Aspergillus nidulans at 1.5 Å resolution and describe it as Brix domain of Rpf2 completed by Rrs1 to form two anticodon-binding domains with functionally important tails. Fitting the X-ray structure into the cryo-EM density of a previously described pre-60S particle correlates with biochemical data. The heterodimer forms specific contacts with the 5S rRNA, RpL5 and the biogenesis factor Rsa4. The flexible protein tails of Rpf2–Rrs1 localize to the central protuberance. Two helices in the Rrs1 C-terminal tail occupy a strategic position to block the rotation of 25S rRNA and the 5S RNP. Our data provide a structural model for 5S RNP recruitment to the pre-60S particle and explain why removal of Rpf2–Rrs1 is necessary for rearrangements to drive 60S maturation.
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Affiliation(s)
- Satyavati Kharde
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Fabiola R Calviño
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Andrea Gumiero
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
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24
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Müller HM, Steringer JP, Wegehingel S, Bleicken S, Münster M, Dimou E, Unger S, Weidmann G, Andreas H, García-Sáez AJ, Wild K, Sinning I, Nickel W. Formation of disulfide bridges drives oligomerization, membrane pore formation, and translocation of fibroblast growth factor 2 to cell surfaces. J Biol Chem 2015; 290:8925-37. [PMID: 25694424 DOI: 10.1074/jbc.m114.622456] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Indexed: 11/06/2022] Open
Abstract
Fibroblast growth factor 2 (FGF2) is a key signaling molecule in tumor-induced angiogenesis. FGF2 is secreted by an unconventional secretory mechanism that involves phosphatidylinositol 4,5-bisphosphate-dependent insertion of FGF2 oligomers into the plasma membrane. This process is regulated by Tec kinase-mediated tyrosine phosphorylation of FGF2. Molecular interactions driving FGF2 monomers into membrane-inserted FGF2 oligomers are unknown. Here we identify two surface cysteines that are critical for efficient unconventional secretion of FGF2. They represent unique features of FGF2 as they are absent from all signal-peptide-containing members of the FGF protein family. We show that phosphatidylinositol 4,5-bisphosphate-dependent FGF2 oligomerization concomitant with the generation of membrane pores depends on FGF2 surface cysteines as either chemical alkylation or substitution with alanines impairs these processes. We further demonstrate that the FGF2 variant forms lacking the two surface cysteines are not secreted from cells. These findings were corroborated by experiments redirecting a signal-peptide-containing FGF family member from the endoplasmic reticulum/Golgi-dependent secretory pathway into the unconventional secretory pathway of FGF2. Cis elements known to be required for unconventional secretion of FGF2, including the two surface cysteines, were transplanted into a variant form of FGF4 without signal peptide. The resulting FGF4/2 hybrid protein was secreted by unconventional means. We propose that the formation of disulfide bridges drives membrane insertion of FGF2 oligomers as intermediates in unconventional secretion of FGF2.
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Affiliation(s)
- Hans-Michael Müller
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Julia P Steringer
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Sabine Wegehingel
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Stephanie Bleicken
- Interfaculty Institute for Biochemistry, University of Tübingen, 72076 Tübingen, Germany, and Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
| | - Maximilian Münster
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Eleni Dimou
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Sebastian Unger
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Georg Weidmann
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Helena Andreas
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Ana J García-Sáez
- Interfaculty Institute for Biochemistry, University of Tübingen, 72076 Tübingen, Germany, and Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
| | - Klemens Wild
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Irmgard Sinning
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Walter Nickel
- From the Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany,
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25
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Abstract
The Alu domain of the signal recognition particle (SRP) arrests protein biosynthesis by competition with elongation factor binding on the ribosome. The mammalian Alu domain is a protein-RNA complex, while prokaryotic Alu domains are protein-free with significant extensions of the RNA. Here we report the crystal structure of the complete Alu domain of Bacillus subtilis SRP RNA at 2.5 Å resolution. The bacterial Alu RNA reveals a compact fold, which is stabilized by prokaryote-specific extensions and interactions. In this 'closed' conformation, the 5' and 3' regions are clamped together by the additional helix 1, the connecting 3-way junction and a novel minor groove interaction, which we term the 'minor-saddle motif' (MSM). The 5' region includes an extended loop-loop pseudoknot made of five consecutive Watson-Crick base pairs. Homology modeling with the human Alu domain in context of the ribosome shows that an additional lobe in the pseudoknot approaches the large subunit, while the absence of protein results in the detachment from the small subunit. Our findings provide the structural basis for purely RNA-driven elongation arrest in prokaryotes, and give insights into the structural adaption of SRP RNA during evolution.
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Affiliation(s)
- Georg Kempf
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
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Xu C, Shi L, Rao S, King C, Sun H, Zhu D, Lehto S, Wild K, Immke D. EHMTI-0315. AMG 334, the first potent and selective human monoclonal antibody antagonist against the CGRP receptor. J Headache Pain 2014. [PMCID: PMC4182181 DOI: 10.1186/1129-2377-15-s1-g43] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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27
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Wild K, Kempf G, Grotwinkel J, Sinning I. The many faces of SRP RNA. Acta Crystallogr A Found Adv 2014. [DOI: 10.1107/s2053273314081868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The signal recognition particle (SRP) is a ribonucleoprotein complex that plays an essential role in co-translational targeting of membrane proteins. It is found in all three domains of life and exhibits a high diversity regarding composition and structure. In most organisms, SRP can be divided into two functional domains. The S domain mediates recognition and transport of ribosome-nascent chain complexes to the translocation channel, while the Alu domain stalls elongation of the ribosome until the complex has been faithfully delivered._x000B_Here we present the crystal structures of the complete bacterial SRP Alu domain and the ternary complex of human SRP S domain RNA, SRP19, and the SRP68-RBD. Together with previous structures, our data underline the taxon-specific evolutionary adaptation of SRP RNA that has important implications in SRP-mediated targeting.
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28
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Abstract
The signal recognition particle (SRP) is central to membrane protein targeting; SRP RNA is essential for SRP assembly, elongation arrest, and activation of SRP guanosine triphosphatases. In eukaryotes, SRP function relies on the SRP68-SRP72 heterodimer. We present the crystal structures of the RNA-binding domain of SRP68 (SRP68-RBD) alone and in complex with SRP RNA and SRP19. SRP68-RBD is a tetratricopeptide-like module that binds to a RNA three-way junction, bends the RNA, and inserts an α-helical arginine-rich motif (ARM) into the major groove. The ARM opens the conserved 5f RNA loop, which in ribosome-bound SRP establishes a contact to ribosomal RNA. Our data provide the structural basis for eukaryote-specific, SRP68-driven RNA remodeling required for protein translocation.
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Affiliation(s)
- Jan Timo Grotwinkel
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
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Dietl A, Wild K, Simon B. ¹H, ¹³C, and ¹⁵N chemical shift assignments of the phosphotyrosine binding domain 2 (PTB2) of human FE65. Biomol NMR Assign 2014; 8:93-95. [PMID: 23315337 DOI: 10.1007/s12104-013-9460-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 01/04/2013] [Indexed: 06/01/2023]
Abstract
Phosphotyrosine binding domains (PTB) are protein-protein interaction domains that play important roles in various cellular signal transduction pathways. The second phosphotyrosine binding domain (PTB2) of the human scaffolding protein FE65 interacts with the C-terminal part of the Amyloid Precursor Protein (APP) involved in Alzheimer's disease. The structure of PTB2 in complex with a 32 amino acid fragment of APP has been solved previously by X-ray crystallography. Here, we report the NMR spectral assignments of the free FE65 PTB2. This provides the basis for further investigation of the interactions of PTB2 with peptides and small organic ligands with the aim of disrupting the PTB2-APP interaction.
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Affiliation(s)
- Andreas Dietl
- European Molecular Biology Laboratory (EMBL), Structural and Computational Biology, Meyerhofstr.1, 69117, Heidelberg, Germany
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30
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Parisotto D, Pfau M, Scheutzow A, Wild K, Mayer MP, Malsam J, Sinning I, Söllner TH. An extended helical conformation in domain 3a of Munc18-1 provides a template for SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex assembly. J Biol Chem 2014; 289:9639-50. [PMID: 24532794 DOI: 10.1074/jbc.m113.514273] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [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: 12/21/2022] Open
Abstract
Munc18-1, a SEC1/Munc18 protein and key regulatory protein in synaptic transmission, can either promote or inhibit SNARE complex assembly. Although the binary inhibitory interaction between Munc18-1 and closed syntaxin 1 is well described, the mechanism of how Munc18-1 stimulates membrane fusion remains elusive. Using a reconstituted assay that resolves vesicle docking, priming, clamping, and fusion during synaptic exocytosis, we show that helix 12 in domain 3a of Munc18-1 stimulates SNAREpin assembly and membrane fusion. A single point mutation (L348R) within helix 12 selectively abolishes VAMP2 binding and the stimulatory function of Munc18-1 in membrane fusion. In contrast, targeting a natural switch site (P335A) at the start of helix 12, which can result in an extended α-helical conformation, further accelerates lipid-mixing. Together with structural modeling, the data suggest that helix 12 provides a folding template for VAMP2, accelerating SNAREpin assembly and membrane fusion. Analogous SEC1/Munc18-SNARE interactions at other transport steps may provide a general mechanism to drive lipid bilayer merger. At the neuronal synapse, Munc18-1 may convert docked synaptic vesicles into a readily releasable pool.
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Affiliation(s)
- Daniel Parisotto
- From the Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany and
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31
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De Franceschi N, Wild K, Schlacht A, Dacks JB, Sinning I, Filippini F. Longin and GAF domains: structural evolution and adaptation to the subcellular trafficking machinery. Traffic 2013; 15:104-21. [PMID: 24107188 DOI: 10.1111/tra.12124] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 09/18/2013] [Accepted: 09/23/2013] [Indexed: 11/28/2022]
Abstract
Endomembrane trafficking is one of the most prominent cytological features of eukaryotes. Given their widespread distribution and specialization, coiled-coil domains, coatomer domains, small GTPases and Longin domains are considered primordial 'building blocks' of the membrane trafficking machineries. Longin domains are conserved across eukaryotes and were likely to be present in the Last Eukaryotic Common Ancestor. The Longin fold is based on the α-β-α sandwich architecture and a unique topology, possibly accounting for the special adaptation to the eukaryotic trafficking machinery. The ancient Per ARNT Sim (PAS) and cGMP-specific phosphodiesterases, Adenylyl cyclases and FhlA (GAF) family domains show a similar architecture, and the identification of prokaryotic counterparts of GAF domains involved in trafficking provides an additional connection for the endomembrane system back into the pre-eukaryotic world. Proteome-wide, comparative bioinformatic analyses of the domains reveal three binding regions (A, B and C) mediating either specific or conserved protein-protein interactions. While the A region mediates intra- and inter-molecular interactions, the B region is involved in binding small GTPases, thus providing an evolutionary connection among major building blocks in the endomembrane system. Finally, we propose that the peculiar interaction surface of the C region of the Longin domain allowed it to extensively integrate into the endomembrane trafficking machinery in the earliest stages of building the eukaryotic cell.
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Affiliation(s)
- Nicola De Franceschi
- Molecular Biology and Bioinformatics Unit, Department of Biology, University of Padova, Padova, Italy; Current address: Centre for Biotechnology, University of Turku, Turku, Finland
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Tenten V, Menzel S, Kunter U, Sicking EM, van Roeyen CRC, Sanden SK, Kaldenbach M, Boor P, Fuss A, Uhlig S, Lanzmich R, Willemsen B, Dijkman H, Grepl M, Wild K, Kriz W, Smeets B, Floege J, Moeller MJ. Albumin is recycled from the primary urine by tubular transcytosis. J Am Soc Nephrol 2013; 24:1966-80. [PMID: 23970123 DOI: 10.1681/asn.2013010018] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Under physiologic conditions, significant amounts of plasma protein pass the renal filter and are reabsorbed by proximal tubular cells, but it is not clear whether the endocytosed protein, particularly albumin, is degraded in lysosomes or returned to the circulatory system intact. To resolve this question, a transgenic mouse with podocyte-specific expression of doxycycline-inducible tagged murine albumin was developed. To assess potential glomerular backfiltration, two types of albumin with different charges were expressed. On administration of doxycycline, podocytes expressed either of the two types of transgenic albumin, which were secreted into the primary filtrate and reabsorbed by proximal tubular cells, resulting in serum accumulation. Renal transplantation experiments confirmed that extrarenal transcription of transgenic albumin was unlikely to account for these results. Genetic deletion of the neonatal Fc receptor (FcRn), which rescues albumin and IgG from lysosomal degradation, abolished transcytosis of both types of transgenic albumin and IgG in proximal tubular cells. In summary, we provide evidence of a transcytosis within the kidney tubular system that protects albumin and IgG from lysosomal degradation, allowing these proteins to be recycled intact.
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Shi L, Rao S, Sun H, Wild K, Xu C. In vitro characterization of AA71, a potent and selective human monoclonal antibody against CGRP receptor. J Headache Pain 2013. [PMCID: PMC3620182 DOI: 10.1186/1129-2377-14-s1-p183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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34
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Shi L, Rao S, Sun H, Wild K, Xu C. In vitro characterization of AA71, a potent and selective human monoclonal antibody against CGRP receptor. J Headache Pain 2013. [DOI: 10.1186/1129-2377-1-s1-p183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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35
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Baumkötter F, Wagner K, Eggert S, Wild K, Kins S. Structural aspects and physiological consequences of APP/APLP trans-dimerization. Exp Brain Res 2012; 217:389-95. [PMID: 21952790 PMCID: PMC3308009 DOI: 10.1007/s00221-011-2878-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 09/13/2011] [Indexed: 12/02/2022]
Abstract
The amyloid precursor protein (APP) is one of the key proteins in Alzheimer's disease (AD), as it is the precursor of amyloid β (Aβ) peptides accumulating in amyloid plaques. The processing of APP and the pathogenic features of especially Aβ oligomers have been analyzed in detail. Remarkably, there is accumulating evidence from cell biological and structural studies suggesting that APP and its mammalian homologs, the amyloid precursor-like proteins (APLP1 and APLP2), participate under physiological conditions via trans-cellular dimerization in synaptogenesis. This offers the possibility that loss of synapses in AD might be partially explained by dysfunction of APP/APLPs cell adhesion properties. In this review, structural characteristics of APP trans-cellular interaction will be placed critically in context with its putative physiological functions focusing on cell adhesion and synaptogenesis.
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Affiliation(s)
- Frederik Baumkötter
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Straße 13, 67663 Kaiserslautern, Germany
| | - Katja Wagner
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Straße 13, 67663 Kaiserslautern, Germany
| | - Simone Eggert
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Straße 13, 67663 Kaiserslautern, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center, University of Heidelberg, 69120 Heidelberg, Germany
| | - Stefan Kins
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Straße 13, 67663 Kaiserslautern, Germany
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36
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Abstract
Tail-anchored (TA) membrane proteins perform essential cellular functions. They are posttranslationally inserted into the endoplasmic reticulum (ER) membrane by interaction of the Get3 chaperone with the Get1/2 receptor. Two independent structural and functional analyses of the Get3/receptor complex by Stefer et al. and Mariappan et al. now provide insights into TA protein insertion.
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Affiliation(s)
- Irmgard Sinning
- Heidelberg University Biochemistry Center, INF 328, 69120 Heidelberg, Germany.
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37
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Klug W, Dietl A, Simon B, Sinning I, Wild K. Phosphorylation of LRP1 regulates the interaction with Fe65. FEBS Lett 2011; 585:3229-35. [PMID: 21968187 DOI: 10.1016/j.febslet.2011.09.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 09/16/2011] [Accepted: 09/21/2011] [Indexed: 10/17/2022]
Abstract
Neuronal Fe65 is a central adapter for the intracellular protein network of Alzheimer's disease related amyloid precursor protein (APP). It contains a unique tandem array of phosphotyrosine-binding (PTB) domains that recognize NPXY internalization motifs present in the intracellular domains of APP (AICD) and the low-density lipoprotein receptor-related protein LRP1 (LICD). The ternary APP/Fe65/LRP1 complex is an important mediator of APP processing and affects β-amyloid peptide production. Here we dissect by biochemical and biophysical methods the direct interactions within the ternary complex and reveal a phosphorylation-dependent insulin receptor substrate (IRS-) like interaction of the distal NPVY(4507) motif of LICD with Fe65-PTB1.
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Affiliation(s)
- Wilfried Klug
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
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38
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Stefer S, Reitz S, Wang F, Wild K, Pang YY, Schwarz D, Bomke J, Hein C, Löhr F, Bernhard F, Denic V, Dötsch V, Sinning I. Structural basis for tail-anchored membrane protein biogenesis by the Get3-receptor complex. Science 2011; 333:758-62. [PMID: 21719644 DOI: 10.1126/science.1207125] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tail-anchored (TA) proteins are involved in cellular processes including trafficking, degradation, and apoptosis. They contain a C-terminal membrane anchor and are posttranslationally delivered to the endoplasmic reticulum (ER) membrane by the Get3 adenosine triphosphatase interacting with the hetero-oligomeric Get1/2 receptor. We have determined crystal structures of Get3 in complex with the cytosolic domains of Get1 and Get2 in different functional states at 3.0, 3.2, and 4.6 angstrom resolution. The structural data, together with biochemical experiments, show that Get1 and Get2 use adjacent, partially overlapping binding sites and that both can bind simultaneously to Get3. Docking to the Get1/2 complex allows for conformational changes in Get3 that are required for TA protein insertion. These data suggest a molecular mechanism for nucleotide-regulated delivery of TA proteins.
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Affiliation(s)
- Susanne Stefer
- Institute for Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, Goethe University, D-60325 Frankfurt am Main, Germany
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Stjepanovic G, Kapp K, Bange G, Graf C, Parlitz R, Wild K, Mayer MP, Sinning I. Lipids trigger a conformational switch that regulates signal recognition particle (SRP)-mediated protein targeting. J Biol Chem 2011; 286:23489-97. [PMID: 21543314 DOI: 10.1074/jbc.m110.212340] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Co-translational protein targeting to the membrane is mediated by the signal recognition particle and its receptor (FtsY). Their homologous GTPase domains interact at the membrane and form a heterodimer in which both GTPases are activated. The prerequisite for protein targeting is the interaction of FtsY with phospholipids. However, the mechanism of FtsY regulation by phospholipids remained unclear. Here we show that the N terminus of FtsY (A domain) is natively unfolded in solution and define the complete membrane-targeting sequence. We show that the membrane-targeting sequence is highly dynamic in solution, independent of nucleotides and directly responds to the density of anionic phospholipids by a random coil-helix transition. This conformational switch is essential for tethering FtsY to membranes and activates the GTPase for its subsequent interaction with the signal recognition particle. Our results underline the dynamics of lipid-protein interactions and their importance in the regulation of protein targeting and translocation across biological membranes.
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Affiliation(s)
- Goran Stjepanovic
- Biochemie Zentrum (BZH), University of Heidelberg, INF 328, 69120 Heidelberg, Germany
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40
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Lovera JF, Frohman E, Brown TR, Bandari D, Nguyen L, Yadav V, Stuve O, Karman J, Bogardus K, Heimburger G, Cua L, Remingon G, Fowler J, Monahan T, Kilcup S, Courtney Y, McAleenan J, Butler K, Wild K, Whitham R, Bourdette D. Memantine for cognitive impairment in multiple sclerosis: a randomized placebo-controlled trial. Mult Scler 2010; 16:715-23. [DOI: 10.1177/1352458510367662] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: Memantine, an NMDA antagonist, is effective for moderate to severe Alzheimer’s disease. Objective: Determine whether memantine improves cognitive performance (CP) among subjects with multiple sclerosis (MS) and cognitive impairment (CI). Methods: This double-blind, randomized, placebo-controlled trial (Clinicaltrials.gov NCT00300716) compared memantine 10 mg twice a day (4 week titration followed by 12 weeks on the highest tolerated dose) with placebo. The primary outcome was the change from baseline to exit on the Paced Auditory Serial Addition Test (PASAT) and the California Verbal Learning Test-II (CVLT-II) Long Delay Free Recall (LDFR). Secondary outcomes included additional neuropsychological tests; self-report measures of quality of life, fatigue, and depression; and family/caregiver reports of subjects’ CI and neuropsychiatric symptoms. Results: The differences between the groups on the change on the PASAT (placebo—memantine = 0.0 correct responses, 95% CI 3.4, 3.4; p = 0.9) and on CVLT-II LDFR (placebo—memantine =—0.6 words, 95% CI —2.1, 0.8; p = 0.4) as well as on the other cognitive tests were not significant. Subjects on memantine had no serious adverse events (AEs) but had more fatigue and neurological AEs as well as, per family members’ reports, less cognitive improvement and greater neuropsychiatric symptoms than subjects on placebo. Conclusion: Memantine 10 mg twice a day does not improve CP in subjects with MS, ages 18—65, without major depression, who have subjective cognitive complaints and perform worse than one SD below the mean on the PASAT or on the California Verbal Learning Test-II (total recall or delayed free recall).
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Affiliation(s)
- JF Lovera
- Neurology, Louisiana State University Health Sciences Center, New Orleans, LA 70003, USA,
| | - E. Frohman
- Neurology, UT Southwestern, Dallas, TX, USA
| | - TR Brown
- Neurorehabilitation, Evergreen Neuroscience Institute and Medical Center, Kirkland, WA, USA
| | - D. Bandari
- Neurology, University of Southern California, Los Angeles, CA, USA
| | - L. Nguyen
- Neurology, Oregon Health and Science University, Portland, OR, USA
| | - V. Yadav
- Neurology, Oregon Health and Science University, Portland, OR, USA
| | - O. Stuve
- Neurology, UT Southwestern, Dallas, TX, USA
| | - J. Karman
- Neurology, Oregon Health and Science University, Portland, OR, USA
| | - K. Bogardus
- Neurology, Oregon Health and Science University, Portland, OR, USA
| | - G. Heimburger
- Neurology, Oregon Health and Science University, Portland, OR, USA
| | - L. Cua
- Neurology, University of Southern California, Los Angeles, CA, USA
| | | | - J. Fowler
- Neurology, UT Southwestern, Dallas, TX, USA
| | - T. Monahan
- Neurorehabilitation, Evergreen Neuroscience Institute and Medical Center, Kirkland, WA, USA
| | - S. Kilcup
- Neurorehabilitation, Evergreen Neuroscience Institute and Medical Center, Kirkland, WA, USA
| | - Y. Courtney
- Neurorehabilitation, Evergreen Neuroscience Institute and Medical Center, Kirkland, WA, USA
| | - J. McAleenan
- Neurorehabilitation, Evergreen Neuroscience Institute and Medical Center, Kirkland, WA, USA
| | - K. Butler
- Neurorehabilitation, Evergreen Neuroscience Institute and Medical Center, Kirkland, WA, USA
| | - K. Wild
- Neurology, Oregon Health and Science University, Portland, OR, USA
| | - R. Whitham
- Neurology, Oregon Health and Science University, Portland, OR, USA, Neurology, Portland VA Medical Center, Portland, OR, Oregon Health and Science University, Portland, OR, USA
| | - D. Bourdette
- Neurology, Oregon Health and Science University, Portland, OR, USA, Neurology, Portland VA Medical Center, Portland, OR, Oregon Health and Science University, Portland, OR, USA
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Bozkurt G, Wild K, Amlacher S, Hurt E, Dobberstein B, Sinning I. The structure of Get4 reveals an alpha-solenoid fold adapted for multiple interactions in tail-anchored protein biogenesis. FEBS Lett 2010; 584:1509-14. [PMID: 20206626 DOI: 10.1016/j.febslet.2010.02.070] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 02/24/2010] [Accepted: 02/25/2010] [Indexed: 01/22/2023]
Abstract
Tail-anchored proteins play important roles in protein translocation, membrane fusion and apoptosis. They are targeted to the endoplasmic reticulum membrane via the guided-entry of tail-anchored proteins (Get) pathway. We present the 2A crystal structure of Get4 which participates in early steps of the Get pathway. The structure shows an alpha-solenoid fold with particular deviations from the regular pairwise arrangement of alpha-helices. A conserved hydrophobic groove accommodates the flexible C-terminal region in trans. The structural organization of the Get4 helical hairpin motifs provides a scaffold for protein-protein interactions in the Get pathway.
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Affiliation(s)
- Gunes Bozkurt
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
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Wild K, Bange G, Bozkurt G, Segnitz B, Hendricks A, Sinning I. Structural insights into the assembly of the human and archaeal signal recognition particles. Acta Crystallogr D Biol Crystallogr 2010; 66:295-303. [DOI: 10.1107/s0907444910000879] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 01/07/2010] [Indexed: 11/10/2022]
Abstract
The signal recognition particle (SRP) is a conserved ribonucleoprotein (RNP) complex that co-translationally targets membrane and secretory proteins to membranes. The assembly of the particle depends on the proper folding of the SRP RNA, which in mammalia and archaea involves an induced-fit mechanism within helices 6 and 8 in the S domain of SRP. The two helices are juxtaposed and clamped together upon binding of the SRP19 protein to their apices. In the current assembly paradigm, archaeal SRP19 causes the asymmetric loop of helix 8 to bulge out and expose the binding platform for the key player SRP54. Based on a heterologous archaeal SRP19–human SRP RNA structure, mammalian SRP19 was thought not to be able to induce this change, thus explaining the different requirements of SRP19 for SRP54 recruitment. In contrast, the crystal structures of a crenarchaeal and the all-human SRP19–SRP RNA binary complexes presented here show that the asymmetric loop is bulged out in both binary complexes. Differences in SRP assembly between mammalia and archaea are therefore independent of SRP19 and are based on differences in SRP RNA itself. A new SRP-assembly scheme is presented.
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Wild K, Radzimanowski J, Beyreuther K, Sinning I. P4‐226: Crystal structure of the amyloid precursor protein intracellular domain in complex with Fe65‐PTB2. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.04.692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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44
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Klug W, Radzimanowski J, Schlesinger S, Beyreuther K, Sinning I, Wild K. P4‐215: Crystal structure of the crossroad in APP transport and signaling: The Fe65‐PTB1 domain. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.04.681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Verheyen V, Cruickshank A, Wild K, Heaven M, McGee R, Watkins M, Nash D. Soluble, semivolatile phenol and nitrogen compounds in milk-processing wastewaters. J Dairy Sci 2009; 92:3484-93. [DOI: 10.3168/jds.2009-2217] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Radzimanowski J, Simon B, Sattler M, Beyreuther K, Sinning I, Wild K. Structure of the intracellular domain of the amyloid precursor protein in complex with Fe65-PTB2. EMBO Rep 2008; 9:1134-40. [PMID: 18833287 DOI: 10.1038/embor.2008.188] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 08/27/2008] [Accepted: 09/08/2008] [Indexed: 11/09/2022] Open
Abstract
Cleavage of the amyloid precursor protein (APP) is a crucial event in Alzheimer disease pathogenesis that creates the amyloid-beta peptide (Abeta) and liberates the carboxy-terminal APP intracellular domain (AICD) into the cytosol. The interaction of the APP C terminus with the adaptor protein Fe65 mediates APP trafficking and signalling, and is thought to regulate APP processing and Abeta generation. We determined the crystal structure of the AICD in complex with the C-terminal phosphotyrosine-binding (PTB) domain of Fe65. The unique interface involves the NPxY PTB-binding motif and two alpha helices. The amino-terminal helix of the AICD is capped by threonine T(668), an Alzheimer disease-relevant phosphorylation site involved in Fe65-binding regulation. The structure together with mutational studies, isothermal titration calorimetry and nuclear magnetic resonance experiments sets the stage for understanding T(668) phosphorylation-dependent complex regulation at a molecular level. A molecular switch model is proposed.
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Affiliation(s)
- Jens Radzimanowski
- Heidelberg University Biochemistry Center, University of Heidelberg, INF328, D-69120 Heidelberg, Germany
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Radzimanowski J, Ravaud S, Schlesinger S, Koch J, Beyreuther K, Sinning I, Wild K. Crystal Structure of the Human Fe65-PTB1 Domain. J Biol Chem 2008; 283:23113-20. [DOI: 10.1074/jbc.m800861200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Stengel KF, Holdermann I, Cain P, Robinson C, Wild K, Sinning I. Structural basis for specific substrate recognition by the chloroplast signal recognition particle protein cpSRP43. Science 2008; 321:253-6. [PMID: 18621669 DOI: 10.1126/science.1158640] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Secretory and membrane proteins carry amino-terminal signal sequences that, in cotranslational targeting, are recognized by the signal recognition particle protein SRP54 without sequence specificity. The most abundant membrane proteins on Earth are the light-harvesting chlorophyll a/b binding proteins (LHCPs). They are synthesized in the cytoplasm, imported into the chloroplast, and posttranslationally targeted to the thylakoid membrane by cpSRP, a heterodimer formed by cpSRP54 and cpSRP43. We present the 1.5 angstrom crystal structure of cpSRP43 characterized by a unique arrangement of chromodomains and ankyrin repeats. The overall shape and charge distribution of cpSRP43 resembles the SRP RNA, which is absent in chloroplasts. The complex with the internal signal sequence of LHCPs reveals that cpSRP43 specifically recognizes a DPLG peptide motif. We describe how cpSPR43 adapts the universally conserved SRP system to posttranslational targeting and insertion of the LHCP family of membrane proteins.
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Affiliation(s)
- Katharina F Stengel
- Biochemie-Zentrum der Universität Heidelberg, INF328, D-69120 Heidelberg, Germany
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Radzimanowski J, Ravaud S, Beyreuther K, Sinning I, Wild K. Mercury-induced crystallization and SAD phasing of the human Fe65-PTB1 domain. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:382-5. [PMID: 18453707 PMCID: PMC2376396 DOI: 10.1107/s174430910800835x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 03/27/2008] [Indexed: 11/10/2022]
Abstract
Fe65 is a three-domain neuronal adaptor protein involved in brain development and amyloid precursor protein (APP) signalling. The phosphotyrosine-binding domain 1 (PTB1) of human Fe65 has been cloned, overexpressed, purified and crystallized using the hanging-drop vapour-diffusion method. Native crystals belong to the space group R3 and diffract to 2.6 A resolution. This crystal form suffered from high thermal B factors and pseudo-symmetry, resulting in a bisection of the c axis. Co-crystallization with a mercury compound under similar conditions induced an orthorhombic crystal form in the space group P2(1)2(1)2(1) diffracting to 2.2 A resolution. SAD phases have been computed to the diffraction limit at the wavelength of maximum absorption (L(III) edge).
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Affiliation(s)
- Jens Radzimanowski
- Heidelberg University Biochemistry Center, INF328, D-69120 Heidelberg, Germany
| | - Stéphanie Ravaud
- Heidelberg University Biochemistry Center, INF328, D-69120 Heidelberg, Germany
| | - Konrad Beyreuther
- Center for Molecular Biology, University Heidelberg, INF282, D-69120 Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center, INF328, D-69120 Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center, INF328, D-69120 Heidelberg, Germany
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Radzimanowski J, Beyreuther K, Sinning I, Wild K. Overproduction, purification, crystallization and preliminary X-ray analysis of human Fe65-PTB2 in complex with the amyloid precursor protein intracellular domain. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:409-12. [PMID: 18453713 PMCID: PMC2376414 DOI: 10.1107/s1744309108009524] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 04/07/2008] [Indexed: 11/11/2022]
Abstract
Alzheimer's disease is associated with typical brain deposits (senile plaques) that mainly contain the neurotoxic amyloid beta peptide. This peptide results from proteolytic processing of the type I transmembrane protein amyloid precursor protein (APP). During this proteolytic pathway the APP intracellular domain (AICD) is released into the cytosol, where it associates with various adaptor proteins. The interaction of the AICD with the C-terminal phosphotyrosine-binding domain of Fe65 (Fe65-PTB2) regulates APP translocation, signalling and processing. Human AICD and Fe65-PTB2 have been cloned, overproduced and purified in large amounts in Escherichia coli. A complex of Fe65-PTB2 with the C-terminal 32 amino acids of the AICD gave well diffracting hexagonal crystals and data have been collected to 2.1 A resolution. Initial phases obtained by the molecular-replacement method are of good quality and revealed well defined electron density for the substrate peptide.
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Affiliation(s)
- Jens Radzimanowski
- Heidelberg University Biochemistry Center, INF328, D-69120 Heidelberg, Germany
| | - Konrad Beyreuther
- Center for Molecular Biology, University Heidelberg, INF282, D-69120 Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center, INF328, D-69120 Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center, INF328, D-69120 Heidelberg, Germany
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