1
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Ramírez AS, de Capitani M, Pesciullesi G, Kowal J, Bloch JS, Irobalieva RN, Reymond JL, Aebi M, Locher KP. Molecular basis for glycan recognition and reaction priming of eukaryotic oligosaccharyltransferase. Nat Commun 2022; 13:7296. [PMID: 36435935 PMCID: PMC9701220 DOI: 10.1038/s41467-022-35067-x] [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: 10/03/2022] [Accepted: 11/17/2022] [Indexed: 11/28/2022] Open
Abstract
Oligosaccharyltransferase (OST) is the central enzyme of N-linked protein glycosylation. It catalyzes the transfer of a pre-assembled glycan, GlcNAc2Man9Glc3, from a dolichyl-pyrophosphate donor to acceptor sites in secretory proteins in the lumen of the endoplasmic reticulum. Precise recognition of the fully assembled glycan by OST is essential for the subsequent quality control steps of glycoprotein biosynthesis. However, the molecular basis of the OST-donor glycan interaction is unknown. Here we present cryo-EM structures of S. cerevisiae OST in distinct functional states. Our findings reveal that the terminal glucoses (Glc3) of a chemo-enzymatically generated donor glycan analog bind to a pocket formed by the non-catalytic subunits WBP1 and OST2. We further find that binding either donor or acceptor substrate leads to distinct primed states of OST, where subsequent binding of the other substrate triggers conformational changes required for catalysis. This alternate priming allows OST to efficiently process closely spaced N-glycosylation sites.
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Affiliation(s)
- Ana S. Ramírez
- grid.5801.c0000 0001 2156 2780Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
| | - Mario de Capitani
- grid.5734.50000 0001 0726 5157Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Giorgio Pesciullesi
- grid.5734.50000 0001 0726 5157Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Julia Kowal
- grid.5801.c0000 0001 2156 2780Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
| | - Joël S. Bloch
- grid.5801.c0000 0001 2156 2780Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
| | - Rossitza N. Irobalieva
- grid.5801.c0000 0001 2156 2780Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
| | - Jean-Louis Reymond
- grid.5734.50000 0001 0726 5157Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Markus Aebi
- grid.5801.c0000 0001 2156 2780Institute of Microbiology, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
| | - Kaspar P. Locher
- grid.5801.c0000 0001 2156 2780Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
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2
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Losfeld ME, Scibona E, Lin CW, Aebi M. Glycosylation network mapping and site-specific glycan maturation in vivo. iScience 2022; 25:105417. [DOI: 10.1016/j.isci.2022.105417] [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] [Received: 05/26/2022] [Revised: 09/12/2022] [Accepted: 10/18/2022] [Indexed: 11/09/2022] Open
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3
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Bleuler-Martinez S, Varrot A, Olieric V, Schubert M, Vogt E, Fetz C, Wohlschlager T, Plaza DF, Wälti M, Duport Y, Capitani G, Aebi M, Künzler M. Structure-function relationship of a novel fucoside-binding fruiting body lectin from Coprinopsis cinerea exhibiting nematotoxic activity. Glycobiology 2022; 32:600-615. [PMID: 35323921 PMCID: PMC9191617 DOI: 10.1093/glycob/cwac020] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 11/14/2022] Open
Abstract
Lectins are non-immunoglobulin-type proteins that bind to specific carbohydrate epitopes and play important roles in intra- and inter-organismic interactions. Here, we describe a novel fucose-specific lectin, termed CML1, which we identified from fruiting body extracts of Coprinopsis cinerea. For further characterization, the coding sequence for CML1 was cloned and heterologously expressed in Escherichia coli. Feeding of CML1-producing bacteria inhibited larval development of the bacterivorous nematode Caenorhabditis tropicalis, but not of C. elegans. The crystal structure of the recombinant protein in its apo-form and in complex with H type I or Lewis A blood group antigens was determined by X-ray crystallography. The protein folds as a sandwich of 2 antiparallel β-sheets and forms hexamers resulting from a trimer of dimers. The hexameric arrangement was confirmed by small-angle X-ray scattering (SAXS). One carbohydrate-binding site per protomer was found at the dimer interface with both protomers contributing to ligand binding, resulting in a hexavalent lectin. In terms of lectin activity of recombinant CML1, substitution of the carbohydrate-interacting residues His54, Asn55, Trp94, and Arg114 by Ala abolished carbohydrate-binding and nematotoxicity. Although no similarities to any characterized lectin were found, sequence alignments identified many non-characterized agaricomycete proteins. These results suggest that CML1 is the founding member of a novel family of fucoside-binding lectins involved in the defense of agaricomycete fruiting bodies against predation by fungivorous nematodes.
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Affiliation(s)
- Silvia Bleuler-Martinez
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Annabelle Varrot
- University Grenoble Alpes, CNRS, CERMAV, 38000, Grenoble, France
| | - Vincent Olieric
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - Mario Schubert
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, Zürich, Switzerland.,Department of Biosciences, University of Salzburg, 5020, Salzburg, Austria
| | - Eva Vogt
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Céline Fetz
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Therese Wohlschlager
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - David Fernando Plaza
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland.,Division of Infectious Diseases, Karolinska University Hospital, 171 64, Solna, Sweden
| | - Martin Wälti
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Yannick Duport
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Guido Capitani
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Markus Künzler
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
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4
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Neuhaus JD, Wild R, Eyring J, Irobalieva RN, Kowal J, Lin CW, Locher KP, Aebi M. Functional analysis of Ost3p and Ost6p containing yeast oligosaccharyltransferases. Glycobiology 2021; 31:1604-1615. [PMID: 34974622 DOI: 10.1093/glycob/cwab084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 07/14/2021] [Revised: 07/14/2021] [Accepted: 08/05/2021] [Indexed: 11/14/2022] Open
Abstract
The oligosaccharyltransferase (OST) is the central enzyme in the N-glycosylation pathway. It transfers a defined oligosaccharide from a lipid-linker onto the asparagine side chain of proteins. The yeast OST consists of eight subunits and exists in two catalytically distinct isoforms that differ in one subunit, Ost3p or Ost6p. The cryo-electron microscopy structure of the Ost6p containing complex was found to be highly similar to the Ost3p containing OST. OST enzymes with altered Ost3p/Ost6p subunits were generated and functionally analyzed. The three C-terminal transmembrane helices were responsible for the higher turnover-rate of the Ost3p vs. the Ost6p containing enzyme in vitro and the more severe hypoglycosylation in Ost3p lacking strains in vivo. Glycosylation of specific OST target sites required the N-terminal thioredoxin domain of Ost3p or Ost6p. This Ost3p/Ost6p dependence was glycosylation site but not protein specific. We concluded that the Ost3p/Ost6p subunits modulate the catalytic activity of OST and provide additional specificity for OST substrate recognition.
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Affiliation(s)
- Julia D Neuhaus
- Institute of Microbiology, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Rebekka Wild
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland.,Institut de Biologie Structurale, CNRS, CEA, Université Grenoble-Alpes, 38000 Grenoble, France
| | - Jillianne Eyring
- Institute of Microbiology, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Rossitza N Irobalieva
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Julia Kowal
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Chia-Wei Lin
- Institute of Microbiology, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland.,Functional Genomic Center Zurich, 8057 Zurich, Switzerland
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
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5
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Weiß RG, Losfeld ME, Aebi M, Riniker S. N-Glycosylation Enhances Conformational Flexibility of Protein Disulfide Isomerase Revealed by Microsecond Molecular Dynamics and Markov State Modeling. J Phys Chem B 2021; 125:9467-9479. [PMID: 34379416 DOI: 10.1021/acs.jpcb.1c04279] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Secreted proteins of eukaryotes are decorated with branched carbohydrate oligomers called glycans. This fact is only starting to be considered for in silico investigations of protein dynamics. Using all-atom molecular dynamics (MD) simulations and Markov state modeling (MSM), we unveil the influence of glycans on the conformational flexibility of the multidomain protein disulfide isomerase (PDI), which is a ubiquitous chaperone in the endoplasmic reticulum (ER). Yeast PDI (yPDI) from Saccharomyces cerevisiae is glycosylated at asparagine side chains and the knowledge of its five modified sites enables a realistic computational modeling. We compare simulations of glycosylated and unglycosylated yPDI and find that the presence of glycan-glycan and glycan-protein interactions influences the flexibility of PDI in different ways. For example, glycosylation reduces interdomain interactions, shifting the conformational ensemble toward more open, extended structures. In addition, we compare our results on yPDI with structural information of homologous proteins such as human PDI (hPDI), which is natively unglycosylated. Interestingly, hPDI lacks a surface recess that is present in yPDI. We find that glycosylation of yPDI facilitates its catalytic site to reach close to this surface recess. Hence, this might point to a possible functional relevance of glycosylation in yeast to act on substrates, while glycosylation seems redundant for the human homologous protein. We conclude that glycosylation is fundamental for protein dynamics, making it a necessity for a truthful representation of the flexibility and function in in silico studies of glycoproteins.
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Affiliation(s)
- R Gregor Weiß
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, ETH Zürich, 8093 Zürich, Switzerland
| | - Marie-Estelle Losfeld
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, 8093 Zürich, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, 8093 Zürich, Switzerland
| | - Sereina Riniker
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, ETH Zürich, 8093 Zürich, Switzerland
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6
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Eyring J, Lin CW, Ngwa EM, Boilevin J, Pesciullesi G, Locher KP, Darbre T, Reymond JL, Aebi M. Substrate specificities and reaction kinetics of the yeast oligosaccharyltransferase isoforms. J Biol Chem 2021; 296:100809. [PMID: 34023382 PMCID: PMC8191290 DOI: 10.1016/j.jbc.2021.100809] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 05/07/2021] [Accepted: 05/19/2021] [Indexed: 12/02/2022] Open
Abstract
Oligosaccharyltransferase (OST) catalyzes the central step in N-linked protein glycosylation, the transfer of a preassembled oligosaccharide from its lipid carrier onto asparagine residues of secretory proteins. The prototypic hetero-octameric OST complex from the yeast Saccharomyces cerevisiae exists as two isoforms that contain either Ost3p or Ost6p, both noncatalytic subunits. These two OST complexes have different protein substrate specificities in vivo. However, their detailed biochemical mechanisms and the basis for their different specificities are not clear. The two OST complexes were purified from genetically engineered strains expressing only one isoform. The kinetic properties and substrate specificities were characterized using a quantitative in vitro glycosylation assay with short peptides and different synthetic lipid-linked oligosaccharide (LLO) substrates. We found that the peptide sequence close to the glycosylation sequon affected peptide affinity and turnover rate. The length of the lipid moiety affected LLO affinity, while the lipid double-bond stereochemistry had a greater influence on LLO turnover rates. The two OST complexes had similar affinities for both the peptide and LLO substrates but showed significantly different turnover rates. These data provide the basis for a functional analysis of the Ost3p and Ost6p subunits.
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Affiliation(s)
- Jillianne Eyring
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Chia-Wei Lin
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland; Functional Genomics Center Zürich, University of Zürich/ETH Zürich, Zürich, Switzerland
| | - Elsy Mankah Ngwa
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Jérémy Boilevin
- Department of Chemistry and Biochemistry, University of Berne, Bern, Switzerland
| | - Giorgio Pesciullesi
- Department of Chemistry and Biochemistry, University of Berne, Bern, Switzerland
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Tamis Darbre
- Department of Chemistry and Biochemistry, University of Berne, Bern, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Berne, Bern, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland.
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7
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Mathew C, Weiß RG, Giese C, Lin CW, Losfeld ME, Glockshuber R, Riniker S, Aebi M. Glycan-protein interactions determine kinetics of N-glycan remodeling. RSC Chem Biol 2021; 2:917-931. [PMID: 34212152 PMCID: PMC8207518 DOI: 10.1039/d1cb00019e] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [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] [Indexed: 12/12/2022] Open
Abstract
A hallmark of N-linked glycosylation in the secretory compartments of eukaryotic cells is the sequential remodeling of an initially uniform oligosaccharide to a site-specific, heterogeneous ensemble of glycostructures on mature proteins. To understand site-specific processing, we used protein disulfide isomerase (PDI), a model protein with five glycosylation sites, for molecular dynamics (MD) simulations and compared the result to a biochemical in vitro analysis with four different glycan processing enzymes. As predicted by an analysis of the accessibility of the N-glycans for their processing enzymes derived from the MD simulations, N-glycans at different glycosylation sites showed different kinetic properties for the processing enzymes. In addition, altering the tertiary structure of the glycoprotein PDI affected its N-glycan remodeling in a site-specific way. We propose that the observed differential N-glycan reactivities depend on the surrounding protein tertiary structure and lead to different glycan structures in the same protein through kinetically controlled processing pathways. Atomistic glycoprotein simulations reveal a site-specific availability of glycan substrates in time-resolved mass spectrometry of maturating enzyme kinetics.![]()
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Affiliation(s)
- Corina Mathew
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich 8093 Zürich Switzerland
| | - R Gregor Weiß
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, ETH Zürich 8093 Zürich Switzerland
| | - Christoph Giese
- Institute of Molecular Biology & Biophysics, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich 8093 Zürich Switzerland
| | - Chia-Wei Lin
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich 8093 Zürich Switzerland .,Functional Genomics Center Zürich 8057 Zürich Switzerland
| | - Marie-Estelle Losfeld
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich 8093 Zürich Switzerland
| | - Rudi Glockshuber
- Institute of Molecular Biology & Biophysics, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich 8093 Zürich Switzerland
| | - Sereina Riniker
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, ETH Zürich 8093 Zürich Switzerland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich 8093 Zürich Switzerland
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8
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Weiss GL, Stanisich JJ, Sauer MM, Lin CW, Eras J, Zyla DS, Trück J, Devuyst O, Aebi M, Pilhofer M, Glockshuber R. Architecture and function of human uromodulin filaments in urinary tract
infections. Science 2020; 369:1005-1010. [DOI: 10.1126/science.aaz9866] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 04/22/2020] [Accepted: 06/18/2020] [Indexed: 12/28/2022]
Abstract
Uromodulin is the most abundant protein in human urine, and it forms
filaments that antagonize the adhesion of uropathogens; however, the filament
structure and mechanism of protection remain poorly understood. We used
cryo–electron tomography to show that the uromodulin filament consists of a
zigzag-shaped backbone with laterally protruding arms. N-glycosylation mapping and
biophysical assays revealed that uromodulin acts as a multivalent ligand for the
bacterial type 1 pilus adhesin, presenting specific epitopes on the regularly
spaced arms. Imaging of uromodulin-uropathogen interactions in vitro and in
patient urine showed that uromodulin filaments associate with uropathogens and
mediate bacterial aggregation, which likely prevents adhesion and allows clearance
by micturition. These results provide a framework for understanding uromodulin in
urinary tract infections and in its more enigmatic roles in physiology and
disease.
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Affiliation(s)
- Gregor L. Weiss
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Jessica J. Stanisich
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Maximilian M. Sauer
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Chia-Wei Lin
- Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, CH-8093 Zürich, Switzerland
| | - Jonathan Eras
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Dawid S. Zyla
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Johannes Trück
- University Children’s Hospital Zürich, Steinwiesstrasse 75, CH-8032 Zürich, Switzerland
| | - Olivier Devuyst
- Institute of Physiology, Mechanisms of Inherited Kidney Disorders, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
- Division of Nephrology, UCLouvain Medical School, Brussels, Belgium
| | - Markus Aebi
- Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, CH-8093 Zürich, Switzerland
| | - Martin Pilhofer
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Rudi Glockshuber
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
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9
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Arigoni-Affolter I, Scibona E, Lin CW, Brühlmann D, Souquet J, Broly H, Aebi M. Mechanistic reconstruction of glycoprotein secretion through monitoring of intracellular N-glycan processing. Sci Adv 2019; 5:eaax8930. [PMID: 31807707 PMCID: PMC6881162 DOI: 10.1126/sciadv.aax8930] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 09/18/2019] [Indexed: 05/06/2023]
Abstract
N-linked glycosylation plays a fundamental role in determining the thermodynamic stability of proteins and is involved in multiple key biological processes. The mechanistic understanding of the intracellular machinery responsible for the stepwise biosynthesis of N-glycans is still incomplete due to limited understanding of in vivo kinetics of N-glycan processing along the secretory pathway. We present a glycoproteomics approach to monitor the processing of site-specific N-glycans in CHO cells. On the basis of a model-based analysis of structure-specific turnover rates, we provide a kinetic description of intracellular N-glycan processing along the entire secretory pathway. This approach refines and further extends the current knowledge on N-glycans biosynthesis and provides a basis to quantify alterations in the glycoprotein processing machinery.
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Affiliation(s)
| | - Ernesto Scibona
- Institute for Chemical and Bioengineering, Department of Chemistry, ETH Zürich, 8093 Zürich, Switzerland
| | - Chia-Wei Lin
- Institute of Microbiology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - David Brühlmann
- Merck Healthcare, Biotech Process Sciences, Route de Fenil 25, 1804 Corsier-sur-Vevey, Switzerland
| | - Jonathan Souquet
- Merck Healthcare, Biotech Process Sciences, Route de Fenil 25, 1804 Corsier-sur-Vevey, Switzerland
| | - Hervé Broly
- Merck Healthcare, Biotech Process Sciences, Route de Fenil 25, 1804 Corsier-sur-Vevey, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
- Corresponding author.
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10
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Freimoser FM, Grundschober A, Aebi M, Tuor U. In vitro cultivation of the entomopathogenic fungusEntomophthora thripidum: isolation, growth requirements, and sporulation. Mycologia 2019. [DOI: 10.1080/00275514.2000.12061146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Florian M. Freimoser
- Eidgenössische Technische Hochschule ETH, Mikrobiologisches Institut, Schmelzbergstr. 7, CH-8092 Zürich, Switzerland
| | - Anne Grundschober
- Eidgenössische Technische Hochschule ETH, Mikrobiologisches Institut, Schmelzbergstr. 7, CH-8092 Zürich, Switzerland
| | - Markus Aebi
- Eidgenössische Technische Hochschule ETH, Mikrobiologisches Institut, Schmelzbergstr. 7, CH-8092 Zürich, Switzerland
| | - Urs Tuor
- Eidgenössische Technische Hochschule ETH, Mikrobiologisches Institut, Schmelzbergstr. 7, CH-8092 Zürich, Switzerland
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11
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Schmieder SS, Stanley CE, Rzepiela A, van Swaay D, Sabotič J, Nørrelykke SF, deMello AJ, Aebi M, Künzler M. Bidirectional Propagation of Signals and Nutrients in Fungal Networks via Specialized Hyphae. Curr Biol 2019; 29:217-228.e4. [PMID: 30612903 DOI: 10.1016/j.cub.2018.11.058] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [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: 07/04/2018] [Revised: 10/05/2018] [Accepted: 11/23/2018] [Indexed: 11/15/2022]
Abstract
Intercellular distribution of nutrients and coordination of responses to internal and external cues via endogenous signaling molecules are hallmarks of multicellular organisms. Vegetative mycelia of multicellular fungi are syncytial networks of interconnected hyphae resulting from hyphal tip growth, branching, and fusion. Such mycelia can reach considerable dimensions and, thus, different parts can be exposed to quite different environmental conditions. Our knowledge about the mechanisms by which fungal mycelia can adjust nutrient gradients or coordinate their defense response to fungivores is scarce, in part due to limitations in technologies currently available for examining different parts of a mycelium over longer time periods at the microscopic level. Here, we combined a tailor-made microfluidic platform with time-lapse fluorescence microscopy to visualize the dynamic response of the vegetative mycelium of a basidiomycete to two different stimuli. The microfluidic platform allows simultaneous monitoring at both the colony and single-hypha level. We followed the dynamics of the distribution of a locally administered nutrient analog and the defense response to spatially confined predation by a fungivorous nematode. Although both responses of the mycelium were constrained locally, we observed long-distance propagation for both the nutrient analog and defense response in a subset of hyphae. This propagation along hyphae occurred in both acropetal and basipetal directions and, intriguingly, the direction was found to alternate every 3 hr in an individual hypha. These results suggest that multicellular fungi have, as of yet, undescribed mechanisms to coordinate the distribution of nutrients and their behavioral response upon attack by fungivores.
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Affiliation(s)
- Stefanie S Schmieder
- Department of Biology, Institute of Microbiology, ETH Zürich, Zürich, Switzerland
| | - Claire E Stanley
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zürich, Zürich, Switzerland
| | - Andrzej Rzepiela
- Scientific Center for Optical and Electron Microscopy, ETH Zürich, Switzerland
| | - Dirk van Swaay
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zürich, Zürich, Switzerland
| | - Jerica Sabotič
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Simon F Nørrelykke
- Scientific Center for Optical and Electron Microscopy, ETH Zürich, Switzerland
| | - Andrew J deMello
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zürich, Zürich, Switzerland
| | - Markus Aebi
- Department of Biology, Institute of Microbiology, ETH Zürich, Zürich, Switzerland
| | - Markus Künzler
- Department of Biology, Institute of Microbiology, ETH Zürich, Zürich, Switzerland.
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12
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Kombrink A, Tayyrov A, Essig A, Stöckli M, Micheller S, Hintze J, van Heuvel Y, Dürig N, Lin CW, Kallio PT, Aebi M, Künzler M. Induction of antibacterial proteins and peptides in the coprophilous mushroom Coprinopsis cinerea in response to bacteria. ISME J 2018; 13:588-602. [PMID: 30301946 PMCID: PMC6461984 DOI: 10.1038/s41396-018-0293-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 08/23/2018] [Accepted: 09/25/2018] [Indexed: 12/22/2022]
Abstract
Bacteria are the main nutritional competitors of saprophytic fungi during colonization of their ecological niches. This competition involves the mutual secretion of antimicrobials that kill or inhibit the growth of the competitor. Over the last years it has been demonstrated that fungi respond to the presence of bacteria with changes of their transcriptome, but the significance of these changes with respect to competition for nutrients is not clear as functional proof of the antibacterial activity of the induced gene products is often lacking. Here, we report the genome-wide transcriptional response of the coprophilous mushroom Coprinopsis cinerea to the bacteria Bacillus subtilis and Escherichia coli. The genes induced upon co-cultivation with each bacterium were highly overlapping, suggesting that the fungus uses a similar arsenal of effectors against Gram-positive and -negative bacteria. Intriguingly, the induced genes appeare to encode predominantly secreted peptides and proteins with predicted antibacterial activities, which was validated by comparative proteomics of the C. cinerea secretome. Induced members of two putative antibacterial peptide and protein families in C. cinerea, the cysteine-stabilized αβ-defensins (Csαβ-defensins) and the GH24-type lysozymes, were purified, and their antibacterial activity was confirmed. These results provide compelling evidence that fungi are able to recognize the presence of bacteria and respond with the expression of an arsenal of secreted antibacterial peptides and proteins.
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Affiliation(s)
- Anja Kombrink
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland
| | - Annageldi Tayyrov
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland
| | - Andreas Essig
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland
| | - Martina Stöckli
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland.,rqmicro AG, Brandstrasse 24, 8952, Schlieren, Switzerland
| | - Sebastian Micheller
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland
| | - John Hintze
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland.,Department of Cellular and Molecular Medicine, The Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen, Denmark
| | - Yasemin van Heuvel
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland
| | - Natalia Dürig
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland
| | - Chia-Wei Lin
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland
| | - Pauli T Kallio
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland
| | - Markus Aebi
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland
| | - Markus Künzler
- Department of Biology, Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, CH-8093, Zürich, Switzerland.
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13
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Song H, van der Velden NS, Shiran SL, Bleiziffer P, Zach C, Sieber R, Imani AS, Krausbeck F, Aebi M, Freeman MF, Riniker S, Künzler M, Naismith JH. A molecular mechanism for the enzymatic methylation of nitrogen atoms within peptide bonds. Sci Adv 2018; 4:eaat2720. [PMID: 30151425 PMCID: PMC6108569 DOI: 10.1126/sciadv.aat2720] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 07/17/2018] [Indexed: 05/04/2023]
Abstract
The peptide bond, the defining feature of proteins, governs peptide chemistry by abolishing nucleophilicity of the nitrogen. This and the planarity of the peptide bond arise from the delocalization of the lone pair of electrons on the nitrogen atom into the adjacent carbonyl. While chemical methylation of an amide bond uses a strong base to generate the imidate, OphA, the precursor protein of the fungal peptide macrocycle omphalotin A, self-hypermethylates amides at pH 7 using S-adenosyl methionine (SAM) as cofactor. The structure of OphA reveals a complex catenane-like arrangement in which the peptide substrate is clamped with its amide nitrogen aligned for nucleophilic attack on the methyl group of SAM. Biochemical data and computational modeling suggest a base-catalyzed reaction with the protein stabilizing the reaction intermediate. Backbone N-methylation of peptides enhances their protease resistance and membrane permeability, a property that holds promise for applications to medicinal chemistry.
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Affiliation(s)
- Haigang Song
- Biomedical Sciences Research Complex, North Haugh, University of St. Andrews, Fife KY16 9ST, UK
- Division of Structural Biology, Wellcome Trust Centre of Human Genomics, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Niels S. van der Velden
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Sally L. Shiran
- Biomedical Sciences Research Complex, North Haugh, University of St. Andrews, Fife KY16 9ST, UK
| | - Patrick Bleiziffer
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Christina Zach
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Ramon Sieber
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Aman S. Imani
- Department of Biochemistry, Molecular Biology, and Biophysics, and BioTechnology Institute, University of Minnesota–Twin Cities, St. Paul, MN 55108, USA
| | - Florian Krausbeck
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Michael F. Freeman
- Department of Biochemistry, Molecular Biology, and Biophysics, and BioTechnology Institute, University of Minnesota–Twin Cities, St. Paul, MN 55108, USA
| | - Sereina Riniker
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
- Corresponding author. (S.R.); (M.K.); (J.H.N.)
| | - Markus Künzler
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
- Corresponding author. (S.R.); (M.K.); (J.H.N.)
| | - James H. Naismith
- Division of Structural Biology, Wellcome Trust Centre of Human Genomics, Roosevelt Drive, Oxford OX3 7BN, UK
- State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
- Research Complex at Harwell, Rutherford Laboratory, Didcot, Oxfordshire OX11 0FA, UK
- Corresponding author. (S.R.); (M.K.); (J.H.N.)
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14
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Sailer A, Nagata K, Näf D, Aebi M, Weissmann C. Interferon regulatory factor-1 (IRF-1) activates the synthetic IRF-1-responsive sequence (GAAAGT)4 in Saccharomyces cerevisiae. Gene Expr 2018; 2:329-37. [PMID: 1472868 PMCID: PMC6057371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In appropriate mammalian cells, interferon regulatory factor-1 (IRF-1) can activate the virus-responsive element of the IFN-beta promoter (VRE beta") or the synthetic oligonucleotide (GAAAGT)4. The latter contains two copies of the functional equivalent of PRDI, one of the regulatory domains of VRE beta". We prepared yeast strains containing an IRF-1 expression plasmid under the control of the galactose-inducible Gal1 promoter and a reporter plasmid with either (GAAAGT)4, VRE beta", or other test sequences placed upstream of a minimal promoter linked to the beta-galactosidase coding sequence. Upon induction of IRF-1 expression, the (GAAAGT)4-containing promoter was activated, but VRE beta" and all other sequences tested were inactive. Our results showed that IRF-1 belongs to a class of higher eukaryotic transcription factors that can interact with the yeast transcriptional machinery. Our findings also raised the question why the duplicate PRDI-like sequences in (GAAAGT)4 can be activated by IRF-1 synthesized in yeast, but not VRE beta", which also contains at least two PRDI-like sequences.
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Affiliation(s)
- A Sailer
- Institut für Molekularbiologie I, Universität Zürich, Switzerland
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15
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Ramírez AS, Boilevin J, Biswas R, Gan BH, Janser D, Aebi M, Darbre T, Reymond JL, Locher KP. Characterization of the single-subunit oligosaccharyltransferase STT3A from Trypanosoma brucei using synthetic peptides and lipid-linked oligosaccharide analogs. Glycobiology 2018; 27:525-535. [PMID: 28204532 PMCID: PMC5421464 DOI: 10.1093/glycob/cwx017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [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: 01/16/2017] [Accepted: 02/10/2017] [Indexed: 01/11/2023] Open
Abstract
The initial transfer of a complex glycan in protein N-glycosylation is catalyzed by oligosaccharyltransferase (OST), which is generally a multisubunit membrane protein complex in the endoplasmic reticulum but a single-subunit enzyme (ssOST) in some protists. To investigate the reaction mechanism of ssOST, we recombinantly expressed, purified and characterized the STT3A protein from Trypanosoma brucei (TbSTT3A). We analyzed the in vitro activity of TbSTT3A by synthesizing fluorescently labeled acceptor peptides as well as lipid-linked oligosaccharide (LLO) analogs containing a chitobiose moiety coupled to oligoprenyl carriers of distinct lengths (C10, C15, C20 and C25) and with different double bond stereochemistry. We found that in addition to proline, charged residues at the +1 position of the sequon inhibited glycan transfer. An acidic residue at the −2 position significantly increased catalytic turnover but was not essential, in contrast to the bacterial OST. While all synthetic LLO analogs were processed by TbSTT3A, the length of the polyprenyl tail, but not the stereochemistry of the double bonds, determined their apparent affinity. We also synthesized phosphonate analogs of the LLOs, which were found to be competitive inhibitors of the reaction, although with lower apparent affinity to TbSTT3A than the active pyrophosphate analogs.
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Affiliation(s)
- Ana S Ramírez
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), CH-8093 Zürich, Switzerland
| | - Jérémy Boilevin
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Rasomoy Biswas
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Bee Ha Gan
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Daniel Janser
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), CH-8093 Zürich, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH), CH-8093 Zürich, Switzerland
| | - Tamis Darbre
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), CH-8093 Zürich, Switzerland
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16
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Affiliation(s)
- Markus Aebi
- Department of BiologyETH ZürichZürichSwitzerland
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17
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Schmid-Hempel P, Aebi M, Barribeau S, Kitajima T, du Plessis L, Schmid-Hempel R, Zoller S. The genomes of Crithidia bombi and C. expoeki, common parasites of bumblebees. PLoS One 2018; 13:e0189738. [PMID: 29304093 PMCID: PMC5755769 DOI: 10.1371/journal.pone.0189738] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [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: 07/15/2017] [Accepted: 11/30/2017] [Indexed: 11/19/2022] Open
Abstract
Trypanosomatids (Trypanosomatidae, Kinetoplastida) are flagellated protozoa containing many parasites of medical or agricultural importance. Among those, Crithidia bombi and C. expoeki, are common parasites in bumble bees around the world, and phylogenetically close to Leishmania and Leptomonas. They have a simple and direct life cycle with one host, and partially castrate the founding queens greatly reducing their fitness. Here, we report the nuclear genome sequences of one clone of each species, extracted from a field-collected infection. Using a combination of Roche 454 FLX Titanium, Pacific Biosciences PacBio RS, and Illumina GA2 instruments for C. bombi, and PacBio for C. expoeki, we could produce high-quality and well resolved sequences. We find that these genomes are around 32 and 34 MB, with 7,808 and 7,851 annotated genes for C. bombi and C. expoeki, respectively-which is somewhat less than reported from other trypanosomatids, with few introns, and organized in polycistronic units. A large fraction of genes received plausible functional support in comparison primarily with Leishmania and Trypanosoma. Comparing the annotated genes of the two species with those of six other trypanosomatids (C. fasciculata, L. pyrrhocoris, L. seymouri, B. ayalai, L. major, and T. brucei) shows similar gene repertoires and many orthologs. Similar to other trypanosomatids, we also find signs of concerted evolution in genes putatively involved in the interaction with the host, a high degree of synteny between C. bombi and C. expoeki, and considerable overlap with several other species in the set. A total of 86 orthologous gene groups show signatures of positive selection in the branch leading to the two Crithidia under study, mostly of unknown function. As an example, we examined the initiating glycosylation pathway of surface components in C. bombi, finding it deviates from most other eukaryotes and also from other kinetoplastids, which may indicate rapid evolution in the extracellular matrix that is involved in interactions with the host. Bumble bees are important pollinators and Crithidia-infections are suspected to cause substantial selection pressure on their host populations. These newly sequenced genomes provide tools that should help better understand host-parasite interactions in these pollinator pathogens.
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Affiliation(s)
| | - Markus Aebi
- Institute of Microbiology, ETH Zurich, Zürich, Switzerland
| | - Seth Barribeau
- Institute of Integrative Biology (IBZ), ETH Zurich, Zürich, Switzerland
| | | | - Louis du Plessis
- Institute of Integrative Biology (IBZ), ETH Zurich, Zürich, Switzerland
| | | | - Stefan Zoller
- Genetic Diversity Centre (GDC), ETH Zurich, Zürich, Switzerland
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18
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Wild R, Kowal J, Eyring J, Ngwa EM, Aebi M, Locher KP. Structure of the yeast oligosaccharyltransferase complex gives insight into eukaryotic N-glycosylation. Science 2018; 359:545-550. [PMID: 29301962 DOI: 10.1126/science.aar5140] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 12/22/2017] [Indexed: 12/18/2022]
Abstract
Oligosaccharyltransferase (OST) is an essential membrane protein complex in the endoplasmic reticulum, where it transfers an oligosaccharide from a dolichol-pyrophosphate-activated donor to glycosylation sites of secretory proteins. Here we describe the atomic structure of yeast OST determined by cryo-electron microscopy, revealing a conserved subunit arrangement. The active site of the catalytic STT3 subunit points away from the center of the complex, allowing unhindered access to substrates. The dolichol-pyrophosphate moiety binds to a lipid-exposed groove of STT3, whereas two noncatalytic subunits and an ordered N-glycan form a membrane-proximal pocket for the oligosaccharide. The acceptor polypeptide site faces an oxidoreductase domain in stand-alone OST complexes or is immediately adjacent to the translocon, suggesting how eukaryotic OSTs efficiently glycosylate a large number of polypeptides before their folding.
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Affiliation(s)
- Rebekka Wild
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Julia Kowal
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Jillianne Eyring
- Institute of Microbiology, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Elsy M Ngwa
- Institute of Microbiology, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland.
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19
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Joshi HJ, Narimatsu Y, Schjoldager KT, Tytgat HL, Aebi M, Clausen H, Halim A. SnapShot: O-Glycosylation Pathways across Kingdoms. Cell 2018; 172:632-632.e2. [DOI: 10.1016/j.cell.2018.01.016] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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20
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Poljak K, Breitling J, Gauss R, Rugarabamu G, Pellanda M, Aebi M. Analysis of substrate specificity of Trypanosoma brucei oligosaccharyltransferases (OSTs) by functional expression of domain-swapped chimeras in yeast. J Biol Chem 2017; 292:20342-20352. [PMID: 29042445 DOI: 10.1074/jbc.m117.811133] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 08/09/2017] [Revised: 10/11/2017] [Indexed: 11/06/2022] Open
Abstract
N-Linked protein glycosylation is an essential and highly conserved post-translational modification in eukaryotes. The transfer of a glycan from a lipid-linked oligosaccharide (LLO) donor to the asparagine residue of a nascent polypeptide chain is catalyzed by an oligosaccharyltransferase (OST) in the lumen of the endoplasmic reticulum (ER). Trypanosoma brucei encodes three paralogue single-protein OSTs called TbSTT3A, TbSTT3B, and TbSTT3C that can functionally complement the Saccharomyces cerevisiae OST, making it an ideal experimental system to study the fundamental properties of OST activity. We characterized the LLO and polypeptide specificity of all three TbOST isoforms and their chimeric forms in the heterologous expression host S. cerevisiae where we were able to apply yeast genetic tools and newly developed glycoproteomics methods. We demonstrated that TbSTT3A accepted LLO substrates ranging from Man5GlcNAc2 to Man7GlcNAc2 In contrast, TbSTT3B required more complex precursors ranging from Man6GlcNAc2 to Glc3Man9GlcNAc2 structures, and TbSTT3C did not display any LLO preference. Sequence differences between the isoforms cluster in three distinct regions. We have swapped the individual regions between different OST proteins and identified region 2 to influence the specificity toward the LLO and region 1 to influence polypeptide substrate specificity. These results provide a basis to further investigate the molecular mechanisms and contribution of single amino acids in OST interaction with its substrates.
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Affiliation(s)
- Kristina Poljak
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland
| | - Jörg Breitling
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland
| | - Robert Gauss
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland
| | - George Rugarabamu
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland
| | - Mauro Pellanda
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland
| | - Markus Aebi
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland.
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21
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Cuccui J, Terra VS, Bossé JT, Naegeli A, Abouelhadid S, Li Y, Lin CW, Vohra P, Tucker AW, Rycroft AN, Maskell DJ, Aebi M, Langford PR, Wren BW. The N-linking glycosylation system from Actinobacillus pleuropneumoniae is required for adhesion and has potential use in glycoengineering. Open Biol 2017; 7:rsob.160212. [PMID: 28077594 PMCID: PMC5303269 DOI: 10.1098/rsob.160212] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [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: 07/18/2016] [Accepted: 11/28/2016] [Indexed: 12/16/2022] Open
Abstract
Actinobacillus pleuropneumoniae is a mucosal respiratory pathogen causing contagious porcine pleuropneumonia. Pathogenesis studies have demonstrated a major role for the capsule, exotoxins and outer membrane proteins. Actinobacillus pleuropneumoniae can also glycosylate proteins, using a cytoplasmic N-linked glycosylating enzyme designated NGT, but its transcriptional arrangement and role in virulence remains unknown. We investigated the NGT locus and demonstrated that the putative transcriptional unit consists of rimO, ngt and a glycosyltransferase termed agt. From this information we used the A. pleuropneumoniae glycosylation locus to decorate an acceptor protein, within Escherichia coli, with a hexose polymer that reacted with an anti-dextran antibody. Mass spectrometry analysis of a truncated protein revealed that this operon could add up to 29 repeat units to the appropriate sequon. We demonstrated the importance of NGT in virulence, by creating deletion mutants and testing them in a novel respiratory cell line adhesion model. This study demonstrates the importance of the NGT glycosylation system for pathogenesis and its potential biotechnological application for glycoengineering.
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Affiliation(s)
- Jon Cuccui
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Vanessa S Terra
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Janine T Bossé
- Section of Paediatrics, Department of Medicine, Imperial College London, St. Mary's Campus, London W2 1PG, UK
| | - Andreas Naegeli
- Institute of Microbiology, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland
| | - Sherif Abouelhadid
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Yanwen Li
- Section of Paediatrics, Department of Medicine, Imperial College London, St. Mary's Campus, London W2 1PG, UK
| | - Chia-Wei Lin
- Institute of Microbiology, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland
| | - Prerna Vohra
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Alexander W Tucker
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - Andrew N Rycroft
- The Royal Veterinary College, Hawkshead Campus, Hatfield, Hertfordshire AL9 7TA, UK
| | - Duncan J Maskell
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - Markus Aebi
- Institute of Microbiology, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland
| | - Paul R Langford
- Section of Paediatrics, Department of Medicine, Imperial College London, St. Mary's Campus, London W2 1PG, UK
| | - Brendan W Wren
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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22
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Keys TG, Wetter M, Hang I, Rutschmann C, Russo S, Mally M, Steffen M, Zuppiger M, Müller F, Schneider J, Faridmoayer A, Lin CW, Aebi M. A biosynthetic route for polysialylating proteins in Escherichia coli. Metab Eng 2017; 44:293-301. [PMID: 29101090 DOI: 10.1016/j.ymben.2017.10.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [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: 07/17/2017] [Revised: 09/12/2017] [Accepted: 10/27/2017] [Indexed: 01/08/2023]
Abstract
Polysialic acid (polySia) is a posttranslational modification found on only a handful of proteins in the central nervous and immune systems. The addition of polySia to therapeutic proteins improves pharmacokinetics and reduces immunogenicity. To date, polysialylation of therapeutic proteins has only been achieved in vitro by chemical or chemoenzymatic strategies. In this work, we develop a biosynthetic pathway for site-specific polysialylation of recombinant proteins in the cytoplasm of Escherichia coli. The pathway takes advantage of a bacterial cytoplasmic polypeptide-glycosyltransferase to establish a site-specific primer on the target protein. The glucose primer is extended by glycosyltransferases derived from lipooligosaccharide, lipopolysaccharide and capsular polysaccharide biosynthesis from different bacterial species to synthesize long chain polySia. We demonstrate the new biosynthetic route by modifying green fluorescent proteins and a therapeutic DARPin (designed ankyrin repeat protein).
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Affiliation(s)
- Timothy G Keys
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | | | - Ivan Hang
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | | | | | | | | | | | | | | | | | - Chia-Wei Lin
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.
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23
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Napiórkowska M, Boilevin J, Sovdat T, Darbre T, Reymond JL, Aebi M, Locher KP. Molecular basis of lipid-linked oligosaccharide recognition and processing by bacterial oligosaccharyltransferase. Nat Struct Mol Biol 2017; 24:1100-1106. [PMID: 29058712 DOI: 10.1038/nsmb.3491] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 09/21/2017] [Indexed: 11/09/2022]
Abstract
Oligosaccharyltransferase (OST) is a membrane-integral enzyme that catalyzes the transfer of glycans from lipid-linked oligosaccharides (LLOs) onto asparagine side chains, the first step in protein N-glycosylation. Here, we report the X-ray structure of a single-subunit OST, PglB from Campylobacter lari, trapped in an intermediate state bound to an acceptor peptide and a synthetic LLO analog. The structure reveals the role of the external loop EL5, present in all OST enzymes, in substrate recognition. Whereas the N-terminal half of EL5 binds LLO, the C-terminal half interacts with the acceptor peptide. The glycan moiety of LLO must thread under EL5 to access the active site. Reducing EL5 mobility decreases the catalytic rate of OST when full-size heptasaccharide LLO is provided, but not for a monosaccharide-containing LLO analog. Our results define the chemistry of a ternary complex state, assign functional roles to conserved OST motifs, and provide opportunities for glycoengineering by rational design of PglB.
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Affiliation(s)
- Maja Napiórkowska
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Jérémy Boilevin
- Department of Chemistry and Biochemistry, University of Berne, Berne, Switzerland
| | - Tina Sovdat
- Department of Chemistry and Biochemistry, University of Berne, Berne, Switzerland
| | - Tamis Darbre
- Department of Chemistry and Biochemistry, University of Berne, Berne, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Berne, Berne, Switzerland
| | - Markus Aebi
- Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
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24
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Poljak K, Selevsek N, Ngwa E, Grossmann J, Losfeld ME, Aebi M. Quantitative Profiling of N-linked Glycosylation Machinery in Yeast Saccharomyces cerevisiae. Mol Cell Proteomics 2017; 17:18-30. [PMID: 28993419 DOI: 10.1074/mcp.ra117.000096] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Indexed: 11/06/2022] Open
Abstract
Asparagine-linked glycosylation is a common posttranslational protein modification regulating the structure, stability and function of many proteins. The N-linked glycosylation machinery involves enzymes responsible for the assembly of the lipid-linked oligosaccharide (LLO), which is then transferred to the asparagine residues on the polypeptides by the enzyme oligosaccharyltransferase (OST). A major goal in the study of protein glycosylation is to establish quantitative methods for the analysis of site-specific extent of glycosylation. We developed a sensitive approach to examine glycosylation site occupancy in Saccharomyces cerevisiae by coupling stable isotope labeling (SILAC) approach to parallel reaction monitoring (PRM) mass spectrometry (MS). We combined the method with genetic tools and validated the approach with the identification of novel glycosylation sites dependent on the Ost3p and Ost6p regulatory subunits of OST. Based on the observations that alternations in LLO substrate structure and OST subunits activity differentially alter the systemic output of OST, we conclude that sequon recognition is a direct property of the catalytic subunit Stt3p, auxiliary subunits such as Ost3p and Ost6p extend the OST substrate range by modulating interfering pathways such as protein folding. In addition, our proteomics approach revealed a novel regulatory network that connects isoprenoid lipid biosynthesis and LLO substrate assembly.
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Affiliation(s)
- Kristina Poljak
- From the ‡Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland
| | - Nathalie Selevsek
- §Functional Genomics Center Zurich, UZH/ETH Zurich, CH-8057 Zurich, Switzerland
| | - Elsy Ngwa
- From the ‡Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland
| | - Jonas Grossmann
- §Functional Genomics Center Zurich, UZH/ETH Zurich, CH-8057 Zurich, Switzerland
| | - Marie Estelle Losfeld
- From the ‡Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland
| | - Markus Aebi
- From the ‡Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland;
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25
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Losfeld ME, Scibona E, Lin CW, Villiger TK, Gauss R, Morbidelli M, Aebi M. Influence of protein/glycan interaction on site-specific glycan heterogeneity. FASEB J 2017; 31:4623-4635. [PMID: 28679530 DOI: 10.1096/fj.201700403r] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 06/19/2017] [Indexed: 01/23/2023]
Abstract
To study how the interaction between N-linked glycans and the surrounding amino acids influences oligosaccharide processing, we used protein disulfide isomerase (PDI), a glycoprotein bearing 5 N-glycosylation sites, as a model system and expressed it transiently in a Chinese hamster ovary (CHO)-S cell line. PDI was produced as both secreted Sec-PDI and endoplasmic reticulum-retained glycoprotein (ER)-PDI, to study glycan processing by ER and Golgi resident enzymes. Quantitative site-specific glycosylation profiles were obtained, and flux analysis enabled modeling site-specific glycan processing. By altering the primary sequence of PDI, we changed the glycan/protein interaction and thus the site-specific glycoprofile because of the improved enzymatic fluxes at enzymatic bottlenecks. Our results highlight the importance of direct interactions between N-glycans and surface-exposed amino acids of glycoproteins on processing in the ER and the Golgi and the possibility of changing a site-specific N-glycan profile by modulating such interactions and thus the associated enzymatic fluxes. Altering the primary protein sequence can therefore be used to glycoengineer recombinant proteins.-Losfeld, M.-E., Scibona, E., Lin, C.-W., Villiger, T. K., Gauss, R., Morbidelli, M., Aebi, M. Influence of protein/glycan interaction on site-specific glycan heterogeneity.
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Affiliation(s)
- Marie-Estelle Losfeld
- Department of Biology, Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland
| | - Ernesto Scibona
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology ETH Zürich, Zürich, Switzerland
| | - Chia-Wei Lin
- Department of Biology, Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland
| | - Thomas K Villiger
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology ETH Zürich, Zürich, Switzerland
| | - Robert Gauss
- Department of Biology, Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland
| | - Massimo Morbidelli
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology ETH Zürich, Zürich, Switzerland
| | - Markus Aebi
- Department of Biology, Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland;
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26
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Ramírez AS, Boilevin J, Lin CW, Ha Gan B, Janser D, Aebi M, Darbre T, Reymond JL, Locher KP. Chemo-enzymatic synthesis of lipid-linked GlcNAc2Man5 oligosaccharides using recombinant Alg1, Alg2 and Alg11 proteins. Glycobiology 2017; 27:726-733. [PMID: 28575298 PMCID: PMC5881667 DOI: 10.1093/glycob/cwx045] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [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: 03/03/2017] [Revised: 05/10/2017] [Accepted: 05/27/2017] [Indexed: 11/14/2022] Open
Abstract
The biosynthesis of eukaryotic lipid-linked oligosaccharides (LLOs) that act as donor substrates in eukaryotic protein N-glycosylation starts on the cytoplasmic side of the endoplasmic reticulum and includes the sequential addition of five mannose units to dolichol-pyrophosphate-GlcNAc2. These reactions are catalyzed by the Alg1, Alg2 and Alg11 gene products and yield Dol-PP-GlcNAc2Man5, an LLO intermediate that is subsequently flipped to the lumen of the endoplasmic reticulum. While the purification of active Alg1 has previously been described, Alg11 and Alg2 have been mostly studied in vivo. We here describe the expression and purification of functional, full length Alg2 protein. Along with the purified soluble domains Alg1 and Alg11, we used Alg2 to chemo-enzymatically generate Dol-PP-GlcNAc2Man5 analogs starting from synthetic LLOs containing a chitobiose moiety coupled to oligoprenyl carriers of distinct lengths (C10, C15, C20 and C25). We found that while the addition of the first mannose unit by Alg1 was successful with all of the LLO molecules, the Alg2-catalyzed reaction was only efficient if the acceptor LLOs contained a sufficiently long lipid tail of four or five isoprenyl units (C20 and C25). Following conversion with Alg11, the resulting C20 or C25 -containing GlcNAc2Man5 LLO analogs were successfully used as donor substrates of purified single-subunit oligosaccharyltransferase STT3A from Trypanosoma brucei. Our results provide a chemo-enzymatic method for the generation of eukaryotic LLO analogs and are the basis of subsequent mechanistic studies of the enigmatic Alg2 reaction mechanism.
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Affiliation(s)
- Ana S Ramírez
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), Schafmattstrasse 20, CH-8093 Zürich, Switzerland
| | - Jérémy Boilevin
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Chia-Wei Lin
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH), CH-8093 Zürich, Switzerland
| | - Bee Ha Gan
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Daniel Janser
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), Schafmattstrasse 20, CH-8093 Zürich, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH), CH-8093 Zürich, Switzerland
| | - Tamis Darbre
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Kaspar P Locher
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), Schafmattstrasse 20, CH-8093 Zürich, Switzerland
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27
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Cuccui J, Terra VS, Bossé JT, Naegeli A, Abouelhadid S, Li Y, Lin CW, Vohra P, Tucker AW, Rycroft AN, Maskell DJ, Aebi M, Langford PR, Wren BW. The N-linking glycosylation system from Actinobacillus pleuropneumoniae is required for adhesion and has potential use in glycoengineering. Open Biol 2017. [PMID: 28077594 DOI: 10.1098/rsob.160212.] [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] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Actinobacillus pleuropneumoniae is a mucosal respiratory pathogen causing contagious porcine pleuropneumonia. Pathogenesis studies have demonstrated a major role for the capsule, exotoxins and outer membrane proteins. Actinobacillus pleuropneumoniae can also glycosylate proteins, using a cytoplasmic N-linked glycosylating enzyme designated NGT, but its transcriptional arrangement and role in virulence remains unknown. We investigated the NGT locus and demonstrated that the putative transcriptional unit consists of rimO, ngt and a glycosyltransferase termed agt. From this information we used the A. pleuropneumoniae glycosylation locus to decorate an acceptor protein, within Escherichia coli, with a hexose polymer that reacted with an anti-dextran antibody. Mass spectrometry analysis of a truncated protein revealed that this operon could add up to 29 repeat units to the appropriate sequon. We demonstrated the importance of NGT in virulence, by creating deletion mutants and testing them in a novel respiratory cell line adhesion model. This study demonstrates the importance of the NGT glycosylation system for pathogenesis and its potential biotechnological application for glycoengineering.
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Affiliation(s)
- Jon Cuccui
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Vanessa S Terra
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Janine T Bossé
- Section of Paediatrics, Department of Medicine, Imperial College London, St. Mary's Campus, London W2 1PG, UK
| | - Andreas Naegeli
- Institute of Microbiology, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland
| | - Sherif Abouelhadid
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Yanwen Li
- Section of Paediatrics, Department of Medicine, Imperial College London, St. Mary's Campus, London W2 1PG, UK
| | - Chia-Wei Lin
- Institute of Microbiology, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland
| | - Prerna Vohra
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Alexander W Tucker
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - Andrew N Rycroft
- The Royal Veterinary College, Hawkshead Campus, Hatfield, Hertfordshire AL9 7TA, UK
| | - Duncan J Maskell
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - Markus Aebi
- Institute of Microbiology, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland
| | - Paul R Langford
- Section of Paediatrics, Department of Medicine, Imperial College London, St. Mary's Campus, London W2 1PG, UK
| | - Brendan W Wren
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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28
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Lin CW, Haeuptle MA, Aebi M. Supercharging Reagent for Enhanced Liquid Chromatographic Separation and Charging of Sialylated and High-Molecular-Weight Glycopeptides for NanoHPLC–ESI-MS/MS Analysis. Anal Chem 2016; 88:8484-94. [DOI: 10.1021/acs.analchem.6b00938] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Chia-wei Lin
- Institute of Microbiology, Department of
Biology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland
| | | | - Markus Aebi
- Institute of Microbiology, Department of
Biology, ETH Zurich, Vladimir-Prelog-Weg 4, CH-8093 Zurich, Switzerland
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29
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Abstract
During the years 2012 to 2014, a total of 5 affected Simmental cattle showing persistent bleeding after minor or unknown trauma, were presented at the Clinic for Ruminants or at the Institute for Genetics of the Vetsuisse-Faculty, University of Berne. The homozygous mutation RASGRP2, initially reported in 2007, was present in all these cases and all available parents were heterozygous carriers thus confirming the recessive mode of inheritance. Three affected animals died as a result of persistent bleeding. One animal was stabilized at the Clinic for Ruminants and was slaughtered one month later. Another case showing persistent bleeding and several hematomas was euthanized after genotyping. A frequency of 10% carriers for the associated mutation was detected in a sample of 145 Simmental sires which were used 2013 for artificial insemination in Switzerland. These bulls are designated as TP carriers and should not be used uncontrolled. Breeding organizations in Switzerland make use of the gene test to select bulls which do not carry the mutation.
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30
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Abstract
Obtaining good estimates for the distribution function of random variables like (‘perpetuity’) and (‘aggregate claim amount’), where the (Yi), (Zi) are independent i.i.d. sequences and (N(t)) is a general point process, is a key question in insurance mathematics. In this paper, we show how suitably chosen metrics provide a theoretical justification for bootstrap estimation in these cases. In the perpetuity case, we also give a detailed discussion of how the method works in practice.
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31
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Wüthrich M, Lechner I, Aebi M, Vögtlin A, Posthaus H, Schüpbach-Regula G, Meylan M. A case–control study to estimate the effects of acute clinical infection with the Schmallenberg virus on milk yield, fertility and veterinary costs in Swiss dairy herds. Prev Vet Med 2016; 126:54-65. [DOI: 10.1016/j.prevetmed.2016.01.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 01/22/2016] [Accepted: 01/25/2016] [Indexed: 01/13/2023]
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32
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Kandiba L, Lin CW, Aebi M, Eichler J, Guerardel Y. Structural characterization of the N-linked pentasaccharide decorating glycoproteins of the halophilic archaeon Haloferax volcanii. Glycobiology 2016; 26:745-756. [PMID: 26863921 DOI: 10.1093/glycob/cww014] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [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: 01/08/2016] [Accepted: 02/03/2016] [Indexed: 12/30/2022] Open
Abstract
N-Glycosylation is a post-translational modification performed in all three domains of life. In the halophilic archaea Haloferax volcanii, glycoproteins such as the S-layer glycoprotein are modified by an N-linked pentasaccharide assembled by a series of Agl (archaeal glycosylation) proteins. In the present study, mass spectrometry (MS) and nuclear magnetic resonance spectroscopy were used to define the structure of this glycan attached to at least four of the seven putative S-layer glycoprotein N-glycosylation sites, namely Asn-13, Asn-83, Asn-274 and Asn-279. Such approaches detected a trisaccharide corresponding to glucuronic acid (GlcA)-β1,4-GlcA-β1,4-glucose-β1-Asn, a tetrasaccharide corresponding to methyl-O-4-GlcA-β-1,4-galacturonic acid-α1,4-GlcA-β1,4-glucose-β1-Asn, and a pentasaccharide corresponding to hexose-1,2-[methyl-O-4-]GlcA-β-1,4-galacturonic acid-α1,4-GlcA-β1,4-glucose-β1-Asn, with previous MS and radiolabeling experiments showing the hexose at the non-reducing end of the pentasaccharide to be mannose. The present analysis thus corrects the earlier assignment of the penultimate sugar as a methyl ester of a hexuronic acid, instead revealing this sugar to be a methylated GlcA. The assignments made here are in good agreement with what was already known of the Hfx. volcanii N-glycosylation pathway from previous genetic and biochemical efforts while providing new insight into the process.
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Affiliation(s)
- Lina Kandiba
- Department of Life Sciences, Ben Gurion University of the Negev, PO Box 653, Beersheva 84105, Israel
| | - Chia-Wei Lin
- Institute of Microbiology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Markus Aebi
- Institute of Microbiology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Jerry Eichler
- Department of Life Sciences, Ben Gurion University of the Negev, PO Box 653, Beersheva 84105, Israel
| | - Yann Guerardel
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F 59000 Lille, France
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33
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Varki A, Cummings RD, Aebi M, Packer NH, Seeberger PH, Esko JD, Stanley P, Hart G, Darvill A, Kinoshita T, Prestegard JJ, Schnaar RL, Freeze HH, Marth JD, Bertozzi CR, Etzler ME, Frank M, Vliegenthart JF, Lütteke T, Perez S, Bolton E, Rudd P, Paulson J, Kanehisa M, Toukach P, Aoki-Kinoshita KF, Dell A, Narimatsu H, York W, Taniguchi N, Kornfeld S. Symbol Nomenclature for Graphical Representations of Glycans. Glycobiology 2016; 25:1323-4. [PMID: 26543186 DOI: 10.1093/glycob/cwv091] [Citation(s) in RCA: 684] [Impact Index Per Article: 85.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ajit Varki
- Editor, Third Edition of Essentials of Glycobiology Glycan Symbol Nomenclature Discussion Group, 2014-2015 UC San Diego, La Jolla, CA, USA
| | - Richard D Cummings
- Editor, Third Edition of Essentials of Glycobiology Glycan Symbol Nomenclature Discussion Group, 2014-2015 Illustrations Editor, Essentials of Glycobiology Chair, Consortium for Functional Glycomics Harvard Medical School, Boston, MA, USA
| | - Markus Aebi
- Editor, Third Edition of Essentials of Glycobiology Glycan Symbol Nomenclature Discussion Group, 2014-2015 ETH Zürich, Zürich, Switzerland
| | - Nicole H Packer
- Editor, Third Edition of Essentials of Glycobiology Glycan Symbol Nomenclature Discussion Group, 2014-2015 Macquarie University, Sydney, NSW, Australia
| | - Peter H Seeberger
- Editor, Third Edition of Essentials of Glycobiology Glycan Symbol Nomenclature Discussion Group, 2014-2015 Max-Planck-Institute, Potsdam-Golm, Germany
| | - Jeffrey D Esko
- Editor, Third Edition of Essentials of Glycobiology UC San Diego, La Jolla, CA, USA
| | - Pamela Stanley
- Editor, Third Edition of Essentials of Glycobiology Albert Einstein College of Medicine, New York, NY, USA
| | - Gerald Hart
- Editor, Third Edition of Essentials of Glycobiology Johns Hopkins University, Baltimore, MD, USA
| | - Alan Darvill
- Editor, Third Edition of Essentials of Glycobiology University of Georgia, Athens, GA, USA
| | - Taroh Kinoshita
- Editor, Third Edition of Essentials of Glycobiology Osaka University, Osaka, Japan
| | - James J Prestegard
- Editor, Third Edition of Essentials of Glycobiology University of Georgia, Athens, GA, USA
| | - Ronald L Schnaar
- Editor, Third Edition of Essentials of Glycobiology Johns Hopkins University, Baltimore, MD, USA
| | - Hudson H Freeze
- Editor, earlier Edition of Essentials of Glycobiology Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Jamey D Marth
- Editor, earlier Edition of Essentials of Glycobiology UC Santa Barbara, Santa Barbara, CA, USA
| | - Carolyn R Bertozzi
- Editor, earlier Edition of Essentials of Glycobiology Stanford University, Stanford, CA, USA
| | - Marilynn E Etzler
- Editor, earlier Edition of Essentials of Glycobiology UC Davis, Davis, CA, USA
| | - Martin Frank
- Glycan Symbol Nomenclature Discussion Group, 2014-2015 IUPAC Carbohydrate Nomenclature Committee Biognos AB, Gothenburg, Sweden
| | - Johannes Fg Vliegenthart
- Glycan Symbol Nomenclature Discussion Group, 2014-2015 IUPAC Carbohydrate Nomenclature Committee Utrecht University, Utrecht, Netherlands
| | - Thomas Lütteke
- Glycan Symbol Nomenclature Discussion Group, 2014-2015 IUPAC Carbohydrate Nomenclature Committee Curator, MonosaccharideDB Justus-Liebig-University Giessen, Giessen, Germany
| | - Serge Perez
- Glycan Symbol Nomenclature Discussion Group, 2014-2015 Curator, Glycopedia CNRS-University Grenoble Alpes, Saint-Martin-d'Hères, France
| | - Evan Bolton
- Glycan Symbol Nomenclature Discussion Group, 2014-2015 Lead Scientist, PubChem, National Center for Biotechnology Information National Library of Medicine, Bethesda, MD, USA
| | - Pauline Rudd
- Oxford Glycobiology Institute National Institute for Bioprocessing, Research and Training, Dublin, Ireland
| | - James Paulson
- Past Chair, Consortium for Functional Glycomics The Scripps Research Institute La Jolla, La Jolla, CA, USA
| | - Minoru Kanehisa
- Principal Investigator, KEGG Database Kyoto University, Kyoto, Japan
| | - Philip Toukach
- Glycan Symbol Nomenclature Discussion Group, 2014-2015 Curator, Carbohydrate Structure Database (CSDB) Zelinsky Institute of Organic Chemistry, Moscow, Russia
| | | | | | - Hisashi Narimatsu
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | | | | | - Stuart Kornfeld
- Washington University School of Medicine, St. Louis, MO, USA
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34
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Neubert P, Halim A, Zauser M, Essig A, Joshi HJ, Zatorska E, Larsen ISB, Loibl M, Castells-Ballester J, Aebi M, Clausen H, Strahl S. Mapping the O-Mannose Glycoproteome in Saccharomyces cerevisiae. Mol Cell Proteomics 2016; 15:1323-37. [PMID: 26764011 PMCID: PMC4824858 DOI: 10.1074/mcp.m115.057505] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Indexed: 11/17/2022] Open
Abstract
O-Mannosylation is a vital protein modification conserved from fungi to humans. Yeast is a perfect model to study this post-translational modification, because in contrast to mammals O-mannosylation is the only type of O-glycosylation. In an essential step toward the full understanding of protein O-mannosylation we mapped the O-mannose glycoproteome in baker's yeast. Taking advantage of an O-glycan elongation deficient yeast strain to simplify sample complexity, we identified over 500 O-glycoproteins from all subcellular compartments for which over 2300 O-mannosylation sites were mapped by electron-transfer dissociation (ETD)-based MS/MS. In this study, we focus on the 293 O-glycoproteins (over 1900 glycosylation sites identified by ETD-MS/MS) that enter the secretory pathway and are targets of ER-localized protein O-mannosyltransferases. We find that O-mannosylation is not only a prominent modification of cell wall and plasma membrane proteins, but also of a large number of proteins from the secretory pathway with crucial functions in protein glycosylation, folding, quality control, and trafficking. The analysis of glycosylation sites revealed that O-mannosylation is favored in unstructured regions and β-strands. Furthermore, O-mannosylation is impeded in the proximity of N-glycosylation sites suggesting the interplay of these types of post-translational modifications. The detailed knowledge of the target proteins and their O-mannosylation sites opens for discovery of new roles of this essential modification in eukaryotes, and for a first glance on the evolution of different types of O-glycosylation from yeast to mammals.
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Affiliation(s)
- Patrick Neubert
- From the ‡Centre for Organismal Studies (COS), Department of Cell Chemistry, Heidelberg University, Im Neuenheimer Feld 360, D-69120 Heidelberg, Germany
| | - Adnan Halim
- §Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Martin Zauser
- From the ‡Centre for Organismal Studies (COS), Department of Cell Chemistry, Heidelberg University, Im Neuenheimer Feld 360, D-69120 Heidelberg, Germany
| | - Andreas Essig
- ¶Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Hiren J Joshi
- §Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Ewa Zatorska
- From the ‡Centre for Organismal Studies (COS), Department of Cell Chemistry, Heidelberg University, Im Neuenheimer Feld 360, D-69120 Heidelberg, Germany
| | - Ida Signe Bohse Larsen
- §Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Martin Loibl
- From the ‡Centre for Organismal Studies (COS), Department of Cell Chemistry, Heidelberg University, Im Neuenheimer Feld 360, D-69120 Heidelberg, Germany
| | - Joan Castells-Ballester
- From the ‡Centre for Organismal Studies (COS), Department of Cell Chemistry, Heidelberg University, Im Neuenheimer Feld 360, D-69120 Heidelberg, Germany
| | - Markus Aebi
- ¶Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Henrik Clausen
- §Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Sabine Strahl
- From the ‡Centre for Organismal Studies (COS), Department of Cell Chemistry, Heidelberg University, Im Neuenheimer Feld 360, D-69120 Heidelberg, Germany;
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35
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Hang I, Lin CW, Grant OC, Fleurkens S, Villiger TK, Soos M, Morbidelli M, Woods RJ, Gauss R, Aebi M. Analysis of site-specific N-glycan remodeling in the endoplasmic reticulum and the Golgi. Glycobiology 2015; 25:1335-49. [PMID: 26240167 PMCID: PMC4634314 DOI: 10.1093/glycob/cwv058] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [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: 06/12/2015] [Revised: 07/14/2015] [Accepted: 07/27/2015] [Indexed: 11/14/2022] Open
Abstract
The hallmark of N-linked protein glycosylation is the generation of diverse glycan structures in the secretory pathway. Dynamic, non-template-driven processes of N-glycan remodeling in the endoplasmic reticulum and the Golgi provide the cellular setting for structural diversity. We applied newly developed mass spectrometry-based analytics to quantify site-specific N-glycan remodeling of the model protein Pdi1p expressed in insect cells. Molecular dynamics simulation, mutational analysis, kinetic studies of in vitro processing events and glycan flux analysis supported the defining role of the protein in N-glycan processing.
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Affiliation(s)
- Ivan Hang
- Institute of Microbiology, Department of Biology
| | - Chia-wei Lin
- Institute of Microbiology, Department of Biology
| | - Oliver C Grant
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | | | - Thomas K Villiger
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Miroslav Soos
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Massimo Morbidelli
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Robert J Woods
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Robert Gauss
- Institute of Microbiology, Department of Biology
| | - Markus Aebi
- Institute of Microbiology, Department of Biology
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36
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Rodrigues JA, Acosta-Serrano A, Aebi M, Ferguson MAJ, Routier FH, Schiller I, Soares S, Spencer D, Titz A, Wilson IBH, Izquierdo L. Parasite Glycobiology: A Bittersweet Symphony. PLoS Pathog 2015; 11:e1005169. [PMID: 26562305 PMCID: PMC4642930 DOI: 10.1371/journal.ppat.1005169] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Affiliation(s)
- Joao A. Rodrigues
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
- * E-mail: (JAR); (LI)
| | - Alvaro Acosta-Serrano
- Department of Parasitology & Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - Michael A. J. Ferguson
- Division of Biological Chemistry and Drug Discovery, The College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | | | | | | | - Daniel Spencer
- Ludger Ltd., Culham Science Centre, Abingdon, Oxfordshire, United Kingdom
| | - Alexander Titz
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarbrücken, Germany
| | | | - Luis Izquierdo
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- * E-mail: (JAR); (LI)
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37
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Heim C, Hertzberg H, Butschi A, Bleuler-Martinez S, Aebi M, Deplazes P, Künzler M, Štefanić S. Inhibition of Haemonchus contortus larval development by fungal lectins. Parasit Vectors 2015; 8:425. [PMID: 26283415 PMCID: PMC4539729 DOI: 10.1186/s13071-015-1032-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [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: 04/13/2015] [Accepted: 08/05/2015] [Indexed: 11/10/2022] Open
Abstract
Background Lectins are carbohydrate-binding proteins that are involved in fundamental intra- and extracellular biological processes. They occur ubiquitously in nature and are especially abundant in plants and fungi. It has been well established that certain higher fungi produce lectins in their fruiting bodies and/or sclerotia as a part of their natural resistance against free-living fungivorous nematodes and other pests. Despite relatively high diversity of the glycan structures in nature, many of the glycans targeted by fungal lectins are conserved among organisms of the same taxon and sometimes even among different taxa. Such conservation of glycans between free-living and parasitic nematodes is providing us with a useful tool for discovery of novel chemotherapeutic and vaccine targets. In our study, a subset of fungal lectins emanating from toxicity screens on Caenorhabditis elegans was tested for their potential to inhibit larval development of Haemonchus contortus. Methods The effect of Coprinopsis cinerea lectins - CCL2, CGL2, CGL3; Aleuria aurantia lectin – AAL; Marasmius oreades agglutinin - MOA; and Laccaria bicolor lectin – Lb-Tec2, on cultivated Haemonchus contortus larval stages was investigated using a larval development test (LDT). To validate the results of the toxicity assay and determine lectin binding capacity to the nematode digestive tract, biotinylated versions of lectins were fed to pre-infective larval stages of H. contortus and visualized by fluorescent microscopy. Lectin histochemistry on fixed adult worms was performed to investigate the presence and localisation of lectin binding sites in the disease-relevant developmental stage. Results Using an improved larval development test we found that four of the six tested lectins: AAL, CCL2, MOA and CGL2, exhibited a dose-dependent toxicity in LDT, as measured by the number of larvae developing to the L3 stage. In the case of AAL, CGL2 and MOA lectin, doses as low as 5 μg/ml caused >95 % inhibition of larval development while 40 μg/ml were needed to achieve the same inhibition by CCL2 lectin. MOA was the only lectin tested that caused larval death while other toxic lectins had larvistatic effect manifesting as L1 growth arrest. Using lectin histochemistry we demonstrate that of all lectins tested, only the four toxic ones displayed binding to the larvae’s gut and likewise were found to interact with glycans localized to the gastrodermal tissue of adults. Conclusion The results of our study suggest a correlation between the presence of target glycans of lectins in the digestive tract and the lectin-mediated toxicity in Haemonchus contortus. We demonstrate that binding to the structurally conserved glycan structures found in H. contortus gastrodermal tissue by the set of fungal lectins has detrimental effect on larval development. Some of these glycan structures might represent antigens which are not exposed to the host immune system (hidden antigens) and thus have a potential for vaccine or drug development. Nematotoxic fungal lectins prove to be a useful tool to identify such targets in parasitic nematodes. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-1032-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Christian Heim
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057, Zurich, Switzerland.
| | - Hubertus Hertzberg
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057, Zurich, Switzerland.
| | - Alex Butschi
- Malcisbo AG, Wagistrasse 27a, 8952, Schlieren, Switzerland.
| | - Silvia Bleuler-Martinez
- Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, 8093, Zürich, Switzerland.
| | - Markus Aebi
- Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, 8093, Zürich, Switzerland.
| | - Peter Deplazes
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057, Zurich, Switzerland.
| | - Markus Künzler
- Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, 8093, Zürich, Switzerland.
| | - Saša Štefanić
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057, Zurich, Switzerland.
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38
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Perez C, Gerber S, Boilevin J, Bucher M, Darbre T, Aebi M, Reymond JL, Locher KP. Structure and mechanism of an active lipid-linked oligosaccharide flippase. Nature 2015; 524:433-8. [PMID: 26266984 DOI: 10.1038/nature14953] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 07/15/2015] [Indexed: 02/06/2023]
Abstract
The flipping of membrane-embedded lipids containing large, polar head groups is slow and energetically unfavourable, and is therefore catalysed by flippases, the mechanisms of which are unknown. A prominent example of a flipping reaction is the translocation of lipid-linked oligosaccharides that serve as donors in N-linked protein glycosylation. In Campylobacter jejuni, this process is catalysed by the ABC transporter PglK. Here we present a mechanism of PglK-catalysed lipid-linked oligosaccharide flipping based on crystal structures in distinct states, a newly devised in vitro flipping assay, and in vivo studies. PglK can adopt inward- and outward-facing conformations in vitro, but only outward-facing states are required for flipping. While the pyrophosphate-oligosaccharide head group of lipid-linked oligosaccharides enters the translocation cavity and interacts with positively charged side chains, the lipidic polyprenyl tail binds and activates the transporter but remains exposed to the lipid bilayer during the reaction. The proposed mechanism is distinct from the classical alternating-access model applied to other transporters.
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Affiliation(s)
- Camilo Perez
- Institute of Molecular Biology and Biophysics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Sabina Gerber
- Institute of Molecular Biology and Biophysics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Jérémy Boilevin
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Monika Bucher
- Institute of Molecular Biology and Biophysics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Tamis Darbre
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Markus Aebi
- Institute of Microbiology, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics, ETH Zürich, CH-8093 Zürich, Switzerland
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39
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Schwarz F, Aebi M. Production of Glycoproteins with Asparagine-Linked N-Acetylglucosamine in Escherichia coli. Methods Mol Biol 2015; 1321:49-56. [PMID: 26082214 DOI: 10.1007/978-1-4939-2760-9_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Glycans linked to asparagine (N) residues of eukaryotic glycoproteins are typically heterogeneous. This diversity complicates the study of biological functions associated with particular glycan structures and impairs the application of glycoproteins in medicine. Several approaches have been developed to produce homogeneous glycoproteins. We describe a method to produce glycoproteins carrying N-linked N-acetylglucosamine (GlcNAc) through glyco-engineered E. coli cells and enzymatic treatment. N-linked GlcNAc can then be extended by existing methods to produce homogeneous glycoproteins.
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Affiliation(s)
- Flavio Schwarz
- Department of Medicine, Glycobiology Research and Training Center, La Jolla, CA, USA
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40
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Schubert M, Walczak MJ, Aebi M, Wider G. Posttranslational Modifications of Intact Proteins Detected by NMR Spectroscopy: Application to Glycosylation. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502093] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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41
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Mueller S, Wahlander A, Selevsek N, Otto C, Ngwa EM, Poljak K, Frey AD, Aebi M, Gauss R. Protein degradation corrects for imbalanced subunit stoichiometry in OST complex assembly. Mol Biol Cell 2015; 26:2596-608. [PMID: 25995378 PMCID: PMC4501358 DOI: 10.1091/mbc.e15-03-0168] [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: 03/23/2015] [Accepted: 05/11/2015] [Indexed: 01/06/2023] Open
Abstract
A combination of SILAC and targeted mass spectrometry provides a sensitive method to measure protein half-lives in yeast. Degradation rates are generally low in wild-type cells; however, ERAD is important to correct for imbalanced subunit stoichiometry. This approach is used to establish an assembly model for the OST complex. Protein degradation is essential for cellular homeostasis. We developed a sensitive approach to examining protein degradation rates in Saccharomyces cerevisiae by coupling a SILAC approach to selected reaction monitoring (SRM) mass spectrometry. Combined with genetic tools, this analysis made it possible to study the assembly of the oligosaccharyl transferase complex. The ER-associated degradation machinery compensated for disturbed homeostasis of complex components by degradation of subunits in excess. On a larger scale, protein degradation in the ER was found to be a minor factor in the regulation of protein homeostasis in exponentially growing cells, but ERAD became relevant when the gene dosage was affected, as demonstrated in heterozygous diploid cells. Hence the alleviation of fitness defects due to abnormal gene copy numbers might be an important function of protein degradation.
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Affiliation(s)
- Susanne Mueller
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Asa Wahlander
- Functional Genomics Center Zurich, UZH/ETH Zurich, CH-8057 Zurich, Switzerland
| | - Nathalie Selevsek
- Functional Genomics Center Zurich, UZH/ETH Zurich, CH-8057 Zurich, Switzerland
| | - Claudia Otto
- Department of Health Sciences and Technology, Institute of Food, Nutrition and Health, ETH Zürich, CH-8092 Zurich, Switzerland
| | - Elsy Mankah Ngwa
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Kristina Poljak
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Alexander D Frey
- Department of Biotechnology and Chemical Technology, Aalto University, FI-00076 Aalto, Finland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Robert Gauss
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland
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42
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Schubert M, Walczak MJ, Aebi M, Wider G. Posttranslational modifications of intact proteins detected by NMR spectroscopy: application to glycosylation. Angew Chem Int Ed Engl 2015; 54:7096-100. [PMID: 25924827 DOI: 10.1002/anie.201502093] [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: 03/05/2015] [Indexed: 02/02/2023]
Abstract
Posttranslational modifications (PTMs) are an integral part of the majority of proteins. The characterization of structure and function of PTMs can be very challenging especially for glycans. Existing methods to analyze PTMs require complicated sample preparations and suffer from missing certain modifications, the inability to identify linkage types and thus chemical structure. We present a direct, robust, and simple NMR spectroscopy method for the detection and identification of PTMs in proteins. No isotope labeling is required, nor does the molecular weight of the studied protein limit the application. The method can directly detect modifications on intact proteins without sophisticated sample preparation. This approach is well suited for diagnostics of proteins derived from native organisms and for the quality control of biotechnologically produced therapeutic proteins.
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Affiliation(s)
- Mario Schubert
- Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich (Switzerland). .,Present address: Department of Molecular Biology, University of Salzburg, Billrothstrasse 11, 5020 Salzburg (Austria).
| | - Michal J Walczak
- Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich (Switzerland).
| | - Markus Aebi
- Institute of Microbiology, ETH Zürich, 8093 Zürich (Switzerland)
| | - Gerhard Wider
- Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich (Switzerland)
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43
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Ngwa E, Aebi M. Structure‐to‐Function Characterization of
Saccharomyces cerevisiae STT3. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.890.2] [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: 11/11/2022]
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44
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Abstract
N-Linked protein glycosylation is a common posttranslational protein modification in eukaryotes involved in many biological processes. As glycosylation is also important for the function and the pharmacokinetic properties of many protein therapeutics, there is an increasing interest in expression systems able to produce glycoproteins of well-defined structure. Bacterial expression hosts generally do not glycosylate proteins at all. However, the discovery of bacterial N-glycosylation systems has opened up a new route for the production of therapeutically interesting glycoproteins in glyco-engineered bacteria. This review offers an introduction to the many efforts taken to engineer bacteria in order to produce N-glycoproteins with defined eukaryotic glycan structures, completely novel protein glycoconjugates as well as to establish screening approaches for improvement and adaptation of the glycosylation machinery to specific applications.
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Affiliation(s)
- Andreas Naegeli
- Department of Biology, Institute of Microbiology, ETH Zurich, Zurich, Switzerland
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45
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Edwards KL, Schizas C, Mannion AF, Aebi M, Gunzburg R. How to be a good reviewer. Eur Spine J 2014; 24:1-2. [PMID: 25510517 DOI: 10.1007/s00586-014-3719-7] [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] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Indexed: 11/30/2022]
Affiliation(s)
- K L Edwards
- School of Medicine, University of Nottingham, Nottingham, UK,
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46
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Essig A, Hofmann D, Münch D, Gayathri S, Künzler M, Kallio PT, Sahl HG, Wider G, Schneider T, Aebi M. Copsin, a novel peptide-based fungal antibiotic interfering with the peptidoglycan synthesis. J Biol Chem 2014; 289:34953-64. [PMID: 25342741 PMCID: PMC4263892 DOI: 10.1074/jbc.m114.599878] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [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: 08/08/2014] [Revised: 10/17/2014] [Indexed: 01/06/2023] Open
Abstract
Fungi and bacteria compete with an arsenal of secreted molecules for their ecological niche. This repertoire represents a rich and inexhaustible source for antibiotics and fungicides. Antimicrobial peptides are an emerging class of fungal defense molecules that are promising candidates for pharmaceutical applications. Based on a co-cultivation system, we studied the interaction of the coprophilous basidiomycete Coprinopsis cinerea with different bacterial species and identified a novel defensin, copsin. The polypeptide was recombinantly produced in Pichia pastoris, and the three-dimensional structure was solved by NMR. The cysteine stabilized α/β-fold with a unique disulfide connectivity, and an N-terminal pyroglutamate rendered copsin extremely stable against high temperatures and protease digestion. Copsin was bactericidal against a diversity of Gram-positive bacteria, including human pathogens such as Enterococcus faecium and Listeria monocytogenes. Characterization of the antibacterial activity revealed that copsin bound specifically to the peptidoglycan precursor lipid II and therefore interfered with the cell wall biosynthesis. In particular, and unlike lantibiotics and other defensins, the third position of the lipid II pentapeptide is essential for effective copsin binding. The unique structural properties of copsin make it a possible scaffold for new antibiotics.
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Affiliation(s)
| | - Daniela Hofmann
- the Institute of Molecular Biology and Biophysics, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Daniela Münch
- the Institute of Medical Microbiology, Immunology, and Parasitology, Pharmaceutical Microbiology Section, University of Bonn, Bonn 53115, Germany, and
| | | | | | | | - Hans-Georg Sahl
- the Institute of Medical Microbiology, Immunology, and Parasitology, Pharmaceutical Microbiology Section, University of Bonn, Bonn 53115, Germany, and
| | - Gerhard Wider
- the Institute of Molecular Biology and Biophysics, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Tanja Schneider
- the Institute of Medical Microbiology, Immunology, and Parasitology, Pharmaceutical Microbiology Section, University of Bonn, Bonn 53115, Germany, and the German Centre for Infection Research (Deutsches Zentrum für Infektionsforschung), partner site Bonn-Cologne, Bonn 53115, Germany
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47
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Frey AD, Aebi M. An enzyme-based screening system for the rapid assessment of protein N-glycosylation efficiency in yeast. Glycobiology 2014; 25:252-7. [DOI: 10.1093/glycob/cwu134] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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48
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Mehnert M, Sommermeyer F, Berger M, Kumar Lakshmipathy S, Gauss R, Aebi M, Jarosch E, Sommer T. The interplay of Hrd3 and the molecular chaperone system ensures efficient degradation of malfolded secretory proteins. Mol Biol Cell 2014; 26:185-94. [PMID: 25428985 PMCID: PMC4294667 DOI: 10.1091/mbc.e14-07-1202] [Citation(s) in RCA: 26] [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] [Indexed: 11/11/2022] Open
Abstract
A central ubiquitin ligase involved in endoplasmic reticulum (ER)–associated protein degradation is the HRD-ligase. The ER-luminal subunit Hrd3 cooperates with the cochaperone Scj1 in clearing misfolded proteins from the ER. Misfolded proteins of the secretory pathway are extracted from the endoplasmic reticulum (ER), polyubiquitylated by a protein complex termed the Hmg-CoA reductase degradation ligase (HRD-ligase), and degraded by cytosolic 26S proteasomes. This process is termed ER-associated protein degradation (ERAD). We previously showed that the membrane protein Der1, which is a subunit of the HRD-ligase, is involved in the export of aberrant polypeptides from the ER. Unexpectedly, we also uncovered a close spatial proximity of Der1 and the substrate receptor Hrd3 in the ER lumen. We report here on a mutant Hrd3KR that is selectively defective for ERAD of soluble proteins. Hrd3KR displays subtle structural changes that affect its positioning toward Der1. Furthermore, increased quantities of the ER-resident Hsp70-type chaperone Kar2 and the Hsp40-type cochaperone Scj1 bind to Hrd3KR. Of note, deletion of SCJ1 impairs ERAD of model substrates and causes the accumulation of client proteins at Hrd3. Our data imply a function of Scj1 in the removal of malfolded proteins from the receptor Hrd3, which facilitates their delivery to downstream-acting components like Der1.
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Affiliation(s)
- Martin Mehnert
- Max-Delbrück-Center for Molecular Medicine, 13125 Berlin, Germany
| | | | - Maren Berger
- Max-Delbrück-Center for Molecular Medicine, 13125 Berlin, Germany
| | | | - Robert Gauss
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology Zurich, 8093 Zurich, Switzerland
| | - Markus Aebi
- Institute of Microbiology, Department of Biology, Swiss Federal Institute of Technology Zurich, 8093 Zurich, Switzerland
| | - Ernst Jarosch
- Max-Delbrück-Center for Molecular Medicine, 13125 Berlin, Germany
| | - Thomas Sommer
- Max-Delbrück-Center for Molecular Medicine, 13125 Berlin, Germany Institute of Biology, Humboldt Universität zu Berlin, 10115 Berlin, Germany
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Stanley CE, Stöckli M, van Swaay D, Sabotič J, Kallio PT, Künzler M, deMello AJ, Aebi M. Probing bacterial–fungal interactions at the single cell level. Integr Biol (Camb) 2014; 6:935-45. [DOI: 10.1039/c4ib00154k] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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50
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Naegeli A, Michaud G, Schubert M, Lin CW, Lizak C, Darbre T, Reymond JL, Aebi M. Substrate specificity of cytoplasmic N-glycosyltransferase. J Biol Chem 2014; 289:24521-32. [PMID: 24962585 DOI: 10.1074/jbc.m114.579326] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
N-Linked protein glycosylation is a very common post-translational modification that can be found in all kingdoms of life. The classical, highly conserved pathway entails the assembly of a lipid-linked oligosaccharide and its transfer to an asparagine residue in the sequon NX(S/T) of a secreted protein by the integral membrane protein oligosaccharyltransferase. A few species in the class of γ-proteobacteria encode a cytoplasmic N-glycosylation system mediated by a soluble N-glycosyltransferase (NGT). This enzyme uses nucleotide-activated sugars to modify asparagine residues with single monosaccharides. As these enzymes are not related to oligosaccharyltransferase, NGTs constitute a novel class of N-glycosylation catalyzing enzymes. To characterize the NGT-catalyzed reaction, we developed a sensitive and quantitative in vitro assay based on HPLC separation and quantification of fluorescently labeled substrate peptides. With this assay we were able to directly quantify glycopeptide formation by Actinobacillus pleuropneumoniae NGT and determine its substrate specificities: NGT turns over a number of different sugar donor substrates and allows for activation by both UDP and GDP. Quantitative analysis of peptide substrate turnover demonstrated a strikingly similar specificity as the classical, oligosaccharyltransferase-catalyzed N-glycosylation, with NX(S/T) sequons being the optimal NGT substrates.
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Affiliation(s)
- Andreas Naegeli
- From the Department of Biology, Institute of Microbiology, ETH Zurich, CH-8093 Zurich
| | - Gaëlle Michaud
- the Department of Chemistry and Biochemistry, University of Berne, 3012 Berne, and
| | - Mario Schubert
- the Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Chia-Wei Lin
- From the Department of Biology, Institute of Microbiology, ETH Zurich, CH-8093 Zurich
| | - Christian Lizak
- the Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Tamis Darbre
- the Department of Chemistry and Biochemistry, University of Berne, 3012 Berne, and
| | - Jean-Louis Reymond
- the Department of Chemistry and Biochemistry, University of Berne, 3012 Berne, and
| | - Markus Aebi
- From the Department of Biology, Institute of Microbiology, ETH Zurich, CH-8093 Zurich,
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