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Gebhard LJ, Vershinin Z, Alarcón-Schumacher T, Eichler J, Erdmann S. Influence of N-Glycosylation on Virus-Host Interactions in Halorubrum lacusprofundi. Viruses 2023; 15:1469. [PMID: 37515157 PMCID: PMC10384203 DOI: 10.3390/v15071469] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/23/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
N-glycosylation is a post-translational modification of proteins that occurs across all three domains of life. In Archaea, N-glycosylation is crucial for cell stability and motility, but importantly also has significant implications for virus-host interactions. While some archaeal viruses present glycosylated proteins or interact with glycosylated host proteins, the direct influence of N-glycosylation on archaeal virus-host interactions remains to be elucidated. In this study, we generated an N-glycosylation-deficient mutant of Halorubrum lacusprofundi, a halophilic archaeon commonly used to study cold adaptation, and examined the impact of compromised N-glycosylation on the infection dynamics of two very diverse viruses. While compromised N-glycosylation had no influence on the life cycle of the head-tailed virus HRTV-DL1, we observed a significant effect on membrane-containing virus HFPV-1. Both intracellular genome numbers and extracellular virus particle numbers of HFPV-1 were increased in the mutant strain, which we attribute to instability of the surface-layer which builds the protein envelope of the cell. When testing the impact of compromised N-glycosylation on the life cycle of plasmid vesicles, specialized membrane vesicles that transfer a plasmid between host cells, we determined that plasmid vesicle stability is strongly dependent on the host glycosylation machinery. Our study thus provides important insight into the role of N-glycosylation in virus-host interactions in Archaea, while pointing to how this influence strongly differs amongst various viruses and virus-like elements.
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Affiliation(s)
- L Johanna Gebhard
- Max Planck Institute for Marine Microbiology, Archaeal Virology, 28359 Bremen, Germany
| | - Zlata Vershinin
- Department of Life Sciences, Ben-Gurion University of the Negev, Beersheva 84105, Israel
| | | | - Jerry Eichler
- Department of Life Sciences, Ben-Gurion University of the Negev, Beersheva 84105, Israel
| | - Susanne Erdmann
- Max Planck Institute for Marine Microbiology, Archaeal Virology, 28359 Bremen, Germany
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2
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De Castro RE, Giménez MI, Cerletti M, Paggi RA, Costa MI. Proteolysis at the Archaeal Membrane: Advances on the Biological Function and Natural Targets of Membrane-Localized Proteases in Haloferax volcanii. Front Microbiol 2022; 13:940865. [PMID: 35814708 PMCID: PMC9263693 DOI: 10.3389/fmicb.2022.940865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/06/2022] [Indexed: 11/23/2022] Open
Abstract
Proteolysis plays a fundamental role in many processes that occur within the cellular membrane including protein quality control, protein export, cell signaling, biogenesis of the cell envelope among others. Archaea are a distinct and physiologically diverse group of prokaryotes found in all kinds of habitats, from the human and plant microbiomes to those with extreme salt concentration, pH and/or temperatures. Thus, these organisms provide an excellent opportunity to extend our current understanding on the biological functions that proteases exert in cell physiology including the adaptation to hostile environments. This revision describes the advances that were made on archaeal membrane proteases with regard to their biological function and potential natural targets focusing on the model haloarchaeon Haloferax volcanii.
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3
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Kelly J, Vinogradov E, Robotham A, Tessier L, Logan SM, Jarrell KF. Characterizing the N- and O-linked glycans of the PGF-CTERM sorting domain-containing S-layer protein of Methanoculleus marisnigri. Glycobiology 2022; 32:629-644. [PMID: 35481895 DOI: 10.1093/glycob/cwac019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/28/2022] [Accepted: 03/09/2022] [Indexed: 01/05/2023] Open
Abstract
The glycosylation of structural proteins is a widespread posttranslational modification in Archaea. Although only a handful of archaeal N-glycan structures have been determined to date, it is evident that the diversity of structures expressed is greater than in the other domains of life. Here, we report on our investigation of the N- and O-glycan modifications expressed by Methanoculleus marisnigri, a mesophilic methanogen from the Order Methanomicrobiales. Unusually, mass spectrometry (MS) analysis of purified archaella revealed no evidence for N- or O-glycosylation of the constituent archaellins, In contrast, the S-layer protein, identified as a PGF-CTERM sorting domain-containing protein encoded by MEMAR_RS02690, is both N- and O-glycosylated. Two N-glycans were identified by NMR and MS analysis: a trisaccharide α-GlcNAc-4-β-GlcNAc3NGaAN-4-β-Glc-Asn where the second residue is 2-N-acetyl, 3-N-glyceryl-glucosamide and a disaccharide β-GlcNAc3NAcAN-4-β-Glc-Asn, where the terminal residue is 2,3 di-N-acetyl-glucosamide. The same trisaccharide was also found N-linked to a type IV pilin. The S-layer protein is also extensively modified in the threonine-rich region near the C-terminus with O-glycans composed exclusively of hexoses. While the S-layer protein has a predicted PGF-CTERM processing site, no evidence of a truncated and lipidated C-terminus, the expected product of processing by an archaeosortase, was found. Finally, NMR also identified a polysaccharide expressed by M. marisnigri and composed of a repeating tetrasaccharide unit of [-2-β-Ribf-3-α-Rha2OMe-3-α-Rha - 2-α-Rha-]. This is the first report of N- and O-glycosylation in an archaeon from the Order Methanomicrobiales.
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Affiliation(s)
- John Kelly
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Evgeny Vinogradov
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Anna Robotham
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Luc Tessier
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Susan M Logan
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Ken F Jarrell
- Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
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4
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von Kügelgen A, Alva V, Bharat TAM. Complete atomic structure of a native archaeal cell surface. Cell Rep 2021; 37:110052. [PMID: 34818541 PMCID: PMC8640222 DOI: 10.1016/j.celrep.2021.110052] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/28/2021] [Accepted: 11/01/2021] [Indexed: 12/20/2022] Open
Abstract
Many prokaryotic cells are covered by an ordered, proteinaceous, sheet-like structure called a surface layer (S-layer). S-layer proteins (SLPs) are usually the highest copy number macromolecules in prokaryotes, playing critical roles in cellular physiology such as blocking predators, scaffolding membranes, and facilitating environmental interactions. Using electron cryomicroscopy of two-dimensional sheets, we report the atomic structure of the S-layer from the archaeal model organism Haloferax volcanii. This S-layer consists of a hexagonal array of tightly interacting immunoglobulin-like domains, which are also found in SLPs across several classes of archaea. Cellular tomography reveal that the S-layer is nearly continuous on the cell surface, completed by pentameric defects in the hexagonal lattice. We further report the atomic structure of the SLP pentamer, which shows markedly different relative arrangements of SLP domains needed to complete the S-layer. Our structural data provide a framework for understanding cell surfaces of archaea at the atomic level.
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Affiliation(s)
| | - Vikram Alva
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, Tübingen 72076, Germany
| | - Tanmay A M Bharat
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK; Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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Distinct regions of the Haloferax volcanii dolichol phosphate-mannose synthase AglD mediate the assembly and subsequent processing of the lipid-linked mannose. J Bacteriol 2021; 204:e0044721. [PMID: 34633871 DOI: 10.1128/jb.00447-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Haloferax volcanii AglD is currently the only archaeal dolichol phosphate (DolP)-mannose synthase shown to participate in N-glycosylation. However, the relation between AglD and Pyrococcus furiosus PF0058, the only archaeal DolP-mannose synthase for which structural information is presently available, was unclear. In this report, similarities between the PF0058 and AglD catalytic domains were revealed. At the same time, AglD includes a transmembrane domain far longer than that of PF0058 or other DolP-mannose synthases. To determine whether this extension affords AglD functions in addition to generating mannose-charged DolP, a series of Hfx. volcanii strains expressing truncated versions of AglD was generated. Mass spectrometry revealed that a version of AglD comprising the catalytic domain and only two of the six to nine predicted membrane-spanning domains could mediate mannose addition to DolP. However, in cells expressing this or other truncated versions of AglD, mannose was not transferred from the lipid to the protein-bound tetrasaccharide precursor of the N-linked pentasaccharide normally decorating Hfx. volcanii glycoproteins. These results thus point to AglD as contributing to additional aspects of Hfx. volcanii N-glycosylation beyond charging DolP with mannose. Accordingly, the possibility that AglD, possibly in coordination with AglR, translocates DolP-mannose across the plasma membrane is discussed. Layman summary In the archaea Haloferax volcanii, the dolichol phosphate (DolP)-mannose synthase AglD charges the lipid DolP with mannose, which is delivered to a protein-bound tetrasaccharide to generate the pentasaccharide decorating glycoproteins in this organism. Structural studies demonstrated the similarity of AglD to Pyrococcus furiosus PF0058, the only archaeal DolP-mannose synthase with a solved 3D structure. Truncated AglD containing the catalytic domain and only two of the predicted six to nine membrane-spanning regions catalyzed mannose-charging of DolP. Yet, no mannose was delivered to protein-linked tetrasaccharide in cells expressing AglD mutants including only up to five membrane-spanning regions, pointing to a role for the extended C-terminal region in a subsequent step of Hfx. volcanii N-glycosylation, such as DolP-mannose translocation across the plasma membrane.
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Open Issues for Protein Function Assignment in Haloferax volcanii and Other Halophilic Archaea. Genes (Basel) 2021; 12:genes12070963. [PMID: 34202810 PMCID: PMC8305020 DOI: 10.3390/genes12070963] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/10/2021] [Accepted: 06/15/2021] [Indexed: 12/14/2022] Open
Abstract
Background: Annotation ambiguities and annotation errors are a general challenge in genomics. While a reliable protein function assignment can be obtained by experimental characterization, this is expensive and time-consuming, and the number of such Gold Standard Proteins (GSP) with experimental support remains very low compared to proteins annotated by sequence homology, usually through automated pipelines. Even a GSP may give a misleading assignment when used as a reference: the homolog may be close enough to support isofunctionality, but the substrate of the GSP is absent from the species being annotated. In such cases, the enzymes cannot be isofunctional. Here, we examined a variety of such issues in halophilic archaea (class Halobacteria), with a strong focus on the model haloarchaeon Haloferax volcanii. Results: Annotated proteins of Hfx. volcanii were identified for which public databases tend to assign a function that is probably incorrect. In some cases, an alternative, probably correct, function can be predicted or inferred from the available evidence, but this has not been adopted by public databases because experimental validation is lacking. In other cases, a probably invalid specific function is predicted by homology, and while there is evidence that this assigned function is unlikely, the true function remains elusive. We listed 50 of those cases, each with detailed background information, so that a conclusion about the most likely biological function can be drawn. For reasons of brevity and comprehension, only the key aspects are listed in the main text, with detailed information being provided in a corresponding section of the Supplementary Materials. Conclusions: Compiling, describing and summarizing these open annotation issues and functional predictions will benefit the scientific community in the general effort to improve the evaluation of protein function assignments and more thoroughly detail them. By highlighting the gaps and likely annotation errors currently in the databases, we hope this study will provide a framework for experimentalists to systematically confirm (or disprove) our function predictions or to uncover yet more unexpected functions.
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7
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Comprehensive glycoproteomics shines new light on the complexity and extent of glycosylation in archaea. PLoS Biol 2021; 19:e3001277. [PMID: 34138841 PMCID: PMC8241124 DOI: 10.1371/journal.pbio.3001277] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/29/2021] [Accepted: 05/10/2021] [Indexed: 12/19/2022] Open
Abstract
Glycosylation is one of the most complex posttranslational protein modifications. Its importance has been established not only for eukaryotes but also for a variety of prokaryotic cellular processes, such as biofilm formation, motility, and mating. However, comprehensive glycoproteomic analyses are largely missing in prokaryotes. Here, we extend the phenotypic characterization of N-glycosylation pathway mutants in Haloferax volcanii and provide a detailed glycoproteome for this model archaeon through the mass spectrometric analysis of intact glycopeptides. Using in-depth glycoproteomic datasets generated for the wild-type (WT) and mutant strains as well as a reanalysis of datasets within the Archaeal Proteome Project (ArcPP), we identify the largest archaeal glycoproteome described so far. We further show that different N-glycosylation pathways can modify the same glycosites under the same culture conditions. The extent and complexity of the Hfx. volcanii N-glycoproteome revealed here provide new insights into the roles of N-glycosylation in archaeal cell biology. A comprehensive glycoproteomic analysis of Haloferax volcanii reveals the extent and complexity of glycosylation in archaea and provides new insights into the roles of this post-translational modification in various cellular processes, including cell shape determination.
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8
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Jarrell KF, Albers SV, Machado JNDS. A comprehensive history of motility and Archaellation in Archaea. FEMS MICROBES 2021; 2:xtab002. [PMID: 37334237 PMCID: PMC10117864 DOI: 10.1093/femsmc/xtab002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/18/2021] [Indexed: 08/24/2023] Open
Abstract
Each of the three Domains of life, Eukarya, Bacteria and Archaea, have swimming structures that were all originally called flagella, despite the fact that none were evolutionarily related to either of the other two. Surprisingly, this was true even in the two prokaryotic Domains of Bacteria and Archaea. Beginning in the 1980s, evidence gradually accumulated that convincingly demonstrated that the motility organelle in Archaea was unrelated to that found in Bacteria, but surprisingly shared significant similarities to type IV pili. This information culminated in the proposal, in 2012, that the 'archaeal flagellum' be assigned a new name, the archaellum. In this review, we provide a historical overview on archaella and motility research in Archaea, beginning with the first simple observations of motile extreme halophilic archaea a century ago up to state-of-the-art cryo-tomography of the archaellum motor complex and filament observed today. In addition to structural and biochemical data which revealed the archaellum to be a type IV pilus-like structure repurposed as a rotating nanomachine (Beeby et al. 2020), we also review the initial discoveries and subsequent advances using a wide variety of approaches to reveal: complex regulatory events that lead to the assembly of the archaellum filaments (archaellation); the roles of the various archaellum proteins; key post-translational modifications of the archaellum structural subunits; evolutionary relationships; functions of archaella other than motility and the biotechnological potential of this fascinating structure. The progress made in understanding the structure and assembly of the archaellum is highlighted by comparing early models to what is known today.
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Affiliation(s)
- Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Sonja-Verena Albers
- Institute for Biology II- Microbiology, Molecular Biology of Archaea, University of Freiburg, Schänzlestraße 1, Freiburg 79104, Germany
| | - J Nuno de Sousa Machado
- Institute for Biology II- Microbiology, Molecular Biology of Archaea, University of Freiburg, Schänzlestraße 1, Freiburg 79104, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19A, 79104, Freiburg, Germany
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9
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Evolutionary considerations of the oligosaccharyltransferase AglB and other aspects of N-glycosylation across Archaea. Mol Phylogenet Evol 2020; 153:106951. [PMID: 32889138 DOI: 10.1016/j.ympev.2020.106951] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 08/01/2020] [Accepted: 08/28/2020] [Indexed: 12/13/2022]
Abstract
Various biological markers in members of the TACK and Asgard archaeal super-phyla show Eukarya-like traits. These include the oligosaccharyltransferase, responsible for transferring glycans from the lipid carrier upon which they are assembled onto selected asparagine residues of target proteins during N-glycosylation. In Archaea, oligosaccharyltransferase activity is catalyzed by AglB. To gain deeper insight into AglB and N-glycosylation across archaeal phylogeny, bioinformatics approaches were employed to address variability in AglB sequence motifs involved in enzyme activity, construct a phylogenetic tree based on AglB sequences, search for archaeal homologues of non-catalytic subunits of the multimeric eukaryal oligosaccharyltransferase complex and predict the presence of aglB-based clusters of glycosylation-related genes in the Euryarchaeota and the DPANN, TACK and Asgard super-phyla. In addition, site-directed mutagenesis and mass spectrometry were employed to study the natural variability in the WWDXG motif central to oligosaccharyltransferase activity seen in archaeal AglB. The results clearly distinguish AglB from members of the DPANN super-phylum and the Euryarchaeota from the same enzyme in members of the TACK and Asgard super-phyla, which showed considerable similarity to its eukaryal homologue Stt3. The results thus support the evolutionary proximity of Eukarya and the TACK and Asgard archaea.
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10
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Kelly JF, Vinogradov E, Stupak J, Robotham AC, Logan SM, Berezuk A, Khursigara CM, Jarrell KF. Identification of a novel N-linked glycan on the archaellins and S-layer protein of the thermophilic methanogen, Methanothermococcus thermolithotrophicus. J Biol Chem 2020; 295:14618-14629. [PMID: 32817340 DOI: 10.1074/jbc.ra120.012790] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 07/28/2020] [Indexed: 01/25/2023] Open
Abstract
Motility in archaea is facilitated by a unique structure termed the archaellum. N-Glycosylation of the major structural proteins (archaellins) is important for their subsequent incorporation into the archaellum filament. The identity of some of these N-glycans has been determined, but archaea exhibit extensive variation in their glycans, meaning that further investigations can shed light not only on the specific details of archaellin structure and function, but also on archaeal glycobiology in general. Here we describe the structural characterization of the N-linked glycan modifications on the archaellins and S-layer protein of Methanothermococcus thermolithotrophicus, a methanogen that grows optimally at 65 °C. SDS-PAGE and MS analysis revealed that the sheared archaella are composed principally of two of the four predicted archaellins, FlaB1 and FlaB3, which are modified with a branched, heptameric glycan at all N-linked sequons except for the site closest to the N termini of both proteins. NMR analysis of the purified glycan determined the structure to be α-d-glycero-d-manno-Hep3OMe6OMe-(1-3)-[α-GalNAcA3OMe-(1-2)-]-β-Man-(1-4)-[β-GalA3OMe4OAc6CMe-(1-4)-α-GalA-(1-2)-]-α-GalAN-(1-3)-β-GalNAc-Asn. A detailed investigation by hydrophilic interaction liquid ion chromatography-MS discovered the presence of several, less abundant glycan variants, related to but distinct from the main heptameric glycan. In addition, we confirmed that the S-layer protein is modified with the same heptameric glycan, suggesting a common N-glycosylation pathway. The M. thermolithotrophicus archaellin N-linked glycan is larger and more complex than those previously identified on the archaellins of related mesophilic methanogens, Methanococcus voltae and Methanococcus maripaludis This could indicate that the nature of the glycan modification may have a role to play in maintaining stability at elevated temperatures.
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Affiliation(s)
- John F Kelly
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario, Canada.
| | - Evgeny Vinogradov
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Jacek Stupak
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Anna C Robotham
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Susan M Logan
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Alison Berezuk
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Cezar M Khursigara
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
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11
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Eichler J. N-glycosylation in Archaea-New roles for an ancient posttranslational modification. Mol Microbiol 2020; 114:735-741. [PMID: 32633872 DOI: 10.1111/mmi.14569] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/27/2020] [Indexed: 12/26/2022]
Abstract
Genome analysis points to N-glycosylation as being an almost universal posttranslational modification in Archaea. Although such predictions have been confirmed in only a limited number of species, such studies are making it increasingly clear that the N-linked glycans which decorate archaeal glycoproteins present diversity in terms of both glycan composition and architecture far beyond what is seen in the other two domains of life. In addition to continuing to decipher pathways of N-glycosylation, recent efforts have revealed how Archaea exploit this variability in novel roles. As well as encouraging glycoprotein synthesis, folding and assembly into properly functioning higher ordered complexes, N-glycosylation also provides Archaea with a strategy to cope with changing environments. Archaea can, moreover, exploit the apparent species-specific nature of N-glycosylation for selectivity in mating, and hence, to maintain species boundaries, and in other events where cell-selective interactions are required. At the same time, addressing components of N-glycosylation pathways across archaeal phylogeny offers support for the concept of an archaeal origin for eukaryotes. In this MicroReview, these and other recent discoveries related to N-glycosylation in Archaea are considered.
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Affiliation(s)
- Jerry Eichler
- Department of Life Sciences, Ben-Gurion University of the Negev, Beersheva, Israel
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12
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The Archaeal Proteome Project advances knowledge about archaeal cell biology through comprehensive proteomics. Nat Commun 2020; 11:3145. [PMID: 32561711 PMCID: PMC7305310 DOI: 10.1038/s41467-020-16784-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 05/18/2020] [Indexed: 11/08/2022] Open
Abstract
While many aspects of archaeal cell biology remain relatively unexplored, systems biology approaches like mass spectrometry (MS) based proteomics offer an opportunity for rapid advances. Unfortunately, the enormous amount of MS data generated often remains incompletely analyzed due to a lack of sophisticated bioinformatic tools and field-specific biological expertise for data interpretation. Here we present the initiation of the Archaeal Proteome Project (ArcPP), a community-based effort to comprehensively analyze archaeal proteomes. Starting with the model archaeon Haloferax volcanii, we reanalyze MS datasets from various strains and culture conditions. Optimized peptide spectrum matching, with strict control of false discovery rates, facilitates identifying > 72% of the reference proteome, with a median protein sequence coverage of 51%. These analyses, together with expert knowledge in diverse aspects of cell biology, provide meaningful insights into processes such as N-terminal protein maturation, N-glycosylation, and metabolism. Altogether, ArcPP serves as an invaluable blueprint for comprehensive prokaryotic proteomics.
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13
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Eichler J. Modifying Post‐Translational Modifications: A Strategy Used by Archaea for Adapting to Changing Environments? Bioessays 2020; 42:e1900207. [DOI: 10.1002/bies.201900207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/15/2019] [Indexed: 01/07/2023]
Affiliation(s)
- Jerry Eichler
- Department of Life SciencesBen Gurion University of the Negev Beersheva 84105 Israel
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14
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Pohlschroder M, Pfeiffer F, Schulze S, Abdul Halim MF. Archaeal cell surface biogenesis. FEMS Microbiol Rev 2018; 42:694-717. [PMID: 29912330 PMCID: PMC6098224 DOI: 10.1093/femsre/fuy027] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 06/12/2018] [Indexed: 12/13/2022] Open
Abstract
Cell surfaces are critical for diverse functions across all domains of life, from cell-cell communication and nutrient uptake to cell stability and surface attachment. While certain aspects of the mechanisms supporting the biosynthesis of the archaeal cell surface are unique, likely due to important differences in cell surface compositions between domains, others are shared with bacteria or eukaryotes or both. Based on recent studies completed on a phylogenetically diverse array of archaea, from a wide variety of habitats, here we discuss advances in the characterization of mechanisms underpinning archaeal cell surface biogenesis. These include those facilitating co- and post-translational protein targeting to the cell surface, transport into and across the archaeal lipid membrane, and protein anchoring strategies. We also discuss, in some detail, the assembly of specific cell surface structures, such as the archaeal S-layer and the type IV pili. We will highlight the importance of post-translational protein modifications, such as lipid attachment and glycosylation, in the biosynthesis as well as the regulation of the functions of these cell surface structures and present the differences and similarities in the biogenesis of type IV pili across prokaryotic domains.
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Affiliation(s)
| | - Friedhelm Pfeiffer
- Computational Biology Group, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Stefan Schulze
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
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15
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Zaretsky M, Roine E, Eichler J. Sialic Acid-Like Sugars in Archaea: Legionaminic Acid Biosynthesis in the Halophile Halorubrum sp. PV6. Front Microbiol 2018; 9:2133. [PMID: 30245679 PMCID: PMC6137143 DOI: 10.3389/fmicb.2018.02133] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/20/2018] [Indexed: 11/25/2022] Open
Abstract
N-glycosylation is a post-translational modification that occurs in all three domains. In Archaea, however, N-linked glycans present a degree of compositional diversity not observed in either Eukarya or Bacteria. As such, it is surprising that nonulosonic acids (NulOs), nine-carbon sugars that include sialic acids, pseudaminic acids, and legionaminic acids, are routinely detected as components of protein-linked glycans in Eukarya and Bacteria but not in Archaea. In the following, we report that the N-linked glycan attached to the S-layer glycoprotein of the haloarchaea Halorubrum sp. PV6 includes an N-formylated legionaminic acid. Analysis of the Halorubrum sp. PV6 genome led to the identification of sequences predicted to comprise the legionaminic acid biosynthesis pathway. The transcription of pathway genes was confirmed, as was the co-transcription of several of these genes. In addition, the activities of LegI, which catalyzes the condensation of 2,4-di-N-acetyl-6-deoxymannose and phosphoenolpyruvate to generate legionaminic acid, and LegF, which catalyzes the addition of cytidine monophosphate (CMP) to legionaminic acid, both heterologously expressed in Haloferax volcanii, were demonstrated. Further genome analysis predicts that the genes encoding enzymes of the legionaminic acid biosynthetic pathway are clustered together with sequences seemingly encoding components of the N-glycosylation pathway in this organism. In defining the first example of a legionaminic acid biosynthesis pathway in Archaea, the findings reported here expand our insight into archaeal N-glycosylation, an almost universal post-translational modification in this domain of life.
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Affiliation(s)
- Marianna Zaretsky
- Department of Life Sciences, Ben-Gurion University of the Negev, Beersheva, Israel
| | - Elina Roine
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Jerry Eichler
- Department of Life Sciences, Ben-Gurion University of the Negev, Beersheva, Israel
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16
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Shalev Y, Soucy SM, Papke RT, Gogarten JP, Eichler J, Gophna U. Comparative Analysis of Surface Layer Glycoproteins and Genes Involved in Protein Glycosylation in the Genus Haloferax. Genes (Basel) 2018; 9:genes9030172. [PMID: 29558455 PMCID: PMC5867893 DOI: 10.3390/genes9030172] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/01/2018] [Accepted: 03/09/2018] [Indexed: 11/16/2022] Open
Abstract
Within the Haloferax genus, both the surface (S)-layer protein, and the glycans that can decorate it, vary between species, which can potentially result in many different surface types, analogous to bacterial serotypes. This variation may mediate phenotypes, such as sensitivity to different viruses and mating preferences. Here, we describe S-layer glycoproteins found in multiple Haloferax strains and perform comparative genomics analyses of major and alternative glycosylation clusters of isolates from two coastal sites. We analyze the phylogeny of individual glycosylation genes and demonstrate that while the major glycosylation cluster tends to be conserved among closely related strains, the alternative cluster is highly variable. Thus, geographically- and genetically-related strains may exhibit diverse surface structures to such an extent that no two isolates present an identical surface profile.
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Affiliation(s)
- Yarden Shalev
- School of Molecular and Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Shannon M Soucy
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA.
| | - R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA.
| | - J Peter Gogarten
- Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA.
| | - Jerry Eichler
- Department of Life Sciences, Ben Gurion University of the Negev, Beersheva 8410501, Israel.
| | - Uri Gophna
- School of Molecular and Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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17
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Costa MI, Cerletti M, Paggi RA, Trötschel C, De Castro RE, Poetsch A, Giménez MI. Haloferax volcanii Proteome Response to Deletion of a Rhomboid Protease Gene. J Proteome Res 2018; 17:961-977. [PMID: 29301397 DOI: 10.1021/acs.jproteome.7b00530] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rhomboids are conserved intramembrane serine proteases involved in cell signaling processes. Their role in prokaryotes is scarcely known and remains to be investigated in Archaea. We previously constructed a rhomboid homologue deletion mutant (ΔrhoII) in Haloferax volcanii, which showed reduced motility, increased novobiocin sensitivity, and an N- glycosylation defect. To address the impact of rhoII deletion on H. volcanii physiology, the proteomes of mutant and parental strains were compared by shotgun proteomics. A total of 1847 proteins were identified (45.8% of H. volcanii predicted proteome), from which 103 differed in amount. Additionally, the mutant strain evidenced 99 proteins with altered electrophoretic migration, which suggested differential post-translational processing/modification. Integral membrane proteins that evidenced variations in concentration, electrophoretic migration, or semitryptic cleavage in the mutant were considered as potential RhoII targets. These included a PrsW protease homologue (which was less stable in the mutant strain), a predicted halocyanin, and six integral membrane proteins potentially related to the mutant glycosylation (S-layer glycoprotein, Agl15) and cell adhesion/motility (flagellin1, HVO_1153, PilA1, and PibD) defects. This study investigated for the first time the impact of a rhomboid protease on the whole proteome of an organism.
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Affiliation(s)
- Mariana I Costa
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata (UNMdP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Funes 3250 4to nivel, Mar del Plata, Buenos Aires 7600, Argentina
| | - Micaela Cerletti
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata (UNMdP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Funes 3250 4to nivel, Mar del Plata, Buenos Aires 7600, Argentina
| | - Roberto A Paggi
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata (UNMdP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Funes 3250 4to nivel, Mar del Plata, Buenos Aires 7600, Argentina
| | - Christian Trötschel
- Plant Biochemistry, Faculty of Biology & Biotechnology, Ruhr University Bochum , 44801 Bochum, Germany
| | - Rosana E De Castro
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata (UNMdP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Funes 3250 4to nivel, Mar del Plata, Buenos Aires 7600, Argentina
| | - Ansgar Poetsch
- Plant Biochemistry, Faculty of Biology & Biotechnology, Ruhr University Bochum , 44801 Bochum, Germany.,School of Biomedical and Healthcare Sciences, Plymouth University , Plymouth PL4 8AA, United Kingdom
| | - María I Giménez
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata (UNMdP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Funes 3250 4to nivel, Mar del Plata, Buenos Aires 7600, Argentina
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18
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Eichler J, Imperiali B. Stereochemical Divergence of Polyprenol Phosphate Glycosyltransferases. Trends Biochem Sci 2017; 43:10-17. [PMID: 29183665 DOI: 10.1016/j.tibs.2017.10.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 10/27/2017] [Accepted: 10/30/2017] [Indexed: 01/22/2023]
Abstract
In the three domains of life, lipid-linked glycans contribute to various cellular processes ranging from protein glycosylation to glycosylphosphatidylinositol anchor biosynthesis to peptidoglycan assembly. In generating many of these glycoconjugates, phosphorylated polyprenol-based lipids are charged with single sugars by polyprenol phosphate glycosyltransferases. The resultant substrates serve as glycosyltransferase donors, complementing the more common nucleoside diphosphate sugars. It had been accepted that these polyprenol phosphate glycosyltransferases acted similarly, given their considerable sequence homology. Recent findings, however, suggest that matters may not be so simple. In this Opinion we propose that the stereochemistry of sugar addition by polyprenol phosphate glycosyltransferases is not conserved across evolution, even though the GT-A fold that characterizes such enzymes is omnipresent.
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Affiliation(s)
- Jerry Eichler
- Department of Life Sciences, Ben Gurion University of the Negev, Beersheva, Israel.
| | - Barbara Imperiali
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA.
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19
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Elharar Y, Podilapu AR, Guan Z, Kulkarni SS, Eichler J. Assembling Glycan-Charged Dolichol Phosphates: Chemoenzymatic Synthesis of a Haloferax volcanii N-Glycosylation Pathway Intermediate. Bioconjug Chem 2017; 28:2461-2470. [PMID: 28809486 DOI: 10.1021/acs.bioconjchem.7b00436] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
N-glycosylation, the covalent attachment of glycans to select protein target Asn residues, is a post-translational modification performed by all three domains of life. In the halophilic archaea Haloferax volcanii, in which understanding of this universal protein-processing event is relatively well-advanced, genes encoding the components of the archaeal glycosylation (Agl) pathway responsible for the assembly and attachment of an N-linked pentasaccharide have been identified. As elsewhere, the N-linked glycan is assembled on phosphodolichol carriers before transfer to target Asn residues. However, as little is presently known of the Hfx. volcanii Agl pathway at the protein level, the seemingly unique ability of Archaea to use dolichol phosphate (DolP) as the glycan lipid carrier, rather than dolichol pyrophosphate used by eukaryotes, remains poorly understood. With this in mind, a chemoenzymatic approach was taken to biochemically study AglG, one of the five glycosyltransferases of the pathway. Accordingly, a novel regio- and stereoselective reduction of naturally isolated polyprenol gave facile access to S-dolichol via asymmetric transfer hydrogenation under very mild conditions. This compound was used to generate glucose-charged DolP, a precursor of the N-linked pentasaccharide, as well as DolP-glucose-glucuronic acid and DolP-glucuronic acid. AglG, purified from Hfx. volcanii membranes in hypersaline conditions, like those encountered in situ, was subsequently combined with uridine diphosphate (UDP)-glucuronic acid and DolP-glucose to yield DolP-glucose-glucuronic acid. The in vitro system for the study of AglG activity developed here represents the first such tool for studying halophilic glycosyltransferases and will allow for a detailed understanding of archaeal N-glycosylation.
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Affiliation(s)
- Yifat Elharar
- Department of Life Sciences, Ben Gurion University of the Negev , Beersheva 8410501, Israel
| | - Ananda Rao Podilapu
- Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India
| | - Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center , Durham, North Carolina 27710, United States
| | - Suvarn S Kulkarni
- Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India
| | - Jerry Eichler
- Department of Life Sciences, Ben Gurion University of the Negev , Beersheva 8410501, Israel
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20
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Shalev Y, Turgeman-Grott I, Tamir A, Eichler J, Gophna U. Cell Surface Glycosylation Is Required for Efficient Mating of Haloferax volcanii. Front Microbiol 2017; 8:1253. [PMID: 28725221 PMCID: PMC5496957 DOI: 10.3389/fmicb.2017.01253] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 06/21/2017] [Indexed: 01/30/2023] Open
Abstract
Halophilic archaea use a fusion-based mating system for lateral gene transfer across cells, yet the molecular mechanisms involved remain unknown. Previous work implied that cell fusion involves cell-cell recognition since fusion occurs more efficiently between cells from the same species. Long believed to be restricted only to Eukarya, it is now known that cells of all three domains of life perform N-glycosylation, the covalent attachment of glycans to select target asparagine residues in proteins, and that this post-translational modification is common for archaeal cell surface proteins. Here, we show that differences in glycosylation of the Haloferax volcanii surface-layer glycoprotein, brought about either by changing medium salinity or by knocking out key glycosylation genes, reduced mating success. Thus, different glycosylation patterns are likely to underlie mating preference in halophilic archaea, contributing to speciation processes.
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Affiliation(s)
- Yarden Shalev
- School of Molecular and Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv UniversityTel Aviv, Israel
| | - Israela Turgeman-Grott
- School of Molecular and Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv UniversityTel Aviv, Israel
| | - Adi Tamir
- Department of Life Sciences, Ben-Gurion University of the NegevBeersheva, Israel
| | - Jerry Eichler
- Department of Life Sciences, Ben-Gurion University of the NegevBeersheva, Israel
| | - Uri Gophna
- School of Molecular and Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv UniversityTel Aviv, Israel
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21
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Halim A, Anonsen JH. Microbial glycoproteomics. Curr Opin Struct Biol 2017; 44:143-150. [PMID: 28365498 DOI: 10.1016/j.sbi.2017.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/24/2017] [Accepted: 03/06/2017] [Indexed: 02/02/2023]
Abstract
Mass spectrometry-based "-omics" technologies are important tools for global and detailed mapping of post-translational modifications. Protein glycosylation is an abundant and important post translational modification widespread throughout all domains of life. Characterization of glycoproteins, including identification of glycan structure and components, their attachment sites and protein carriers, remains challenging. However, recent advances in glycoproteomics, a subbranch that studies and categorizes protein glycosylations, have greatly expanded the known protein glycosylation space and research in this area is rapidly accelerating. Here, we review recent developments in glycoproteomic technologies with a special focus on microbial protein glycosylation.
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Affiliation(s)
- 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.
| | - Jan Haug Anonsen
- Center for Integrative Microbial Evolution, The Mass Spectrometry and Proteomics Unit, Department of Biosciences, University of Oslo, Blindernveien 31, 0371 Oslo, Norway.
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22
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Eichler J, Koomey M. Sweet New Roles for Protein Glycosylation in Prokaryotes. Trends Microbiol 2017; 25:662-672. [PMID: 28341406 DOI: 10.1016/j.tim.2017.03.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 02/19/2017] [Accepted: 03/01/2017] [Indexed: 12/29/2022]
Abstract
Long-held to be a post-translational modification unique to Eukarya, it is now clear that both Bacteria and Archaea also perform protein glycosylation, namely the covalent attachment of mono- to polysaccharides to specific protein targets. At the same time, many of the roles assigned to this protein-processing event in eukaryotes, such as guiding protein folding/quality control, intracellular trafficking, dictating cellular recognition events and others, do not apply or are even irrelevant to prokaryotes. As such, protein glycosylation must serve novel functions in Bacteria and Archaea. Recent efforts have begun to elucidate some of these prokaryote-specific roles, which are addressed in this review.
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Affiliation(s)
- Jerry Eichler
- Department of Life Sciences, Ben Gurion University of the Negev, Beersheva 84105, Israel.
| | - Michael Koomey
- Department of Biosciences, University of Oslo, 0316 Oslo, Norway
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23
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N-Glycosylation Is Important for Proper Haloferax volcanii S-Layer Stability and Function. Appl Environ Microbiol 2017; 83:AEM.03152-16. [PMID: 28039139 DOI: 10.1128/aem.03152-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 12/28/2016] [Indexed: 12/13/2022] Open
Abstract
N-Glycosylation, the covalent linkage of glycans to select Asn residues of target proteins, is an almost universal posttranslational modification in archaea. However, whereas roles for N-glycosylation have been defined in eukarya and bacteria, the function of archaeal N-glycosylation remains unclear. Here, the impact of perturbed N-glycosylation on the structure and physiology of the haloarchaeon Haloferax volcanii was considered. Cryo-electron microscopy was used to examine right-side-out membrane vesicles prepared from cells of a parent strain and from strains lacking genes encoding glycosyltransferases involved in assembling the N-linked pentasaccharide decorating the surface layer (S-layer) glycoprotein, the sole component of the S-layer surrounding H. volcanii cells. Whereas a regularly repeating S-layer covered the entire surface of vesicles prepared from parent strain cells, vesicles from the mutant cells were only partially covered. To determine whether such N-glycosylation-related effects on S-layer assembly also affected cell function, the secretion of a reporter protein was addressed in the parent and N-glycosylation mutant strains. Compromised S-layer glycoprotein N-glycosylation resulted in impaired transfer of the reporter past the S-layer and into the growth medium. Finally, an assessment of S-layer glycoprotein susceptibility to added proteases in the mutants revealed that in cells lacking AglD, which is involved in adding the final pentasaccharide sugar, a distinct S-layer glycoprotein conformation was assumed in which the N-terminal region was readily degraded. Perturbed N-glycosylation thus affects S-layer glycoprotein folding. These findings suggest that H. volcanii could adapt to changes in its surroundings by modulating N-glycosylation so as to affect S-layer architecture and function.IMPORTANCE Long held to be a process unique to eukaryotes, it is now accepted that bacteria and archaea also perform N-glycosylation, namely, the covalent attachment of sugars to select asparagine residues of target proteins. Yet, while information on the importance of N-glycosylation in eukaryotes and bacteria is available, the role of this posttranslational modification in archaea remains unclear. Here, insight into the purpose of archaeal N-glycosylation was gained by addressing the surface layer (S-layer) surrounding cells of the halophilic species Haloferax volcanii Relying on mutant strains defective in N-glycosylation, such efforts revealed that compromised N-glycosylation affected S-layer integrity and the transfer of a secreted reporter protein across the S-layer into the growth medium, as well as the conformation of the S-layer glycoprotein, the sole component of the S-layer. Thus, by modifying N-glycosylation, H. volcanii cells can change how they interact with their surroundings.
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24
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Complementation of an aglB Mutant of Methanococcus maripaludis with Heterologous Oligosaccharyltransferases. PLoS One 2016; 11:e0167611. [PMID: 27907170 PMCID: PMC5131992 DOI: 10.1371/journal.pone.0167611] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 11/17/2016] [Indexed: 01/04/2023] Open
Abstract
The oligosaccharyltransferase is the signature enzyme for N-linked glycosylation in all domains of life. In Archaea, this enzyme termed AglB, is responsible for transferring lipid carrier-linked glycans to select asparagine residues in a variety of target proteins including archaellins, S-layer proteins and pilins. This study investigated the ability of a variety of AglBs to compensate for the oligosaccharyltransferase activity in Methanococcus maripaludis deleted for aglB, using archaellin FlaB2 as the reporter protein since all archaellins in Mc. maripaludis are modified at multiple sites by an N-linked tetrasaccharide and this modification is required for archaellation. In the Mc. maripaludis ΔaglB strain FlaB2 runs as at a smaller apparent molecular weight in western blots and is nonarchaellated. We demonstrate that AglBs from Methanococcus voltae and Methanothermococcus thermolithotrophicus functionally replaced the oligosaccharyltransferase activity missing in the Mc. maripaludis ΔaglB strain, both returning the apparent molecular weight of FlaB2 to wildtype size and restoring archaellation. This demonstrates that AglB from Mc. voltae has a relaxed specificity for the linking sugar of the transferred glycan since while the N-linked glycan present in Mc. voltae is similar to that of Mc. maripaludis, the Mc. voltae glycan uses N-acetylglucosamine as the linking sugar. In Mc. maripaludis that role is held by N-acetylgalactosamine. This study also identifies aglB from Mtc. thermolithotrophicus for the first time by its activity. Attempts to use AglB from Methanocaldococcus jannaschii, Haloferax volcanii or Sulfolobus acidocaldarius to functionally replace the oligosaccharyltransferase activity missing in the Mc. maripaludis ΔaglB strain were unsuccessful.
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25
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Guan Z, Delago A, Nußbaum P, Meyer B, Albers SV, Eichler J. N-glycosylation in the thermoacidophilic archaeon Sulfolobus acidocaldarius involves a short dolichol pyrophosphate carrier. FEBS Lett 2016; 590:3168-78. [PMID: 27490243 DOI: 10.1002/1873-3468.12341] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 07/27/2016] [Accepted: 07/29/2016] [Indexed: 01/31/2023]
Abstract
N-glycosylation is a post-translational modification that occurs across evolution. In the thermoacidophilic archaea Sulfolobus acidocaldarius, glycoproteins are modified by an N-linked tribranched hexasaccharide reminiscent of the N-glycans assembled in Eukarya. Previously, hexose-bearing dolichol phosphate was detected in a S. acidocaldarius Bligh-Dyer lipid extract. Here, we used a specialized protocol for extracting lipid-linked oligosaccharides to detect a dolichol pyrophosphate bearing the intact hexasaccharide, as well as its biosynthetic intermediates. Furthermore, evidence for N-glycosylation of two S. acidocaldarius proteins by the same hexasaccharide and its derivatives was collected. These findings thus provide novel insight into archaeal N-glycosylation.
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Affiliation(s)
- Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC, USA
| | - Antonia Delago
- Department of Life Sciences, Ben Gurion University of the Negev, Beersheva, Israel
| | - Phillip Nußbaum
- Molecular Biology of Archaea, Institute for Biology II-Microbiology, Albert-Ludwigs-University of Freiburg, Germany
| | - Benjamin Meyer
- Molecular Biology of Archaea, Institute for Biology II-Microbiology, Albert-Ludwigs-University of Freiburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute for Biology II-Microbiology, Albert-Ludwigs-University of Freiburg, Germany
| | - Jerry Eichler
- Department of Life Sciences, Ben Gurion University of the Negev, Beersheva, Israel.
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26
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Schäffer C, Messner P. Emerging facets of prokaryotic glycosylation. FEMS Microbiol Rev 2016; 41:49-91. [PMID: 27566466 DOI: 10.1093/femsre/fuw036] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/17/2016] [Accepted: 08/01/2016] [Indexed: 12/16/2022] Open
Abstract
Glycosylation of proteins is one of the most prevalent post-translational modifications occurring in nature, with a wide repertoire of biological implications. Pathways for the main types of this modification, the N- and O-glycosylation, can be found in all three domains of life-the Eukarya, Bacteria and Archaea-thereby following common principles, which are valid also for lipopolysaccharides, lipooligosaccharides and glycopolymers. Thus, studies on any glycoconjugate can unravel novel facets of the still incompletely understood fundamentals of protein N- and O-glycosylation. While it is estimated that more than two-thirds of all eukaryotic proteins would be glycosylated, no such estimate is available for prokaryotic glycoproteins, whose understanding is lagging behind, mainly due to the enormous variability of their glycan structures and variations in the underlying glycosylation processes. Combining glycan structural information with bioinformatic, genetic, biochemical and enzymatic data has opened up an avenue for in-depth analyses of glycosylation processes as a basis for glycoengineering endeavours. Here, the common themes of glycosylation are conceptualised for the major classes of prokaryotic (i.e. bacterial and archaeal) glycoconjugates, with a special focus on glycosylated cell-surface proteins. We describe the current knowledge of biosynthesis and importance of these glycoconjugates in selected pathogenic and beneficial microbes.
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Affiliation(s)
- Christina Schäffer
- Department of NanoBiotechnology, Institute of Biologically Inspired Materials, NanoGlycobiology unit, Universität für Bodenkultur Wien, A-1180 Vienna, Austria
| | - Paul Messner
- Department of NanoBiotechnology, Institute of Biologically Inspired Materials, NanoGlycobiology unit, Universität für Bodenkultur Wien, A-1180 Vienna, Austria
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27
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Esquivel RN, Schulze S, Xu R, Hippler M, Pohlschroder M. Identification of Haloferax volcanii Pilin N-Glycans with Diverse Roles in Pilus Biosynthesis, Adhesion, and Microcolony Formation. J Biol Chem 2016; 291:10602-14. [PMID: 26966177 DOI: 10.1074/jbc.m115.693556] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Indexed: 01/02/2023] Open
Abstract
N-Glycosylation is a post-translational modification common to all three domains of life. In many archaea, the oligosacharyltransferase (AglB)-dependent N-glycosylation of flagellins is required for flagella assembly. However, whether N-glycosylation is required for the assembly and/or function of the structurally related archaeal type IV pili is unknown. Here, we show that of six Haloferax volcanii adhesion pilins, PilA1 and PilA2, the most abundant pilins in pili of wild-type and ΔaglB strains, are modified under planktonic conditions in an AglB-dependent manner by the same pentasaccharide detected on H. volcanii flagellins. However, unlike wild-type cells, which have surfaces decorated with discrete pili and form a dispersed layer of cells on a plastic surface, ΔaglB cells have thick pili bundles and form microcolonies. Moreover, expressing PilA1, PilA2, or PilA6 in ΔpilA[1-6]ΔaglB stimulates microcolony formation compared with their expression in ΔpilA[1-6]. Conversely, expressing PilA3 or PilA4 in ΔpilA[1-6] cells results in strong surface adhesion, but not microcolony formation, and neither pilin stimulates surface adhesion in ΔpilA[1-6]ΔaglB cells. Although PilA4 assembles into pili in the ΔpilA[1-6]ΔaglB cells, these pili are, unlike wild-type pili, curled, perhaps rendering them non-functional. To our knowledge, this is the first demonstration of a differential effect of glycosylation on pilus assembly and function of paralogous pilins. The growth of wild-type cells in low salt media, a condition that decreases AglB glycosylation, also stimulates microcolony formation and inhibits motility, supporting our hypothesis that N-glycosylation plays an important role in regulating the transition between planktonic to sessile cell states as a response to stress.
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Affiliation(s)
- Rianne N Esquivel
- From the Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Stefan Schulze
- the Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Rachel Xu
- From the Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Michael Hippler
- the Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Mechthild Pohlschroder
- From the Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
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