1
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Abel NB, Nørgaard MMM, Hansen SB, Gysel K, Díez IA, Jensen ON, Stougaard J, Andersen KR. Phosphorylation of the alpha-I motif in SYMRK drives root nodule organogenesis. Proc Natl Acad Sci U S A 2024; 121:e2311522121. [PMID: 38363863 PMCID: PMC10895371 DOI: 10.1073/pnas.2311522121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 12/15/2023] [Indexed: 02/18/2024] Open
Abstract
Symbiosis receptor-like kinase SYMRK is required for root nodule symbiosis between legume plants and nitrogen-fixing bacteria. To understand symbiotic signaling from SYMRK, we determined the crystal structure to 1.95 Å and mapped the phosphorylation sites onto the intracellular domain. We identified four serine residues in a conserved "alpha-I" motif, located on the border between the kinase core domain and the flexible C-terminal tail, that, when phosphorylated, drives organogenesis. Substituting the four serines with alanines abolished symbiotic signaling, while substituting them with phosphorylation-mimicking aspartates induced the formation of spontaneous nodules in the absence of bacteria. These findings show that the signaling pathway controlling root nodule organogenesis is mediated by SYMRK phosphorylation, which may help when engineering this trait into non-legume plants.
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Affiliation(s)
- Nikolaj B. Abel
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C8000, Denmark
| | - Malita M. M. Nørgaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C8000, Denmark
| | - Simon B. Hansen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C8000, Denmark
| | - Kira Gysel
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C8000, Denmark
| | - Ignacio Arribas Díez
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M5230, Denmark
| | - Ole N. Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M5230, Denmark
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C8000, Denmark
| | - Kasper R. Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C8000, Denmark
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2
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Ferguson S, Abel NB, Reid D, Madsen LH, Luu TB, Andersen KR, Stougaard J, Radutoiu S. A simple and efficient protocol for generating transgenic hairy roots using Agrobacterium rhizogenes. PLoS One 2023; 18:e0291680. [PMID: 37910566 PMCID: PMC10619795 DOI: 10.1371/journal.pone.0291680] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 09/01/2023] [Indexed: 11/03/2023] Open
Abstract
For decades, Agrobacterium rhizogenes (now Rhizobium rhizogenes), the causative agent of hairy root disease, has been harnessed as an interkingdom DNA delivery tool for generating transgenic hairy roots on a wide variety of plants. One of the strategies involves the construction of transconjugant R. rhizogenes by transferring gene(s) of interest into previously constructed R. rhizogenes pBR322 acceptor strains; little has been done, however, to improve upon this system since its implementation. We developed a simplified method utilising bi-parental mating in conjunction with effective counterselection for generating R. rhizogenes transconjugants. Central to this was the construction of a new Modular Cloning (MoClo) compatible pBR322-derived integration vector (pIV101). Although this protocol remains limited to pBR322 acceptor strains, pIV101 facilitated an efficient construction of recombinant vectors, effective screening of transconjugants, and RP4-based mobilisation compatibility that enabled simplified conjugal transfer. Transconjugants from this system were tested on Lotus japonicus and found to be efficient for the transformation of transgenic hairy roots and supported infection of nodules by a rhizobia symbiont. The expedited protocol detailed herein substantially decreased both the time and labour for creating transconjugant R. rhizogenes for the subsequent transgenic hairy root transformation of Lotus, and it could readily be applied for the transformation of other plants.
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Affiliation(s)
- Shaun Ferguson
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Nikolaj B. Abel
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Dugald Reid
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- Department of Animal, Plant and Soil Sciences, School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - Lene H. Madsen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Thi-Bich Luu
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Kasper R. Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Simona Radutoiu
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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3
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Kelly S, Hansen SB, Rübsam H, Saake P, Pedersen EB, Gysel K, Madland E, Wu S, Wawra S, Reid D, Sullivan JT, Blahovska Z, Vinther M, Muszynski A, Azadi P, Thygesen MB, Aachmann FL, Ronson CW, Zuccaro A, Andersen KR, Radutoiu S, Stougaard J. A glycan receptor kinase facilitates intracellular accommodation of arbuscular mycorrhiza and symbiotic rhizobia in the legume Lotus japonicus. PLoS Biol 2023; 21:e3002127. [PMID: 37200394 DOI: 10.1371/journal.pbio.3002127] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 05/31/2023] [Accepted: 04/18/2023] [Indexed: 05/20/2023] Open
Abstract
Receptors that distinguish the multitude of microbes surrounding plants in the environment enable dynamic responses to the biotic and abiotic conditions encountered. In this study, we identify and characterise a glycan receptor kinase, EPR3a, closely related to the exopolysaccharide receptor EPR3. Epr3a is up-regulated in roots colonised by arbuscular mycorrhizal (AM) fungi and is able to bind glucans with a branching pattern characteristic of surface-exposed fungal glucans. Expression studies with cellular resolution show localised activation of the Epr3a promoter in cortical root cells containing arbuscules. Fungal infection and intracellular arbuscule formation are reduced in epr3a mutants. In vitro, the EPR3a ectodomain binds cell wall glucans in affinity gel electrophoresis assays. In microscale thermophoresis (MST) assays, rhizobial exopolysaccharide binding is detected with affinities comparable to those observed for EPR3, and both EPR3a and EPR3 bind a well-defined β-1,3/β-1,6 decasaccharide derived from exopolysaccharides of endophytic and pathogenic fungi. Both EPR3a and EPR3 function in the intracellular accommodation of microbes. However, contrasting expression patterns and divergent ligand affinities result in distinct functions in AM colonisation and rhizobial infection in Lotus japonicus. The presence of Epr3a and Epr3 genes in both eudicot and monocot plant genomes suggest a conserved function of these receptor kinases in glycan perception.
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Affiliation(s)
- Simon Kelly
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Simon B Hansen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Henriette Rübsam
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Pia Saake
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Plant Sciences, Cologne, Germany
| | - Emil B Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Kira Gysel
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Eva Madland
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Shunliang Wu
- Department of Chemistry, University of Copenhagen, Frederiksberg, Denmark
| | - Stephan Wawra
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Plant Sciences, Cologne, Germany
| | - Dugald Reid
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - John T Sullivan
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Zuzana Blahovska
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Maria Vinther
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Artur Muszynski
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America
| | - Mikkel B Thygesen
- Department of Chemistry, University of Copenhagen, Frederiksberg, Denmark
| | - Finn L Aachmann
- NOBIPOL (Norwegian Biopolymer Laboratory), Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Trondheim, Norway
| | - Clive W Ronson
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Alga Zuccaro
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Plant Sciences, Cologne, Germany
| | - Kasper R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Simona Radutoiu
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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4
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Jensen RK, Pihl R, Gadeberg TA, Jensen JK, Andersen KR, Thiel S, Laursen NS, Andersen GR. Correction: A potent complement factor C3-specific nanobody inhibiting multiple functions in the alternative pathway of human and murine complement. J Biol Chem 2023; 299:102951. [PMID: 36739657 PMCID: PMC9932098 DOI: 10.1016/j.jbc.2023.102951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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5
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Rübsam H, Krönauer C, Abel NB, Ji H, Lironi D, Hansen SB, Nadzieja M, Kolte MV, Abel D, de Jong N, Madsen LH, Liu H, Stougaard J, Radutoiu S, Andersen KR. Nanobody-driven signaling reveals the core receptor complex in root nodule symbiosis. Science 2023; 379:272-277. [PMID: 36656954 DOI: 10.1126/science.ade9204] [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: 01/20/2023]
Abstract
Understanding the composition and activation of multicomponent receptor complexes is a challenge in biology. To address this, we developed a synthetic approach based on nanobodies to drive assembly and activation of cell surface receptors and apply the concept by manipulating receptors that govern plant symbiosis with nitrogen-fixing bacteria. We show that the Lotus japonicus Nod factor receptors NFR1 and NFR5 constitute the core receptor complex initiating the cortical root nodule organogenesis program as well as the epidermal program controlling infection. We find that organogenesis signaling is mediated by the intracellular kinase domains whereas infection requires functional ectodomains. Finally, we identify evolutionarily distant barley receptors that activate root nodule organogenesis, which could enable engineering of biological nitrogen-fixation into cereals.
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Affiliation(s)
- Henriette Rübsam
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Christina Krönauer
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Nikolaj B Abel
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Hongtao Ji
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark.,National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Damiano Lironi
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Simon B Hansen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Marcin Nadzieja
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Marie V Kolte
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Dörte Abel
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Noor de Jong
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Lene H Madsen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Huijun Liu
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Simona Radutoiu
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Kasper R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
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6
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Kawaharada Y, Sandal N, Gupta V, Jin H, Kawaharada M, Taniuchi M, Ruman H, Nadzieja M, Andersen KR, Schneeberger K, Stougaard J, Andersen SU. Natural variation identifies a Pxy gene controlling vascular organisation and formation of nodules and lateral roots in Lotus japonicus. New Phytol 2021; 230:2459-2473. [PMID: 33759450 DOI: 10.1111/nph.17356] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 03/01/2021] [Indexed: 05/06/2023]
Abstract
Forward and reverse genetics using the model legumes Lotus japonicus and Medicago truncatula have been instrumental in identifying the essential genes governing legume-rhizobia symbiosis. However, little information is known about the effects of intraspecific variation on symbiotic signalling. Here, we use quantitative trait locus sequencing (QTL-seq) to investigate the genetic basis of the differentiated phenotypic responses shown by the Lotus accessions Gifu and MG20 to inoculation with the Mesorhizobium loti exoU mutant that produces truncated exopolysaccharides. We identified through genetic complementation the Pxy gene as a component of this differential exoU response. Lotus Pxy encodes a leucine-rich repeat receptor-like kinase similar to Arabidopsis thaliana PXY, which regulates stem vascular development. We show that Lotus pxy insertion mutants displayed defects in root and stem vascular organisation, as well as lateral root and nodule formation. Our work links Pxy to de novo organogenesis in the root, highlights the genetic overlap between regulation of lateral root and nodule formation, and demonstrates that natural variation in Pxy affects nodulation signalling.
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Affiliation(s)
- Yasuyuki Kawaharada
- Department of Plant BioSciences, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate, Japan
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Niels Sandal
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Vikas Gupta
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Haojie Jin
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Maya Kawaharada
- Department of Plant BioSciences, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate, Japan
| | - Makoto Taniuchi
- Department of Plant BioSciences, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate, Japan
| | - Hafijur Ruman
- United Graduate School of Agricultural Sciences, Iwate University, 3-18-8 Ueda, Morioka, Iwate, Japan
| | - Marcin Nadzieja
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Kasper R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Korbinian Schneeberger
- Department for Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Stig U Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
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7
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Bozsoki Z, Gysel K, Hansen SB, Lironi D, Krönauer C, Feng F, de Jong N, Vinther M, Kamble M, Thygesen MB, Engholm E, Kofoed C, Fort S, Sullivan JT, Ronson CW, Jensen KJ, Blaise M, Oldroyd G, Stougaard J, Andersen KR, Radutoiu S. Ligand-recognizing motifs in plant LysM
receptors are major determinants of
specificity. Science 2020; 369:663-670. [DOI: 10.1126/science.abb3377] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 06/12/2020] [Indexed: 01/02/2023]
Abstract
Plants evolved lysine motif (LysM)
receptors to recognize and parse microbial
elicitors and drive intracellular signaling to
limit or facilitate microbial colonization. We
investigated how chitin and nodulation (Nod)
factor receptors of Lotus
japonicus initiate differential
signaling of immunity or root nodule symbiosis.
Two motifs in the LysM1 domains of these receptors
determine specific recognition of ligands and
discriminate between their in planta functions.
These motifs define the ligand-binding site and
make up the most structurally divergent regions in
cognate Nod factor receptors. An adjacent motif
modulates the specificity for Nod factor
recognition and determines the selection of
compatible rhizobial symbionts in legumes. We also
identified how binding specificities in LysM
receptors can be altered to facilitate Nod factor
recognition and signaling from a chitin receptor,
advancing the prospects of engineering rhizobial
symbiosis into nonlegumes.
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Affiliation(s)
- Zoltan Bozsoki
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Kira Gysel
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Simon B. Hansen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Damiano Lironi
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Christina Krönauer
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Feng Feng
- Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK
| | - Noor de Jong
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Maria Vinther
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Manoj Kamble
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Mikkel B. Thygesen
- Department of Chemistry, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Ebbe Engholm
- Department of Chemistry, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Christian Kofoed
- Department of Chemistry, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Sébastien Fort
- Université Grenoble Alpes, CNRS, CERMAV, 38000 Grenoble, France
| | - John T. Sullivan
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Clive W. Ronson
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Knud J. Jensen
- Department of Chemistry, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Mickaël Blaise
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Giles Oldroyd
- Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Kasper R. Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Simona Radutoiu
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
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8
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Wong JEMM, Gysel K, Birkefeldt TG, Vinther M, Muszyński A, Azadi P, Laursen NS, Sullivan JT, Ronson CW, Stougaard J, Andersen KR. Structural signatures in EPR3 define a unique class of plant carbohydrate receptors. Nat Commun 2020; 11:3797. [PMID: 32732998 PMCID: PMC7392887 DOI: 10.1038/s41467-020-17568-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [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: 03/05/2020] [Accepted: 07/05/2020] [Indexed: 11/21/2022] Open
Abstract
Receptor-mediated perception of surface-exposed carbohydrates like lipo- and exo-polysaccharides (EPS) is important for non-self recognition and responses to microbial associated molecular patterns in mammals and plants. In legumes, EPS are monitored and can either block or promote symbiosis with rhizobia depending on their molecular composition. To establish a deeper understanding of receptors involved in EPS recognition, we determined the structure of the Lotus japonicus (Lotus) exopolysaccharide receptor 3 (EPR3) ectodomain. EPR3 forms a compact structure built of three putative carbohydrate-binding modules (M1, M2 and LysM3). M1 and M2 have unique βαββ and βαβ folds that have not previously been observed in carbohydrate binding proteins, while LysM3 has a canonical βααβ fold. We demonstrate that this configuration is a structural signature for a ubiquitous class of receptors in the plant kingdom. We show that EPR3 is promiscuous, suggesting that plants can monitor complex microbial communities though this class of receptors. Exopolysaccharides (EPS) are perceived by legumes and regulate symbiosis with rhizobia. Here the authors describe the structure of the Lotus EPS receptor, EPR3 and show that it has atypical βαββ and βαβ folds that represent a structural signature for a unique class of EPS receptors in the plant kingdom.
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Affiliation(s)
- Jaslyn E M M Wong
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark.,MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Kira Gysel
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Thea G Birkefeldt
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Maria Vinther
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Artur Muszyński
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Nick S Laursen
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - John T Sullivan
- Department of Microbiology and Immunology, University of Otago, Dunedin, 9054, New Zealand
| | - Clive W Ronson
- Department of Microbiology and Immunology, University of Otago, Dunedin, 9054, New Zealand
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark
| | - Kasper R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus C, Denmark.
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9
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Pedersen DV, Rösner T, Hansen AG, Andersen KR, Thiel S, Andersen GR, Valerius T, Laursen NS. Recruitment of properdin by bi-specific nanobodies activates the alternative pathway of complement. Mol Immunol 2020; 124:200-210. [PMID: 32599335 DOI: 10.1016/j.molimm.2020.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 04/28/2020] [Accepted: 06/01/2020] [Indexed: 02/07/2023]
Abstract
The complement system represents a powerful part of the innate immune system capable of removing pathogens and damaged host cells. Nevertheless, only a subset of therapeutic antibodies are capable of inducing complement dependent cytotoxicity, which has fuelled the search for new strategies to potentiate complement activation. Properdin (FP) functions as a positive complement regulator by stabilizing the alternative pathway C3 convertase. Here, we explore a novel strategy for direct activation of the alternative pathway of complement using bi-specific single domain antibodies (nanobodies) that recruit endogenous FP to a cell surface. As a proof-of-principle, we generated bi-specific nanobodies with specificity toward FP and the validated cancer antigen epidermal growth factor receptor (EGFR) and tested their ability to activate complement onto cancer cell lines expressing EGFR. Treatment led to recruitment of FP, complement activation and significant deposition of C3 fragments on the cells in a manner sensitive to the geometry of FP recruitment. The bi-specific nanobodies induced complement dependent lysis of baby hamster kidney cells expressing human EGFR but were unable to lyse human tumour cells due to the presence of complement regulators. Our results confirm that FP can function as a surface bound focal point for initiation of complement activation independent of prior C3b deposition. However, recruitment of FP by bi-specific nanobodies appears insufficient for overcoming the inhibitory action of the negative complement regulators overexpressed by many human tumour cell lines. Our data provide general information on the efficacy of properdin as an initiator of complement but suggest that properdin recruitment on its own may have limited utility as a platform for potent complement activation on regulated cell surfaces.
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Affiliation(s)
- Dennis V Pedersen
- Department of Molecular Biology and Genetics, Center for Structural Biology, Aarhus University, Gustav Wieds vej 10 C, 8000 Aarhus C, Denmark
| | - Thies Rösner
- Section for Stem Cell Transplantation and Immunotherapy, Department of Medicine II, Christian-Albrechts-University, Rosalind-Franklin-Straße 12, 24103 Kiel, Germany
| | - Annette G Hansen
- Department of Biomedicine, Aarhus University, Høgh-Guldbergs Gade 10, 8000 Aarhus C, Denmark
| | - Kasper R Andersen
- Department of Molecular Biology and Genetics, Center for Structural Biology, Aarhus University, Gustav Wieds vej 10 C, 8000 Aarhus C, Denmark
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Høgh-Guldbergs Gade 10, 8000 Aarhus C, Denmark
| | - Gregers R Andersen
- Department of Molecular Biology and Genetics, Center for Structural Biology, Aarhus University, Gustav Wieds vej 10 C, 8000 Aarhus C, Denmark
| | - Thomas Valerius
- Section for Stem Cell Transplantation and Immunotherapy, Department of Medicine II, Christian-Albrechts-University, Rosalind-Franklin-Straße 12, 24103 Kiel, Germany
| | - Nick S Laursen
- Department of Molecular Biology and Genetics, Center for Structural Biology, Aarhus University, Gustav Wieds vej 10 C, 8000 Aarhus C, Denmark.
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10
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Mortensen MR, Skovsgaard MB, Märcher A, Andersen VL, Palmfeldt J, Nielsen TB, Tørring T, Laursen NS, Andersen KR, Kjems J, Gothelf KV. Introduction of an Aldehyde Handle on Nanobodies by Affinity-Guided Labeling. Bioconjug Chem 2020; 31:1295-1300. [PMID: 32320218 DOI: 10.1021/acs.bioconjchem.0c00151] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chemically modified antigen-binding proteins are widely applied for their targeting abilities in the fields of biotechnology, medicine, and diagnostics. However, the production of site-selectively modified proteins remains a challenge. Here, we have designed a chemical probe for the introduction of a reactive aldehyde on nanobodies by metal-complex-guided conjugation. The probe design allows for purification of the conjugates, and the aldehyde constitutes an efficient handle for further modification of the nanobodies. In vitro experiments confirmed the binding activity and selectivity of fluorescent conjugates toward the native antigen. Furthermore, the modification strategy allowed for production of a nanobody-drug conjugate that was active in vitro.
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Affiliation(s)
- Michael R Mortensen
- Center for Multifunctional Biomolecular Drug Design at the Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.,Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Mikkel B Skovsgaard
- Center for Multifunctional Biomolecular Drug Design at the Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.,Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Anders Märcher
- Center for Multifunctional Biomolecular Drug Design at the Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.,Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Veronica L Andersen
- Center for Multifunctional Biomolecular Drug Design at the Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.,Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Johan Palmfeldt
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Thorbjørn B Nielsen
- Center for Multifunctional Biomolecular Drug Design at the Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.,Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Thomas Tørring
- Department of Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark
| | - Nick S Laursen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Kasper R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Jørgen Kjems
- Center for Multifunctional Biomolecular Drug Design and DNRF Center for Cellular Signal Patterns (CellPat) at the Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Kurt V Gothelf
- Center for Multifunctional Biomolecular Drug Design at the Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.,Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
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11
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Wong JEMM, Nadzieja M, Madsen LH, Bücherl CA, Dam S, Sandal NN, Couto D, Derbyshire P, Uldum-Berentsen M, Schroeder S, Schwämmle V, Nogueira FCS, Asmussen MH, Thirup S, Radutoiu S, Blaise M, Andersen KR, Menke FLH, Zipfel C, Stougaard J. A Lotus japonicus cytoplasmic kinase connects Nod factor perception by the NFR5 LysM receptor to nodulation. Proc Natl Acad Sci U S A 2019; 116:14339-14348. [PMID: 31239345 PMCID: PMC6628658 DOI: 10.1073/pnas.1815425116] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The establishment of nitrogen-fixing root nodules in legume-rhizobia symbiosis requires an intricate communication between the host plant and its symbiont. We are, however, limited in our understanding of the symbiosis signaling process. In particular, how membrane-localized receptors of legumes activate signal transduction following perception of rhizobial signaling molecules has mostly remained elusive. To address this, we performed a coimmunoprecipitation-based proteomics screen to identify proteins associated with Nod factor receptor 5 (NFR5) in Lotus japonicus. Out of 51 NFR5-associated proteins, we focused on a receptor-like cytoplasmic kinase (RLCK), which we named NFR5-interacting cytoplasmic kinase 4 (NiCK4). NiCK4 associates with heterologously expressed NFR5 in Nicotiana benthamiana, and directly binds and phosphorylates the cytoplasmic domains of NFR5 and NFR1 in vitro. At the cellular level, Nick4 is coexpressed with Nfr5 in root hairs and nodule cells, and the NiCK4 protein relocates to the nucleus in an NFR5/NFR1-dependent manner upon Nod factor treatment. Phenotyping of retrotransposon insertion mutants revealed that NiCK4 promotes nodule organogenesis. Together, these results suggest that the identified RLCK, NiCK4, acts as a component of the Nod factor signaling pathway downstream of NFR5.
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Affiliation(s)
- Jaslyn E M M Wong
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Marcin Nadzieja
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Lene H Madsen
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Christoph A Bücherl
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, United Kingdom
| | - Svend Dam
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Niels N Sandal
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Daniel Couto
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, United Kingdom
| | - Paul Derbyshire
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, United Kingdom
| | - Mette Uldum-Berentsen
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Sina Schroeder
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Veit Schwämmle
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense, Denmark
| | - Fábio C S Nogueira
- Proteomics Unit, Chemistry Institute, Federal University of Rio de Janeiro, 21941-909, Rio de Janeiro, Brazil
| | - Mette H Asmussen
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Søren Thirup
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Simona Radutoiu
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Mickaël Blaise
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Kasper R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Frank L H Menke
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, United Kingdom
| | - Cyril Zipfel
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, United Kingdom
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark;
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12
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Liu H, Sandal N, Andersen KR, James EK, Stougaard J, Kelly S, Kawaharada Y. A genetic screen for plant mutants with altered nodulation phenotypes in response to rhizobial glycan mutants. New Phytol 2018; 220:526-538. [PMID: 29959893 DOI: 10.1111/nph.15293] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 05/24/2018] [Indexed: 05/08/2023]
Abstract
Nodule primordia induced by rhizobial glycan mutants often remain uninfected. To identify processes involved in infection and organogenesis we used forward genetics to identify plant genes involved in perception and responses to bacterial glycans. To dissect the mechanisms underlying the negative plant responses to the Mesorhizobium loti R7AexoU and ML001cep mutants, a screen for genetic suppressors of the nodulation phenotypes was performed on a chemically mutagenized Lotus population. Two mutant lines formed infected nitrogen-fixing pink nodules, while five mutant lines developed uninfected large white nodules, presumably altered in processes controlling organogenesis. Genetic mapping identified a mutation in the cytokinin receptor Lhk1 resulting in an alanine to valine substitution adjacent to a coiled-coil motif in the juxta-membrane region of LHK1. This results in a spontaneous nodulation phenotype and increased ethylene production. The allele was renamed snf5, and segregation studies of snf5 together with complementation studies suggest that snf5 is a gain-of-function allele. This forward genetic approach to investigate the role of glycans in the pathway synchronizing infection and organogenesis shows that a combination of plant and bacterial genetics opens new possibilities to study glycan responses in plants as well as identification of mutant alleles affecting nodule organogenesis.
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Affiliation(s)
- Huijun Liu
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Niels Sandal
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Kasper R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Euan K James
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Simon Kelly
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Yasuyuki Kawaharada
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
- Department of Plant BioSciences, Faculty of Agriculture, Iwate University, 3-18-8-Ueda, Morioka, Iwate, Japan
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13
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Jensen RK, Pihl R, Gadeberg TAF, Jensen JK, Andersen KR, Thiel S, Laursen NS, Andersen GR. A potent complement factor C3-specific nanobody inhibiting multiple functions in the alternative pathway of human and murine complement. J Biol Chem 2018; 293:6269-6281. [PMID: 29497000 PMCID: PMC5925797 DOI: 10.1074/jbc.ra117.001179] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [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: 11/30/2017] [Revised: 02/07/2018] [Indexed: 12/30/2022] Open
Abstract
The complement system is a complex, carefully regulated proteolytic cascade for which suppression of aberrant activation is of increasing clinical relevance, and inhibition of the complement alternative pathway is a subject of intense research. Here, we describe the nanobody hC3Nb1 that binds to multiple functional states of C3 with subnanomolar affinity. The nanobody causes a complete shutdown of alternative pathway activity in human and murine serum when present in concentrations comparable with that of C3, and hC3Nb1 is shown to prevent proconvertase assembly, as well as binding of the C3 substrate to C3 convertases. Our crystal structure of the C3b-hC3Nb1 complex and functional experiments demonstrate that proconvertase formation is blocked by steric hindrance between the nanobody and an Asn-linked glycan on complement factor B. In addition, hC3Nb1 is shown to prevent factor H binding to C3b, rationalizing its inhibition of factor I activity. Our results identify hC3Nb1 as a versatile, inexpensive, and powerful inhibitor of the alternative pathway in both human and murine in vitro model systems of complement activation.
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Affiliation(s)
| | - Rasmus Pihl
- Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark
| | | | - Jan K. Jensen
- From the Departments of Molecular Biology and Genetics and
| | | | - Steffen Thiel
- Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark
| | | | - Gregers R. Andersen
- From the Departments of Molecular Biology and Genetics and , To whom correspondence should be addressed:
Dept. of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus, Denmark. Tel.:
45-5144-6530; Fax:
45-8619-6500; E-mail:
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14
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Onischenko E, Tang JH, Andersen KR, Knockenhauer KE, Vallotton P, Derrer CP, Kralt A, Mugler CF, Chan LY, Schwartz TU, Weis K. Natively Unfolded FG Repeats Stabilize the Structure of the Nuclear Pore Complex. Cell 2017; 171:904-917.e19. [PMID: 29033133 DOI: 10.1016/j.cell.2017.09.033] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 08/25/2017] [Accepted: 09/19/2017] [Indexed: 12/30/2022]
Abstract
Nuclear pore complexes (NPCs) are ∼100 MDa transport channels assembled from multiple copies of ∼30 nucleoporins (Nups). One-third of these Nups contain phenylalanine-glycine (FG)-rich repeats, forming a diffusion barrier, which is selectively permeable for nuclear transport receptors that interact with these repeats. Here, we identify an additional function of FG repeats in the structure and biogenesis of the yeast NPC. We demonstrate that GLFG-containing FG repeats directly bind to multiple scaffold Nups in vitro and act as NPC-targeting determinants in vivo. Furthermore, we show that the GLFG repeats of Nup116 function in a redundant manner with Nup188, a nonessential scaffold Nup, to stabilize critical interactions within the NPC scaffold needed for late steps of NPC assembly. Our results reveal a previously unanticipated structural role for natively unfolded GLFG repeats as Velcro to link NPC subcomplexes and thus add a new layer of connections to current models of the NPC architecture.
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Affiliation(s)
- Evgeny Onischenko
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, CH-8093 Zurich, Switzerland
| | - Jeffrey H Tang
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, CH-8093 Zurich, Switzerland
| | - Kasper R Andersen
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Kevin E Knockenhauer
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Pascal Vallotton
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, CH-8093 Zurich, Switzerland
| | - Carina P Derrer
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, CH-8093 Zurich, Switzerland
| | - Annemarie Kralt
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, CH-8093 Zurich, Switzerland
| | - Christopher F Mugler
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Leon Y Chan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Thomas U Schwartz
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Karsten Weis
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, CH-8093 Zurich, Switzerland.
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15
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Hansen SB, Laursen NS, Andersen GR, Andersen KR. Introducing site-specific cysteines into nanobodies for mercury labelling allows de novo phasing of their crystal structures. Acta Crystallogr D Struct Biol 2017; 73:804-813. [PMID: 28994409 PMCID: PMC5633906 DOI: 10.1107/s2059798317013171] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 09/14/2017] [Indexed: 11/10/2022] Open
Abstract
The generation of high-quality protein crystals and the loss of phase information during an X-ray crystallography diffraction experiment represent the major bottlenecks in the determination of novel protein structures. A generic method for introducing Hg atoms into any crystal independent of the presence of free cysteines in the target protein could considerably facilitate the process of obtaining unbiased experimental phases. Nanobodies (single-domain antibodies) have recently been shown to promote the crystallization and structure determination of flexible proteins and complexes. To extend the usability of nanobodies for crystallographic work, variants of the Nb36 nanobody with a single free cysteine at one of four framework-residue positions were developed. These cysteines could be labelled with fluorophores or Hg. For one cysteine variant (Nb36-C85) two nanobody structures were experimentally phased using single-wavelength anomalous dispersion (SAD) and single isomorphous replacement with anomalous signal (SIRAS), taking advantage of radiation-induced changes in Cys-Hg bonding. Importantly, Hg labelling influenced neither the interaction of Nb36 with its antigen complement C5 nor its structure. The results suggest that Cys-Hg-labelled nanobodies may become efficient tools for obtaining de novo phase information during the structure determination of nanobody-protein complexes.
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Affiliation(s)
- Simon Boje Hansen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus, Denmark
| | - Nick Stub Laursen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus, Denmark
| | - Gregers Rom Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus, Denmark
| | - Kasper R. Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus, Denmark
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16
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Bozsoki Z, Cheng J, Feng F, Gysel K, Vinther M, Andersen KR, Oldroyd G, Blaise M, Radutoiu S, Stougaard J. Receptor-mediated chitin perception in legume roots is functionally separable from Nod factor perception. Proc Natl Acad Sci U S A 2017; 114:E8118-E8127. [PMID: 28874587 PMCID: PMC5617283 DOI: 10.1073/pnas.1706795114] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [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] [Indexed: 12/22/2022] Open
Abstract
The ability of root cells to distinguish mutualistic microbes from pathogens is crucial for plants that allow symbiotic microorganisms to infect and colonize their internal root tissues. Here we show that Lotus japonicus and Medicago truncatula possess very similar LysM pattern-recognition receptors, LjLYS6/MtLYK9 and MtLYR4, enabling root cells to separate the perception of chitin oligomeric microbe-associated molecular patterns from the perception of lipochitin oligosaccharide by the LjNFR1/MtLYK3 and LjNFR5/MtNFP receptors triggering symbiosis. Inactivation of chitin-receptor genes in Ljlys6, Mtlyk9, and Mtlyr4 mutants eliminates early reactive oxygen species responses and induction of defense-response genes in roots. Ljlys6, Mtlyk9, and Mtlyr4 mutants were also more susceptible to fungal and bacterial pathogens, while infection and colonization by rhizobia and arbuscular mycorrhizal fungi was maintained. Biochemical binding studies with purified LjLYS6 ectodomains further showed that at least six GlcNAc moieties (CO6) are required for optimal binding efficiency. The 2.3-Å crystal structure of the LjLYS6 ectodomain reveals three LysM βααβ motifs similar to other LysM proteins and a conserved chitin-binding site. These results show that distinct receptor sets in legume roots respond to chitin and lipochitin oligosaccharides found in the heterogeneous mixture of chitinaceous compounds originating from soil microbes. This establishes a foundation for genetic and biochemical dissection of the perception and the downstream responses separating defense from symbiosis in the roots of the 80-90% of land plants able to develop rhizobial and/or mycorrhizal endosymbiosis.
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Affiliation(s)
- Zoltan Bozsoki
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, University of Aarhus, DK-8000 Aarhus, Denmark
| | - Jeryl Cheng
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, University of Aarhus, DK-8000 Aarhus, Denmark
| | - Feng Feng
- John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Kira Gysel
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, University of Aarhus, DK-8000 Aarhus, Denmark
| | - Maria Vinther
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, University of Aarhus, DK-8000 Aarhus, Denmark
| | - Kasper R Andersen
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, University of Aarhus, DK-8000 Aarhus, Denmark
| | | | - Mickael Blaise
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, University of Aarhus, DK-8000 Aarhus, Denmark
| | - Simona Radutoiu
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, University of Aarhus, DK-8000 Aarhus, Denmark
| | - Jens Stougaard
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, University of Aarhus, DK-8000 Aarhus, Denmark;
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17
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Aunsbjerg SD, Andersen KR, Knøchel S. Real-time monitoring of fungal inhibition and morphological changes. J Microbiol Methods 2015; 119:196-202. [PMID: 26541062 DOI: 10.1016/j.mimet.2015.10.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 10/29/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
Abstract
Mold growth constitutes a problem in many food and clinical environments and there is therefore focus on studying antifungal activity. Methods for determining growth inhibition by measuring colony growth or biomass are, however, time-taking and rapid methods for evaluation of antifungal effects are needed. Propionic acid and diacetyl are antifungal compounds produced by a range of dairy-associated bacteria. Their activity against Penicillium spp. was monitored real-time using an optical detection system with tilted focus plane to assess growth and morphological changes of Penicillium spp. by image recording inside a 96 well microplate. Images were used for generation of growth curves by using a segmentation and extraction of surface areas (SESA) algorithm and for quantifying morphology changes. Using image analysis growth could be detected within 15 h compared with more than 30 h when using standard optical density measurements. Induced morphological changes of fungi could furthermore be visualized and quantified using morphological descriptors such as circularity, branch points, perimeter and area of spores and growing hyphae. Propionic acid inhibited two out of two Penicillium spp. while morphological changes were strain dependent at the concentrations tested. Diacetyl inhibited six out of six Penicillium spp. strains and increased spore size and number of germination sites in two out of six of the strains prior to germination.
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Affiliation(s)
- S D Aunsbjerg
- Department of Food Science, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark.
| | | | - S Knøchel
- Department of Food Science, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
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18
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Andersen KR, Leksa NC, Schwartz TU. Optimized E. coli expression strain LOBSTR eliminates common contaminants from His-tag purification. Proteins 2013; 81:1857-61. [PMID: 23852738 DOI: 10.1002/prot.24364] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [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: 03/26/2013] [Revised: 06/19/2013] [Accepted: 06/28/2013] [Indexed: 11/07/2022]
Abstract
His-tag affinity purification is one of the most commonly used methods to purify recombinant proteins expressed in E. coli. One drawback of using the His-tag is the co-purification of contaminating histidine-rich E. coli proteins. We engineered a new E. coli expression strain, LOBSTR (low background strain), which eliminates the most abundant contaminants. LOBSTR is derived from the E. coli BL21(DE3) strain and carries genomically modified copies of arnA and slyD, whose protein products exhibit reduced affinities to Ni and Co resins, resulting in a much higher purity of the target protein. The use of LOBSTR enables the pursuit of challenging low-expressing protein targets by reducing background contamination with no additional purification steps, materials, or costs, and thus pushes the limits of standard His-tag purifications.
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Affiliation(s)
- Kasper R Andersen
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139
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19
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Andersen KR, Onischenko E, Tang JH, Kumar P, Chen JZ, Ulrich A, Liphardt JT, Weis K, Schwartz TU. Scaffold nucleoporins Nup188 and Nup192 share structural and functional properties with nuclear transport receptors. eLife 2013; 2:e00745. [PMID: 23795296 PMCID: PMC3679522 DOI: 10.7554/elife.00745] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [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: 03/14/2013] [Accepted: 05/08/2013] [Indexed: 02/07/2023] Open
Abstract
Nucleocytoplasmic transport is mediated by nuclear pore complexes (NPCs) embedded in the nuclear envelope. About 30 different proteins (nucleoporins, nups) arrange around a central eightfold rotational axis to build the modular NPC. Nup188 and Nup192 are related and evolutionary conserved, large nucleoporins that are part of the NPC scaffold. Here we determine the structure of Nup188. The protein folds into an extended stack of helices where an N-terminal 130 kDa segment forms an intricate closed ring, while the C-terminal region is a more regular, superhelical structure. Overall, the structure has distant similarity with flexible S-shaped nuclear transport receptors (NTRs). Intriguingly, like NTRs, both Nup188 and Nup192 specifically bind FG-repeats and are able to translocate through NPCs by facilitated diffusion. This blurs the existing dogma of a clear distinction between stationary nups and soluble NTRs and suggests an evolutionary relationship between the NPC and the soluble nuclear transport machinery. DOI:http://dx.doi.org/10.7554/eLife.00745.001 The nucleus of a cell is surrounded by a two-layered membrane that controls the flow of molecules from the cytoplasm into the nucleus and vice versa. The molecular traffic between the cytoplasm and nucleus is essentially controlled by nuclear pore complexes—large, multi-protein structures that are embedded in the membrane. Each nuclear pore complex contains about 30 different proteins called nucleoporins or nups, which combine to form a structure with a central pore that allows the molecules to enter and leave the nucleus. The centre of the nuclear pore complex is thought to be filled with protein filaments that contain a large number of so-called FG repeats (where F and G are the amino acids phenylalanine and glycine). Specialized molecules called soluble nuclear transport receptors, which carry various cargoes between the cytoplasm and nucleus, can bind to these FG repeats, and the interaction between the receptors and the FG repeats is crucial for the selective transport of molecules between the cytoplasm and the nucleus. The large size of the nuclear pore complex has hindered efforts to work out its structure, but in recent years researchers have been able to obtain structures for many individual nups and their subcomplexes. Now, Andersen et al. have determined the structure of one of the largest nups, Nup188. This has led to the discovery that it and a related nup, Nup192, share unexpected features with soluble nuclear transport receptors. In general the first step when attempting to determine the structure of a biomolecule is to form a crystal. Since full-length Nup188 did not crystallize, Andersen et al. instead crystallized two large fragments of Nup188, determined the structures of these fragments, and then combined these to produce the likely structure of the full-length protein. They found that Nup188 has a structure that consists of stacked helices and is more flexible than other nups. Moreover, its structure was very similar to those of soluble nuclear transport receptors, and this led Andersen et al. to investigate whether Nup188 also had similar functional features. Surprisingly, they discovered that both Nup188 and Nup192 could bind FG repeats, just like nuclear transport receptors. What is more, this binding allowed both nups to travel through nuclear pore complexes in in vitro transport reactions. These findings have implications for the understanding of the organization and function of FG-repeats and suggest that the stationary elements of the nuclear pore complex and soluble nuclear transport receptors are evolutionarily related. DOI:http://dx.doi.org/10.7554/eLife.00745.002
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Affiliation(s)
- Kasper R Andersen
- Department of Biology , Massachusetts Institute of Technology , Cambridge , United States
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Ulrich A, Andersen KR, Schwartz TU. Exponential megapriming PCR (EMP) cloning--seamless DNA insertion into any target plasmid without sequence constraints. PLoS One 2012; 7:e53360. [PMID: 23300917 PMCID: PMC3534072 DOI: 10.1371/journal.pone.0053360] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [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: 11/12/2012] [Accepted: 11/30/2012] [Indexed: 11/23/2022] Open
Abstract
We present a fast, reliable and inexpensive restriction-free cloning method for seamless DNA insertion into any plasmid without sequence limitation. Exponential megapriming PCR (EMP) cloning requires two consecutive PCR steps and can be carried out in one day. We show that EMP cloning has a higher efficiency than restriction-free (RF) cloning, especially for long inserts above 2.5 kb. EMP further enables simultaneous cloning of multiple inserts.
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Affiliation(s)
- Alexander Ulrich
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Institut für Chemie und Biochemie, Freie Universität Berlin, Berlin, Germany
| | - Kasper R. Andersen
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Thomas U. Schwartz
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
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Bøggild A, Sofos N, Andersen KR, Feddersen A, Easter AD, Passmore LA, Brodersen DE. The crystal structure of the intact E. coli RelBE toxin-antitoxin complex provides the structural basis for conditional cooperativity. Structure 2012; 20:1641-8. [PMID: 22981948 PMCID: PMC3507626 DOI: 10.1016/j.str.2012.08.017] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 08/17/2012] [Accepted: 08/17/2012] [Indexed: 12/15/2022]
Abstract
The bacterial relBE locus encodes a toxin-antitoxin complex in which the toxin, RelE, is capable of cleaving mRNA in the ribosomal A site cotranslationally. The antitoxin, RelB, both binds and inhibits RelE, and regulates transcription through operator binding and conditional cooperativity controlled by RelE. Here, we present the crystal structure of the intact Escherichia coli RelB2E2 complex at 2.8 Å resolution, comprising both the RelB-inhibited RelE and the RelB dimerization domain that binds DNA. RelE and RelB associate into a V-shaped heterotetrameric complex with the ribbon-helix-helix (RHH) dimerization domain at the apex. Our structure supports a model in which relO is optimally bound by two adjacent RelB2E heterotrimeric units, and is not compatible with concomitant binding of two RelB2E2 heterotetramers. The results thus provide a firm basis for understanding the model of conditional cooperativity at the molecular level.
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Affiliation(s)
- Andreas Bøggild
- Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus C, Denmark
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Jonasson C, Moum B, Bang C, Andersen KR, Hatlebakk JG. Randomised clinical trial: a comparison between a GerdQ-based algorithm and an endoscopy-based approach for the diagnosis and initial treatment of GERD. Aliment Pharmacol Ther 2012; 35:1290-300. [PMID: 22510027 DOI: 10.1111/j.1365-2036.2012.05092.x] [Citation(s) in RCA: 41] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 03/14/2012] [Accepted: 03/22/2012] [Indexed: 12/13/2022]
Abstract
BACKGROUND The diagnosis of gastro-oesophageal reflux disease (GERD) remains challenging. An algorithm, facilitated by a questionnaire, may provide a more structured and cost-effective care of patients. AIM To compare symptom control achieved with empirical therapy for GERD, in an algorithm based on the GerdQ (new structured pathway, NSP), with that of current care after endoscopy (ordinary clinical pathway, OCP). METHODS Patients with symptoms of GERD, but without alarm features, were randomised in an open, parallel-group study and followed for 4-8 weeks. In the NSP, GerdQ score was used as a basis for both diagnosis and a treatment algorithm. Patients with high likelihood of GERD were treated empirically with a PPI whereas patients with low likelihood of GERD received therapy chosen by the clinician. In the OCP, diagnosis and treatment were based on endoscopy or pH-metry findings. The statistical hypothesis was non-inferiority of NSP to OCP. RESULTS A total of 147 patients (86.5%) in the NSP and 133 patients (80.1%) in the OCP arm were responders. Overall, NSP was non-inferior to OCP, but not superior (P = 0.14). Patients with high likelihood of GERD had significantly better symptom relief in the NSP (P = 0.03), whereas those with low likelihood of GERD showed a numerical difference in favour of an endoscopy-based approach (OCP). NSP saved 146 € per patient. CONCLUSIONS A symptom-based approach using GerdQ reduced health care costs without loss in efficacy. Patients with high likelihood GERD benefited from empirical treatment. An algorithm based on GerdQ may provide physicians with a tool for a more structured care of patients (ClinicalTrials.gov NCT00842387).
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Affiliation(s)
- C Jonasson
- University of Bergen, Institute of Medicine, Norway.
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Poulsen JB, Andersen KR, Kjær KH, Vestergaard AL, Justesen J, Martensen PM. Characterization of human phosphodiesterase 12 and identification of a novel 2'-5' oligoadenylate nuclease - The ectonucleotide pyrophosphatase/phosphodiesterase 1. Biochimie 2012; 94:1098-107. [PMID: 22285541 DOI: 10.1016/j.biochi.2012.01.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 01/12/2012] [Indexed: 11/19/2022]
Abstract
The vertebrate 2-5A system is part of the innate immune response and central to cellular antiviral activities. Upon activation by viral double-stranded RNA, 5'-triphosphorylated, 2'-5'-linked oligoadenylate polyribonucleotides (2-5As) are synthesized by one of several 2'-5' oligoadenylate synthetases. The 2-5As bind and activate RNase L, an unspecific endoribonuclease, resulting in viral and cellular RNA decay. Given that most endogenous RNAs are degraded by RNase L, continued enzyme activity will eventually lead to cell growth arrest and cell death. This is averted, when 2-5As and their 5'-dephosphorylated forms, the so-called 2-5A core molecules, are cleaved and thus inactivated by 2'-5'-specific nuclease(s), e.g. phosphodiesterase 12, thereby turning RNase L into its latent form. In this study, we have characterized the human phosphodiesterase 12 in vitro focusing on its ability to degrade 2-5As and 2-5A core molecules. We have found that the enzyme activity is distributive and is influenced by temperature, pH and divalent cations. This allowed us to determine V(max) and K(m) kinetic parameters for the enzyme. We have also identified a novel 2'-5'-oligoadenylate nuclease; the human plasma membrane-bound ectonucleotide pyrophosphatase/phosphodiesterase 1, suggesting that 2-5A catabolism may be a multienzyme-regulated process.
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Affiliation(s)
- Jesper B Poulsen
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, DK-8000 Aarhus C, Denmark.
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Neubauer C, Gao YG, Andersen KR, Dunham CM, Kelley AC, Hentschel J, Gerdes K, Ramakrishnan V, Brodersen DE. The structural basis for mRNA recognition and cleavage by the ribosome-dependent endonuclease RelE. Cell 2010; 139:1084-95. [PMID: 20005802 PMCID: PMC2807027 DOI: 10.1016/j.cell.2009.11.015] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 09/30/2009] [Accepted: 11/06/2009] [Indexed: 11/26/2022]
Abstract
Translational control is widely used to adjust gene expression levels. During the stringent response in bacteria, mRNA is degraded on the ribosome by the ribosome-dependent endonuclease, RelE. The molecular basis for recognition of the ribosome and mRNA by RelE and the mechanism of cleavage are unknown. Here, we present crystal structures of E. coli RelE in isolation (2.5 Å) and bound to programmed Thermus thermophilus 70S ribosomes before (3.3 Å) and after (3.6 Å) cleavage. RelE occupies the A site and causes cleavage of mRNA after the second nucleotide of the codon by reorienting and activating the mRNA for 2′-OH-induced hydrolysis. Stacking of A site codon bases with conserved residues in RelE and 16S rRNA explains the requirement for the ribosome in catalysis and the subtle sequence specificity of the reaction. These structures provide detailed insight into the translational regulation on the bacterial ribosome by mRNA cleavage.
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Assenholt J, Mouaikel J, Andersen KR, Brodersen DE, Libri D, Jensen TH. Exonucleolysis is required for nuclear mRNA quality control in yeast THO mutants. RNA 2008; 14:2305-13. [PMID: 18824516 PMCID: PMC2578857 DOI: 10.1261/rna.1108008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Production of aberrant messenger ribonucleoprotein particles (mRNPs) is subject to quality control (QC). In yeast strains carrying mutations of the THO complex, transcription induction triggers a number of interconnected QC phenotypes: (1) rapid degradation of several mRNAs; (2) retention of a fraction of THO-dependent mRNAs in transcription site-associated foci; and (3) formation of a high molecular weight DNA/protein complex in the 3'-ends of THO target genes. Here, we demonstrate that the 3'-5' exonucleolytic domain of the nuclear exosome factor Rrp6p is necessary for establishing all QC phenotypes associated with THO mutations. The N terminus of Rrp6p is also important presumably through its binding to the Rrp6p co-factor Rrp47p. Interestingly, the 3'-5' exonucleolytic activity of Dis3p, the only other active exonuclease of the nuclear exosome, can also contribute to RNA QC in THO mutants, while other nuclear 3'-5' exonucleases cannot. Our data show that exonucleolytic attack by the nuclear exosome is needed both for provoking mRNP QC and for its ensuing elimination of faulty RNA.
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Affiliation(s)
- Jannie Assenholt
- Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology, The Faculty of Science, Aarhus University, DK-8000 Aarhus C, Denmark
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Andersen KR, Jensen TH, Brodersen DE. Take the "A" tail--quality control of ribosomal and transfer RNA. Biochim Biophys Acta 2008; 1779:532-7. [PMID: 18657638 DOI: 10.1016/j.bbagrm.2008.06.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 05/30/2008] [Accepted: 06/30/2008] [Indexed: 11/16/2022]
Abstract
The overall fidelity of RNA biosynthesis and processing is very high. This goes for both mRNAs, which are turned over relatively quickly, and for stable RNAs, such as the components of the translational apparatus, the transfer and ribosomal RNAs. However, no enzymatic process is completely error-free, so to minimize the number of non-functional transcripts, the cell has degradation pathways in place to efficiently deal with those mistakes that inevitably occur. Though several "RNA surveillance" or "RNA quality control" systems have been described that are able to specifically eliminate misfolded and non-functional RNAs, we still do not understand neither what precise features define a faulty RNA, nor the molecular basis for recognition of such molecules. Nonetheless, our knowledge about the controlled degradation of both stable and labile RNAs is now converging into a unified picture that points to the poly(A) tail as a key discriminator of RNA quality in both bacteria and eukaryotes.
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Affiliation(s)
- Kasper R Andersen
- Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology, University of Aarhus, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark
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Jonstrup AT, Andersen KR, Van LB, Brodersen DE. The 1.4-A crystal structure of the S. pombe Pop2p deadenylase subunit unveils the configuration of an active enzyme. Nucleic Acids Res 2007; 35:3153-64. [PMID: 17452359 PMCID: PMC1888821 DOI: 10.1093/nar/gkm178] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [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] [Indexed: 11/29/2022] Open
Abstract
Deadenylation is the first and probably also rate-limiting step of controlled mRNA decay in eukaryotes and therefore central for the overall rate of gene expression. In yeast, the process is maintained by the mega-Dalton Ccr4-Not complex, of which both the Ccr4p and Pop2p subunits are 3′–5′ exonucleases potentially responsible for the deadenylation reaction. Here, we present the crystal structure of the Pop2p subunit from Schizosaccharomyces pombe determined to 1.4 Å resolution and show that the enzyme is a competent ribonuclease with a tunable specificity towards poly-A. In contrast to S. cerevisiae Pop2p, the S. pombe enzyme contains a fully conserved DEDDh active site, and the high resolution allows for a detailed analysis of its configuration, including divalent metal ion binding. Functional data further indicates that the identity of the ions in the active site can modulate both activity and specificity of the enzyme, and finally structural superposition of single nucleotides and poly-A oligonucleotides provide insight into the catalytic cycle of the protein.
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