1
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Varshavsky A. N-degron pathways. Proc Natl Acad Sci U S A 2024; 121:e2408697121. [PMID: 39264755 DOI: 10.1073/pnas.2408697121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2024] Open
Abstract
An N-degron is a degradation signal whose main determinant is a "destabilizing" N-terminal residue of a protein. Specific N-degrons, discovered in 1986, were the first identified degradation signals in short-lived intracellular proteins. These N-degrons are recognized by a ubiquitin-dependent proteolytic system called the Arg/N-degron pathway. Although bacteria lack the ubiquitin system, they also have N-degron pathways. Studies after 1986 have shown that all 20 amino acids of the genetic code can act, in specific sequence contexts, as destabilizing N-terminal residues. Eukaryotic proteins are targeted for the conditional or constitutive degradation by at least five N-degron systems that differ both functionally and mechanistically: the Arg/N-degron pathway, the Ac/N-degron pathway, the Pro/N-degron pathway, the fMet/N-degron pathway, and the newly named, in this perspective, GASTC/N-degron pathway (GASTC = Gly, Ala, Ser, Thr, Cys). I discuss these systems and the expanded terminology that now encompasses the entire gamut of known N-degron pathways.
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Affiliation(s)
- Alexander Varshavsky
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
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2
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Eckardt NA, Avin-Wittenberg T, Bassham DC, Chen P, Chen Q, Fang J, Genschik P, Ghifari AS, Guercio AM, Gibbs DJ, Heese M, Jarvis RP, Michaeli S, Murcha MW, Mursalimov S, Noir S, Palayam M, Peixoto B, Rodriguez PL, Schaller A, Schnittger A, Serino G, Shabek N, Stintzi A, Theodoulou FL, Üstün S, van Wijk KJ, Wei N, Xie Q, Yu F, Zhang H. The lowdown on breakdown: Open questions in plant proteolysis. THE PLANT CELL 2024; 36:2931-2975. [PMID: 38980154 PMCID: PMC11371169 DOI: 10.1093/plcell/koae193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/16/2024] [Accepted: 06/19/2024] [Indexed: 07/10/2024]
Abstract
Proteolysis, including post-translational proteolytic processing as well as protein degradation and amino acid recycling, is an essential component of the growth and development of living organisms. In this article, experts in plant proteolysis pose and discuss compelling open questions in their areas of research. Topics covered include the role of proteolysis in the cell cycle, DNA damage response, mitochondrial function, the generation of N-terminal signals (degrons) that mark many proteins for degradation (N-terminal acetylation, the Arg/N-degron pathway, and the chloroplast N-degron pathway), developmental and metabolic signaling (photomorphogenesis, abscisic acid and strigolactone signaling, sugar metabolism, and postharvest regulation), plant responses to environmental signals (endoplasmic-reticulum-associated degradation, chloroplast-associated degradation, drought tolerance, and the growth-defense trade-off), and the functional diversification of peptidases. We hope these thought-provoking discussions help to stimulate further research.
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Affiliation(s)
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
| | - Poyu Chen
- School of Biological Science and Technology, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Qian Chen
- Ministry of Agriculture and Rural Affairs Key Laboratory for Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Jun Fang
- Section of Molecular Plant Biology, Department of Biology, University of Oxford, Oxford OX1 3RB, UK
| | - Pascal Genschik
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12, rue du Général Zimmer, Strasbourg 67084, France
| | - Abi S Ghifari
- School of Molecular Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Angelica M Guercio
- Department of Plant Biology, College of Biological Sciences, University of California-Davis, Davis, CA 95616, USA
| | - Daniel J Gibbs
- School of Biosciences, University of Birmingham, Edgbaston B1 2RU, UK
| | - Maren Heese
- Department of Developmental Biology, University of Hamburg, Ohnhorststr. 18, Hamburg 22609, Germany
| | - R Paul Jarvis
- Section of Molecular Plant Biology, Department of Biology, University of Oxford, Oxford OX1 3RB, UK
| | - Simon Michaeli
- Department of Postharvest Sciences, Agricultural Research Organization (ARO), Volcani Institute, Rishon LeZion 7505101, Israel
| | - Monika W Murcha
- School of Molecular Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Sergey Mursalimov
- Department of Postharvest Sciences, Agricultural Research Organization (ARO), Volcani Institute, Rishon LeZion 7505101, Israel
| | - Sandra Noir
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12, rue du Général Zimmer, Strasbourg 67084, France
| | - Malathy Palayam
- Department of Plant Biology, College of Biological Sciences, University of California-Davis, Davis, CA 95616, USA
| | - Bruno Peixoto
- Section of Molecular Plant Biology, Department of Biology, University of Oxford, Oxford OX1 3RB, UK
| | - Pedro L Rodriguez
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Cientificas-Universidad Politecnica de Valencia, Valencia ES-46022, Spain
| | - Andreas Schaller
- Department of Plant Physiology and Biochemistry, Institute of Biology, University of Hohenheim, Stuttgart 70599, Germany
| | - Arp Schnittger
- Department of Developmental Biology, University of Hamburg, Ohnhorststr. 18, Hamburg 22609, Germany
| | - Giovanna Serino
- Department of Biology and Biotechnology, Sapienza Universita’ di Roma, p.le A. Moro 5, Rome 00185, Italy
| | - Nitzan Shabek
- Department of Plant Biology, College of Biological Sciences, University of California-Davis, Davis, CA 95616, USA
| | - Annick Stintzi
- Department of Plant Physiology and Biochemistry, Institute of Biology, University of Hohenheim, Stuttgart 70599, Germany
| | | | - Suayib Üstün
- Faculty of Biology and Biotechnology, Ruhr-University of Bochum, Bochum 44780, Germany
| | - Klaas J van Wijk
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, NY 14853, USA
| | - Ning Wei
- School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Qi Xie
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, the Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Feifei Yu
- College of Grassland Science and Technology, China Agricultural University, Beijing 100083, China
| | - Hongtao Zhang
- Plant Sciences and the Bioeconomy, Rothamsted Research, Harpenden AL5 2JQ, UK
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3
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Zhang H, Rundle C, Winter N, Miricescu A, Mooney BC, Bachmair A, Graciet E, Theodoulou FL. BIG enhances Arg/N-degron pathway-mediated protein degradation to regulate Arabidopsis hypoxia responses and suberin deposition. THE PLANT CELL 2024; 36:3177-3200. [PMID: 38608155 PMCID: PMC11371152 DOI: 10.1093/plcell/koae117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 03/15/2024] [Accepted: 03/21/2024] [Indexed: 04/14/2024]
Abstract
BIG/DARK OVEREXPRESSION OF CAB1/TRANSPORT INHIBITOR RESPONSE3 is a 0.5 MDa protein associated with multiple functions in Arabidopsis (Arabidopsis thaliana) signaling and development. However, the biochemical functions of BIG are unknown. We investigated a role for BIG in the Arg/N-degron pathways, in which substrate protein fate is influenced by the N-terminal residue. We crossed a big loss-of-function allele to 2 N-degron pathway E3 ligase mutants, proteolysis6 (prt6) and prt1, and examined the stability of protein substrates. Stability of model substrates was enhanced in prt6-1 big-2 and prt1-1 big-2 relative to the respective single mutants, and the abundance of the PRT6 physiological substrates, HYPOXIA-RESPONSIVE ERF2 (HRE2) and VERNALIZATION2 (VRN2), was similarly increased in prt6 big double mutants. Hypoxia marker expression was enhanced in prt6 big double mutants; this constitutive response required arginyl transferase activity and RAP-type Group VII ethylene response factor (ERFVII) transcription factors. Transcriptomic analysis of roots not only demonstrated increased expression of multiple hypoxia-responsive genes in the double mutant relative to prt6, but also revealed other roles for PRT6 and BIG, including regulation of suberin deposition through both ERFVII-dependent and independent mechanisms, respectively. Our results show that BIG acts together with PRT6 to regulate the hypoxia-response and broader processes in Arabidopsis.
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Affiliation(s)
- Hongtao Zhang
- Plant Sciences and the Bioeconomy, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Chelsea Rundle
- Plant Sciences and the Bioeconomy, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Nikola Winter
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna, Austria
| | | | - Brian C Mooney
- Department of Biology, Maynooth University, Maynooth, Ireland
| | - Andreas Bachmair
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna, Austria
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4
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Raffeiner M. That's a BIG deal: Identification of a regulator in hypoxia responses and suberin deposition. THE PLANT CELL 2024; 36:2980-2981. [PMID: 38691541 PMCID: PMC11371142 DOI: 10.1093/plcell/koae138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 04/23/2024] [Accepted: 04/23/2024] [Indexed: 05/03/2024]
Affiliation(s)
- Margot Raffeiner
- Assistant Features Editor, The Plant Cell, American Society of Plant Biologists
- Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum 44801, Germany
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5
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van Wijk KJ. Intra-chloroplast proteases: A holistic network view of chloroplast proteolysis. THE PLANT CELL 2024; 36:3116-3130. [PMID: 38884601 PMCID: PMC11371162 DOI: 10.1093/plcell/koae178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/12/2024] [Accepted: 06/12/2024] [Indexed: 06/18/2024]
Abstract
Different proteases and peptidases are present within chloroplasts and nonphotosynthetic plastids to process precursor proteins and to degrade cleaved chloroplast transit peptides and damaged, misfolded, or otherwise unwanted proteins. Collectively, these proteases and peptidases form a proteolysis network, with complementary activities and hierarchies, and build-in redundancies. Furthermore, this network is distributed across the different intra-chloroplast compartments (lumen, thylakoid, stroma, envelope). The challenge is to determine the contributions of each peptidase (system) to this network in chloroplasts and nonphotosynthetic plastids. This will require an understanding of substrate recognition mechanisms, degrons, substrate, and product size limitations, as well as the capacity and degradation kinetics of each protease. Multiple extra-plastidial degradation pathways complement these intra-chloroplast proteases. This review summarizes our current understanding of these intra-chloroplast proteases in Arabidopsis and crop plants with an emphasis on considerations for building a qualitative and quantitative network view.
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Affiliation(s)
- Klaas J van Wijk
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, NY 14853, USA
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6
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Komatsu S, Nishiuchi T, Furuya T, Tani M. Millmeter-wave irradiation regulates mRNA-expression and the ubiquitin-proteasome system in wheat exposed to flooding stress. J Proteomics 2024; 294:105073. [PMID: 38218429 DOI: 10.1016/j.jprot.2024.105073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/31/2023] [Accepted: 01/03/2024] [Indexed: 01/15/2024]
Abstract
The irradiation with millimeter-wave (MMW) of wheat seeds promotes root growth under flooding stress; however, its role is not completely clarified. Nuclear proteomics was performed, to reveal the role of MMW irradiation in enhancing flooding tolerance. The purity of nuclear fractions purified from roots was verified. Histone, which is a protein marker for nuclear-purification efficiency, was enriched; and cytosolic ascorbate peroxidase was reduced in the nuclear fraction. The principal-component analysis of proteome displayed that the irradiation of seeds affected nuclear proteins in roots grown under flooding stress. Proteins detected using proteomic analysis were verified using immunoblot analysis. Histone H3 accumulated under flooding stress; however, it decreased to the control level by irradiation. Whereas the ubiquitin accumulated in roots grown under stress when seeds were irradiated. These results suggest that MMW irradiation improves wheat-root growth under flooding stress through the regulation of mRNA-expression level and the ubiquitin-proteasome system. SIGNIFICANCE: To reveal the role of millimeter-wave irradiation in enhancing flooding tolerance in wheat, nuclear proteomics was performed. The principal-component analysis of proteome displayed that irradiation of seeds affected nuclear proteins in roots grown under flooding stress. Proteins detected using proteomic analysis were verified using immunoblot analysis. Histone H3 accumulated under flooding stress; however, it decreased to the control level with irradiation. Whereas the ubiquitin accumulated in roots grown under stress when seeds were irradiated. These results suggest that millimeter-wave irradiation improves wheat-root growth under flooding stress through the regulation of mRNA-expression level and the ubiquitin-proteasome system.
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Affiliation(s)
- Setsuko Komatsu
- Department of Applied Chemistry and Food Science, Fukui University of Technology, Fukui 910-8505, Japan.
| | - Takumi Nishiuchi
- Research Center for Experimental Modeling of Human Disease, Kanazawa University, Kanazawa 920-8640, Japan
| | - Takashi Furuya
- Research Center for Development of Far-Infrared Region, University of Fukui, Fukui 910-8507, Japan
| | - Masahiko Tani
- Research Center for Development of Far-Infrared Region, University of Fukui, Fukui 910-8507, Japan
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7
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Chen Y, Vermeersch M, Van Leene J, De Jaeger G, Li Y, Vanhaeren H. A dynamic ubiquitination balance of cell proliferation and endoreduplication regulators determines plant organ size. SCIENCE ADVANCES 2024; 10:eadj2570. [PMID: 38478622 PMCID: PMC10936951 DOI: 10.1126/sciadv.adj2570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 02/08/2024] [Indexed: 03/17/2024]
Abstract
Ubiquitination plays a crucial role throughout plant growth and development. The E3 ligase DA2 has been reported to activate the peptidase DA1 by ubiquitination, hereby limiting cell proliferation. However, the molecular mechanisms that regulate DA2 remain elusive. Here, we demonstrate that DA2 has a very high turnover and auto-ubiquitinates with K48-linkage polyubiquitin chains, which is counteracted by two deubiquitinating enzymes, UBIQUITIN-SPECIFIC PROTEASE 12 (UBP12) and UBP13. Unexpectedly, we found that auto-ubiquitination of DA2 does not influence its stability but determines its E3 ligase activity. We also demonstrate that impairing the protease activity of DA1 abolishes the growth-reducing effect of DA2. Last, we show that synthetic, constitutively activated DA1-ubiquitin fusion proteins overrule this complex balance of ubiquitination and deubiquitination and strongly restrict growth and promote endoreduplication. Our findings highlight a nonproteolytic function of K48-linked polyubiquitination and reveal a mechanism by which DA2 auto-ubiquitination levels, in concert with UBP12 and UBP13, precisely monitor the activity of DA1 and fine-tune plant organ size.
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Affiliation(s)
- Ying Chen
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052 Ghent, Belgium
| | - Mattias Vermeersch
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052 Ghent, Belgium
| | - Jelle Van Leene
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052 Ghent, Belgium
| | - Geert De Jaeger
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052 Ghent, Belgium
| | - Yunhai Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, CAS Centre for Excellence in Molecular Plant, Institute of Genetics and Development Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hannes Vanhaeren
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052 Ghent, Belgium
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Proeftuinstraat 86, 9000 Ghent, Belgium
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8
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Triozzi PM, Brunello L, Novi G, Ferri G, Cardarelli F, Loreti E, Perales M, Perata P. Spatiotemporal oxygen dynamics in young leaves reveal cyclic hypoxia in plants. MOLECULAR PLANT 2024; 17:377-394. [PMID: 38243593 DOI: 10.1016/j.molp.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/11/2024] [Accepted: 01/15/2024] [Indexed: 01/21/2024]
Abstract
Oxygen is essential for plant growth and development. Hypoxia occurs in plants due to limited oxygen availability following adverse environmental conditions as well in hypoxic niches in otherwise normoxic environments. However, the existence and functional integration of spatiotemporal oxygen dynamics with plant development remains unknown. In animal systems dynamic fluctuations in oxygen availability are known as cyclic hypoxia. In this study, we demonstrate that cyclic fluctuations in internal oxygen levels occur in young emerging leaves of Arabidopsis plants. Cyclic hypoxia in plants is based on a mechanism requiring the ETHYLENE RESPONSE FACTORS type VII (ERFVII) that are central components of the oxygen-sensing machinery in plants. The ERFVII-dependent mechanism allows precise adjustment of leaf growth in response to carbon status and oxygen availability within plant cells. This study thus establishes a functional connection between internal spatiotemporal oxygen dynamics and developmental processes of plants.
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Affiliation(s)
- Paolo M Triozzi
- PlantLab, Center of Plant Sciences, Sant'Anna School of Advanced Studies, 56010 Pisa, Italy; Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Campus de Montegancedo UPM, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Luca Brunello
- PlantLab, Center of Plant Sciences, Sant'Anna School of Advanced Studies, 56010 Pisa, Italy
| | - Giacomo Novi
- PlantLab, Center of Plant Sciences, Sant'Anna School of Advanced Studies, 56010 Pisa, Italy
| | | | - Francesco Cardarelli
- Laboratorio NEST, Scuola Normale Superiore, Istituto Nanoscienze-CNR, Piazza S. Silvestro, 12, 56127 Pisa, Italy
| | - Elena Loreti
- Institute of Agricultural Biology and Biotechnology, National Research Council, 56124 Pisa, Italy
| | - Mariano Perales
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Campus de Montegancedo UPM, Pozuelo de Alarcón, 28223 Madrid, Spain; Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Pierdomenico Perata
- PlantLab, Center of Plant Sciences, Sant'Anna School of Advanced Studies, 56010 Pisa, Italy.
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9
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Demko V, Belova T, Messerer M, Hvidsten TR, Perroud PF, Ako AE, Johansen W, Mayer KFX, Olsen OA, Lang D. Regulation of developmental gatekeeping and cell fate transition by the calpain protease DEK1 in Physcomitrium patens. Commun Biol 2024; 7:261. [PMID: 38438476 PMCID: PMC10912778 DOI: 10.1038/s42003-024-05933-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 02/19/2024] [Indexed: 03/06/2024] Open
Abstract
Calpains are cysteine proteases that control cell fate transitions whose loss of function causes severe, pleiotropic phenotypes in eukaryotes. Although mainly considered as modulatory proteases, human calpain targets are directed to the N-end rule degradation pathway. Several such targets are transcription factors, hinting at a gene-regulatory role. Here, we analyze the gene-regulatory networks of the moss Physcomitrium patens and characterize the regulons that are misregulated in mutants of the calpain DEFECTIVE KERNEL1 (DEK1). Predicted cleavage patterns of the regulatory hierarchies in five DEK1-controlled subnetworks are consistent with a pleiotropic and regulatory role during cell fate transitions targeting multiple functions. Network structure suggests DEK1-gated sequential transitions between cell fates in 2D-to-3D development. Our method combines comprehensive phenotyping, transcriptomics and data science to dissect phenotypic traits, and our model explains the protease function as a switch gatekeeping cell fate transitions potentially also beyond plant development.
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Affiliation(s)
- Viktor Demko
- Department of Plant Sciences, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432, Ås, Norway
- Department of Plant Physiology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovicova 6, 84104, Bratislava, Slovakia
- Plant Science and Biodiversity Center, Slovak Academy of Sciences, Dubravska cesta 9, 84104, Bratislava, Slovakia
| | - Tatiana Belova
- Department of Plant Sciences, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432, Ås, Norway
- Centre for Molecular Medicine Norway, University of Oslo, Oslo, Norway
| | - Maxim Messerer
- Plant Genome and Systems Biology, Helmholtz Center Munich-Research Center for Environmental Health, 85764, Neuherberg, Germany
| | - Torgeir R Hvidsten
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Pierre-François Perroud
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000, Versailles, France
| | - Ako Eugene Ako
- Department of Biotechnology, Inland Norway University of Applied Sciences, Holsetgata 31, 2318, Hamar, Norway
- School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, Southwell, Nottinghamshire, NG25 0QF, UK
| | - Wenche Johansen
- Department of Biotechnology, Inland Norway University of Applied Sciences, Holsetgata 31, 2318, Hamar, Norway
| | - Klaus F X Mayer
- Plant Genome and Systems Biology, Helmholtz Center Munich-Research Center for Environmental Health, 85764, Neuherberg, Germany
- School of Life Sciences, Technical University Munich, 85354, Freising, Germany
| | - Odd-Arne Olsen
- Department of Plant Sciences, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432, Ås, Norway
| | - Daniel Lang
- Plant Genome and Systems Biology, Helmholtz Center Munich-Research Center for Environmental Health, 85764, Neuherberg, Germany.
- Bundeswehr Institute of Microbiology, Microbial Genomics and Bioforensics, 80937, Munich, Germany.
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10
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Ye S, Wang S, Chan R, Cao L, Wang H. Identification of short protein-destabilizing sequences in Arabidopsis cyclin-dependent kinase inhibitors, ICKs. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:772-788. [PMID: 37862584 DOI: 10.1093/jxb/erad411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/18/2023] [Indexed: 10/22/2023]
Abstract
Plants have a family of cyclin-dependent kinase (CDK) inhibitors called interactors/inhibitors of CDK (ICKs) or Kip-related proteins (KRPs). ICK proteins have important functions in cell proliferation, endoreduplication, plant growth, and reproductive development, and their functions depend on the protein levels. However, understanding of how ICK protein levels are regulated is very limited. We fused Arabidopsis ICK sequences to green fluorescent protein (GFP) and determined their effects on the fusion proteins in plants, yeast, and Escherichia coli. The N-terminal regions of ICKs drastically reduced GFP fusion protein levels in Arabidopsis plants. A number of short sequences of 10-20 residues were found to decrease GFP fusion protein levels when fused at the N-terminus or C-terminus. Three of the four short sequences from ICK3 showed a similar function in yeast. Intriguingly, three short sequences from ICK1 and ICK3 caused the degradation of the fusion proteins in E. coli. In addition, computational analyses showed that ICK proteins were mostly disordered and unstructured except for the conserved C-terminal region, suggesting that ICKs are intrinsically disordered proteins. This study has identified a number of short protein-destabilizing sequences, and evidence suggests that some of them may cause protein degradation through structural disorder and instability.
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Affiliation(s)
- Shengjian Ye
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada
| | - Sheng Wang
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada
| | - Ron Chan
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada
| | - Ling Cao
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada
| | - Hong Wang
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada
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11
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Lavilla-Puerta M, Latter R, Bellè F, Cervelli T, Galli A, Perata P, Chini A, Flashman E, Giuntoli B. Identification of novel plant cysteine oxidase inhibitors from a yeast chemical genetic screen. J Biol Chem 2023; 299:105366. [PMID: 37863264 PMCID: PMC10692734 DOI: 10.1016/j.jbc.2023.105366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/28/2023] [Accepted: 10/11/2023] [Indexed: 10/22/2023] Open
Abstract
Hypoxic responses in plants involve Plant Cysteine Oxidases (PCOs). They catalyze the N-terminal cysteine oxidation of Ethylene Response Factors VII (ERF-VII) in an oxygen-dependent manner, leading to their degradation via the cysteine N-degron pathway (Cys-NDP) in normoxia. In hypoxia, PCO activity drops, leading to the stabilization of ERF-VIIs and subsequent hypoxic gene upregulation. Thus far, no chemicals have been described to specifically inhibit PCO enzymes. In this work, we devised an in vivo pipeline to discover Cys-NDP effector molecules. Budding yeast expressing AtPCO4 and plant-based ERF-VII reporters was deployed to screen a library of natural-like chemical scaffolds and was further combined with an Arabidopsis Cys-NDP reporter line. This strategy allowed us to identify three PCO inhibitors, two of which were shown to affect PCO activity in vitro. Application of these molecules to Arabidopsis seedlings led to an increase in ERF-VII stability, induction of anaerobic gene expression, and improvement of tolerance to anoxia. By combining a high-throughput heterologous platform and the plant model Arabidopsis, our synthetic pipeline provides a versatile system to study how the Cys-NDP is modulated. Its first application here led to the discovery of at least two hypoxia-mimicking molecules with the potential to impact plant tolerance to low oxygen stress.
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Affiliation(s)
| | - Rebecca Latter
- Department of Chemistry, University of Oxford, Oxford, UK
| | | | | | | | | | - Andrea Chini
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | | | - Beatrice Giuntoli
- Plantlab, Center of Plant Sciences, Scuola Superiore Sant'Anna, Pisa, Italy; Biology Department, University of Pisa, Pisa, Italy.
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12
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Sakato-Antoku M, Balsbaugh JL, King SM. N-Terminal Processing and Modification of Ciliary Dyneins. Cells 2023; 12:2492. [PMID: 37887336 PMCID: PMC10605206 DOI: 10.3390/cells12202492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/17/2023] [Accepted: 10/19/2023] [Indexed: 10/28/2023] Open
Abstract
Axonemal dyneins are highly complex microtubule motors that power ciliary motility. These multi-subunit enzymes are assembled at dedicated sites within the cytoplasm. At least nineteen cytosolic factors are specifically needed to generate dynein holoenzymes and/or for their trafficking to the growing cilium. Many proteins are subject to N-terminal processing and acetylation, which can generate degrons subject to the AcN-end rule, alter N-terminal electrostatics, generate new binding interfaces, and affect subunit stoichiometry through targeted degradation. Here, we have used mass spectrometry of cilia samples and electrophoretically purified dynein heavy chains from Chlamydomonas to define their N-terminal processing; we also detail the N-terminal acetylase complexes present in this organism. We identify four classes of dynein heavy chain based on their processing pathways by two distinct acetylases, one of which is dependent on methionine aminopeptidase activity. In addition, we find that one component of both the outer dynein arm intermediate/light chain subcomplex and the docking complex is processed to yield an unmodified Pro residue, which may provide a setpoint to direct the cytosolic stoichiometry of other dynein complex subunits that contain N-terminal degrons. Thus, we identify and describe an additional level of processing and complexity in the pathways leading to axonemal dynein formation in cytoplasm.
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Affiliation(s)
- Miho Sakato-Antoku
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030-3305, USA;
| | - Jeremy L. Balsbaugh
- Proteomics and Metabolomics Facility, University of Connecticut, 75 North Eagleville Road, Storrs, CT 06269, USA;
| | - Stephen M. King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030-3305, USA;
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13
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Akbar MA, Mohd Yusof NY, Usup G, Ahmad A, Baharum SN, Bunawan H. Nutrient Deficiencies Impact on the Cellular and Metabolic Responses of Saxitoxin Producing Alexandrium minutum: A Transcriptomic Perspective. Mar Drugs 2023; 21:497. [PMID: 37755110 PMCID: PMC10532982 DOI: 10.3390/md21090497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 09/28/2023] Open
Abstract
Dinoflagellate Alexandrium minutum Halim is commonly associated with harmful algal blooms (HABs) in tropical marine waters due to its saxitoxin production. However, limited information is available regarding the cellular and metabolic changes of A. minutum in nutrient-deficient environments. To fill this gap, our study aimed to investigate the transcriptomic responses of A. minutum under nitrogen and phosphorus deficiency. The induction of nitrogen and phosphorus deficiency resulted in the identification of 1049 and 763 differently expressed genes (DEGs), respectively. Further analysis using gene set enrichment analysis (GSEA) revealed 702 and 1251 enriched gene ontology (GO) terms associated with nitrogen and phosphorus deficiency, respectively. Our results indicate that in laboratory cultures, nitrogen deficiency primarily affects meiosis, carbohydrate catabolism, ammonium assimilation, ion homeostasis, and protein kinase activity. On the other hand, phosphorus deficiency primarily affects the carbon metabolic response, cellular ion transfer, actin-dependent cell movement, signalling pathways, and protein recycling. Our study provides valuable insights into biological processes and genes regulating A. minutum's response to nutrient deficiencies, furthering our understanding of the ecophysiological response of HABs to environmental change.
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Affiliation(s)
- Muhamad Afiq Akbar
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
- Institute of System Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
| | - Nurul Yuziana Mohd Yusof
- Department of Earth Science and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia; (N.Y.M.Y.); (G.U.)
| | - Gires Usup
- Department of Earth Science and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia; (N.Y.M.Y.); (G.U.)
| | - Asmat Ahmad
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
| | - Syarul Nataqain Baharum
- Institute of System Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
| | - Hamidun Bunawan
- Institute of System Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
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14
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Robson JK, Ferguson JN, McAusland L, Atkinson JA, Tranchant-Dubreuil C, Cubry P, Sabot F, Wells DM, Price AH, Wilson ZA, Murchie EH. Chlorophyll fluorescence-based high-throughput phenotyping facilitates the genetic dissection of photosynthetic heat tolerance in African (Oryza glaberrima) and Asian (Oryza sativa) rice. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5181-5197. [PMID: 37347829 PMCID: PMC10498015 DOI: 10.1093/jxb/erad239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 06/20/2023] [Indexed: 06/24/2023]
Abstract
Rising temperatures and extreme heat events threaten rice production. Half of the global population relies on rice for basic nutrition, and therefore developing heat-tolerant rice is essential. During vegetative development, reduced photosynthetic rates can limit growth and the capacity to store soluble carbohydrates. The photosystem II (PSII) complex is a particularly heat-labile component of photosynthesis. We have developed a high-throughput chlorophyll fluorescence-based screen for photosynthetic heat tolerance capable of screening hundreds of plants daily. Through measuring the response of maximum PSII efficiency to increasing temperature, this platform generates data for modelling the PSII-temperature relationship in large populations in a small amount of time. Coefficients from these models (photosynthetic heat tolerance traits) demonstrated high heritabilities across African (Oryza glaberrima) and Asian (Oryza sativa, Bengal Assam Aus Panel) rice diversity sets, highlighting valuable genetic variation accessible for breeding. Genome-wide association studies were performed across both species for these traits, representing the first documented attempt to characterize the genetic basis of photosynthetic heat tolerance in any species to date. A total of 133 candidate genes were highlighted. These were significantly enriched with genes whose predicted roles suggested influence on PSII activity and the response to stress. We discuss the most promising candidates for improving photosynthetic heat tolerance in rice.
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Affiliation(s)
- Jordan K Robson
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, UK
| | - John N Ferguson
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, UK
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
- School of Life Sciences, University of Essex, Colchester, UK
| | - Lorna McAusland
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, UK
| | - Jonathan A Atkinson
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, UK
| | | | - Phillipe Cubry
- Institut de Recherche pour le Developpement, 911 Av. Agropolis, 34394 Montpellier, France
| | - François Sabot
- Institut de Recherche pour le Developpement, 911 Av. Agropolis, 34394 Montpellier, France
| | - Darren M Wells
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, UK
| | - Adam H Price
- Institut de Recherche pour le Developpement, 911 Av. Agropolis, 34394 Montpellier, France
| | - Zoe A Wilson
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, UK
| | - Erik H Murchie
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, UK
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
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15
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Zubrycka A, Dambire C, Dalle Carbonare L, Sharma G, Boeckx T, Swarup K, Sturrock CJ, Atkinson BS, Swarup R, Corbineau F, Oldham NJ, Holdsworth MJ. ERFVII action and modulation through oxygen-sensing in Arabidopsis thaliana. Nat Commun 2023; 14:4665. [PMID: 37537157 PMCID: PMC10400637 DOI: 10.1038/s41467-023-40366-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 07/25/2023] [Indexed: 08/05/2023] Open
Abstract
Oxygen is a key signalling component of plant biology, and whilst an oxygen-sensing mechanism was previously described in Arabidopsis thaliana, key features of the associated PLANT CYSTEINE OXIDASE (PCO) N-degron pathway and Group VII ETHYLENE RESPONSE FACTOR (ERFVII) transcription factor substrates remain untested or unknown. We demonstrate that ERFVIIs show non-autonomous activation of root hypoxia tolerance and are essential for root development and survival under oxygen limiting conditions in soil. We determine the combined effects of ERFVIIs in controlling gene expression and define genetic and environmental components required for proteasome-dependent oxygen-regulated stability of ERFVIIs through the PCO N-degron pathway. Using a plant extract, unexpected amino-terminal cysteine sulphonic acid oxidation level of ERFVIIs was observed, suggesting a requirement for additional enzymatic activity within the pathway. Our results provide a holistic understanding of the properties, functions and readouts of this oxygen-sensing mechanism defined through its role in modulating ERFVII stability.
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Affiliation(s)
- Agata Zubrycka
- School of Biosciences, University of Nottingham, LE12 5RD, Loughborough, UK
| | - Charlene Dambire
- School of Biosciences, University of Nottingham, LE12 5RD, Loughborough, UK
| | - Laura Dalle Carbonare
- School of Biosciences, University of Nottingham, LE12 5RD, Loughborough, UK
- Department of Biology, University of Oxford, OX1 3RB, Oxford, UK
| | - Gunjan Sharma
- School of Biosciences, University of Nottingham, LE12 5RD, Loughborough, UK
| | - Tinne Boeckx
- School of Biosciences, University of Nottingham, LE12 5RD, Loughborough, UK
| | - Kamal Swarup
- School of Biosciences, University of Nottingham, LE12 5RD, Loughborough, UK
| | - Craig J Sturrock
- School of Biosciences, University of Nottingham, LE12 5RD, Loughborough, UK
| | - Brian S Atkinson
- School of Biosciences, University of Nottingham, LE12 5RD, Loughborough, UK
| | - Ranjan Swarup
- School of Biosciences, University of Nottingham, LE12 5RD, Loughborough, UK
| | - Françoise Corbineau
- UMR 7622 CNRS-UPMC, Biologie du développement, Institut de Biologie Paris Seine, Sorbonne Université, Paris, France
| | - Neil J Oldham
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
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16
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Shim SM, Choi HR, Kwon SC, Kim HY, Sung KW, Jung EJ, Mun SR, Bae TH, Kim DH, Son YS, Jung CH, Lee J, Lee MJ, Park JW, Kwon YT. The Cys-N-degron pathway modulates pexophagy through the N-terminal oxidation and arginylation of ACAD10. Autophagy 2023; 19:1642-1661. [PMID: 36184612 PMCID: PMC10262816 DOI: 10.1080/15548627.2022.2126617] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 09/15/2022] [Accepted: 09/15/2022] [Indexed: 11/02/2022] Open
Abstract
In the N-degron pathway, N-recognins recognize cognate substrates for degradation via the ubiquitin (Ub)-proteasome system (UPS) or the autophagy-lysosome system (hereafter autophagy). We have recently shown that the autophagy receptor SQSTM1/p62 (sequestosome 1) is an N-recognin that binds the N-terminal arginine (Nt-Arg) as an N-degron to modulate autophagic proteolysis. Here, we show that the N-degron pathway mediates pexophagy, in which damaged peroxisomal fragments are degraded by autophagy under normal and oxidative stress conditions. This degradative process initiates when the Nt-Cys of ACAD10 (acyl-CoA dehydrogenase family, member 10), a receptor in pexophagy, is oxidized into Cys sulfinic (CysO2) or sulfonic acid (CysO3) by ADO (2-aminoethanethiol (cysteamine) dioxygenase). Under oxidative stress, the Nt-Cys of ACAD10 is chemically oxidized by reactive oxygen species (ROS). The oxidized Nt-Cys2 is arginylated by ATE1-encoded R-transferases, generating the RCOX N-degron. RCOX-ACAD10 marks the site of pexophagy via the interaction with PEX5 and binds the ZZ domain of SQSTM1/p62, recruiting LC3+-autophagic membranes. In mice, knockout of either Ate1 responsible for Nt-arginylation or Sqstm1/p62 leads to increased levels of peroxisomes. In the cells from patients with peroxisome biogenesis disorders (PBDs), characterized by peroxisomal loss due to uncontrolled pexophagy, inhibition of either ATE1 or SQSTM1/p62 was sufficient to recover the level of peroxisomes. Our results demonstrate that the Cys-N-degron pathway generates an N-degron that regulates the removal of damaged peroxisomal membranes along with their contents. We suggest that tannic acid, a commercially available drug on the market, has a potential to treat PBDs through its activity to inhibit ATE1 R-transferases.Abbreviations: ACAA1, acetyl-Coenzyme A acyltransferase 1; ACAD, acyl-Coenzyme A dehydrogenase; ADO, 2-aminoethanethiol (cysteamine) dioxygenase; ATE1, arginyltransferase 1; CDO1, cysteine dioxygenase type 1; ER, endoplasmic reticulum; LIR, LC3-interacting region; MOXD1, monooxygenase, DBH-like 1; NAC, N-acetyl-cysteine; Nt-Arg, N-terminal arginine; Nt-Cys, N-terminal cysteine; PB1, Phox and Bem1p; PBD, peroxisome biogenesis disorder; PCO, plant cysteine oxidase; PDI, protein disulfide isomerase; PTS, peroxisomal targeting signal; R-COX, Nt-Arg-CysOX; RNS, reactive nitrogen species; ROS, reactive oxygen species; SNP, sodium nitroprusside; UBA, ubiquitin-associated; UPS, ubiquitinproteasome system.
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Affiliation(s)
- Sang Mi Shim
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Ha Rim Choi
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Soon Chul Kwon
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
- Cellular Degradation Biology Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Hye Yeon Kim
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
- Cellular Degradation Biology Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Ki Woon Sung
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
- Cellular Degradation Biology Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
- AUTOTAC Bio Inc., Seoul, Republic of Korea
| | - Eui Jung Jung
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
- Cellular Degradation Biology Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Su Ran Mun
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
- Cellular Degradation Biology Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Tae Hyun Bae
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
- Cellular Degradation Biology Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Dong Hyun Kim
- Anticancer Agents Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongwon, Korea
| | - Yeon Sung Son
- Neuroscience Research Institute, Medical Research Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Chan Hoon Jung
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
- Cellular Degradation Biology Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Jihoon Lee
- Cellular Degradation Biology Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
- AUTOTAC Bio Inc., Seoul, Republic of Korea
| | - Min Jae Lee
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
- Cellular Degradation Biology Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Joo-Won Park
- Department of Biochemistry, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Yong Tae Kwon
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
- Cellular Degradation Biology Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
- AUTOTAC Bio Inc., Seoul, Republic of Korea
- Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul, Republic of Korea
- SNU Dementia Research Center, College of Medicine, Seoul National University, Seoul, Republic of Korea
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17
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Heo AJ, Kim SB, Kwon YT, Ji CH. The N-degron pathway: From basic science to therapeutic applications. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194934. [PMID: 36990317 DOI: 10.1016/j.bbagrm.2023.194934] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/22/2023] [Accepted: 03/22/2023] [Indexed: 03/30/2023]
Abstract
The N-degron pathway is a degradative system in which single N-terminal (Nt) amino acids regulate the half-lives of proteins and other biological materials. These determinants, called N-degrons, are recognized by N-recognins that link them to the ubiquitin (Ub)-proteasome system (UPS) or autophagy-lysosome system (ALS). In the UPS, the Arg/N-degron pathway targets the Nt-arginine (Nt-Arg) and other N-degrons to assemble Lys48 (K48)-linked Ub chains by UBR box N-recognins for proteasomal proteolysis. In the ALS, Arg/N-degrons are recognized by the N-recognin p62/SQSTSM-1/Sequestosome-1 to induce cis-degradation of substrates and trans-degradation of various cargoes such as protein aggregates and subcellular organelles. This crosstalk between the UPS and ALP involves reprogramming of the Ub code. Eukaryotic cells developed diverse ways to target all 20 principal amino acids for degradation. Here we discuss the components, regulation, and functions of the N-degron pathways, with an emphasis on the basic mechanisms and therapeutic applications of Arg/N-degrons and N-recognins.
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Affiliation(s)
- Ah Jung Heo
- Cellular Degradation Biology Center and Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea
| | - Su Bin Kim
- Cellular Degradation Biology Center and Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea
| | - Yong Tae Kwon
- Cellular Degradation Biology Center and Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea; AUTOTAC Bio Inc., Changkyunggung-ro 254, Jongno-gu, Seoul 03077, Republic of Korea; Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul 110-799, Republic of Korea; SNU Dementia Research Center, College of Medicine, Seoul National University, Seoul 110-799, Republic of Korea.
| | - Chang Hoon Ji
- Cellular Degradation Biology Center and Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea; AUTOTAC Bio Inc., Changkyunggung-ro 254, Jongno-gu, Seoul 03077, Republic of Korea.
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18
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Dalle Carbonare L, Jiménez JDLC, Lichtenauer S, van Veen H. Plant responses to limited aeration: Advances and future challenges. PLANT DIRECT 2023; 7:e488. [PMID: 36993903 PMCID: PMC10040318 DOI: 10.1002/pld3.488] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 06/19/2023]
Abstract
Limited aeration that is caused by tissue geometry, diffusion barriers, high elevation, or a flooding event poses major challenges to plants and is often, but not exclusively, associated with low oxygen. These processes span a broad interest in the research community ranging from whole plant and crop responses, post-harvest physiology, plant morphology and anatomy, fermentative metabolism, plant developmental processes, oxygen sensing by ERF-VIIs, gene expression profiles, the gaseous hormone ethylene, and O2 dynamics at cellular resolution. The International Society for Plant Anaerobiosis (ISPA) gathers researchers from all over the world contributing to understand the causes, responses, and consequences of limited aeration in plants. During the 14th ISPA meeting, major research progress was related to the evolution of O2 sensing mechanisms and the intricate network that balances low O2 signaling. Here, the work moved beyond flooding stress and emphasized novel underexplored roles of low O2 and limited aeration in altitude adaptation, fruit development and storage, and the vegetative development of growth apices. Regarding tolerance towards flooding, the meeting stressed the relevance and regulation of developmental plasticity, aerenchyma, and barrier formation to improve internal aeration. Additional newly explored flood tolerance traits concerned resource balance, senescence, and the exploration of natural genetic variation for novel tolerance loci. In this report, we summarize and synthesize the major progress and future challenges for low O2 and aeration research presented at the conference.
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Affiliation(s)
| | | | - Sophie Lichtenauer
- Institute of Plant Biology and BiotechnologyUniversity of MünsterMünsterGermany
| | - Hans van Veen
- Plant Stress Resilience, Institute of Environmental BiologyUtrecht UniversityUtrechtThe Netherlands
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
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19
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Yuan L, Chen M, Wang L, Sasidharan R, Voesenek LACJ, Xiao S. Multi-stress resilience in plants recovering from submergence. PLANT BIOTECHNOLOGY JOURNAL 2023; 21:466-481. [PMID: 36217562 PMCID: PMC9946147 DOI: 10.1111/pbi.13944] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/14/2022] [Accepted: 10/04/2022] [Indexed: 05/03/2023]
Abstract
Submergence limits plants' access to oxygen and light, causing massive changes in metabolism; after submergence, plants experience additional stresses, including reoxygenation, dehydration, photoinhibition and accelerated senescence. Plant responses to waterlogging and partial or complete submergence have been well studied, but our understanding of plant responses during post-submergence recovery remains limited. During post-submergence recovery, whether a plant can repair the damage caused by submergence and reoxygenation and re-activate key processes to continue to grow, determines whether the plant survives. Here, we summarize the challenges plants face when recovering from submergence, primarily focusing on studies of Arabidopsis thaliana and rice (Oryza sativa). We also highlight recent progress in elucidating the interplay among various regulatory pathways, compare post-hypoxia reoxygenation between plants and animals and provide new perspectives for future studies.
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Affiliation(s)
- Li‐Bing Yuan
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Mo‐Xian Chen
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Lin‐Na Wang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Rashmi Sasidharan
- Plant Stress Resilience, Institute of Environmental BiologyUtrecht UniversityUtrechtThe Netherlands
| | | | - Shi Xiao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
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20
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Böhm J, Winter N, Kozlic A, Telser T, Nehlin L, Bachmair A. Analysis of higher plant N-degron pathway components and substrates via expression in S. cerevisiae. Methods Enzymol 2023. [PMID: 37532401 DOI: 10.1016/bs.mie.2023.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Heterologous expression of enzymes can generate a background-free environment that facilitates investigation of enzyme properties, for instance to focus on particular isoforms in case of gene families, or on individual splicing variants. If a proper host can be found, in vivo assays are often simpler than overexpression and purification, followed by in vitro measurements, would be. We expressed plant ubiquitin ligase PRT6 in the budding yeast Saccharomyces cerevisiae for studies on activity and substrate preferences. Expression of this large enzyme profits from the eukaryotic folding catalysis provided by budding yeast, and from the presence of endogenous ubiquitin activating enzyme. While yeast encodes a ubiquitin ligase, Ubr1, that is functionally related to PRT6, a strain with deletion of the UBR1 gene offers a background-free host. Two different substrates were analyzed. One was a model substate, and the other one a natural substrate fused to a reporter. Two different methods were compared for assessment of protein stability. A method based on internal standardization via tandem fluorescent timer measurement turned out to be complementary to standardization based on cell culture density.
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21
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Xia X, Tang CM, Chen GZ, Han JJ. Proteasome Dysfunction Leads to Suppression of the Hypoxic Response Pathway in Arabidopsis. Int J Mol Sci 2022; 23:ijms232416148. [PMID: 36555789 PMCID: PMC9785350 DOI: 10.3390/ijms232416148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 12/05/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Proteasome is a large proteolytic complex that consists of a 20S core particle (20SP) and 19S regulatory particle (19SP) in eukaryotes. The proteasome degrades most cellular proteins, thereby controlling many key processes, including gene expression and protein quality control. Proteasome dysfunction in plants leads to abnormal development and reduced adaptability to environmental stresses. Previous studies have shown that proteasome dysfunction upregulates the gene expression of proteasome subunits, which is known as the proteasome bounce-back response. However, the proteasome bounce-back response cannot explain the damaging effect of proteasome dysfunction on plant growth and stress adaptation. To address this question, we focused on downregulated genes caused by proteasome dysfunction. We first confirmed that the 20SP subunit PBE is an essential proteasome subunit in Arabidopsis and that PBE1 mutation impaired the function of the proteasome. Transcriptome analyses showed that hypoxia-responsive genes were greatly enriched in the downregulated genes in pbe1 mutants. Furthermore, we found that the pbe1 mutant is hypersensitive to waterlogging stress, a typical hypoxic condition, and hypoxia-related developments are impaired in the pbe1 mutant. Meanwhile, the 19SP subunit rpn1a mutant seedlings are also hypersensitive to waterlogging stress. In summary, our results suggested that proteasome dysfunction downregulated the hypoxia-responsive pathway and impaired plant growth and adaptability to hypoxia stress.
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Affiliation(s)
- Xue Xia
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China
| | - Chun-Meng Tang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China
| | - Gu-Zi Chen
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China
| | - Jia-Jia Han
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
- Correspondence:
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22
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Barreto P, Koltun A, Nonato J, Yassitepe J, Maia IDG, Arruda P. Metabolism and Signaling of Plant Mitochondria in Adaptation to Environmental Stresses. Int J Mol Sci 2022; 23:ijms231911176. [PMID: 36232478 PMCID: PMC9570015 DOI: 10.3390/ijms231911176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/29/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
The interaction of mitochondria with cellular components evolved differently in plants and mammals; in plants, the organelle contains proteins such as ALTERNATIVE OXIDASES (AOXs), which, in conjunction with internal and external ALTERNATIVE NAD(P)H DEHYDROGENASES, allow canonical oxidative phosphorylation (OXPHOS) to be bypassed. Plant mitochondria also contain UNCOUPLING PROTEINS (UCPs) that bypass OXPHOS. Recent work revealed that OXPHOS bypass performed by AOXs and UCPs is linked with new mechanisms of mitochondrial retrograde signaling. AOX is functionally associated with the NO APICAL MERISTEM transcription factors, which mediate mitochondrial retrograde signaling, while UCP1 can regulate the plant oxygen-sensing mechanism via the PRT6 N-Degron. Here, we discuss the crosstalk or the independent action of AOXs and UCPs on mitochondrial retrograde signaling associated with abiotic stress responses. We also discuss how mitochondrial function and retrograde signaling mechanisms affect chloroplast function. Additionally, we discuss how mitochondrial inner membrane transporters can mediate mitochondrial communication with other organelles. Lastly, we review how mitochondrial metabolism can be used to improve crop resilience to environmental stresses. In this respect, we particularly focus on the contribution of Brazilian research groups to advances in the topic of mitochondrial metabolism and signaling.
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Affiliation(s)
- Pedro Barreto
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências, Universidade Estadual Paulista, Botucatu 18618-970, Brazil
| | - Alessandra Koltun
- Genomics for Climate Change Research Center, Universidade Estadual de Campinas, Campinas 13083-875, Brazil
- Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas, Campinas 13083-862, Brazil
| | - Juliana Nonato
- Genomics for Climate Change Research Center, Universidade Estadual de Campinas, Campinas 13083-875, Brazil
- Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas, Campinas 13083-862, Brazil
| | - Juliana Yassitepe
- Genomics for Climate Change Research Center, Universidade Estadual de Campinas, Campinas 13083-875, Brazil
- Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas, Campinas 13083-862, Brazil
- Embrapa Agricultura Digital, Campinas 13083-886, Brazil
| | - Ivan de Godoy Maia
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências, Universidade Estadual Paulista, Botucatu 18618-970, Brazil
| | - Paulo Arruda
- Genomics for Climate Change Research Center, Universidade Estadual de Campinas, Campinas 13083-875, Brazil
- Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas, Campinas 13083-862, Brazil
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas 13083-875, Brazil
- Correspondence:
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Langan P, Bernád V, Walsh J, Henchy J, Khodaeiaminjan M, Mangina E, Negrão S. Phenotyping for waterlogging tolerance in crops: current trends and future prospects. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:5149-5169. [PMID: 35642593 PMCID: PMC9440438 DOI: 10.1093/jxb/erac243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Yield losses to waterlogging are expected to become an increasingly costly and frequent issue in some regions of the world. Despite the extensive work that has been carried out examining the molecular and physiological responses to waterlogging, phenotyping for waterlogging tolerance has proven difficult. This difficulty is largely due to the high variability of waterlogging conditions such as duration, temperature, soil type, and growth stage of the crop. In this review, we highlight use of phenotyping to assess and improve waterlogging tolerance in temperate crop species. We start by outlining the experimental methods that have been utilized to impose waterlogging stress, ranging from highly controlled conditions of hydroponic systems to large-scale screenings in the field. We also describe the phenotyping traits used to assess tolerance ranging from survival rates and visual scoring to precise photosynthetic measurements. Finally, we present an overview of the challenges faced in attempting to improve waterlogging tolerance, the trade-offs associated with phenotyping in controlled conditions, limitations of classic phenotyping methods, and future trends using plant-imaging methods. If effectively utilized to increase crop resilience to changing climates, crop phenotyping has a major role to play in global food security.
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Affiliation(s)
- Patrick Langan
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Villő Bernád
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Jason Walsh
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
- School of Computer Science and UCD Energy Institute, University College Dublin, Dublin, Ireland
| | - Joey Henchy
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | | | - Eleni Mangina
- School of Computer Science and UCD Energy Institute, University College Dublin, Dublin, Ireland
| | - Sónia Negrão
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
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24
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You X, Nasrullah, Wang D, Mei Y, Bi J, Liu S, Xu W, Wang NN. N 7 -SSPP fusion gene improves salt stress tolerance in transgenic Arabidopsis and soybean through ROS scavenging. PLANT, CELL & ENVIRONMENT 2022; 45:2794-2809. [PMID: 35815549 DOI: 10.1111/pce.14392] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/30/2022] [Accepted: 07/02/2022] [Indexed: 06/15/2023]
Abstract
Considerable signal crosstalk exists in the regulatory network of senescence and stress response. Numerous senescence-associated genes are also involved in plant stress tolerance. However, the underlying mechanisms and application potential of these genes in stress-tolerant crop breeding remain poorly explored. We found that overexpression of SENESCENCE-SUPPRESSED PROTEIN PHOSPHATASE (SSPP), a negative regulator of leaf senescence, significantly improved plant salt tolerance by increasing reactive oxygen species (ROS) scavenging in both Arabidopsis and soybean. However, overexpression of SSPP severely suppressed normal plant growth, limiting its direct use in agriculture. We previously revealed that the N-terminal 1-14 residues of ACS7 (termed 'N7 ') negatively regulated its protein stability through the ubiquitin/proteasome pathway, and the N7 -mediated protein degradation was suppressed by environmental and senescence signals. To avoid the adverse effects of SSPP, the N7 element was fused to the N-terminus of SSPP. We demonstrated that N7 -SSPP fusion gene effectively rescued SSPP-induced growth suppression but maintained enhanced salt tolerance in Arabidopsis and soybean. Particularly, N7 -SSPP enhanced tolerance to long-term salt stress and increased seed yield in soybean. These results suggest that N7 -SSPP overcomes the disadvantages of SSPP on plant growth inhibition and effectively improves salt tolerance through enhanced ROS scavenging, providing an effective strategy of using posttranslational regulatory element for salt-tolerant crop breeding.
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Affiliation(s)
- Xiang You
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin, China
| | - Nasrullah
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin, China
| | - Dan Wang
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin, China
| | - Yuanyuan Mei
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin, China
| | - Juanjuan Bi
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin, China
| | - Sheng Liu
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin, China
| | - Wei Xu
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin, China
| | - Ning Ning Wang
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin, China
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25
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Crystal structure of the Ate1 arginyl-tRNA-protein transferase and arginylation of N-degron substrates. Proc Natl Acad Sci U S A 2022; 119:e2209597119. [PMID: 35878037 PMCID: PMC9351520 DOI: 10.1073/pnas.2209597119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
N-degron pathways are proteolytic systems that target proteins bearing N-terminal (Nt) degradation signals (degrons) called N-degrons. Nt-Arg of a protein is among Nt-residues that can be recognized as destabilizing ones by the Arg/N-degron pathway. A proteolytic cleavage of a protein can generate Arg at the N terminus of a resulting C-terminal (Ct) fragment either directly or after Nt-arginylation of that Ct-fragment by the Ate1 arginyl-tRNA-protein transferase (R-transferase), which uses Arg-tRNAArg as a cosubstrate. Ate1 can Nt-arginylate Nt-Asp, Nt-Glu, and oxidized Nt-Cys* (Cys-sulfinate or Cys-sulfonate) of proteins or short peptides. Ate1 genes of fungi, animals, and plants have been cloned decades ago, but a three-dimensional structure of Ate1 remained unknown. A detailed mechanism of arginylation is unknown as well. We describe here the crystal structure of the Ate1 R-transferase from the budding yeast Kluyveromyces lactis. The 58-kDa R-transferase comprises two domains that recognize, together, an acidic Nt-residue of an acceptor substrate, the Arg residue of Arg-tRNAArg, and a 3'-proximal segment of the tRNAArg moiety. The enzyme's active site is located, at least in part, between the two domains. In vitro and in vivo arginylation assays with site-directed Ate1 mutants that were suggested by structural results yielded inferences about specific binding sites of Ate1. We also analyzed the inhibition of Nt-arginylation activity of Ate1 by hemin (Fe3+-heme), and found that hemin induced the previously undescribed disulfide-mediated oligomerization of Ate1. Together, these results advance the understanding of R-transferase and the Arg/N-degron pathway.
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26
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Song ZT, Chen XJ, Luo L, Yu F, Liu JX, Han JJ. UBA domain protein SUF1 interacts with NatA-complex subunit NAA15 to regulate thermotolerance in Arabidopsis. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:1297-1302. [PMID: 35524486 DOI: 10.1111/jipb.13273] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 05/05/2022] [Indexed: 06/14/2023]
Abstract
During recovery from heat stress, plants clear away the heat-stress-induced misfolded proteins through the ubiquitin-proteasome system (UPS). In the UPS, the recognition of substrate proteins by E3 ligase can be regulated by the N-terminal acetyltransferase A (NatA) complex. Here, we determined that Arabidopsis STRESS-RELATED UBIQUITIN-ASSOCIATED-DOMAIN PROTEIN FACTOR 1 (SUF1) interacts with the NatA complex core subunit NAA15 and positively regulates NAA15. The suf1 and naa15 mutants are sensitive to heat stress; the NatA substrate N SNC1 is stabilized in suf1 mutant plants during heat stress recovery. Therefore, SUF1 and its interactor NAA15 play important roles in basal thermotolerance in Arabidopsis.
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Affiliation(s)
- Ze-Ting Song
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310027, China
- Laboratory of Ecology and Evolutionary Biology, State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, 650500, China
| | - Xiao-Jie Chen
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, 650500, China
| | - Ling Luo
- Laboratory of Ecology and Evolutionary Biology, State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, 650500, China
| | - Feifei Yu
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100083, China
| | - Jian-Xiang Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310027, China
| | - Jia-Jia Han
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310027, China
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, 650500, China
- Laboratory of Ecology and Evolutionary Biology, State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, 650500, China
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27
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Abbas M, Sharma G, Dambire C, Marquez J, Alonso-Blanco C, Proaño K, Holdsworth MJ. An oxygen-sensing mechanism for angiosperm adaptation to altitude. Nature 2022; 606:565-569. [PMID: 35650430 PMCID: PMC9200633 DOI: 10.1038/s41586-022-04740-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 04/07/2022] [Indexed: 11/10/2022]
Abstract
Flowering plants (angiosperms) can grow at extreme altitudes, and have been observed growing as high as 6,400 metres above sea level1,2; however, the molecular mechanisms that enable plant adaptation specifically to altitude are unknown. One distinguishing feature of increasing altitude is a reduction in the partial pressure of oxygen (pO2). Here we investigated the relationship between altitude and oxygen sensing in relation to chlorophyll biosynthesis—which requires molecular oxygen3—and hypoxia-related gene expression. We show that in etiolated seedlings of angiosperm species, steady-state levels of the phototoxic chlorophyll precursor protochlorophyllide are influenced by sensing of atmospheric oxygen concentration. In Arabidopsis thaliana, this is mediated by the PLANT CYSTEINE OXIDASE (PCO) N-degron pathway substrates GROUP VII ETHYLENE RESPONSE FACTOR transcription factors (ERFVIIs). ERFVIIs positively regulate expression of FLUORESCENT IN BLUE LIGHT (FLU), which represses the first committed step of chlorophyll biosynthesis, forming an inactivation complex with tetrapyrrole synthesis enzymes that are negatively regulated by ERFVIIs, thereby suppressing protochlorophyllide. In natural populations representing diverse angiosperm clades, we find oxygen-dependent altitudinal clines for steady-state levels of protochlorophyllide, expression of inactivation complex components and hypoxia-related genes. Finally, A. thaliana accessions from contrasting altitudes display altitude-dependent ERFVII activity and accumulation. We thus identify a mechanism for genetic adaptation to absolute altitude through alteration of the sensitivity of the oxygen-sensing system. Plants have adapted to grow at specific altitudes by regulating chlorophyll synthesis in response to ambient oxygen concentration, calibrated by altitude-dependent activity of GROUP VII ETHYLENE RESPONSE FACTOR.
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Affiliation(s)
- Mohamad Abbas
- School of Biosciences, University of Nottingham, Nottingham, UK
| | - Gunjan Sharma
- School of Biosciences, University of Nottingham, Nottingham, UK
| | | | | | - Carlos Alonso-Blanco
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Karina Proaño
- Laboratorio de Biotecnología Vegetal, Departamento de Ciencias de la Vida y la Agricultura, Universidad de las Fuerzas Armadas ESPE, Sangolquí, Ecuador
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28
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Zhang Y, Zhou J, Zhang Y, Zhang D. The ABI3 Transcription Factor Interaction and Antagonism with Ubiquitin E3 Ligase ScPRT1 in Syntrichia caninervis. Genes (Basel) 2022; 13:genes13050718. [PMID: 35627103 PMCID: PMC9141515 DOI: 10.3390/genes13050718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/17/2022] [Accepted: 04/18/2022] [Indexed: 02/05/2023] Open
Abstract
The ubiquitination pathway has been found to regulate plant responses to environmental stress. However, the role of E3 ubiquitin ligase in desiccation tolerant moss has not yet been elucidated. Previous research has shown that the abscisic acid (ABA) signaling factor ScABI3 can significantly increase desiccation tolerance and reduce ABA sensitivity in the desert moss Syntrichia caninervis. In this study, we identified a RING-type E3 ubiquitin ligase, ScPRT1, and showed that ScABI3 can directly interact with ScPRT1 in vitro and in vivo. Furthermore, we found that the high expression of ScPRT1 can interfere with the transcription of ScABI3 under ABA treatment. Therefore, we speculate that ScPRT1 may degrade ScABI3 through the ubiquitin-26S proteasome system and participate in ABA-dependent signaling in response to ABA-insensitivity or desiccation tolerance in S. caninervis. The findings from our study may enrich our knowledge of the role of E3 ubiquitin ligase in desiccation tolerance and lay a theoretical foundation for an in-depth study of the relationship between ubiquitination modification and ABA signal transduction under environmental stress.
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Affiliation(s)
- Yigong Zhang
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830017, China; (Y.Z.); (J.Z.); (Y.Z.)
| | - Jiyang Zhou
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830017, China; (Y.Z.); (J.Z.); (Y.Z.)
| | - Yi Zhang
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830017, China; (Y.Z.); (J.Z.); (Y.Z.)
| | - Daoyuan Zhang
- Xinjiang Key Laboratory of Conservation and Utilization of Plant Gene Resources, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
- Turpan Eremophytes Botanical Garden, Chinese Academy of Sciences, Turpan 838099, China
- Correspondence:
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29
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Barreto P, Dambire C, Sharma G, Vicente J, Osborne R, Yassitepe J, Gibbs DJ, Maia IG, Holdsworth MJ, Arruda P. Mitochondrial retrograde signaling through UCP1-mediated inhibition of the plant oxygen-sensing pathway. Curr Biol 2022; 32:1403-1411.e4. [PMID: 35114096 PMCID: PMC8967405 DOI: 10.1016/j.cub.2022.01.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/10/2021] [Accepted: 01/12/2022] [Indexed: 12/19/2022]
Abstract
Mitochondrial retrograde signaling is an important component of intracellular stress signaling in eukaryotes. UNCOUPLING PROTEIN (UCP)1 is an abundant plant inner-mitochondrial membrane protein with multiple functions including uncoupled respiration and amino-acid transport1,2 that influences broad abiotic stress responses. Although the mechanism(s) through which this retrograde function acts is unknown, overexpression of UCP1 activates expression of hypoxia (low oxygen)-associated nuclear genes.3,4 Here we show in Arabidopsis thaliana that UCP1 influences nuclear gene expression and physiological response by inhibiting the cytoplasmic PLANT CYSTEINE OXIDASE (PCO) branch of the PROTEOLYSIS (PRT)6 N-degron pathway, a major mechanism of oxygen and nitric oxide (NO) sensing.5 Overexpression of UCP1 (UCP1ox) resulted in the stabilization of an artificial PCO N-degron pathway substrate, and stability of this reporter protein was influenced by pharmacological interventions that control UCP1 activity. Hypoxia and salt-tolerant phenotypes observed in UCP1ox lines resembled those observed for the PRT6 N-recognin E3 ligase mutant prt6-1. Genetic analysis showed that UCP1 regulation of hypoxia responses required the activity of PCO N-degron pathway ETHYLENE RESPONSE FACTOR (ERF)VII substrates. Transcript expression analysis indicated that UCP1 regulation of hypoxia-related gene expression is a normal component of seedling development. Our results show that mitochondrial retrograde signaling represses the PCO N-degron pathway, enhancing substrate function, thus facilitating downstream stress responses. This work reveals a novel mechanism through which mitochondrial retrograde signaling influences nuclear response to hypoxia by inhibition of an ancient cytoplasmic pathway of eukaryotic oxygen sensing. UCP1 inhibits the PCO branch of the PRT6 N-degron pathway Inhibition leads to substrate stabilization and altered gene expression Inhibition transduces UCP1 function during development and in response to stress
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Affiliation(s)
- Pedro Barreto
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências de Botucatu, UNESP, Botucatu 18618-970, SP, Brazil
| | - Charlene Dambire
- School of Biosciences, University of Nottingham, Loughborough, Leicestershire LE12 5RD, UK
| | - Gunjan Sharma
- School of Biosciences, University of Nottingham, Loughborough, Leicestershire LE12 5RD, UK
| | - Jorge Vicente
- School of Biosciences, University of Nottingham, Loughborough, Leicestershire LE12 5RD, UK
| | - Rory Osborne
- School of Biosciences, University of Birmingham, Edgbaston B15 2TT, UK
| | - Juliana Yassitepe
- Genomics for Climate Change Research Center, Universidade Estadual de Campinas, Campinas 13083-875, SP, Brazil
| | - Daniel J Gibbs
- School of Biosciences, University of Birmingham, Edgbaston B15 2TT, UK
| | - Ivan G Maia
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências de Botucatu, UNESP, Botucatu 18618-970, SP, Brazil
| | - Michael J Holdsworth
- School of Biosciences, University of Nottingham, Loughborough, Leicestershire LE12 5RD, UK.
| | - Paulo Arruda
- Genomics for Climate Change Research Center, Universidade Estadual de Campinas, Campinas 13083-875, SP, Brazil; Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-862 Campinas, SP, Brazil; Centro de Biologia Molecular e Engenharia Genetica, Universidade Estadual de Campinas, Campinas 13083-875, SP, Brazil.
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30
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Kozlic A, Winter N, Telser T, Reimann J, Rose K, Nehlin L, Berckhan S, Sharma G, Dambire C, Boeckx T, Holdsworth MJ, Bachmair A. A Yeast-Based Functional Assay to Study Plant N-Degron - N-Recognin Interactions. FRONTIERS IN PLANT SCIENCE 2022; 12:806129. [PMID: 35069663 PMCID: PMC8777003 DOI: 10.3389/fpls.2021.806129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
The N-degron pathway is a branch of the ubiquitin-proteasome system where amino-terminal residues serve as degradation signals. In a synthetic biology approach, we expressed ubiquitin ligase PRT6 and ubiquitin conjugating enzyme 2 (AtUBC2) from Arabidopsis thaliana in a Saccharomyces cerevisiae strain with mutation in its endogenous N-degron pathway. The two enzymes re-constitute part of the plant N-degron pathway and were probed by monitoring the stability of co-expressed GFP-linked plant proteins starting with Arginine N-degrons. The novel assay allows for straightforward analysis, whereas in vitro interaction assays often do not allow detection of the weak binding of N-degron recognizing ubiquitin ligases to their substrates, and in planta testing is usually complex and time-consuming.
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Affiliation(s)
- Aida Kozlic
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna, Austria
| | - Nikola Winter
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna, Austria
| | - Theresia Telser
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna, Austria
| | - Jakob Reimann
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna, Austria
| | - Katrin Rose
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna, Austria
| | - Lilian Nehlin
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna, Austria
| | - Sophie Berckhan
- School of Biosciences, University of Nottingham, Nottingham, United Kingdom
| | - Gunjan Sharma
- School of Biosciences, University of Nottingham, Nottingham, United Kingdom
| | - Charlene Dambire
- School of Biosciences, University of Nottingham, Nottingham, United Kingdom
| | - Tinne Boeckx
- School of Biosciences, University of Nottingham, Nottingham, United Kingdom
| | | | - Andreas Bachmair
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna, Austria
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31
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Castillo MC, Costa-Broseta Á, Gayubas B, León J. NIN-like protein7 and PROTEOLYSIS6 functional interaction enhances tolerance to sucrose, ABA, and submergence. PLANT PHYSIOLOGY 2021; 187:2731-2748. [PMID: 34618055 PMCID: PMC8644111 DOI: 10.1093/plphys/kiab382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/16/2021] [Indexed: 05/05/2023]
Abstract
Nitrate (NO3) assimilation and signaling regulate plant growth through the relevant function of the transcription factor NIN-like Protein7 (NLP7). NO3 is also the main source for plants to produce nitric oxide (NO), which regulates growth and stress responses. NO-mediated regulation requires efficient sensing via the PROTEOLYSIS6 (PRT6)-mediated proteasome-triggered degradation of group VII of ethylene response transcription factors through the Cys/Arg N-degron pathway. The convergence of NO3 signaling and N-degron proteolysis on NO-mediated regulation remains largely unknown. Here, we investigated the functional interaction between NLP7 and PRT6 using Arabidopsis (Arabidopsis thaliana) double prt6 nlp7 mutant plants as well as complementation lines overexpressing NLP7 in different mutant genetic backgrounds. prt6 nlp7 mutant plants displayed several potentiated prt6 characteristic phenotypes, including slower vegetative growth, increased NO content, and diminished tolerance to abiotic stresses such as high-sucrose concentration, abscisic acid, and hypoxia-reoxygenation. Although NLP7 has an N-terminus that could be targeted by the N-degron proteolytic pathway, it was not a PRT6 substrate. The potential PRT6- and NO-regulated nucleocytoplasmic translocation of NLP7, which is likely modulated by posttranslational modifications, is proposed to act as a regulatory loop to control NO homeostasis and action.
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Affiliation(s)
- Mari-Cruz Castillo
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas–Universidad Politécnica de Valencia), Valencia 46022, Spain
| | - Álvaro Costa-Broseta
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas–Universidad Politécnica de Valencia), Valencia 46022, Spain
| | - Beatriz Gayubas
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas–Universidad Politécnica de Valencia), Valencia 46022, Spain
| | - José León
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas–Universidad Politécnica de Valencia), Valencia 46022, Spain
- Author for communication:
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Wang X, Gomes MM, Bailly C, Nambara E, Corbineau F. Role of ethylene and proteolytic N-degron pathway in the regulation of Arabidopsis seed dormancy. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:2110-2122. [PMID: 34542217 DOI: 10.1111/jipb.13173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/16/2021] [Indexed: 05/22/2023]
Abstract
Primary dormant seeds of Arabidopsis thaliana did not germinate in darkness at temperature higher than 10-15°C. Ethylene improved the germination of dormant wild-type (Col-0) seeds at 25°C in darkness but seeds of the mutant affected in the proteolytic N-degron pathway, proteolysis6 (prt6), were insensitive to ethylene suggesting that PRT6 was involved in dormancy release by ethylene. The substrates of the N-degron pathway, the Ethylene Response Factors from group VII (HRE1, HRE2, RAP2.2, RAP2.3, and RAP2.12), were identified to be involved in this insensitivity with an increased germination in prt6 rap2.2 rap2.3 rap2.12 rather than in prt6 hre1 hre2, which also indicated that the three RAPs acted downstream of PRT6, while the two HREs acted upstream of PRT6. Ethylene reduced the expression of the three RAPs in Col-0 seeds but they were maintained or induced by ethylene in prt6 seeds. The promoting effect of ethylene was associated with a down-regulation of dormancy-related genes in gibberellins (GAs) and abscisic acid (ABA) signaling, such as RGA, RGL2, and ABI5, and with a strong decrease in ABA/GA4 ratio in the presence of ethylene. In contrast, we show that the insensitivity of prt6 seeds to ethylene was mainly related to GA signaling disturbance.
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Affiliation(s)
- Xu Wang
- UMR7622 Biologie du Développement, Sorbonne Université, IBPS, CNRS, Paris, F-75005, France
| | - Malaika Maraya Gomes
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
| | - Christophe Bailly
- UMR7622 Biologie du Développement, Sorbonne Université, IBPS, CNRS, Paris, F-75005, France
| | - Eiji Nambara
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
| | - Françoise Corbineau
- UMR7622 Biologie du Développement, Sorbonne Université, IBPS, CNRS, Paris, F-75005, France
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Aminopeptidases trim Xaa-Pro proteins, initiating their degradation by the Pro/N-degron pathway. Proc Natl Acad Sci U S A 2021; 118:2115430118. [PMID: 34663735 DOI: 10.1073/pnas.2115430118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2021] [Indexed: 12/26/2022] Open
Abstract
N-degron pathways are proteolytic systems that recognize proteins bearing N-terminal (Nt) degradation signals (degrons) called N-degrons. Our previous work identified Gid4 as a recognition component (N-recognin) of the Saccharomyces cerevisiae proteolytic system termed the proline (Pro)/N-degron pathway. Gid4 is a subunit of the oligomeric glucose-induced degradation (GID) ubiquitin ligase. Gid4 targets proteins through the binding to their Nt-Pro residue. Gid4 is also required for degradation of Nt-Xaa-Pro (Xaa is any amino acid residue) proteins such as Nt-[Ala-Pro]-Aro10 and Nt-[Ser-Pro]-Pck1, with Pro at position 2. Here, we show that specific aminopeptidases function as components of the Pro/N-degron pathway by removing Nt-Ala or Nt-Ser and yielding Nt-Pro, which can be recognized by Gid4-GID. Nt-Ala is removed by the previously uncharacterized aminopeptidase Fra1. The enzymatic activity of Fra1 is shown to be essential for the GID-dependent degradation of Nt-[Ala-Pro]-Aro10. Fra1 can also trim Nt-[Ala-Pro-Pro-Pro] (stopping immediately before the last Pro) and thereby can target for degradation a protein bearing this Nt sequence. Nt-Ser is removed largely by the mitochondrial/cytosolic/nuclear aminopeptidase Icp55. These advances are relevant to eukaryotes from fungi to animals and plants, as Fra1, Icp55, and the GID ubiquitin ligase are conserved in evolution. In addition to discovering the mechanism of targeting of Xaa-Pro proteins, these insights have also expanded the diversity of substrates of the Pro/N-degron pathway.
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León J, Castillo MC, Gayubas B. The hypoxia-reoxygenation stress in plants. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5841-5856. [PMID: 33367851 PMCID: PMC8355755 DOI: 10.1093/jxb/eraa591] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 12/16/2020] [Indexed: 05/04/2023]
Abstract
Plants are very plastic in adapting growth and development to changing adverse environmental conditions. This feature will be essential for plants to survive climate changes characterized by extreme temperatures and rainfall. Although plants require molecular oxygen (O2) to live, they can overcome transient low-O2 conditions (hypoxia) until return to standard 21% O2 atmospheric conditions (normoxia). After heavy rainfall, submerged plants in flooded lands undergo transient hypoxia until water recedes and normoxia is recovered. The accumulated information on the physiological and molecular events occurring during the hypoxia phase contrasts with the limited knowledge on the reoxygenation process after hypoxia, which has often been overlooked in many studies in plants. Phenotypic alterations during recovery are due to potentiated oxidative stress generated by simultaneous reoxygenation and reillumination leading to cell damage. Besides processes such as N-degron proteolytic pathway-mediated O2 sensing, or mitochondria-driven metabolic alterations, other molecular events controlling gene expression have been recently proposed as key regulators of hypoxia and reoxygenation. RNA regulatory functions, chromatin remodeling, protein synthesis, and post-translational modifications must all be studied in depth in the coming years to improve our knowledge on hypoxia-reoxygenation transition in plants, a topic with relevance in agricultural biotechnology in the context of global climate change.
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Affiliation(s)
- José León
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas – Universidad Politécnica de Valencia), Valencia, Spain
- Correspondence:
| | - Mari Cruz Castillo
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas – Universidad Politécnica de Valencia), Valencia, Spain
| | - Beatriz Gayubas
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas – Universidad Politécnica de Valencia), Valencia, Spain
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Molecular basis for recognition of Gly/N-degrons by CRL2 ZYG11B and CRL2 ZER1. Mol Cell 2021; 81:3262-3274.e3. [PMID: 34214466 DOI: 10.1016/j.molcel.2021.06.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/08/2021] [Accepted: 06/09/2021] [Indexed: 11/21/2022]
Abstract
N-degron pathways are a set of proteolytic systems that target the N-terminal destabilizing residues of substrates for proteasomal degradation. Recently, the Gly/N-degron pathway has been identified as a new branch of the N-degron pathway. The N-terminal glycine degron (Gly/N-degron) is recognized by ZYG11B and ZER1, the substrate receptors of the Cullin 2-RING E3 ubiquitin ligase (CRL2). Here we present the crystal structures of ZYG11B and ZER1 bound to various Gly/N-degrons. The structures reveal that ZYG11B and ZER1 utilize their armadillo (ARM) repeats forming a deep and narrow cavity to engage mainly the first four residues of Gly/N-degrons. The α-amino group of the Gly/N-degron is accommodated in an acidic pocket by five conserved hydrogen bonds. These structures, together with biochemical studies, decipher the molecular basis for the specific recognition of the Gly/N-degron by ZYG11B and ZER1, providing key information for future structure-based chemical probe design.
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Tying up loose ends: the N-degron and C-degron pathways of protein degradation. Biochem Soc Trans 2021; 48:1557-1567. [PMID: 32627813 PMCID: PMC7458402 DOI: 10.1042/bst20191094] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/11/2020] [Accepted: 06/15/2020] [Indexed: 12/13/2022]
Abstract
Selective protein degradation by the ubiquitin-proteasome system (UPS) is thought to be governed primarily by the recognition of specific motifs — degrons — present in substrate proteins. The ends of proteins — the N- and C-termini – have unique properties, and an important subset of protein–protein interactions involve the recognition of free termini. The first degrons to be discovered were located at the extreme N-terminus of proteins, a finding which initiated the study of the N-degron (formerly N-end rule) pathways, but only in the last few years has it emerged that a diverse set of C-degron pathways target analogous degron motifs located at the extreme C-terminus of proteins. In this minireview we summarise the N-degron and C-degron pathways currently known to operate in human cells, focussing primarily on those that have been discovered in recent years. In each case we describe the cellular machinery responsible for terminal degron recognition, and then consider some of the functional roles of terminal degron pathways. Altogether, a broad spectrum of E3 ubiquitin ligases mediate the recognition of a diverse array of terminal degron motifs; these degradative pathways have the potential to influence a wide variety of cellular functions.
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Hong L, Niu F, Lin Y, Wang S, Chen L, Jiang L. MYB106 is a negative regulator and a substrate for CRL3 BPM E3 ligase in regulating flowering time in Arabidopsis thaliana. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:1104-1119. [PMID: 33470537 DOI: 10.1111/jipb.13071] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 01/16/2021] [Indexed: 05/18/2023]
Abstract
Flowering time is crucial for successful reproduction in plants, the onset and progression of which are strictly controlled. However, flowering time is a complex and environmentally responsive history trait and the underlying mechanisms still need to be fully characterized. Post-translational regulation of the activities of transcription factors (TFs) is a dynamic and essential mechanism for plant growth and development. CRL3BPM E3 ligase is a CULLIN3-based E3 ligase involved in orchestrating protein stability via the ubiquitin proteasome pathway. Our study shows that the mutation of MYB106 induced early flowering phenotype while over-expression of MYB106 delayed Arabidopsis flowering. Transcriptome analysis of myb106 mutants reveals 257 differentially expressed genes between wild type and myb106-1 mutants, including Flowering Locus T (FT) which is related to flowering time. Moreover, in vitro electrophoretic mobility shift assays (EMSA), in vivo chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR) assays and dual luciferase assays demonstrate that MYB106 directly binds to the promoter of FT to suppress its expression. Furthermore, we confirm that MYB106 interacts with BPM proteins which are further identified by CRL3BPM E3 ligases as the substrate. Taken together, we have identified MYB106 as a negative regulator in the control of flowering time and a new substrate for CRL3BPM E3 ligases in Arabidopsis.
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Affiliation(s)
- Liu Hong
- Center for Cell & Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Fangfang Niu
- Center for Cell & Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Youshun Lin
- Center for Cell & Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Shuang Wang
- Center for Cell & Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Shenzhen Technology University, Shenzhen, 518000, China
| | - Liyuan Chen
- Center for Cell & Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- School of Chemical Biology & Biotechnology, Peking University Shenzhen Graduate School, Nanshan District, Shenzhen, 518055, China
| | - Liwen Jiang
- Center for Cell & Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518057, China
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Considine MJ, Foyer CH. Oxygen and reactive oxygen species-dependent regulation of plant growth and development. PLANT PHYSIOLOGY 2021; 186:79-92. [PMID: 33793863 PMCID: PMC8154071 DOI: 10.1093/plphys/kiaa077] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/29/2020] [Indexed: 05/04/2023]
Abstract
Oxygen and reactive oxygen species (ROS) have been co-opted during evolution into the regulation of plant growth, development, and differentiation. ROS and oxidative signals arising from metabolism or phytohormone-mediated processes control almost every aspect of plant development from seed and bud dormancy, liberation of meristematic cells from the quiescent state, root and shoot growth, and architecture, to flowering and seed production. Moreover, the phytochrome and phytohormone-dependent transmissions of ROS waves are central to the systemic whole plant signaling pathways that integrate root and shoot growth. The sensing of oxygen availability through the PROTEOLYSIS 6 (PRT6) N-degron pathway functions alongside ROS production and signaling but how these pathways interact in developing organs remains poorly understood. Considerable progress has been made in our understanding of the nature of hydrogen peroxide sensors and the role of thiol-dependent signaling networks in the transmission of ROS signals. Reduction/oxidation (redox) changes in the glutathione (GSH) pool, glutaredoxins (GRXs), and thioredoxins (TRXs) are important in the control of growth mediated by phytohormone pathways. Although, it is clear that the redox states of proteins involved in plant growth and development are controlled by the NAD(P)H thioredoxin reductase (NTR)/TRX and reduced GSH/GRX systems of the cytosol, chloroplasts, mitochondria, and nucleus, we have only scratched the surface of this multilayered control and how redox-regulated processes interact with other cell signaling systems.
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Affiliation(s)
- Michael J Considine
- The School of Molecular Sciences, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Christine H Foyer
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
- Author for communication:
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Mooney BC, Mantz M, Graciet E, Huesgen PF. Cutting the line: manipulation of plant immunity by bacterial type III effector proteases. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:3395-3409. [PMID: 33640987 DOI: 10.1093/jxb/erab095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
Pathogens and their hosts are engaged in an evolutionary arms race. Pathogen-derived effectors promote virulence by targeting components of a host's innate immune system, while hosts have evolved proteins that sense effectors and trigger a pathogen-specific immune response. Many bacterial effectors are translocated into host cells using type III secretion systems. Type III effector proteases irreversibly modify host proteins by cleavage of peptide bonds and are prevalent among both plant and animal bacterial pathogens. In plants, the study of model effector proteases has yielded important insights into the virulence mechanisms employed by pathogens to overcome their host's immune response, as well as into the mechanisms deployed by their hosts to detect these effector proteases and counteract their effects. In recent years, the study of a larger number of effector proteases, across a wider range of pathogens, has yielded novel insights into their functions and recognition. One key limitation that remains is the lack of methods to detect protease cleavage at the proteome-wide level. We review known substrates and mechanisms of plant pathogen type III effector proteases and compare their functions with those of known type III effector proteases of mammalian pathogens. Finally, we discuss approaches to uncover their function on a system-wide level.
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Affiliation(s)
- Brian C Mooney
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - Melissa Mantz
- Central Institute for Engineering, Electronics and Analytics, ZEA-3, Forschungszentrum Jülich, Jülich, Germany
- CECAD, Medical Faculty and University Hospital, University of Cologne, Cologne, Germany
| | - Emmanuelle Graciet
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Pitter F Huesgen
- Central Institute for Engineering, Electronics and Analytics, ZEA-3, Forschungszentrum Jülich, Jülich, Germany
- CECAD, Medical Faculty and University Hospital, University of Cologne, Cologne, Germany
- Institute for Biochemistry, Faculty of Mathematics and Natural Sciences, University of Cologne, Cologne, Germany
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Yang C, Zhang F, Jiang X, Yang X, He F, Wang Z, Long R, Chen L, Yang T, Wang C, Gao T, Kang J, Yang Q. Identification of Genetic Loci Associated With Crude Protein Content and Fiber Composition in Alfalfa ( Medicago sativa L.) Using QTL Mapping. FRONTIERS IN PLANT SCIENCE 2021; 12:608940. [PMID: 33679827 PMCID: PMC7933732 DOI: 10.3389/fpls.2021.608940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 01/27/2021] [Indexed: 05/17/2023]
Abstract
Forage quality determined mainly by protein content and fiber composition has a crucial influence on digestibility and nutrition intake for animal feeding. To explore the genetic basis of quality traits, we conducted QTL mapping based on the phenotypic data of crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and lignin of an F1 alfalfa population generated by crossing of two alfalfa parents with significant difference in quality. In total, 83 QTLs were identified with contribution to the phenotypic variation (PVE) ranging from 1.45 to 14.35%. Among them, 47 QTLs interacted significantly with environment and 12 QTLs were associated with more than one trait. Epistatic effect was also detected for 73 pairs of QTLs with PVE of 1.08-14.06%. The results suggested that the inheritance of quality-related traits was jointly affected by additive, epistasis and environment. In addition, 83.33% of the co-localized QTLs were shared by ADF and NDF with the same genetic direction, while the additive effect of crude protein-associated QTLs was opposite to that fiber composition on the same locus, suggesting that the loci may antagonistically contribute to protein content and fiber composition. Further analysis of a QTL related to all the three traits of fiber composition (qNDF1C, qADF1C-2, and qlignin1C-2) showed that five candidate genes were homologs of cellulose synthase-like protein A1 in Medicago truncatula, indicating the potential role in fiber synthesis. For the protein-associated loci we identified, qCP4C-1 was located in the shortest region (chr 4.3 39.3-39.4 Mb), and two of the seven corresponding genes in this region were predicted to be E3 ubiquitin-protein ligase in protein metabolism. Therefore, our results provide some reliable regions significantly associated with alfalfa quality, and identification of the key genes would facilitate marker-assisted selection for favorable alleles in breeding program of alfalfa quality improvement.
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Affiliation(s)
- Changfu Yang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Fan Zhang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xueqian Jiang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xijiang Yang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Fei He
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhen Wang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ruicai Long
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lin Chen
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Tianhui Yang
- Institute of Animal Science, Ningxia Academy of Agricultural and Forestry Sciences, Yinchuan, China
| | - Chuan Wang
- Institute of Animal Science, Ningxia Academy of Agricultural and Forestry Sciences, Yinchuan, China
| | - Ting Gao
- Institute of Animal Science, Ningxia Academy of Agricultural and Forestry Sciences, Yinchuan, China
| | - Junmei Kang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Qingchuan Yang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
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Zhang J, Zhou M, Zhou H, Zhao D, Gotor C, Romero LC, Shen J, Ge Z, Zhang Z, Shen W, Yuan X, Xie Y. Hydrogen sulfide, a signaling molecule in plant stress responses. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:146-160. [PMID: 33058490 DOI: 10.1111/jipb.13022] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 10/09/2020] [Indexed: 05/22/2023]
Abstract
Gaseous molecules, such as hydrogen sulfide (H2 S) and nitric oxide (NO), are crucial players in cellular and (patho)physiological processes in biological systems. The biological functions of these gaseous molecules, which were first discovered and identified as gasotransmitters in animals, have received unprecedented attention from plant scientists in recent decades. Researchers have arrived at the consensus that H2 S is synthesized endogenously and serves as a signaling molecule throughout the plant life cycle. However, the mechanisms of H2 S action in redox biology is still largely unexplored. This review highlights what we currently know about the characteristics and biosynthesis of H2 S in plants. Additionally, we summarize the role of H2 S in plant resistance to abiotic stress. Moreover, we propose and discuss possible redox-dependent mechanisms by which H2 S regulates plant physiology.
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Affiliation(s)
- Jing Zhang
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Mingjian Zhou
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Heng Zhou
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Didi Zhao
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Cecilia Gotor
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas y Universidad de Sevilla, Sevilla, 41092, Spain
| | - Luis C Romero
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas y Universidad de Sevilla, Sevilla, 41092, Spain
| | - Jie Shen
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhenglin Ge
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhirong Zhang
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wenbiao Shen
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xingxing Yuan
- Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Yanjie Xie
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
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Weits DA, van Dongen JT, Licausi F. Molecular oxygen as a signaling component in plant development. THE NEW PHYTOLOGIST 2021; 229:24-35. [PMID: 31943217 DOI: 10.1111/nph.16424] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 12/10/2019] [Indexed: 05/24/2023]
Abstract
While traditionally hypoxia has been studied as a detrimental component of flooding stress, the last decade has flourished with studies reporting the involvement of molecular oxygen availability in plant developmental processes. Moreover, proliferating and undifferentiated cells from different plant tissues were found to reside in endogenously generated hypoxic niches. Thus, stress-associated acute hypoxia may be distinguished from constitutively generated chronic hypoxia. The Cys/Arg branch of the N-degron pathway assumes a central role in integrating oxygen levels resulting in proteolysis of transcriptional regulators that control different aspects of plant growth and development. As a target of this pathway, group VII of the Ethylene Response Factor (ERF-VII) family has emerged as a hub for the integration of oxygen dynamics in root development and during seedling establishment. Additionally, vegetative shoot meristem activity and reproductive transition were recently associated with oxygen availability via two novel substrates of the N-degron pathways: VERNALISATION 2 (VRN2) and LITTLE ZIPPER 2 (ZPR2). Together, these observations support roles for molecular oxygen as a signalling molecule in plant development, as well as in essential metabolic reactions. Here, we review recent findings regarding oxygen-regulated development, and discuss outstanding questions that spring from these discoveries.
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Affiliation(s)
- Daan A Weits
- Plantlab, Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, 56010, Italy
| | | | - Francesco Licausi
- Plantlab, Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, 56010, Italy
- Biology Department, University of Pisa, Pisa, 56126, Italy
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The Arg/N-degron pathway targets transcription factors and regulates specific genes. Proc Natl Acad Sci U S A 2020; 117:31094-31104. [PMID: 33229537 DOI: 10.1073/pnas.2020124117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The Arg/N-degron pathway targets proteins for degradation by recognizing their N-terminal or internal degrons. Our previous work produced double-knockout (2-KO) HEK293T human cell lines that lacked the functionally overlapping UBR1 and UBR2 E3 ubiquitin ligases of the Arg/N-degron pathway. Here, we studied these cells in conjunction with RNA-sequencing, mass spectrometry (MS), and split-ubiquitin binding assays. 1) Some mRNAs, such as those encoding lactate transporter MCT2 and β-adrenergic receptor ADRB2, are strongly (∼20-fold) up-regulated in 2-KO cells, whereas other mRNAs, including those encoding MAGEA6 (a regulator of ubiquitin ligases) and LCP1 (an actin-binding protein), are completely repressed in 2-KO cells, in contrast to wild-type cells. 2) Glucocorticoid receptor (GR), an immunity-modulating transcription factor (TF), is up-regulated in 2-KO cells and also physically binds to UBR1, strongly suggesting that GR is a physiological substrate of the Arg/N-degron pathway. 3) PREP1, another TF, was also found to bind to UBR1. 4) MS-based analyses identified ∼160 proteins whose levels were increased or decreased by more than 2-fold in 2-KO cells. For example, the homeodomain TF DACH1 and the neurofilament subunits NF-L (NFEL) and NF-M (NFEM) were expressed in wild-type cells but were virtually absent in 2-KO cells. 5) The disappearance of some proteins in 2-KO cells took place despite up-regulation of their mRNAs, strongly suggesting that the Arg/N-degron pathway can also modulate translation of specific mRNAs. In sum, this multifunctional proteolytic system has emerged as a regulator of mammalian gene expression, in part through conditional targeting of TFs that include ATF3, GR, and PREP1.
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Linden KJ, Callis J. The ubiquitin system affects agronomic plant traits. J Biol Chem 2020; 295:13940-13955. [PMID: 32796036 DOI: 10.1074/jbc.rev120.011303] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/11/2020] [Indexed: 12/17/2022] Open
Abstract
In a single vascular plant species, the ubiquitin system consists of thousands of different proteins involved in attaching ubiquitin to substrates, recognizing or processing ubiquitinated proteins, or constituting or regulating the 26S proteasome. The ubiquitin system affects plant health, reproduction, and responses to the environment, processes that impact important agronomic traits. Here we summarize three agronomic traits influenced by ubiquitination: induction of flowering, seed size, and pathogen responses. Specifically, we review how the ubiquitin system affects expression of genes or abundance of proteins important for determining when a plant flowers (focusing on FLOWERING LOCUS C, FRIGIDA, and CONSTANS), highlight some recent studies on how seed size is affected by the ubiquitin system, and discuss how the ubiquitin system affects proteins involved in pathogen or effector recognition with details of recent studies on FLAGELLIN SENSING 2 and SUPPRESSOR OF NPR CONSTITUTIVE 1, respectively, as examples. Finally, we discuss the effects of pathogen-derived proteins on plant host ubiquitin system proteins. Further understanding of the molecular basis of the above processes could identify possible genes for modification or selection for crop improvement.
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Affiliation(s)
- Katrina J Linden
- Department of Molecular and Cellular Biology and the Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, USA
| | - Judy Callis
- Department of Molecular and Cellular Biology and the Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, USA.
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Vu TTM, Varshavsky A. The ATF3 Transcription Factor Is a Short-Lived Substrate of the Arg/N-Degron Pathway. Biochemistry 2020; 59:2796-2812. [PMID: 32692156 DOI: 10.1021/acs.biochem.0c00514] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Arg/N-degron pathway targets proteins for degradation by recognizing their specific N-terminal residues or, alternatively, their non-N-terminal degrons. In mammals, this pathway is mediated by the UBR1, UBR2, UBR4, and UBR5 E3 ubiquitin ligases, and by the p62 regulator of autophagy. UBR1 and UBR2 are sequelogous, functionally overlapping, and dominate the targeting of Arg/N-degron substrates in examined cell lines. We constructed, here, mouse strains in which the double mutant [UBR1-/- UBR2-/-] genotype can be induced conditionally, in adult mice. We also constructed human [UBR1-/- UBR2-/-] HEK293T cell lines that unconditionally lack UBR1/UBR2. ATF3 is a basic leucine zipper transcription factor that regulates hundreds of genes and can act as either a repressor or an activator of transcription. Using the above double-mutant mice and human cells, we found that the levels of endogenous, untagged ATF3 were significantly higher in both of these [UBR1-/- UBR2-/-] settings than in wild-type cells. We also show, through chase-degradation assays with [UBR1-/- UBR2-/-] and wild-type human cells, that the Arg/N-degron pathway mediates a large fraction of ATF3 degradation. Furthermore, we used split-ubiquitin and another protein interaction assay to detect the binding of ATF3 to both UBR1 and UBR2, in agreement with the UBR1/UBR2-mediated degradation of endogenous ATF3. Full-length 24 kDa ATF3 binds to ∼100 kDa fragments of 200 kDa UBR1 and UBR2 but does not bind (in the setting of interaction assays) to full-length UBR1/UBR2. These and other binding patterns, whose mechanics remain to be understood, may signify a conditional (regulated) degradation of ATF3 by the Arg/N-degron pathway.
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Affiliation(s)
- Tri T M Vu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Alexander Varshavsky
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, United States
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Maurel C, Nacry P. Root architecture and hydraulics converge for acclimation to changing water availability. NATURE PLANTS 2020; 6:744-749. [PMID: 32601421 DOI: 10.1038/s41477-020-0684-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 04/29/2020] [Indexed: 05/16/2023]
Abstract
Because of intense transpiration and growth, the needs of plants for water can be immense. Yet water in the soil is most often heterogeneous if not scarce due to more and more frequent and intense drought episodes. The converse context, flooding, is often associated with marked oxygen deficiency and can also challenge the plant water status. Under our feet, roots achieve an incredible challenge to meet the water demand of the plant's aerial parts under such dramatically different environmental conditions. For this, they continuously explore the soil, building a highly complex, branched architecture. On shorter time scales, roots keep adjusting their water transport capacity (their so-called hydraulics) locally or globally. While the mechanisms that directly underlie root growth and development as well as tissue hydraulics are being uncovered, the signalling mechanisms that govern their local and systemic adjustments as a function of water availability remain largely unknown. A comprehensive understanding of root architecture and hydraulics as a whole (in other terms, root hydraulic architecture) is needed to apprehend the strategies used by plants to optimize water uptake and possibly improve crops regarding this crucial trait.
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Affiliation(s)
- Christophe Maurel
- Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France.
| | - Philippe Nacry
- Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
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Mooney BC, Graciet E. A simple and efficient Agrobacterium-mediated transient expression system to dissect molecular processes in Brassica rapa and Brassica napus. PLANT DIRECT 2020; 4:e00237. [PMID: 32775949 PMCID: PMC7403836 DOI: 10.1002/pld3.237] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/05/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
The family Brassicaceae is a source of important crop species, including Brassica napus (oilseed rape), Brassica oleracea, and B. rapa, that is used globally for oil production or as a food source (e.g., pak choi or turnip). However, despite advances in recent years, including genome sequencing, a lack of established tools tailored to the study of Brassica crop species has impeded efforts to understand their molecular processes in greater detail. Here, we describe the use of a simple Agrobacterium-mediated transient expression system adapted to B. rapa and B. napus that could facilitate study of molecular and biochemical events in these species. We also demonstrate the use of this method to characterize the N-degron pathway of protein degradation in B. rapa. The N-degron pathway is a subset of the ubiquitin-proteasome system and represents a mechanism through which proteins may be targeted for degradation based on the identity of their N-terminal amino acid residue. Interestingly, N-degron-mediated processes in plants have been implicated in the regulation of traits with potential agronomic importance, including the responses to pathogens and to abiotic stresses such as flooding tolerance. The stability of transiently expressed N-degron reporter proteins in B. rapa indicates that its N-degron pathway is highly conserved with that of Arabidopsis thaliana. These findings highlight the utility of Agrobacterium-mediated transient expression in B. rapa and B. napus and establish a framework to investigate the N-degron pathway and its roles in regulating agronomical traits in these species. SIGNIFICANCE STATEMENT We describe an Agrobacterium-mediated transient expression system applicable to Brassica crops and demonstrate its utility by identifying the destabilizing residues of the N-degron pathway in B. rapa. As the N-degron pathway functions as an integrator of environmental signals, this study could facilitate efforts to improve the robustness of Brassica crops.
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Affiliation(s)
| | - Emmanuelle Graciet
- Department of BiologyMaynooth UniversityMaynoothIreland
- Kathleen Lonsdale Institute for Human Health ResearchMaynooth UniversityMaynoothIreland
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Five enzymes of the Arg/N-degron pathway form a targeting complex: The concept of superchanneling. Proc Natl Acad Sci U S A 2020; 117:10778-10788. [PMID: 32366662 DOI: 10.1073/pnas.2003043117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Arg/N-degron pathway targets proteins for degradation by recognizing their N-terminal (Nt) residues. If a substrate bears, for example, Nt-Asn, its targeting involves deamidation of Nt-Asn, arginylation of resulting Nt-Asp, binding of resulting (conjugated) Nt-Arg to the UBR1-RAD6 E3-E2 ubiquitin ligase, ligase-mediated synthesis of a substrate-linked polyubiquitin chain, its capture by the proteasome, and substrate's degradation. We discovered that the human Nt-Asn-specific Nt-amidase NTAN1, Nt-Gln-specific Nt-amidase NTAQ1, arginyltransferase ATE1, and the ubiquitin ligase UBR1-UBE2A/B (or UBR2-UBE2A/B) form a complex in which NTAN1 Nt-amidase binds to NTAQ1, ATE1, and UBR1/UBR2. In addition, NTAQ1 Nt-amidase and ATE1 arginyltransferase also bind to UBR1/UBR2. In the yeast Saccharomyces cerevisiae, the Nt-amidase, arginyltransferase, and the double-E3 ubiquitin ligase UBR1-RAD6/UFD4-UBC4/5 are shown to form an analogous targeting complex. These complexes may enable substrate channeling, in which a substrate bearing, for example, Nt-Asn, would be captured by a complex-bound Nt-amidase, followed by sequential Nt modifications of the substrate and its polyubiquitylation at an internal Lys residue without substrate's dissociation into the bulk solution. At least in yeast, the UBR1/UFD4 ubiquitin ligase interacts with the 26S proteasome, suggesting an even larger Arg/N-degron-targeting complex that contains the proteasome as well. In addition, specific features of protein-sized Arg/N-degron substrates, including their partly sequential and partly nonsequential enzymatic modifications, led us to a verifiable concept termed "superchanneling." In superchanneling, the synthesis of a substrate-linked poly-Ub chain can occur not only after a substrate's sequential Nt modifications, but also before them, through a skipping of either some or all of these modifications within a targeting complex.
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Peng Q, Zhao P, Shen Y, Cheng M, Wu Y, Zhu Y. Prognostic implication and functional exploration for microRNA-20a as a molecular biomarker of gastrointestinal cancer. BMC Cancer 2020; 20:420. [PMID: 32410584 PMCID: PMC7227208 DOI: 10.1186/s12885-020-06875-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/16/2020] [Indexed: 02/07/2023] Open
Abstract
Background It is generally accepted that microRNA-20a (miR-20a) is aberrantly expressed in gastrointestinal cancer (GIC), and may be associated with the prognosis of GIC patients. Nevertheless, the clinical prognostic value of miR-20a expression in GIC remains controversial. Methods We first conducted a comprehensive literature search of the clinical data and pooled them for evidence in assessing prognostic significance of miR-20a expression in GIC. Afterwards, we applied some bioinformatic analysis methods to explore the biological function of miR-20a and explain why miR-20a could act as an effective biomarker. Results The pooled results showed that enhanced miR-20a expression was significantly associated with poor survival in GIC patients (HR: 1.36; 95%CI: 1.21–1.52; P < 0.001). According to the subgroup analysis, the ethnicity, cancer type, sample source, and sample size may have an impact on the predictive roles for miR-20a. The gene ontologies enriched by the predicted miR-20a targets were highly associated with some important biological processes, cell components and molecular functions. Moreover, a series of prominent pathways linked with GIC carcinogenesis were identified. Ultimately, the crucial targets and modules were identified by constructing the protein-protein interaction network of miR-20a targets, which were highly associated with the initiation and progression of GIC according to previous molecular biology experiments. Conclusions Our results indicated that high expression of miR-20a may be a credible indicator of worse prognosis in GIC. Further studies involving biological experiments and larger sample sizes should be performed to validate these findings.
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Affiliation(s)
- Qiliang Peng
- Department of Radiotherapy & Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, China.,Institute of Radiotherapy & Oncology, Soochow University, Suzhou, China
| | - Peifeng Zhao
- Department of Radiotherapy & Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, China.,Institute of Radiotherapy & Oncology, Soochow University, Suzhou, China
| | - Yi Shen
- Department of Radiation Oncology, The Affiliated Suzhou Science & Technology Town Hospital of Nanjing Medical University, Suzhou, China
| | - Ming Cheng
- Department of General Surgery, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Yongyou Wu
- Department of General Surgery, The Second Affiliated Hospital of Soochow University, Suzhou, China.
| | - Yaqun Zhu
- Department of Radiotherapy & Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, China. .,Institute of Radiotherapy & Oncology, Soochow University, Suzhou, China.
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