1
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Parra M, Coppola M, Hellmann H. PDX proteins from Arabidopsis thaliana as novel substrates of cathepsin B: implications for vitamin B 6 biosynthesis regulation. FEBS J 2024; 291:2372-2387. [PMID: 38431778 DOI: 10.1111/febs.17110] [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: 05/29/2023] [Revised: 12/18/2023] [Accepted: 02/21/2024] [Indexed: 03/05/2024]
Abstract
Vitamin B6 is a critical molecule for metabolism, development, and stress sensitivity in plants. It is a cofactor for numerous biochemical reactions, can serve as an antioxidant, and has the potential to increase tolerance against both biotic and abiotic stressors. Due to the importance of vitamin B6, its biosynthesis is likely tightly regulated. Plants can synthesize vitamin B6 de novo via the concerted activity of Pyridoxine Biosynthesis Protein 1 (PDX1) and PDX2. Previously, PDX proteins have been identified as targets for ubiquitination, indicating they could be marked for degradation by two highly conserved pathways: the Ubiquitin Proteasome Pathway (UPP) and the autophagy pathway. Initial experiments show that PDXs are in fact degraded, but surprisingly, in a ubiquitin-independent manner. Inhibitor studies pointed toward cathepsin B, a conserved lysosomal cysteine protease, which is implicated in both programed cell death and autophagy in humans and plants. In plants, cathepsin Bs are poorly described, and no confirmed substrates have been identified. Here, we present PDX proteins from Arabidopsis thaliana as interactors and substrates of a plant Cathepsin B. These findings not only describe a novel cathepsin B substrate in plants, but also provide new insights into how plants regulate de novo biosynthesis of vitamin B6.
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Affiliation(s)
- Marcelina Parra
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | | | - Hanjo Hellmann
- School of Biological Sciences, Washington State University, Pullman, WA, USA
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2
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Jung S, Woo J, Park E. Talk to your neighbors in an emergency: Stromule-mediated chloroplast-nucleus communication in plant immunity. CURRENT OPINION IN PLANT BIOLOGY 2024; 79:102529. [PMID: 38604000 DOI: 10.1016/j.pbi.2024.102529] [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: 11/21/2022] [Revised: 03/08/2024] [Accepted: 03/19/2024] [Indexed: 04/13/2024]
Abstract
Hypersensitive response-programmed cell death (HR-PCD) is a response mounted by plants to defend themselves against pathogens. Communication between the chloroplast and the nucleus is critical for the progression of HR-PCD. Tubular protrusions of chloroplasts, known as stromules, are tightly associated with the HR-PCD progression. There is emerging evidence that signaling molecules originating from chloroplasts are transferred to the nucleus through stromules. The translocation of signaling molecules from the chloroplast to the nucleus might trigger defense responses, including transcriptional reprogramming. In this review, we discuss the possible functions of stromules in the rapid transfer of signaling molecules in the chloroplast-nucleus communication.
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Affiliation(s)
- Seungmee Jung
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA
| | - Jongchan Woo
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA
| | - Eunsook Park
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA.
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3
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Adamowski M, Randuch M, Matijević I, Narasimhan M, Friml J. SH3Ps recruit auxilin-like vesicle uncoating factors for clathrin-mediated endocytosis. Cell Rep 2024; 43:114195. [PMID: 38717900 DOI: 10.1016/j.celrep.2024.114195] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 03/09/2024] [Accepted: 04/19/2024] [Indexed: 06/01/2024] Open
Abstract
Clathrin-mediated endocytosis (CME) is an essential process of cargo uptake operating in all eukaryotes. In animals and yeast, BAR-SH3 domain proteins, endophilins and amphiphysins, function at the conclusion of CME to recruit factors for vesicle scission and uncoating. Arabidopsis thaliana contains the BAR-SH3 domain proteins SH3P1-SH3P3, but their role is poorly understood. Here, we identify SH3Ps as functional homologs of endophilin/amphiphysin. SH3P1-SH3P3 bind to discrete foci at the plasma membrane (PM), and SH3P2 recruits late to a subset of clathrin-coated pits. The SH3P2 PM recruitment pattern is nearly identical to its interactor, a putative uncoating factor, AUXILIN-LIKE1. Notably, SH3P1-SH3P3 are required for most of AUXILIN-LIKE1 recruitment to the PM. This indicates a plant-specific modification of CME, where BAR-SH3 proteins recruit auxilin-like uncoating factors rather than the uncoating phosphatases, synaptojanins. SH3P1-SH3P3 act redundantly in overall CME with the plant-specific endocytic adaptor TPLATE complex but not due to an SH3 domain in its TASH3 subunit.
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Affiliation(s)
- Maciek Adamowski
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria; Plant Breeding and Acclimatization Institute - National Research Institute, Radzików, 05-870 Błonie, Poland
| | - Marek Randuch
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Ivana Matijević
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Madhumitha Narasimhan
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Jiří Friml
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
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4
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Yuen ELH, Leary AY, Clavel M, Tumtas Y, Mohseni A, Zhao J, Picchianti L, Jamshidiha M, Pandey P, Duggan C, Cota E, Dagdas Y, Bozkurt TO. A RabGAP negatively regulates plant autophagy and immune trafficking. Curr Biol 2024; 34:2049-2065.e6. [PMID: 38677281 DOI: 10.1016/j.cub.2024.04.002] [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: 09/01/2023] [Revised: 03/11/2024] [Accepted: 04/02/2024] [Indexed: 04/29/2024]
Abstract
Plants rely on autophagy and membrane trafficking to tolerate stress, combat infections, and maintain cellular homeostasis. However, the molecular interplay between autophagy and membrane trafficking is poorly understood. Using an AI-assisted approach, we identified Rab3GAP-like (Rab3GAPL) as a key membrane trafficking node that controls plant autophagy negatively. Rab3GAPL suppresses autophagy by binding to ATG8, the core autophagy adaptor, and deactivating Rab8a, a small GTPase essential for autophagosome formation and defense-related secretion. Rab3GAPL reduces autophagic flux in three model plant species, suggesting that its negative regulatory role in autophagy is conserved in land plants. Beyond autophagy regulation, Rab3GAPL modulates focal immunity against the oomycete pathogen Phytophthora infestans by preventing defense-related secretion. Altogether, our results suggest that Rab3GAPL acts as a molecular rheostat to coordinate autophagic flux and defense-related secretion by restraining Rab8a-mediated trafficking. This unprecedented interplay between a RabGAP-Rab pair and ATG8 sheds new light on the intricate membrane transport mechanisms underlying plant autophagy and immunity.
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Affiliation(s)
- Enoch Lok Him Yuen
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Alexandre Y Leary
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Marion Clavel
- Gregor Mendel Institute of Molecular Plant Biology, Vienna BioCenter, Dr. Bohr-Gasse, 1030 Vienna, Austria; Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Yasin Tumtas
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Azadeh Mohseni
- Gregor Mendel Institute of Molecular Plant Biology, Vienna BioCenter, Dr. Bohr-Gasse, 1030 Vienna, Austria
| | - Jierui Zhao
- Gregor Mendel Institute of Molecular Plant Biology, Vienna BioCenter, Dr. Bohr-Gasse, 1030 Vienna, Austria
| | - Lorenzo Picchianti
- Gregor Mendel Institute of Molecular Plant Biology, Vienna BioCenter, Dr. Bohr-Gasse, 1030 Vienna, Austria
| | - Mostafa Jamshidiha
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Pooja Pandey
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Cian Duggan
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Ernesto Cota
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Yasin Dagdas
- Gregor Mendel Institute of Molecular Plant Biology, Vienna BioCenter, Dr. Bohr-Gasse, 1030 Vienna, Austria.
| | - Tolga O Bozkurt
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
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5
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Kang Y, Lin W, Nagy PD. Subversion of selective autophagy for the biogenesis of tombusvirus replication organelles inhibits autophagy. PLoS Pathog 2024; 20:e1012085. [PMID: 38484009 DOI: 10.1371/journal.ppat.1012085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 03/26/2024] [Accepted: 02/29/2024] [Indexed: 03/27/2024] Open
Abstract
Elaborate viral replication organelles (VROs) are formed to support positive-strand RNA virus replication in infected cells. VRO formation requires subversion of intracellular membranes by viral replication proteins. Here, we showed that the key ATG8f autophagy protein and NBR1 selective autophagy receptor were co-opted by Tomato bushy stunt virus (TBSV) and the closely-related carnation Italian ringspot virus. Knockdown of ATG8f or NBR1 in plants led to reduced tombusvirus replication, suggesting pro-viral function for selective autophagy. BiFC and proximity-labeling experiments showed that the TBSV p33 replication protein interacted with ATG8f and NBR1 to recruit them to VROs. In addition, we observed that several core autophagy proteins, such as ATG1a, ATG4, ATG5, ATG101 and the plant-specific SH3P2 autophagy adaptor proteins were also re-localized to TBSV VROs, suggesting that TBSV hijacks the autophagy machinery in plant cells. We demonstrated that subversion of autophagy components facilitated the recruitment of VPS34 PI3 kinase and enrichment of phospholipids, such as phosphatidylethanolamine and PI3P phosphoinositide in the VRO membranes. Hijacking of autophagy components into TBSV VROs led to inhibition of autophagic flux. We also found that a fraction of the subverted ATG8f and NBR1 was sequestered in biomolecular condensates associated with VROs. We propose that the VRO-associated condensates trap those autophagy proteins, taking them away from the autophagy pathway. Overall, tombusviruses hijack selective autophagy to provide phospholipid-rich membranes for replication and to regulate the antiviral autophagic flux.
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Affiliation(s)
- Yuanrong Kang
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Wenwu Lin
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Peter D Nagy
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
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6
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Liu M, Sui Y, Yu C, Wang X, Zhang W, Wang B, Yan J, Duan L. Coronatine-Induced Maize Defense against Gibberella Stalk Rot by Activating Antioxidants and Phytohormone Signaling. J Fungi (Basel) 2023; 9:1155. [PMID: 38132756 PMCID: PMC10744721 DOI: 10.3390/jof9121155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/25/2023] [Accepted: 11/25/2023] [Indexed: 12/23/2023] Open
Abstract
One of the most destructive diseases, Gibberella stalk rot (GSR), caused by Fusarium graminearum, reduces maize yields significantly. An induced resistance response is a potent and cost-effective plant defense against pathogen attack. The functional counterpart of JAs, coronatine (COR), has attracted a lot of interest recently due to its ability to control plant growth and stimulate secondary metabolism. Although several studies have focused on COR as a plant immune elicitor to improve plant resistance to pathogens, the effectiveness and underlying mechanisms of the suppressive ability against COR to F. graminearum in maize have been limited. We investigated the potential physiological and molecular mechanisms of COR in modulating maize resistance to F. graminearum. COR treatment strongly enhanced disease resistance and promoted stomatal closure with H2O2 accumulation, and 10 μg/mL was confirmed as the best concentration. COR treatment increased defense-related enzyme activity and decreased the malondialdehyde content with enhanced antioxidant enzyme activity. To identify candidate resistance genes and gain insight into the molecular mechanism of GSR resistance associated with COR, we integrated transcriptomic and metabolomic data to systemically explore the defense mechanisms of COR, and multiple hub genes were pinpointed using weighted gene correlation network analysis (WGCNA). We discovered 6 significant modules containing 10 candidate genes: WRKY transcription factor (LOC100279570), calcium-binding protein (LOC100382070), NBR1-like protein (LOC100275089), amino acid permease (LOC100382244), glutathione S-transferase (LOC541830), HXXXD-type acyl-transferase (LOC100191608), prolin-rich extensin-like receptor protein kinase (LOC100501564), AP2-like ethylene-responsive transcription factor (LOC100384380), basic leucine zipper (LOC100275351), and glycosyltransferase (LOC606486), which are highly correlated with the jasmonic acid-ethylene signaling pathway and antioxidants. In addition, a core set of metabolites, including alpha-linolenic acid metabolism and flavonoids biosynthesis linked to the hub genes, were identified. Taken together, our research revealed differentially expressed key genes and metabolites, as well as co-expression networks, associated with COR treatment of maize stems after F. graminearum infection. In addition, COR-treated maize had higher JA (JA-Ile and Me-JA) levels. We postulated that COR plays a positive role in maize resistance to F. graminearum by regulating antioxidant levels and the JA signaling pathway, and the flavonoid biosynthesis pathway is also involved in the resistance response against GSR.
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Affiliation(s)
- Mei Liu
- Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy, China Agricultural University, Beijing 100193, China
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China, Institute of Plant Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Yiping Sui
- Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy, China Agricultural University, Beijing 100193, China
| | - Chunxin Yu
- Beijing Key Laboratory of New Technology in Agricultural Application, College of Plant Science and Technology, Beijing University of Agriculture, Beijing 102206, China
| | - Xuncheng Wang
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China, Institute of Plant Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Wei Zhang
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China, Institute of Plant Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Baomin Wang
- Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy, China Agricultural University, Beijing 100193, China
| | - Jiye Yan
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China, Institute of Plant Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Liusheng Duan
- Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy, China Agricultural University, Beijing 100193, China
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7
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Boll V, Hermanns T, Uthoff M, Erven I, Hörner EM, Kozjak-Pavlovic V, Baumann U, Hofmann K. Functional and structural diversity in deubiquitinases of the Chlamydia-like bacterium Simkania negevensis. Nat Commun 2023; 14:7335. [PMID: 37957213 PMCID: PMC10643670 DOI: 10.1038/s41467-023-43144-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023] Open
Abstract
Besides the regulation of many cellular pathways, ubiquitination is important for defense against invading pathogens. Some intracellular bacteria have evolved deubiquitinase (DUB) effector proteins, which interfere with the host ubiquitin system and help the pathogen to evade xenophagy and lysosomal degradation. Most intracellular bacteria encode one or two DUBs, which are often linkage-promiscuous or preferentially cleave K63-linked chains attached to bacteria or bacteria-containing vacuoles. By contrast, the respiratory pathogen Legionella pneumophila possesses a much larger number of DUB effectors, including a K6-specific enzyme belonging to the OTU family and an M1-specific DUB uniquely found in this bacterium. Here, we report that the opportunistic pathogen Simkania negevensis, which is unrelated to Legionella but has a similar lifestyle, encodes a similarly large number of DUBs, including M1- and K6-specific enzymes. Simkania DUBs are highly diverse and include DUB classes never before seen in bacteria. Interestingly, the M1- and K6-specific DUBs of Legionella and Simkania are unrelated, suggesting that their acquisition occurred independently. We characterize the DUB activity of eight Simkania-encoded enzymes belonging to five different DUB classes. We also provide a structural basis for the M1-specificity of a Simkania DUB, which most likely evolved from a eukaryotic otubain-like precursor.
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Affiliation(s)
- Vanessa Boll
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Thomas Hermanns
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Matthias Uthoff
- Institute of Biochemistry, University of Cologne, Cologne, Germany
- Bayer AG, Research & Development, Pharmaceuticals, Biologics Research, Wuppertal, Germany
| | - Ilka Erven
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Eva-Maria Hörner
- Chair of Microbiology, Biocenter, Julius Maximilian University, Würzburg, Würzburg, Germany
| | - Vera Kozjak-Pavlovic
- Chair of Microbiology, Biocenter, Julius Maximilian University, Würzburg, Würzburg, Germany
| | - Ulrich Baumann
- Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Kay Hofmann
- Institute for Genetics, University of Cologne, Cologne, Germany.
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8
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Agbemafle W, Wong MM, Bassham DC. Transcriptional and post-translational regulation of plant autophagy. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6006-6022. [PMID: 37358252 PMCID: PMC10575704 DOI: 10.1093/jxb/erad211] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/09/2023] [Indexed: 06/27/2023]
Abstract
In response to changing environmental conditions, plants activate cellular responses to enable them to adapt. One such response is autophagy, in which cellular components, for example proteins and organelles, are delivered to the vacuole for degradation. Autophagy is activated by a wide range of conditions, and the regulatory pathways controlling this activation are now being elucidated. However, key aspects of how these factors may function together to properly modulate autophagy in response to specific internal or external signals are yet to be discovered. In this review we discuss mechanisms for regulation of autophagy in response to environmental stress and disruptions in cell homeostasis. These pathways include post-translational modification of proteins required for autophagy activation and progression, control of protein stability of the autophagy machinery, and transcriptional regulation, resulting in changes in transcription of genes involved in autophagy. In particular, we highlight potential connections between the roles of key regulators and explore gaps in research, the filling of which can further our understanding of the autophagy regulatory network in plants.
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Affiliation(s)
- William Agbemafle
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Min May Wong
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
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9
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Barros JAS, Chatt EC, Augustine RC, McLoughlin F, Li F, Otegui MS, Vierstra RD. Autophagy during maize endosperm development dampens oxidative stress and promotes mitochondrial clearance. PLANT PHYSIOLOGY 2023; 193:1395-1415. [PMID: 37335933 PMCID: PMC10517192 DOI: 10.1093/plphys/kiad340] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 05/10/2023] [Accepted: 05/10/2023] [Indexed: 06/21/2023]
Abstract
The selective turnover of macromolecules by autophagy provides a critical homeostatic mechanism for recycling cellular constituents and for removing superfluous and damaged organelles, membranes, and proteins. To better understand how autophagy impacts seed maturation and nutrient storage, we studied maize (Zea mays) endosperm in its early and middle developmental stages via an integrated multiomic approach using mutants impacting the core macroautophagy factor AUTOPHAGY (ATG)-12 required for autophagosome assembly. Surprisingly, the mutant endosperm in these developmental windows accumulated normal amounts of starch and Zein storage proteins. However, the tissue acquired a substantially altered metabolome, especially for compounds related to oxidative stress and sulfur metabolism, including increases in cystine, dehydroascorbate, cys-glutathione disulfide, glucarate, and galactarate, and decreases in peroxide and the antioxidant glutathione. While changes in the associated transcriptome were mild, the proteome was strongly altered in the atg12 endosperm, especially for increased levels of mitochondrial proteins without a concomitant increase in mRNA abundances. Although fewer mitochondria were seen cytologically, a heightened number appeared dysfunctional based on the accumulation of dilated cristae, consistent with attenuated mitophagy. Collectively, our results confirm that macroautophagy plays a minor role in the accumulation of starch and storage proteins during maize endosperm development but likely helps protect against oxidative stress and clears unneeded/dysfunctional mitochondria during tissue maturation.
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Affiliation(s)
- Jessica A S Barros
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Elizabeth C Chatt
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Robert C Augustine
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Fionn McLoughlin
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Faqiang Li
- Department of Genetics, University of Wisconsin, Madison, WI 53706, USA
| | - Marisa S Otegui
- Department of Botany, University of Wisconsin, Madison, WI 53706, USA
- Center for Quantitative Cell Imaging, University of Wisconsin, Madison, WI 53706, USA
| | - Richard D Vierstra
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
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10
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Bialek W, Collawn JF, Bartoszewski R. Ubiquitin-Dependent and Independent Proteasomal Degradation in Host-Pathogen Interactions. Molecules 2023; 28:6740. [PMID: 37764516 PMCID: PMC10536765 DOI: 10.3390/molecules28186740] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/18/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023] Open
Abstract
Ubiquitin, a small protein, is well known for tagging target proteins through a cascade of enzymatic reactions that lead to protein degradation. The ubiquitin tag, apart from its signaling role, is paramount in destabilizing the modified protein. Here, we explore the complex role of ubiquitin-mediated protein destabilization in the intricate proteolysis process by the 26S proteasome. In addition, the significance of the so-called ubiquitin-independent pathway and the role of the 20S proteasome are considered. Next, we discuss the ubiquitin-proteasome system's interplay with pathogenic microorganisms and how the microorganisms manipulate this system to establish infection by a range of elaborate pathways to evade or counteract host responses. Finally, we focus on the mechanisms that rely either on (i) hijacking the host and on delivering pathogenic E3 ligases and deubiquitinases that promote the degradation of host proteins, or (ii) counteracting host responses through the stabilization of pathogenic effector proteins.
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Affiliation(s)
- Wojciech Bialek
- Department of Biophysics, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - James F. Collawn
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35233, USA;
| | - Rafal Bartoszewski
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35233, USA;
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11
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Roberts CG, Franklin TG, Pruneda JN. Ubiquitin-targeted bacterial effectors: rule breakers of the ubiquitin system. EMBO J 2023; 42:e114318. [PMID: 37555693 PMCID: PMC10505922 DOI: 10.15252/embj.2023114318] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/10/2023] [Accepted: 07/18/2023] [Indexed: 08/10/2023] Open
Abstract
Regulation through post-translational ubiquitin signaling underlies a large portion of eukaryotic biology. This has not gone unnoticed by invading pathogens, many of which have evolved mechanisms to manipulate or subvert the host ubiquitin system. Bacteria are particularly adept at this and rely heavily upon ubiquitin-targeted virulence factors for invasion and replication. Despite lacking a conventional ubiquitin system of their own, many bacterial ubiquitin regulators loosely follow the structural and mechanistic rules established by eukaryotic ubiquitin machinery. Others completely break these rules and have evolved novel structural folds, exhibit distinct mechanisms of regulation, or catalyze foreign ubiquitin modifications. Studying these interactions can not only reveal important aspects of bacterial pathogenesis but also shed light on unexplored areas of ubiquitin signaling and regulation. In this review, we discuss the methods by which bacteria manipulate host ubiquitin and highlight aspects that follow or break the rules of ubiquitination.
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Affiliation(s)
- Cameron G Roberts
- Department of Molecular Microbiology & ImmunologyOregon Health & Science UniversityPortlandORUSA
| | - Tyler G Franklin
- Department of Molecular Microbiology & ImmunologyOregon Health & Science UniversityPortlandORUSA
| | - Jonathan N Pruneda
- Department of Molecular Microbiology & ImmunologyOregon Health & Science UniversityPortlandORUSA
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12
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Yuen ELH, Shepherd S, Bozkurt TO. Traffic Control: Subversion of Plant Membrane Trafficking by Pathogens. ANNUAL REVIEW OF PHYTOPATHOLOGY 2023; 61:325-350. [PMID: 37186899 DOI: 10.1146/annurev-phyto-021622-123232] [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] [Indexed: 05/17/2023]
Abstract
Membrane trafficking pathways play a prominent role in plant immunity. The endomembrane transport system coordinates membrane-bound cellular organelles to ensure that immunological components are utilized effectively during pathogen resistance. Adapted pathogens and pests have evolved to interfere with aspects of membrane transport systems to subvert plant immunity. To do this, they secrete virulence factors known as effectors, many of which converge on host membrane trafficking routes. The emerging paradigm is that effectors redundantly target every step of membrane trafficking from vesicle budding to trafficking and membrane fusion. In this review, we focus on the mechanisms adopted by plant pathogens to reprogram host plant vesicle trafficking, providing examples of effector-targeted transport pathways and highlighting key questions for the field to answer moving forward.
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Affiliation(s)
- Enoch Lok Him Yuen
- Department of Life Sciences, Imperial College, London, United Kingdom; , ,
| | - Samuel Shepherd
- Department of Life Sciences, Imperial College, London, United Kingdom; , ,
| | - Tolga O Bozkurt
- Department of Life Sciences, Imperial College, London, United Kingdom; , ,
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13
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Langin G, González-Fuente M, Üstün S. The Plant Ubiquitin-Proteasome System as a Target for Microbial Manipulation. ANNUAL REVIEW OF PHYTOPATHOLOGY 2023; 61:351-375. [PMID: 37253695 DOI: 10.1146/annurev-phyto-021622-110443] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The plant immune system perceives pathogens to trigger defense responses. In turn, pathogens secrete effector molecules to subvert these defense responses. The initiation and maintenance of defense responses involve not only de novo synthesis of regulatory proteins and enzymes but also their regulated degradation. The latter is achieved through protein degradation pathways such as the ubiquitin-proteasome system (UPS). The UPS regulates all stages of immunity, from the perception of the pathogen to the execution of the response, and, therefore, constitutes an ideal candidate for microbial manipulation of the host. Pathogen effector molecules interfere with the plant UPS through several mechanisms. This includes hijacking general UPS functions or perturbing its ability to degrade specific targets. In this review, we describe how the UPS regulates different immunity-related processes and how pathogens subvert this to promote disease.
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Affiliation(s)
- Gautier Langin
- Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany;
- Faculty of Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | | | - Suayib Üstün
- Faculty of Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
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14
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Shi H, Yang Z, Huang J, Wu H, Fu S, Li W, Zou X, Zhou C, Wang X. An effector of 'Candidatus Liberibacter asiaticus' manipulates autophagy to promote bacterial infection. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:4670-4684. [PMID: 37166404 DOI: 10.1093/jxb/erad176] [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: 11/14/2022] [Accepted: 05/10/2023] [Indexed: 05/12/2023]
Abstract
Autophagy functions in plant host immunity responses to pathogen infection. The molecular mechanisms and functions used by the citrus Huanglongbing (HLB)-associated intracellular bacterium 'Candidatus Liberibacter asiaticus' (CLas) to manipulate autophagy are unknown. We identified a CLas effector, SDE4405 (CLIBASIA_04405), which contributes to HLB progression. 'Wanjincheng' orange (Citrus sinensis) transgenic plants expressing SDE4405 promotes CLas proliferation and symptom expression via suppressing host immunity responses. SDE4405 interacts with the ATG8-family of proteins (ATG8s), and their interactions activate autophagy in Nicotiana benthamiana. The occurrence of autophagy is also significantly enhanced in SDE4405-transgenic citrus plants. Interrupting NbATG8s-SDE4405 interaction by silencing of NbATG8c reduces Pseudomonas syringae pv. tomato strain DC3000ΔhopQ1-1 (Pst DC3000ΔhopQ1-1) proliferation in N. benthamiana, and transient overexpression of CsATG8c and SDE4405 in citrus promotes Xanthomonas citri subsp. citri (Xcc) multiplication, suggesting that SDE4405-ATG8s interaction negatively regulates plant defense. These results demonstrate the role of the CLas effector protein in manipulating autophagy, and provide new molecular insights into the interaction between CLas and citrus hosts.
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Affiliation(s)
- Hongwei Shi
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
| | - Zuhui Yang
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
| | - Jie Huang
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
| | - Haodi Wu
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
| | - Shimin Fu
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
| | - Weimin Li
- Key Laboratory for Northern Urban Agriculture of Ministry of Agriculture and Rural Affairs, Beijing University of Agriculture, Beijing 102206, China
| | - Xiuping Zou
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
| | - Changyong Zhou
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
| | - Xuefeng Wang
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
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15
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Zou J, Chen X, Liu C, Guo M, Kanwar MK, Qi Z, Yang P, Wang G, Bao Y, Bassham DC, Yu J, Zhou J. Autophagy promotes jasmonate-mediated defense against nematodes. Nat Commun 2023; 14:4769. [PMID: 37553319 PMCID: PMC10409745 DOI: 10.1038/s41467-023-40472-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 07/28/2023] [Indexed: 08/10/2023] Open
Abstract
Autophagy, as an intracellular degradation system, plays a critical role in plant immunity. However, the involvement of autophagy in the plant immune system and its function in plant nematode resistance are largely unknown. Here, we show that root-knot nematode (RKN; Meloidogyne incognita) infection induces autophagy in tomato (Solanum lycopersicum) and different atg mutants exhibit high sensitivity to RKNs. The jasmonate (JA) signaling negative regulators JASMONATE-ASSOCIATED MYC2-LIKE 1 (JAM1), JAM2 and JAM3 interact with ATG8s via an ATG8-interacting motif (AIM), and JAM1 is degraded by autophagy during RKN infection. JAM1 impairs the formation of a transcriptional activation complex between ETHYLENE RESPONSE FACTOR 1 (ERF1) and MEDIATOR 25 (MED25) and interferes with transcriptional regulation of JA-mediated defense-related genes by ERF1. Furthermore, ERF1 acts in a positive feedback loop and regulates autophagy activity by transcriptionally activating ATG expression in response to RKN infection. Therefore, autophagy promotes JA-mediated defense against RKNs via forming a positive feedback circuit in the degradation of JAMs and transcriptional activation by ERF1.
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Affiliation(s)
- Jinping Zou
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Yuhangtang Road 866, 310058, Hangzhou, China
| | - Xinlin Chen
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Yuhangtang Road 866, 310058, Hangzhou, China
| | - Chenxu Liu
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Yuhangtang Road 866, 310058, Hangzhou, China
| | - Mingyue Guo
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Yuhangtang Road 866, 310058, Hangzhou, China
| | - Mukesh Kumar Kanwar
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Yuhangtang Road 866, 310058, Hangzhou, China
| | - Zhenyu Qi
- Hainan Institute, Zhejiang University, 572000, Sanya, China
- Agricultural Experiment Station, Zhejiang University, 310058, Hangzhou, China
- Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Ministry of Agriculture and Rural Affairs of China, Yuhangtang Road 866, 310058, Hangzhou, China
| | - Ping Yang
- Agricultural Experiment Station, Zhejiang University, 310058, Hangzhou, China
| | - Guanghui Wang
- Shandong (Linyi) Institute of Modern Agriculture, Zhejiang University, 276000, Linyi, China
| | - Yan Bao
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, 50011, USA
| | - Jingquan Yu
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Yuhangtang Road 866, 310058, Hangzhou, China
- Hainan Institute, Zhejiang University, 572000, Sanya, China
- Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Ministry of Agriculture and Rural Affairs of China, Yuhangtang Road 866, 310058, Hangzhou, China
| | - Jie Zhou
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Yuhangtang Road 866, 310058, Hangzhou, China.
- Hainan Institute, Zhejiang University, 572000, Sanya, China.
- Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Ministry of Agriculture and Rural Affairs of China, Yuhangtang Road 866, 310058, Hangzhou, China.
- Shandong (Linyi) Institute of Modern Agriculture, Zhejiang University, 276000, Linyi, China.
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González-Fuente M. Different battle, same strategy: DNA viruses also block plant autophagy. PLANT PHYSIOLOGY 2023; 192:2591-2592. [PMID: 37141318 PMCID: PMC10400024 DOI: 10.1093/plphys/kiad266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 04/27/2023] [Accepted: 04/27/2023] [Indexed: 05/06/2023]
Affiliation(s)
- Manuel González-Fuente
- Assistant Features Editor, Plant Physiology, American Society of Plant Biologists, USA
- Faculty of Biology & Biotechnology, Ruhr-University Bochum, D-44780 Bochum, Germany
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Ortmann S, Marx J, Lampe C, Handrick V, Ehnert TM, Zinecker S, Reimers M, Bonas U, Erickson JL. A conserved microtubule-binding region in Xanthomonas XopL is indispensable for induced plant cell death reactions. PLoS Pathog 2023; 19:e1011263. [PMID: 37578981 PMCID: PMC10449215 DOI: 10.1371/journal.ppat.1011263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/24/2023] [Accepted: 07/17/2023] [Indexed: 08/16/2023] Open
Abstract
Pathogenic Xanthomonas bacteria cause disease on more than 400 plant species. These Gram-negative bacteria utilize the type III secretion system to inject type III effector proteins (T3Es) directly into the plant cell cytosol where they can manipulate plant pathways to promote virulence. The host range of a given Xanthomonas species is limited, and T3E repertoires are specialized during interactions with specific plant species. Some effectors, however, are retained across most strains, such as Xanthomonas Outer Protein L (XopL). As an 'ancestral' effector, XopL contributes to the virulence of multiple xanthomonads, infecting diverse plant species. XopL homologs harbor a combination of a leucine-rich-repeat (LRR) domain and an XL-box which has E3 ligase activity. Despite similar domain structure there is evidence to suggest that XopL function has diverged, exemplified by the finding that XopLs expressed in plants often display bacterial species-dependent differences in their sub-cellular localization and plant cell death reactions. We found that XopL from X. euvesicatoria (XopLXe) directly associates with plant microtubules (MTs) and causes strong cell death in agroinfection assays in N. benthamiana. Localization of XopLXe homologs from three additional Xanthomonas species, of diverse infection strategy and plant host, revealed that the distantly related X. campestris pv. campestris harbors a XopL (XopLXcc) that fails to localize to MTs and to cause plant cell death. Comparative sequence analyses of MT-binding XopLs and XopLXcc identified a proline-rich-region (PRR)/α-helical region important for MT localization. Functional analyses of XopLXe truncations and amino acid exchanges within the PRR suggest that MT-localized XopL activity is required for plant cell death reactions. This study exemplifies how the study of a T3E within the context of a genus rather than a single species can shed light on how effector localization is linked to biochemical activity.
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Affiliation(s)
- Simon Ortmann
- Department of Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
- Department of Biochemistry of Plant Interactions, Leibniz Institute for Plant Biochemistry, Halle, Germany
| | - Jolina Marx
- Department of Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Christina Lampe
- Department of Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Vinzenz Handrick
- Department of Biochemistry of Plant Interactions, Leibniz Institute for Plant Biochemistry, Halle, Germany
| | - Tim-Martin Ehnert
- Department of Biochemistry of Plant Interactions, Leibniz Institute for Plant Biochemistry, Halle, Germany
| | - Sarah Zinecker
- Department of Plant Physiology, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Matthias Reimers
- Department of Plant Physiology, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Ulla Bonas
- Department of Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Jessica Lee Erickson
- Department of Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
- Department of Biochemistry of Plant Interactions, Leibniz Institute for Plant Biochemistry, Halle, Germany
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18
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Wang H, Chen F, Tang G, Ke W, Wang S, Zheng D, Ruan L. A transcriptional Regulator Gar Regulates the Growth and Virulence of Xanthomonas oryzae pv. oryzae. Curr Microbiol 2023; 80:279. [PMID: 37436661 DOI: 10.1007/s00284-023-03396-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 06/28/2023] [Indexed: 07/13/2023]
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent of bacterial blight, one of the most devastating diseases of rice. Pathogenic bacteria possess numerous transcriptional regulators to participate in the regulation of cellular processes. Here, we identified a transcriptional regulator Gar (PXO_RS11965) that is involved in regulating the growth and virulence of Xoo. Notably, the knockout of gar in Xoo enhanced bacterial virulence to the host rice. RNA-sequencing analysis and quantitative β-glucuronidase (GUS) assay indicated that Gar positively regulates the expression of a σ54 factor rpoN2. Further experiments confirmed that overexpression of rpoN2 restored the phenotypic changes caused by gar deletion. Our research revealed that Gar influences bacterial growth and virulence by positively regulating the expression of rpoN2.
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Affiliation(s)
- Huihui Wang
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Fan Chen
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Guiyu Tang
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wenli Ke
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shasha Wang
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Dehong Zheng
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Agro-environment and Agro-product Safety, College of Agriculture, Guangxi University, Nanning, China
| | - Lifang Ruan
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
- College of Resources & Environment, Tibet Agriculture & Animal Husbandry University, Nyingchi, China.
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19
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Raffeiner M, Zhu S, González-Fuente M, Üstün S. Interplay between autophagy and proteasome during protein turnover. TRENDS IN PLANT SCIENCE 2023; 28:698-714. [PMID: 36801193 DOI: 10.1016/j.tplants.2023.01.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 01/13/2023] [Accepted: 01/26/2023] [Indexed: 05/13/2023]
Abstract
Protein homeostasis is epitomized by an equilibrium between protein biosynthesis and degradation: the 'life and death' of proteins. Approximately one-third of newly synthesized proteins are degraded. As such, protein turnover is required to maintain cellular integrity and survival. Autophagy and the ubiquitin-proteasome system (UPS) are the two principal degradation pathways in eukaryotes. Both pathways orchestrate many cellular processes during development and upon environmental stimuli. Ubiquitination of degradation targets is used as a 'death' signal by both processes. Recent findings revealed a direct functional link between both pathways. Here, we summarize key findings in the field of protein homeostasis, with an emphasis on the newly revealed crosstalk between both degradation machineries and how it is decided which pathway facilitates target degradation.
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Affiliation(s)
- Margot Raffeiner
- Eberhard-Karls-Universität Tübingen, Zentrum für Molekular Biologie der Pflanzen, 72076 Tübingen, Germany; Faculty of Biology & Biotechnology, Ruhr-University of Bochum, 44780 Bochum, Germany
| | - Shanshuo Zhu
- Eberhard-Karls-Universität Tübingen, Zentrum für Molekular Biologie der Pflanzen, 72076 Tübingen, Germany; Faculty of Biology & Biotechnology, Ruhr-University of Bochum, 44780 Bochum, Germany
| | - Manuel González-Fuente
- Eberhard-Karls-Universität Tübingen, Zentrum für Molekular Biologie der Pflanzen, 72076 Tübingen, Germany; Faculty of Biology & Biotechnology, Ruhr-University of Bochum, 44780 Bochum, Germany
| | - Suayib Üstün
- Eberhard-Karls-Universität Tübingen, Zentrum für Molekular Biologie der Pflanzen, 72076 Tübingen, Germany; Faculty of Biology & Biotechnology, Ruhr-University of Bochum, 44780 Bochum, Germany.
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20
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Wang Z, Li T, Zhang X, Feng J, Liu Z, Shan W, Joosten MHAJ, Govers F, Du Y. A Phytophthora infestans RXLR effector targets a potato ubiquitin-like domain-containing protein to inhibit the proteasome activity and hamper plant immunity. THE NEW PHYTOLOGIST 2023; 238:781-797. [PMID: 36653957 DOI: 10.1111/nph.18749] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/12/2023] [Indexed: 06/17/2023]
Abstract
Ubiquitin-like domain-containing proteins (UDPs) are involved in the ubiquitin-proteasome system because of their ability to interact with the 26S proteasome. Here, we identified potato StUDP as a target of the Phytophthora infestans RXLR effector Pi06432 (PITG_06432), which supresses the salicylic acid (SA)-related immune pathway. By overexpressing and silencing of StUDP in potato, we show that StUDP negatively regulates plant immunity against P. infestans. StUDP interacts with, and destabilizes, the 26S proteasome subunit that is referred to as REGULATORY PARTICLE TRIPLE-A ATP-ASE (RPT) subunit StRPT3b. This destabilization represses the proteasome activity. Proteomic analysis and Western blotting show that StUDP decreases the stability of the master transcription factor SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1) in SA biosynthesis. StUDP negatively regulates the SA signalling pathway by repressing the proteasome activity and destabilizing StSARD1, leading to a decreased expression of the SARD1-targeted gene ISOCHORISMATE SYNTHASE 1 and thereby a decrease in SA content. Pi06432 stabilizes StUDP, and it depends on StUDP to destabilize StRPT3b and thereby supress the proteasome activity. Our study reveals that the P. infestans effector Pi06432 targets StUDP to hamper the homeostasis of the proteasome by the degradation of the proteasome subunit StRPT3b and thereby suppresses SA-related immunity.
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Affiliation(s)
- Ziwei Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Tingting Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Shaanxi Engineering Research Center for Vegetables, Yangling, Shaanxi, 712100, China
| | - Xiaojiang Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Jiashu Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Zhuting Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Weixing Shan
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Matthieu H A J Joosten
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Francine Govers
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Yu Du
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Shaanxi Engineering Research Center for Vegetables, Yangling, Shaanxi, 712100, China
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Jeon H, Segonzac C. Manipulation of the Host Endomembrane System by Bacterial Effectors. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:208-217. [PMID: 36645655 DOI: 10.1094/mpmi-09-22-0190-fi] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The endomembrane system, extending from the nuclear envelope to the plasma membrane, is critical to the plant response to pathogen infection. Synthesis and transport of immunity-related proteins and antimicrobial compounds to and from the plasma membrane are supported by conventional and unconventional processes of secretion and internalization of vesicles, guided by the cytoskeleton networks. Although plant bacterial pathogens reside mostly in the apoplast, major structural and functional modifications of the endomembrane system in the host cell occur during bacterial infection. Here, we review the dynamics of these cellular compartments, briefly, for their essential contributions to the plant defense responses and, in parallel, for their emerging roles in bacterial pathogenicity. We further focus on Pseudomonas syringae, Xanthomonas spp., and Ralstonia solanacearum type III secreted effectors that one or both localize to and associate with components of the host endomembrane system or the cytoskeleton network to highlight the diversity of virulence strategies deployed by bacterial pathogens beyond the inhibition of the secretory pathway. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Hyelim Jeon
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Republic of Korea
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Republic of Korea
| | - Cécile Segonzac
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Republic of Korea
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Republic of Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Republic of Korea
- Agricultural and Life Science Research Institute, Seoul National University, Seoul, 08826, Republic of Korea
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22
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Li J, Qi L, Diao Z, Zhang M, Li B, Zhai Y, Hao M, Zhou D, Liu W, Jin Y, Wang A. Brucella BtpB Manipulates Apoptosis and Autophagic Flux in RAW264.7 Cells. Int J Mol Sci 2022; 23:ijms232214439. [PMID: 36430916 PMCID: PMC9693124 DOI: 10.3390/ijms232214439] [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: 09/12/2022] [Revised: 11/02/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022] Open
Abstract
Brucella transfers effectors into host cells, manipulating cellular processes to its advantage; however, the mechanism by which effectors regulate cellular processes during infection is poorly understood. A growing number of studies have shown that apoptosis and autophagy are critical mechanisms for target cells to cope with pathogens and maintain cellular homeostasis. BtpB is a Brucella type IV secretion system effector with a complex mechanism for manipulating host infection. Here, we show that the ectopic expression of BtpB promoted DNA fragmentation. In contrast, an isogenic mutant strain, ΔbtpB, inhibited apoptosis compared to the wild-type strain B. suis S2 in RAW264.7 cells. In addition, BtpB inhibited autophagy, as determined by LC3-II protein levels, the number of LC3 puncta, and p62 degradation. We also found that BtpB reduced autophagolysosome formation and blocked the complete autophagic flux. Moreover, our results revealed that the autophagy inhibitor, chloroquine, reduces Brucella's intracellular survival. Overall, our data unveil new mechanisms of virulence implicating the effector BtpB in regulating host intracellular infection.
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Affiliation(s)
- Junmei Li
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
| | - Lin Qi
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
| | - Ziyang Diao
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
| | - Mengyu Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
| | - Bin Li
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
| | - Yunyi Zhai
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
| | - Mingyue Hao
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
| | - Dong Zhou
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
| | - Wei Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
| | - Yaping Jin
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
| | - Aihua Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling District, Xianyang 712100, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling District, Xianyang 712100, China
- Correspondence: or
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Rasmussen NL, Kournoutis A, Lamark T, Johansen T. NBR1: The archetypal selective autophagy receptor. J Cell Biol 2022; 221:213552. [PMID: 36255390 PMCID: PMC9582228 DOI: 10.1083/jcb.202208092] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/03/2022] [Accepted: 10/03/2022] [Indexed: 11/24/2022] Open
Abstract
NBR1 was discovered as an autophagy receptor not long after the first described vertebrate autophagy receptor p62/SQSTM1. Since then, p62 has currently been mentioned in >10,000 papers on PubMed, while NBR1 is mentioned in <350 papers. Nonetheless, evolutionary analysis reveals that NBR1, and likely also selective autophagy, was present already in the last eukaryotic common ancestor (LECA), while p62 appears first in the early Metazoan lineage. Furthermore, yeast-selective autophagy receptors Atg19 and Atg34 represent NBR1 homologs. NBR1 is the main autophagy receptor in plants that do not contain p62, while most animal taxa contain both NBR1 and p62. Mechanistic studies are starting to shed light on the collaboration between mammalian NBR1 and p62 in the autophagic degradation of protein aggregates (aggrephagy). Several domains of NBR1 are involved in cargo recognition, and the list of known substrates for NBR1-mediated selective autophagy is increasing. Lastly, roles of NBR1 in human diseases such as proteinopathies and cancer are emerging.
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Affiliation(s)
- Nikoline Lander Rasmussen
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Athanasios Kournoutis
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Trond Lamark
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Terje Johansen
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
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24
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Autophagy in the Lifetime of Plants: From Seed to Seed. Int J Mol Sci 2022; 23:ijms231911410. [PMID: 36232711 PMCID: PMC9570326 DOI: 10.3390/ijms231911410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 11/16/2022] Open
Abstract
Autophagy is a highly conserved self-degradation mechanism in eukaryotes. Excess or harmful intracellular content can be encapsulated by double-membrane autophagic vacuoles and transferred to vacuoles for degradation in plants. Current research shows three types of autophagy in plants, with macroautophagy being the most important autophagic degradation pathway. Until now, more than 40 autophagy-related (ATG) proteins have been identified in plants that are involved in macroautophagy, and these proteins play an important role in plant growth regulation and stress responses. In this review, we mainly introduce the research progress of autophagy in plant vegetative growth (roots and leaves), reproductive growth (pollen), and resistance to biotic (viruses, bacteria, and fungi) and abiotic stresses (nutrients, drought, salt, cold, and heat stress), and we discuss the application direction of plant autophagy in the future.
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25
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Lebecq A, Doumane M, Fangain A, Bayle V, Leong JX, Rozier F, Marques-Bueno MD, Armengot L, Boisseau R, Simon ML, Franz-Wachtel M, Macek B, Üstün S, Jaillais Y, Caillaud MC. The Arabidopsis SAC9 enzyme is enriched in a cortical population of early endosomes and restricts PI(4,5)P 2 at the plasma membrane. eLife 2022; 11:73837. [PMID: 36044021 PMCID: PMC9436410 DOI: 10.7554/elife.73837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 07/09/2022] [Indexed: 01/10/2023] Open
Abstract
Membrane lipids, and especially phosphoinositides, are differentially enriched within the eukaryotic endomembrane system. This generates a landmark code by modulating the properties of each membrane. Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] specifically accumulates at the plasma membrane in yeast, animal, and plant cells, where it regulates a wide range of cellular processes including endocytic trafficking. However, the functional consequences of mispatterning PI(4,5)P2 in plants are unknown. Here, we functionally characterized the putative phosphoinositide phosphatase SUPPRESSOR OF ACTIN9 (SAC9) in Arabidopsis thaliana (Arabidopsis). We found that SAC9 depletion led to the ectopic localization of PI(4,5)P2 on cortical intracellular compartments, which depends on PI4P and PI(4,5)P2 production at the plasma membrane. SAC9 localizes to a subpopulation of trans-Golgi Network/early endosomes that are enriched in a region close to the cell cortex and that are coated with clathrin. Furthermore, it interacts and colocalizes with Src Homology 3 Domain Protein 2 (SH3P2), a protein involved in endocytic trafficking. In the absence of SAC9, SH3P2 localization is altered and the clathrin-mediated endocytosis rate is reduced. Together, our results highlight the importance of restricting PI(4,5)P2 at the plasma membrane and illustrate that one of the consequences of PI(4,5)P2 misspatterning in plants is to impact the endocytic trafficking.
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Affiliation(s)
- Alexis Lebecq
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Mehdi Doumane
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Aurelie Fangain
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Vincent Bayle
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Jia Xuan Leong
- University of Tübingen, Center for Plant Molecular Biology (ZMBP), Tübingen, Germany
| | - Frédérique Rozier
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | | | - Laia Armengot
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Romain Boisseau
- Division of Biological Science, University of Montana, Missoula, United States
| | | | - Mirita Franz-Wachtel
- Interfaculty Institute for Cell Biology, Department of Quantitative Proteomics, University of Tübingen, Tübingen, Germany
| | - Boris Macek
- Interfaculty Institute for Cell Biology, Department of Quantitative Proteomics, University of Tübingen, Tübingen, Germany
| | - Suayib Üstün
- University of Tübingen, Center for Plant Molecular Biology (ZMBP), Tübingen, Germany.,Faculty of Biology & Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | - Yvon Jaillais
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Marie-Cécile Caillaud
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
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26
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Plant proteostasis: a proven and promising target for crop improvement. Essays Biochem 2022; 66:75-85. [PMID: 35929615 DOI: 10.1042/ebc20210078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/02/2022] [Accepted: 08/02/2022] [Indexed: 11/17/2022]
Abstract
The Green Revolution of the 1960s accomplished dramatic increases in crop yields through genetic improvement, chemical fertilisers, irrigation, and mechanisation. However, the current trajectory of population growth, against a backdrop of climate change and geopolitical unrest, predicts that agricultural production will be insufficient to ensure global food security in the next three decades. Improvements to crops that go beyond incremental gains are urgently needed. Plant biology has also undergone a revolution in recent years, through the development and application of powerful technologies including genome sequencing, a pantheon of 'omics techniques, precise genome editing, and step changes in structural biology and microscopy. Proteostasis - the collective processes that control the protein complement of the cell, comprising synthesis, modification, localisation, and degradation - is a field that has benefitted from these advances. This special issue presents a selection of the latest research in this vibrant field, with a particular focus on protein degradation. In the current article, we highlight the diverse and widespread contributions of plant proteostasis to agronomic traits, suggest opportunities and strategies to manipulate different elements of proteostatic mechanisms for crop improvement, and discuss the challenges involved in bringing these ideas into practice.
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27
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Bullones-Bolaños A, Bernal-Bayard J, Ramos-Morales F. The NEL Family of Bacterial E3 Ubiquitin Ligases. Int J Mol Sci 2022; 23:7725. [PMID: 35887072 PMCID: PMC9320238 DOI: 10.3390/ijms23147725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 12/16/2022] Open
Abstract
Some pathogenic or symbiotic Gram-negative bacteria can manipulate the ubiquitination system of the eukaryotic host cell using a variety of strategies. Members of the genera Salmonella, Shigella, Sinorhizobium, and Ralstonia, among others, express E3 ubiquitin ligases that belong to the NEL family. These bacteria use type III secretion systems to translocate these proteins into host cells, where they will find their targets. In this review, we first introduce type III secretion systems and the ubiquitination process and consider the various ways bacteria use to alter the ubiquitin ligation machinery. We then focus on the members of the NEL family, their expression, translocation, and subcellular localization in the host cell, and we review what is known about the structure of these proteins, their function in virulence or symbiosis, and their specific targets.
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Affiliation(s)
| | | | - Francisco Ramos-Morales
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain; (A.B.-B.); (J.B.-B.)
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28
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Degradation Mechanism of Autophagy-Related Proteins and Research Progress. Int J Mol Sci 2022; 23:ijms23137301. [PMID: 35806307 PMCID: PMC9266641 DOI: 10.3390/ijms23137301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 12/21/2022] Open
Abstract
In all eukaryotes, autophagy is the main pathway for nutrient recycling, which encapsulates parts of the cytoplasm and organelles in double-membrane vesicles, and then fuses with lysosomes/vacuoles to degrade them. Autophagy is a highly dynamic and relatively complex process influenced by multiple factors. Under normal growth conditions, it is maintained at basal levels. However, when plants are subjected to biotic and abiotic stresses, such as pathogens, drought, waterlogging, nutrient deficiencies, etc., autophagy is activated to help cells to survive under stress conditions. At present, the regulation of autophagy is mainly reflected in hormones, second messengers, post-transcriptional regulation, and protein post-translational modification. In recent years, the degradation mechanism of autophagy-related proteins has attracted much attention. In this review, we have summarized how autophagy-related proteins are degraded in yeast, animals, and plants, which will help us to have a more comprehensive and systematic understanding of the regulation mechanisms of autophagy. Moreover, research progress on the degradation of autophagy-related proteins in plants has been discussed.
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