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Li D. Structure and Function of the Glycosylphosphatidylinositol Transamidase, a Transmembrane Complex Catalyzing GPI Anchoring of Proteins. Subcell Biochem 2024; 104:425-458. [PMID: 38963495 DOI: 10.1007/978-3-031-58843-3_16] [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] [Indexed: 07/05/2024]
Abstract
Glycosylphosphatidylinositol (GPI) anchoring of proteins is a ubiquitous posttranslational modification in eukaryotic cells. GPI-anchored proteins (GPI-APs) play critical roles in enzymatic, signaling, regulatory, and adhesion processes. Over 20 enzymes are involved in GPI synthesis, attachment to client proteins, and remodeling after attachment. The GPI transamidase (GPI-T), a large complex located in the endoplasmic reticulum membrane, catalyzes the attachment step by replacing a C-terminal signal peptide of proproteins with GPI. In the last three decades, extensive research has been conducted on the mechanism of the transamidation reaction, the components of the GPI-T complex, the role of each subunit, and the substrate specificity. Two recent studies have reported the three-dimensional architecture of GPI-T, which represent the first structures of the pathway. The structures provide detailed mechanisms for assembly that rationalizes previous biochemical results and subunit-dependent stability data. While the structural data confirm the catalytic role of PIGK, which likely uses a caspase-like mechanism to cleave the proproteins, they suggest that unlike previously proposed, GPAA1 is not a catalytic subunit. The structures also reveal a shared cavity for GPI binding. Somewhat unexpectedly, PIGT, a single-pass membrane protein, plays a crucial role in GPI recognition. Consistent with the assembly mechanisms and the active site architecture, most of the disease mutations occur near the active site or the subunit interfaces. Finally, the catalytic dyad is located ~22 Å away from the membrane interface of the GPI-binding site, and this architecture may confer substrate specificity through topological matching between the substrates and the elongated active site. The research conducted thus far sheds light on the intricate processes involved in GPI anchoring and paves the way for further mechanistic studies of GPI-T.
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Affiliation(s)
- Dianfan Li
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences (CAS), Shanghai, China.
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2
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Zaman S, Shen J, Wang S, Song D, Wang H, Ding S, Pang X, Wang M, Wang Y, Ding Z. Effect of Shading on Physiological Attributes and Proteomic Analysis of Tea during Low Temperatures. PLANTS (BASEL, SWITZERLAND) 2023; 13:63. [PMID: 38202371 PMCID: PMC10780538 DOI: 10.3390/plants13010063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 12/21/2023] [Accepted: 12/22/2023] [Indexed: 01/12/2024]
Abstract
Shading is an important technique to protect tea plantations under abiotic stresses. In this study, we analyzed the effect of shading (SD60% shade vs. SD0% no-shade) on the physiological attributes and proteomic analysis of tea leaves in November and December during low temperatures. The results revealed that shading protected the tea plants, including their soil plant analysis development (SPAD), photochemical efficiency (Fv/Fm), and nitrogen content (N), in November and December. The proteomics analysis of tea leaves was determined using tandem mass tags (TMT) technology and a total of 7263 proteins were accumulated. Further, statistical analysis and the fold change of significant proteins (FC < 0.67 and FC > 1.5 p < 0.05) revealed 14 DAPs, 11 increased and 3 decreased, in November (nCK_vs_nSD60), 20 DAPs, 7 increased and 13 decreased, in December (dCK_vs_dSD60), and 12 DAPs, 3 increased and 9 decreased, in both November and December (nCK_vs_nSD60). These differentially accumulated proteins (DAPs) were dehydrins (DHNs), late-embryogenesis abundant (LEA), thaumatin-like proteins (TLPs), glutathione S-transferase (GSTs), gibberellin-regulated proteins (GAs), proline-rich proteins (PRPs), cold and drought proteins (CORA-like), and early light-induced protein 1, which were found in the cytoplasm, nucleus, chloroplast, extra cell, and plasma membrane, and functioned in catalytic, cellular, stimulus-response, and metabolic pathways. In conclusion, the proliferation of key proteins was triggered by translation and posttranslational modifications, which might sustain membrane permeability in tea cellular compartments and could be responsible for tea protection under shading during low temperatures. This study aimed to investigate the impact of the conventional breeding technique (shading) and modern molecular technologies (proteomics) on tea plants, for the development and protection of new tea cultivars.
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Affiliation(s)
- Shah Zaman
- Tea Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China; (S.Z.); (J.S.); (S.W.)
- School of Tea and Coffee & School of Bioinformatics and Engineering, Pu’er University, 6 Xueyuan Road, Pu’er 665000, China
- International Joint Laboratory of Digital Protection and Germplasm Innovation and Application of China-Laos Tea Tree Resources in Yunnan Province, Pu’er University, 6 Xueyuan Road, Pu’er 665000, China
| | - Jiazhi Shen
- Tea Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China; (S.Z.); (J.S.); (S.W.)
| | - Shuangshuang Wang
- Tea Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China; (S.Z.); (J.S.); (S.W.)
| | - Dapeng Song
- Rizhao Tea Research Institute, Rizhao 276800, China; (D.S.); (H.W.); (S.D.); (X.P.); (M.W.)
| | - Hui Wang
- Rizhao Tea Research Institute, Rizhao 276800, China; (D.S.); (H.W.); (S.D.); (X.P.); (M.W.)
| | - Shibo Ding
- Rizhao Tea Research Institute, Rizhao 276800, China; (D.S.); (H.W.); (S.D.); (X.P.); (M.W.)
| | - Xu Pang
- Rizhao Tea Research Institute, Rizhao 276800, China; (D.S.); (H.W.); (S.D.); (X.P.); (M.W.)
| | - Mengqi Wang
- Rizhao Tea Research Institute, Rizhao 276800, China; (D.S.); (H.W.); (S.D.); (X.P.); (M.W.)
| | - Yu Wang
- Tea Research Institute, Qingdao Agricultural University, Qingdao 266109, China;
| | - Zhaotang Ding
- Tea Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China; (S.Z.); (J.S.); (S.W.)
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3
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Nagasato D, Sugita Y, Tsuno Y, Tanaka R, Fukuda M, Matsuoka K. Glycosylphosphatidylinositol-anchoring is required for the proper transport and extensive glycosylation of a classical arabinogalactan protein precursor in tobacco BY-2 cells. Biosci Biotechnol Biochem 2023; 87:991-1008. [PMID: 37348475 DOI: 10.1093/bbb/zbad081] [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: 03/31/2023] [Accepted: 06/13/2023] [Indexed: 06/24/2023]
Abstract
Many precursors of plant arabinogalactan proteins (AGPs) contain a C-terminal glycosylphosphatidylinositol (GPI)-anchoring signal. Using NtAGP1, a classical tobacco AGP, as a model, and green fluorescent protein (GFP) and sweet potato sporamin (SPO) as tags, we analyzed the localization and modification of AGP and its mutant without GPI-anchoring signal (AGPΔC) in tobacco BY-2 cells. The NtAGP1 fusion proteins migrated as large smear on SDS-polyacrylamide gel, and these proteins also localized preferentially to the plasma membrane. In contrast, fusions of AGPΔC with GFP and SPO yielded several forms: The largest were secreted, whereas others were recovered in the endomembrane organelles, including vacuoles. Comparison of the glycan structures of the microsomal SPO-AGP and the secreted SPO-AGPΔC using antibodies against the glycan epitopes of AGP indicated that the glycan structures of these proteins are different. These observations indicate that GPI-anchoring is required for the proper transport and glycosylation of the AGP precursor.
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Affiliation(s)
- Daiki Nagasato
- Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka, Japan
| | - Yuto Sugita
- Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka, Japan
| | - Yuhei Tsuno
- Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka, Japan
| | | | - Maki Fukuda
- School of Agriculture, Kyushu University, Fukuoka, Japan
| | - Ken Matsuoka
- Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka, Japan
- School of Agriculture, Kyushu University, Fukuoka, Japan
- Faculty of Agriculture, Kyushu University, Fukuoka, Japan
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Nolasco DM, Mendes MPR, Marciano LPDA, Costa LF, Macedo AND, Sakakibara IM, Silvério ACP, Paiva MJN, André LC. An Exploratory Study of the Metabolite Profiling from Pesticides Exposed Workers. Metabolites 2023; 13:metabo13050596. [PMID: 37233637 DOI: 10.3390/metabo13050596] [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: 02/18/2023] [Revised: 03/10/2023] [Accepted: 03/15/2023] [Indexed: 05/27/2023] Open
Abstract
Pesticides constitute a category of chemical products intended specifically for the control and mitigation of pests. With their constant increase in use, the risk to human health and the environment has increased proportionally due to occupational and environmental exposure to these compounds. The use of these chemicals is associated with several toxic effects related to acute and chronic toxicity, such as infertility, hormonal disorders and cancer. The present work aimed to study the metabolic profile of individuals occupationally exposed to pesticides, using a metabolomics tool to identify potential new biomarkers. Metabolomics analysis was carried out on plasma and urine samples from individuals exposed and non-exposed occupationally, using liquid chromatography coupled with mass spectrometry (UPLC-MS). Non-targeted metabolomics analysis, using principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) or partial least squares discriminant orthogonal analysis (OPLS-DA), demonstrated good separation of the samples and identified 21 discriminating metabolites in plasma and 17 in urine. The analysis of the ROC curve indicated the compounds with the greatest potential for biomarkers. Comprehensive analysis of the metabolic pathways influenced by exposure to pesticides revealed alterations, mainly in lipid and amino acid metabolism. This study indicates that the use of metabolomics provides important information about complex biological responses.
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Affiliation(s)
- Daniela Magalhães Nolasco
- Department of Clinical and Toxicological Analysis, Faculty of Pharmacy, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, MG, Brazil
| | - Michele P R Mendes
- Department of Clinical and Toxicological Analysis, Faculty of Pharmacy, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, MG, Brazil
| | - Luiz Paulo de Aguiar Marciano
- Toxicants and Drugs Analysis Laboratory, Faculty of Pharmacy, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, MG, Brazil
| | - Luiz Filipe Costa
- Toxicants and Drugs Analysis Laboratory, Faculty of Pharmacy, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, MG, Brazil
| | - Adriana Nori De Macedo
- Chemistry Department, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, MG, Brazil
| | - Isarita Martins Sakakibara
- Toxicants and Drugs Analysis Laboratory, Faculty of Pharmacy, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, MG, Brazil
| | | | - Maria José N Paiva
- Department of Clinical and Toxicological Analysis, Faculty of Pharmacy, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, MG, Brazil
| | - Leiliane C André
- Department of Clinical and Toxicological Analysis, Faculty of Pharmacy, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, MG, Brazil
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Moreira D, Kaur D, Pereira AM, Held MA, Showalter AM, Coimbra S. Type II arabinogalactans initiated by hydroxyproline-O-galactosyltransferases play important roles in pollen-pistil interactions. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:371-389. [PMID: 36775989 DOI: 10.1111/tpj.16141] [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: 08/10/2022] [Accepted: 02/01/2023] [Indexed: 05/10/2023]
Abstract
Arabinogalactan-proteins (AGPs) are hydroxyproline-rich glycoproteins containing a high sugar content and are widely distributed in the plant kingdom. AGPs have long been suggested to play important roles in sexual plant reproduction. The synthesis of their complex carbohydrates is initiated by a family of hydroxyproline galactosyltransferase (Hyp-GALT) enzymes which add the first galactose to Hyp residues in the protein backbone. Eight Hyp-GALT enzymes have been identified so far, and in the present work a mutant affecting five of these enzymes (galt2galt5galt7galt8galt9) was analyzed regarding the reproductive process. The galt25789 mutant presented a low seed set, and reciprocal crosses indicated a significant female gametophytic contribution to this mutant phenotype. Mutant ovules revealed abnormal callose accumulation inside the embryo sac and integument defects at the micropylar region culminating in defects in pollen tube reception. In addition, immunolocalization and biochemical analyses allowed the detection of a reduction in the amount of glucuronic acid in mutant ovary AGPs. Dramatically low amounts of high-molecular-weight Hyp-O-glycosides obtained following size exclusion chromatography of base-hydrolyzed mutant AGPs compared to the wild type indicated the presence of underglycosylated AGPs in the galt25789 mutant, while the monosaccharide composition of these Hyp-O-glycosides displayed no significant changes compared to the wild-type Hyp-O-glycosides. The present work demonstrates the functional importance of the carbohydrate moieties of AGPs in ovule development and pollen-pistil interactions.
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Affiliation(s)
- Diana Moreira
- LAQV/REQUIMTE, Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal
| | - Dasmeet Kaur
- Department of Environmental & Plant Biology, Ohio University, Athens, Ohio, 45701-2979, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, Ohio, 45701, USA
| | - Ana Marta Pereira
- LAQV/REQUIMTE, Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal
| | - Michael A Held
- Molecular and Cellular Biology Program, Ohio University, Athens, Ohio, 45701, USA
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio, 45701, USA
| | - Allan M Showalter
- Department of Environmental & Plant Biology, Ohio University, Athens, Ohio, 45701-2979, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, Ohio, 45701, USA
| | - Sílvia Coimbra
- LAQV/REQUIMTE, Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal
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Moreira D, Lopes AL, Silva J, Ferreira MJ, Pinto SC, Mendes S, Pereira LG, Coimbra S, Pereira AM. New insights on the expression patterns of specific Arabinogalactan proteins in reproductive tissues of Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2022; 13:1083098. [PMID: 36531351 PMCID: PMC9755587 DOI: 10.3389/fpls.2022.1083098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 11/17/2022] [Indexed: 05/25/2023]
Abstract
Arabinogalactan proteins (AGPs) are hydroxyproline-rich glycoproteins containing a high proportion of carbohydrates, widely distributed in the plant kingdom and ubiquitously present in land plants. AGPs have long been suggested to play important roles in plant reproduction and there is already evidence that specific glycoproteins are essential for male and female gametophyte development, pollen tube growth and guidance, and successful fertilization. However, the functions of many of these proteins have yet to be uncovered, mainly due to the difficulty to study individual AGPs. In this work, we generated molecular tools to analyze the expression patterns of a subgroup of individual AGPs in different Arabidopsis tissues, focusing on reproductive processes. This study focused on six AGPs: four classical AGPs (AGP7, AGP25, AGP26, AGP27), one AG peptide (AGP24) and one chimeric AGP (AGP31). These AGPs were first selected based on their predicted expression patterns along the reproductive tissues from available RNA-seq data. Promoter analysis using β-glucuronidase fusions and qPCR in different Arabidopsis tissues allowed to confirm these predictions. AGP7 was mainly expressed in female reproductive tissues, more precisely in the style, funiculus, and integuments near the micropyle region. AGP25 was found to be expressed in the style, septum and ovules with higher expression in the chalaza and funiculus tissues. AGP26 was present in the ovules and pistil valves. AGP27 was expressed in the transmitting tissue, septum and funiculus during seed development. AGP24 was expressed in pollen grains, in mature embryo sacs, with highest expression at the chalazal pole and in the micropyle. AGP31 was expressed in the mature embryo sac with highest expression at the chalaza and, occasionally, in the micropyle. For all these AGPs a co-expression analysis was performed providing new hints on its possible functions. This work confirmed the detection in Arabidopsis male and female tissues of six AGPs never studied before regarding the reproductive process. These results provide novel evidence on the possible involvement of specific AGPs in plant reproduction, as strong candidates to participate in pollen-pistil interactions in an active way, which is significant for this field of study.
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Affiliation(s)
- Diana Moreira
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Laboratório Associado para a Química Verde (LAQV) Requimte, Sustainable Chemistry, University of Porto, Porto, Portugal
| | - Ana Lúcia Lopes
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Biosystems and Integrative Sciences Institute – BioISI, Porto, Portugal
| | - Jessy Silva
- Laboratório Associado para a Química Verde (LAQV) Requimte, Sustainable Chemistry, University of Porto, Porto, Portugal
- Department of Biology, University of Minho, Campus de Gualtar, Braga, Portugal
| | - Maria João Ferreira
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Laboratório Associado para a Química Verde (LAQV) Requimte, Sustainable Chemistry, University of Porto, Porto, Portugal
| | - Sara Cristina Pinto
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Laboratório Associado para a Química Verde (LAQV) Requimte, Sustainable Chemistry, University of Porto, Porto, Portugal
| | - Sara Mendes
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Laboratório Associado para a Química Verde (LAQV) Requimte, Sustainable Chemistry, University of Porto, Porto, Portugal
| | - Luís Gustavo Pereira
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- GreenUPorto - Sustainable Agrifood Production Research Centre, Universidade do Porto, Porto, Portugal
| | - Sílvia Coimbra
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Laboratório Associado para a Química Verde (LAQV) Requimte, Sustainable Chemistry, University of Porto, Porto, Portugal
| | - Ana Marta Pereira
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Laboratório Associado para a Química Verde (LAQV) Requimte, Sustainable Chemistry, University of Porto, Porto, Portugal
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Zhou K. The regulation of the cell wall by glycosylphosphatidylinositol-anchored proteins in Arabidopsis. Front Cell Dev Biol 2022; 10:904714. [PMID: 36036018 PMCID: PMC9412048 DOI: 10.3389/fcell.2022.904714] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 07/04/2022] [Indexed: 12/04/2022] Open
Abstract
A polysaccharides-based cell wall covers the plant cell, shaping it and protecting it from the harsh environment. Cellulose microfibrils constitute the cell wall backbone and are embedded in a matrix of pectic and hemicellulosic polysaccharides and glycoproteins. Various environmental and developmental cues can regulate the plant cell wall, and diverse glycosylphosphatidylinositol (GPI)-anchored proteins participate in these regulations. GPI is a common lipid modification on eukaryotic proteins, which covalently tethers the proteins to the membrane lipid bilayer. Catalyzed by a series of enzymic complexes, protein precursors are post-translationally modified at their hydrophobic carboxyl-terminus in the endomembrane system and anchored to the lipid bilayer through an oligosaccharidic GPI modification. Ultimately, mature proteins reach the plasma membrane via the secretory pathway facing toward the apoplast and cell wall in plants. In Arabidopsis, more than three hundred GPI-anchored proteins (GPI-APs) have been predicted, and many are reported to be involved in diverse regulations of the cell wall. In this review, we summarize GPI-APs involved in cell wall regulation. GPI-APs are proposed to act as structural components of the cell wall, organize cellulose microfibrils at the cell surface, and during cell wall integrity signaling transduction. Besides regulating protein trafficking, the GPI modification is potentially governed by a GPI shedding system that cleaves and releases the GPI-anchored proteins from the plasma membrane into the cell wall.
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Transcriptome-Guided Identification of Pectin Methyl-Esterase-Related Enzymes and Novel Molecular Processes Effectuating the Hard-to-Cook Defect in Common Bean ( Phaseolus vulgaris L.). Foods 2022; 11:foods11121692. [PMID: 35741889 PMCID: PMC9222787 DOI: 10.3390/foods11121692] [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: 04/27/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 01/27/2023] Open
Abstract
The hard-to-cook defect in common beans is dictated by the ability to achieve cell separation during cooking. Hydrolysis of pectin methyl-esters by the pectin methyl-esterase (PME) enzyme influences cell separation. However, the contributions of the PME enzyme and the cell wall to the hard-to-cook defect have not been studied using molecular tools. We compared relevant molecular processes in fast- and slow-cooking bean varieties to understand the mechanisms underpinning the hard-to-cook defect. A PME spectrophotometric assay showed minor differences in enzyme activity between varieties. Meanwhile, a PME HMMER search in the P. vulgaris genome unveiled 113 genes encoding PMEs and PME inhibitors (PMEIs). Through RNA sequencing, we compared the gene expression of the PME-related genes in both varieties during seed development. A PME (Phvul010g080300) and PMEI gene (Phvul005g007600) showed the highest expression in the fast- and slow-cooking beans, respectively. We further identified 2132 differentially expressed genes (DEGs). Genes encoding cell-wall-related enzymes, mainly glycosylphosphatidylinositol mannosyltransferase, xyloglucan O-acetyltransferase, pectinesterase, and callose synthase, ranked among the top DEGs, indicating novel relations to the hard-to-cook defect. Gene ontology mapping revealed hydrolase activity and protein phosphorylation as functional categories with the most abundant upregulated DEGs in the slow-cooking bean. Additionally, the cell periphery contained 8% of the DEGs upregulated in the slow-cooking bean. This study provides new insights into the role of pectin methyl-esterase-related genes and novel cell wall processes in the occurrence of the hard-to-cook defect.
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Shin YJ, Vavra U, Strasser R. Proper protein folding in the endoplasmic reticulum is required for attachment of a glycosylphosphatidylinositol anchor in plants. PLANT PHYSIOLOGY 2021; 186:1878-1892. [PMID: 33930152 PMCID: PMC8331152 DOI: 10.1093/plphys/kiab181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 04/04/2021] [Indexed: 05/31/2023]
Abstract
Endoplasmic reticulum (ER) quality control processes recognize and eliminate misfolded proteins to maintain cellular protein homeostasis and prevent the accumulation of defective proteins in the secretory pathway. Glycosylphosphatidylinositol (GPI)-anchored proteins carry a glycolipid modification, which provides an efficient ER export signal and potentially prevents the entry into ER-associated degradation (ERAD), which is one of the major pathways for clearance of terminally misfolded proteins from the ER. Here, we analyzed the degradation routes of different misfolded glycoproteins carrying a C-terminal GPI-attachment signal peptide in Arabidopsis thaliana. We found that a fusion protein consisting of the misfolded extracellular domain from Arabidopsis STRUBBELIG and the GPI-anchor attachment sequence of COBRA1 was efficiently targeted to hydroxymethylglutaryl reductase degradation protein 1 complex-mediated ERAD without the detectable attachment of a GPI anchor. Non-native variants of the GPI-anchored lipid transfer protein 1 (LTPG1) that lack a severely misfolded domain, on the other hand, are modified with a GPI anchor and targeted to the vacuole for degradation. Impaired processing of the GPI-anchoring signal peptide by mutation of the cleavage site or in a GPI-transamidase-compromised mutant caused ER retention and routed the non-native LTPG1 to ERAD. Collectively, these results indicate that for severely misfolded proteins, ER quality control processes are dominant over ER export. For less severely misfolded proteins, the GPI anchor provides an efficient ER export signal resulting in transport to the vacuole.
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Affiliation(s)
- Yun-Ji Shin
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Ulrike Vavra
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
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De Coninck T, Gistelinck K, Janse van Rensburg HC, Van den Ende W, Van Damme EJM. Sweet Modifications Modulate Plant Development. Biomolecules 2021; 11:756. [PMID: 34070047 PMCID: PMC8158104 DOI: 10.3390/biom11050756] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 04/28/2021] [Accepted: 05/12/2021] [Indexed: 02/07/2023] Open
Abstract
Plant development represents a continuous process in which the plant undergoes morphological, (epi)genetic and metabolic changes. Starting from pollination, seed maturation and germination, the plant continues to grow and develops specialized organs to survive, thrive and generate offspring. The development of plants and the interplay with its environment are highly linked to glycosylation of proteins and lipids as well as metabolism and signaling of sugars. Although the involvement of these protein modifications and sugars is well-studied, there is still a long road ahead to profoundly comprehend their nature, significance, importance for plant development and the interplay with stress responses. This review, approached from the plants' perspective, aims to focus on some key findings highlighting the importance of glycosylation and sugar signaling for plant development.
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Affiliation(s)
- Tibo De Coninck
- Laboratory of Glycobiology & Biochemistry, Department of Biotechnology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; (T.D.C.); (K.G.)
| | - Koen Gistelinck
- Laboratory of Glycobiology & Biochemistry, Department of Biotechnology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; (T.D.C.); (K.G.)
| | - Henry C. Janse van Rensburg
- Laboratory of Molecular Plant Biology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven, Belgium; (H.C.J.v.R.); (W.V.d.E.)
| | - Wim Van den Ende
- Laboratory of Molecular Plant Biology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven, Belgium; (H.C.J.v.R.); (W.V.d.E.)
| | - Els J. M. Van Damme
- Laboratory of Glycobiology & Biochemistry, Department of Biotechnology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; (T.D.C.); (K.G.)
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Silva J, Ferraz R, Dupree P, Showalter AM, Coimbra S. Three Decades of Advances in Arabinogalactan-Protein Biosynthesis. FRONTIERS IN PLANT SCIENCE 2020; 11:610377. [PMID: 33384708 PMCID: PMC7769824 DOI: 10.3389/fpls.2020.610377] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/23/2020] [Indexed: 05/18/2023]
Abstract
Arabinogalactan-proteins (AGPs) are a large, complex, and highly diverse class of heavily glycosylated proteins that belong to the family of cell wall hydroxyproline-rich glycoproteins. Approximately 90% of the molecules consist of arabinogalactan polysaccharides, which are composed of arabinose and galactose as major sugars and minor sugars such as glucuronic acid, fucose, and rhamnose. About half of the AGP family members contain a glycosylphosphatidylinositol (GPI) lipid anchor, which allows for an association with the outer leaflet of the plasma membrane. The mysterious AGP family has captivated the attention of plant biologists for several decades. This diverse family of glycoproteins is widely distributed in the plant kingdom, including many algae, where they play fundamental roles in growth and development processes. The journey of AGP biosynthesis begins with the assembly of amino acids into peptide chains of proteins. An N-terminal signal peptide directs AGPs toward the endoplasmic reticulum, where proline hydroxylation occurs and a GPI anchor may be added. GPI-anchored AGPs, as well as unanchored AGPs, are then transferred to the Golgi apparatus, where extensive glycosylation occurs by the action of a variety glycosyltransferase enzymes. Following glycosylation, AGPs are transported by secretory vesicles to the cell wall or to the extracellular face of the plasma membrane (in the case of GPI-anchored AGPs). GPI-anchored proteins can be released from the plasma membrane into the cell wall by phospholipases. In this review, we present an overview of the accumulated knowledge on AGP biosynthesis over the past three decades. Particular emphasis is placed on the glycosylation of AGPs as the sugar moiety is essential to their function. Recent genetics and genomics approaches have significantly contributed to a broader knowledge of AGP biosynthesis. However, many questions remain to be elucidated in the decades ahead.
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Affiliation(s)
- Jessy Silva
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
- LAQV Requimte, Sustainable Chemistry, Universidade do Porto, Porto, Portugal
| | - Ricardo Ferraz
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
- LAQV Requimte, Sustainable Chemistry, Universidade do Porto, Porto, Portugal
| | - Paul Dupree
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Allan M. Showalter
- Department of Environmental and Plant Biology, Molecular and Cellular Biology Program, Ohio University, Athens, OH, United States
| | - Sílvia Coimbra
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
- LAQV Requimte, Sustainable Chemistry, Universidade do Porto, Porto, Portugal
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