DOCSLIB.ORG

Characterization of Fasciclin-Like Arabinogalactan Proteins in Arabidopsis Thaliana

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Characterization of Fasciclin-Like Arabinogalactan Proteins in Arabidopsis Thaliana CHARACTERIZATION OF FASCICLIN-LIKE ARABINOGALACTAN- PROTEINS IN ARABIDOPSIS THALIANA Edgar Zhipeng Liu Submitted in total fulfilment of the requirements of the degree of Doctor of Philosophy December 2017 School of Biosciences University of Melbourne ABSTRACT All plant cells are surrounded by an elastic primary cell wall and, in some specialised cell types/tissues such as the vasculature, the cell deposits a secondary wall that is capable of withstanding enormous compressive forces important for water conducting tissues and plant support (Doblin et al., 2010). The primary wall largely consists of polysaccharides such as cellulose, hemicelluloses and pectins and a minor portion of protein components. An abundant superfamily of plant-specific wall proteins are the hydroxyproline-rich glycoproteins (HRGPs), which includes the arabinogalactan- proteins (AGPs). AGPs are characterised by a protein backbone rich in non-contiguous proline (P) residues that direct O-linked glycosylation with type II arabino-(3,6)-galactans (AGs) (Schultz et al., 2002; Johnson et al., 2003; Basu et al., 2015a). AG glycans have been proposed to be important in secretion and trafficking of proteins, and in modulating their biological function (Ellis et al., 2010; Kovall and Blacklow, 2010). Within the AGP family, chimeric AGPs, with recognised PFAM domains other than the AGP regions, include an important class known as the fasciclin-like arabinogalactan-proteins (FLAs) (Schultz et al., 2002; Johnson et al., 2003). In FLAs, AGP regions are found adjacent to fasciclin (FAS) domains (Johnson et al., 2003). FAS domains are known to be conserved in proteins from a broad range of living organisms playing important biological roles related to adhesion (Elkins et al., 1990a; Johnson et al., 2003; Hamilton, 2008; Moody and Williamson, 2013). The combination of O-linked glycans and FAS domains is proposed to confer unique biological roles to FLAs. Bioinformatic studies have shown that FLAs belong to multigene families in all plant species, for example, 21 FLAs have been identified in the Arabidopsis genome (Johnson et al., 2003). The function of some FLAs has been inferred through investigation of their tissue-specific expression profiles and phenotypes of the respective fla mutants. Based on these studies, FLAs are proposed to play roles in cell expansion, plant growth and development (Shi et al., 2003; Seifert and Roberts, 2007; Li et al., 2010; MacMillan et al., 2010). In particular, a subset of FLAs specifically expressed in stems have been shown to influence stem biomechanical properties. MacMillan et al. (2010) demonstrated that loss of FLA11 and FLA12 resulted in changes in cell wall composition and the microfibril angle of cellulose in Arabidopsis stems. No obvious growth phenotypes were observed in fla11 fla12 mutants suggesting further I redundancy with other FLA members. FLA16 was also identified as having stem-specific expression yet its role in stem biomechanics was not explored. In this study, multi-disciplinary approaches, including molecular biology, microscopy, biochemistry, biomechanics and genetics, have been employed to investigate the biological function(s) and genetic relationships of FLA11 (AT5G03170), FLA12 (AT5G60490) and FLA16 (AT2G35860). We developed molecular resources to further explore the role of Arabidopsis FLA11 and FLA12 during stem development and characterise FLA16 as a novel regulator of stem development. Chapter 1 provides an overview of AGP/FLA structures, classification and known biological roles. Chapter 2 provides a detailed description of the experimental materials and research methods used in this thesis. This is followed by Chapter 3, an investigation of FLA11, FLA12 and FLA16 at the protein level. Fluorescent protein fusions of FLA11, FLA12 and FLA16, driven by either their endogenous promoters or the 35S promoter were generated and transformed into either Arabidopsis or tobacco (Nicotiana tabacum), respectively. The tissue/cellular distributions of the FLA proteins in different plant organs as well as their sub-cellular location was determined. In addition, several enrichment methods, including: chelation, immunoprecipitation (IP) and hydrophobic interaction chromatography (HIC), were explored in preparation for structural analyses and identification of potential interacting partners of the FLAs (see Chapter 3, Appendices A3.1). FLA11, FLA12 and FLA16 were shown to be predominantly expressed in inflorescence stems, siliques and branches with lower abundance in cotyledons and roots. The location of FLAs was largely confined to cells with secondary walls, such as interfascicular fibres and xylem cells in stems/branches, endocarp b and replum cells in the siliques, guard cells in the leaves and vasculature in the main roots. Membrane fractionation studies suggest the FLAs are present at the plasma membrane (PM) and in the wall and are glycosylated. Enrichment of detergent-solubilised FLAs showed IP and chelation are the most effective methods, however, improved methods for enriching FLAs from Arabidopsis are needed given the difficulty of extracting proteins from stems due to the abundance of secondary walls. These data suggest that FLA11, FLA12 and FLA16 are likely to function at the PM and/or wall of cells with secondary walls in inflorescence stems. In Chapter 4, the function of FLA16 in stem development is explored through characterisation of a fla16 mutant at different growth stages and tissues. Phenotypic II analyses of the fla16 mutant shows a delay in root growth during early seedling development, early bolting and reduced stem length and thickness. Morphological analysis of stems using light microscopy shows a reduced number of pith cells with no obvious changes in fibre and xylem cells. Cell wall compositional analyses of the stem showed that fla16 has reduced cellulose compared to wild-type (wt). Similar to FLA11 and FLA12, loss of FLA16 altered biomechanical properties of the stems, with increased tensile stiffness in the middle stems and decreased flexure strength in the basal stems. Quantitative RT-PCR (Q-PCR) was used to study the expression of primary and secondary wall-specific cellulose synthases (CesAs) in stems and showed changes of the secondary- wall active CesA7 occurs in fla16. Our results suggest FLA16 plays a role in maintaining biomechanical properties in the stem, likely via regulating cellulose in the secondary walls. In Chapter 5, a series of comparative and functional analyses are undertaken for FLA11, FLA12 and FLA16, based on analysis of the double fla11 fla12, fla11 fla16, fla12 fla16, and triple fla11 fla12 fla16 mutants compared to the respective single fla11, fla12 and fla16 mutants and wt. Through comparative analyses of growth parameters such as the length, thickness and cellulose content of the stems, we found all fla mutants show similar phenotypes, suggesting they act in the same genetic pathway. Q-PCR analyses of the expression of CesAs active in either primary or secondary wall cellulose synthesis show CesA7 expression is consistently increased in fla16, fla11 fla12 and fla11 fla12 fla16 mutant stems. Our results suggest FLA11, FLA12 and FLA16 likely act in similar pathways to regulate stem growth and cellulose biosynthesis during secondary wall formation, and the genetic relationship of these FLAs seems to be epistatic. In Chapter 6 we summarise the implications of these data on plant growth and development and speculate on the roles and properties of FLAs. We pose questions as to whether they function as wall biosynthesis regulators, architectural components, or both. This research provides valuable insights into the biology of FLA11, FLA12 and FLA16, and provides future directions in the study of these cell wall glycoproteins. Greater knowledge of how FLAs influence cellulose deposition and biomechanics will underpin future applications in the forest industry and the agri-food sector. III DECLARATION This is to certify that i. The thesis comprises only my original work, except where indicated to the contrary ii. Due acknowledgement has been made in the text to all other materials used iii. The thesis is less than 100,000 words in length, exclusive of tables, maps, bibliographies and appendix Print Name: EDGAR ZHIPENG LIU Signature: Date: December 21, 2017 IV ACKNOWLEDGEMENTS This PhD would not be achieved without the generous support and warm- hearted assistance from many people whom I will never forget. I would like to give my first thanks to my supervisor Prof Tony Bacic. I was struggling in the intersection whether to continue pursuing my PhD in a new venture or to regretfully admit being beaten by the disadvantageous circumstance in my previous university. Tony encouraged me with his respect and care for students and showed me the scientist’s altitude in studying. He gave me his firm support for my PhD entry application, throughout my PhD course and most importantly he gave me two remarkable supervisors, Dr Kim Johnson and Dr John Humphries. I am always grateful to Kim who has spent a significant portion of her time on the supervision of my project. Kim lights me up on the path towards a PhD and guides me from an outsider to a qualified researcher. She is a passionate and knowledgeable scientist always refuels me when I was in lack of idea and experiencing fatigue in work with a will. I was touched that Kim corrected my works in late nights and even during her pregnancy, on playful weekends and gave me great understanding and mental support when I was down after a traumatic accident. I need to thank John who has been very helpful in my project and is always supportive when I experience difficulties no matter in studies or personal life. It was wonderful time I spent with John when we go out for drinks and foods. I am appreciated to John’s sacrifice of his weekend time correcting my works and giving me valuable opinions. I need to thank Ms Kristina Ford who is a skilful and helpful expert in proteomics, giving me very kind supervision and patient training in my project. I need to thank my course advisors, A/Prof Ed Newbigin and Dr Monika Doblin for their constructive input and valuable discussion in the guidance of my study.
Load more

Recommended publications
  • Disruption of Arabinogalactan Proteins Disorganizes Cortical Microtubules in the Root of Arabidopsis Thaliana
    The Plant Journal (2007) doi: 10.1111/j.1365-313X.2007.03224.x Disruption of arabinogalactan proteins disorganizes cortical microtubules in the root of Arabidopsis thaliana Eric Nguema-Ona1, Alex Bannigan2, Laurence Chevalier1, Tobias I. Baskin2 and Azeddine Driouich1,* 1UMR CNRS 6037, IFRMP 23, Plate Forme de Recherche en Imagerie Cellulaire, Universite´ de Rouen, 76 821 Mont Saint Aignan, Cedex, France, and 2Biology Department, University of Massachusetts Amherst, 611 N. Pleasant Street, MA 01003, USA Received 9 March 2007; revised 31 May 2007; accepted 11 June 2007. *For correspondence (fax +33 235 14 6615; e-mail [email protected]). Summary The cortical array of microtubules inside the cell and arabinogalactan proteins on the external surface of the cell are each implicated in plant morphogenesis. To determine whether the cortical array is influenced by arabinogalactan proteins, we first treated Arabidopsis roots with a Yariv reagent that binds arabinogalactan proteins. Cortical microtubules were markedly disorganized by 1 lM b-D-glucosyl (active) Yariv but not by up to 10 lM b-D-mannosyl (inactive) Yariv. This was observed for 24-h treatments in wild-type roots, fixed and stained with anti-tubulin antibodies, as well as in living roots expressing a green fluorescent protein (GFP) reporter for microtubules. Using the reporter line, microtubule disorganization was evident within 10 min of treatment with 5 lM active Yariv and extensive by 30 min. Active Yariv (5 lM) disorganized cortical microtubules after gadolinium pre-treatment, suggesting that this effect is independent of calcium influx across the plasma membrane. Similar effects on cortical microtubules, over a similar time scale, were induced by two anti-arabinogalactan-protein antibodies (JIM13 and JIM14) but not by antibodies recognizing pectin or xyloglucan epitopes.
    [Show full text]
  • FULLTEXT01.Pdf
    http://www.diva-portal.org This is the published version of a paper published in Molecules. Citation for the original published paper (version of record): Messing, J., Niehues, M., Shevtsova, A., Boren, T., Hensel, A. (2014) Antiadhesive Properties of Arabinogalactan Protein from Ribes nigrum Seeds against Bacterial Adhesion of Helicobacter pylori. Molecules, 19(3): 3696-3717 http://dx.doi.org/10.3390/molecules19033696 Access to the published version may require subscription. N.B. When citing this work, cite the original published paper. Permanent link to this version: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-90090 Molecules 2014, 19, 3696-3717; doi:10.3390/molecules19033696 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Article Antiadhesive Properties of Arabinogalactan Protein from Ribes nigrum Seeds against Bacterial Adhesion of Helicobacter pylori Jutta Messing 1, Michael Niehues 1, Anna Shevtsova 2, Thomas Borén 2 and Andreas Hensel 1,* 1 Institute of Pharmaceutical Biology and Phytochemistry, University of Münster, D-48149 Münster, Germany; E-Mails: [email protected] (J.M.); [email protected] (M.N.) 2 Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, SE-901 87, Sweden; E-Mails: [email protected] (A.S.); [email protected] (T.B.) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +49-251-833-3380. Received: 4 February 2014; in revised form: 7 March 2014 / Accepted: 15 March 2014 / Published: 24 March 2014 Abstract: Fruit extracts from black currants (Ribes nigrum L.) are traditionally used for treatment of gastritis based on seed polysaccharides that inhibit the adhesion of Helicobacter pylori to stomach cells.
    [Show full text]
  • A Survey on Cell Wall Proteins of C. Sinensis Leaf
    A Survey on Cell wall Proteins of C. Sinensis Leaf by Combining Cell Wall Proteomic and N- Glycoproteomic Strategy yanli liu ( [email protected] ) Hubei Academy of Agricultural science https://orcid.org/0000-0001-7397-5966 Linlong Ma Hubei AAS: Hubei Academy of Agricultural Sciences Dan Cao Hubei AAS: Hubei Academy of Agricultural Sciences Ziming Gong Hubei Academy of Agricultural sciences Jing Fan Hubei AAS: Hubei Academy of Agricultural Sciences Hongju Hu Hubei Academy of Agricultural Sciences Xiaofang Jin Hubei Academy of Agricultural Sciences Research article Keywords: Camellia sinensis, Cell wall proteome, N-glycoproteome, Glycoside hydrolases Posted Date: December 23rd, 2020 DOI: https://doi.org/10.21203/rs.3.rs-132373/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Version of Record: A version of this preprint was published at BMC Plant Biology on August 20th, 2021. See the published version at https://doi.org/10.1186/s12870-021-03166-4. Page 1/29 Abstract Background: Camellia sinensis is an important economic crop with uoride over-accumulation in the leaves, which pose a serious threaten to human health due to its leave being used for making tea. Recently, our study found that cell wall proteins (CWPs) probably play a vital role in uoride accumulation/detoxication in C. sinensis. However, CWPs identication and characterization were lacking up to now in C. sinensis. Herein, we aimed at characterizing cell wall proteome of C. sinensis leaves, to develop more CWPs related to stress response. A strategy of combined cell wall proteome and N-glycoproteome were employed to investigate CWPs.
    [Show full text]
  • A Role for Arabinogalactan-Proteins in Root Epidermal Cell Expansion
    Planta (1997) 203: 289±294 A role for arabinogalactan-proteins in root epidermal cell expansion Lei Ding, Jian-Kang Zhu Department of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA Received: 13 February 1997 / Accepted: 1 April 1997 Abstract. Arabinogalactan-proteins (AGPs) are abund- membrane, cell wall and intercellular spaces (Fincher ant plant proteoglycans that react with (b-D-Glc)3 but et al. 1983; Komalavilas et al. 1991; Serpe and Nothnagel not (b-D-Man)3 Yariv reagent. We report here that 1995). The carbohydrate moiety of AGPs consists of treatment with (b-D-Glc)3 Yariv reagent caused inhibi- mainly arabinose and galactose with minor amounts of tion of root growth of Arabidopsis thaliana (L.) Heynh. other sugars including uronic acids (Fincher et al. 1983; seedlings. Moreover, the treated roots exhibited numer- Komalavilas et al. 1991). The protein moieties of AGPs ous bulging epidermal cells. Treatment with (b-D-Man)3 are typically rich in hydroxyproline, serine, alanine, Yariv reagent did not have any such eects. These threonine and glycine (Fincher et al. 1983; Showalter results indicate a role for AGPs in root growth and and Varner 1989). The primary structures of several control of epidermal cell expansion. Because treatment AGP core proteins have recently been elucidated via with (b-D-Glc)3 Yariv reagent phenocopies the reb1 (root gene cloning (Chen et al. 1994; Du et al. 1994; Cheung epidermal cell bulging) mutant of Arabidopsis, AGPs et al. 1995; Mau et al. 1995; Du et al. 1996). were extracted from the reb1-1 mutant and compared The expression of AGPs is highly regulated during with those of the wild type.
    [Show full text]
  • Arabinogalactan Protein – a Potent Immunostimulator
    Available online on www.ijppr.com International Journal of Pharmacognosy and Phytochemical Research 2015; 7(4); 732-734 ISSN: 0975-4873 Review Article Arabinogalactan Protein – A Potent Immunostimulator Selvaraj R*, Mahesh Kumar N and Sivaraman D Centre for Laboratory Animal Technology and Research, Sathyabama University, Chennai, 600119, India Available Online: 29th June, 2015 ABSTRACT For the past several years glycoproteins are the subject of interest for the researches because of their abundant presence and diverse functions. Recent researches reported glycoproteins with potential activities such as antiviral, anti-bacterial, anti-tumor, anti-inflammatory, anti-complementary, anti-coagulant, immunostimulatory, anti-ulcer activity etc. Arabinogalactan proteins are group of polysaccharides found almost in all the plants. Many researchers have reported that arabinogalactan protein with potent immune stimulating ability. In recent years arabinogalactan protein is beginning to gain interest as a carrier to deliver drugs. Beside this drug delivery they can also be used to enhance the drug solubility, enhance the drug stability, extend duration of activity etc. This review covers only a small part of the activity of arabinogalactan protein isolated from plants. It mainly focuses on the invivo and invitro analysis that reveals the immunological activity of arabinogalactan protein. Key Words: Arabinogalactan, Immunostimulatory, Macrophages, T and B cells INTRODUCTION galactose. Arabinogalactan posses various attractive Life threatening infections have become a potential threat properties such as high solubility in water, in recent years particularly in the immune compromised biocompatibility, biodegradability, and ease of drug patients. The enhancement of the host defense mechanism conjugation in an aqueous medium which makes it a can be recognized as a possible means of reducing these potential protein to be explored3.
    [Show full text]
  • The Role of Arabinogalactan Proteins (Agps) in Fruit Ripening—Areview Agata Leszczuk 1, Panagiotis Kalaitzis2, Konstantinos N
    Leszczuk et al. Horticulture Research (2020) 7:176 Horticulture Research https://doi.org/10.1038/s41438-020-00397-8 www.nature.com/hortres REVIEW ARTICLE Open Access The role of arabinogalactan proteins (AGPs) in fruit ripening—areview Agata Leszczuk 1, Panagiotis Kalaitzis2, Konstantinos N. Blazakis2 and Artur Zdunek1 Abstract Arabinogalactan proteins (AGPs) are proteoglycans challenging researchers for decades. However, despite the extremely interesting polydispersity of their structure and essential application potential, studies of AGPs in fruit are limited, and only a few groups deal with this scientific subject. Here, we summarise the results of pioneering studies on AGPs in fruit tissue with their structure, specific localization pattern, stress factors influencing their presence, and a focus on recent advances. We discuss the properties of AGPs, i.e., binding calcium ions, ability to aggregate, adhesive nature, and crosslinking with other cell wall components that may also be implicated in fruit metabolism. The aim of this review is an attempt to associate well-known features and properties of AGPs with their putative roles in fruit ripening. The putative physiological significance of AGPs might provide additional targets of regulation for fruit developmental programme. A comprehensive understanding of the AGP expression, structure, and untypical features may give new information for agronomic, horticulture, and renewable biomaterial applications. Introduction the molecular level that govern cell-to-cell adhesion and fi 1234567890():,; 1234567890():,; 1234567890():,; 1234567890():,; Fruits are one of the main horticultural products. They remodeling of cell walls is still not suf cient to understand are eaten fresh or processed delivering pro-health and and to control the mechanical properties of the whole nutritional components.
    [Show full text]
  • Arabinogalactan Protein–Rare Earth Element Complexes Activate Plant Endocytosis
    Arabinogalactan protein–rare earth element complexes activate plant endocytosis Lihong Wanga,b,1, Mengzhu Chenga,1, Qing Yanga,1, Jigang Lic, Xiang Wanga, Qing Zhoub, Shingo Nagawad,e, Binxin Xiab, Tongda Xud,e, Rongfeng Huangd,e, Jingfang Hea, Changjiang Lic, Ying Fuc, Ying Liua, Jianchun Baoa, Haiyan Weia, Hui Lie,f, Li Tane, Zhenhong Gue, Ao Xiaa, Xiaohua Huanga,2, Zhenbiao Yangg,h, and Xing Wang Dengi,2 aNational and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, 210023 Nanjing, China; bState Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China; cChina State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, 100193 Beijing, China; dFujian Agriculture and Forestry University–University of California, Riverside Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, 350002 Fuzhou, China; eShanghai Center for Plant Stress Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, 201602 Shanghai, China; fSchool of Life Sciences, East China Normal University, 200241 Shanghai, China; gCenter for Plant Cell Biology, Institute of Integrative Genome Biology, University of California, Riverside, CA 92521; hDepartment of Botany and Plant Sciences, University of California,
    [Show full text]
  • Advances in Research of Fasciclin-Like Arabinogalactan Proteins (Flas) in Plants
    POJ 8(2):190-194 (2015) ISSN:1836-3644 Advances in research of fasciclin-like arabinogalactan proteins (FLAs) in plants Lina Zang1,2, Tangchun Zheng1, Xiaohua Su2,3* 1State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, 150040, China 2State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China 3Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Beijing, 100091, China *Corresponding author: [email protected] Abstract Fasciclin-like arabinogalactan proteins (FLAs) family, belonging to a subclass of arabinogalactan proteins (AGPs), contains AGP-like glycosylated domains and fasciclin-like domains. FLAs are widely distributed in various plants and are involved in plant growth and development. In this paper, recent advances in the structure, expression pattern, biological function and application prospect of plant FLAs are summarized. Key words: FLA; Fasciclin-like domains; AGP-like domains; Gene function. Abbreviations: AGP_arabinogalactan protein; FLA_fasciclin-like protein; GPI_glycosyl phosphatidylinositol; GUS_β-glucuronidase; SOS5_salt overly sensitive 5. Introduction As a type of highly glycosylated proteoglycans, signal peptide, 16 GPI anchor signal; 21 FLAs that are arabinogalactan proteins (AGPs) exist in tissues and cells of composed of 247-462 amino acids, only 20 contain signal almost all aquatic and terrestrial plants, containing peptide, 11 GPI anchor signal; 6 nonclassical AGPs that are O-glycosylated core protein backbone that accounts for composed of 222-826 amino acids, only 5 contain signal 2-10% of the total molecular weight and more than 90% of peptide, 1 GPI anchor signal (Showalter et al., 2010). AGP type II arabinogalactan polysaccharide chains, with the proteins are extensively involved in plant growth and molecular weight of 60-300 kD.
    [Show full text]
  • Proline-Rich, Arabinogalactan Proteins, Conserved Cysteines) Domain-Proteins Are Conserved in the Green Lineage
    International Journal of Molecular Sciences Article The Cell Wall PAC (Proline-Rich, Arabinogalactan Proteins, Conserved Cysteines) Domain-Proteins Are Conserved in the Green Lineage 1, 1, 2 2 Huan Nguyen-Kim y,Hélène San Clemente y, Josef Laimer , Peter Lackner , Gabriele Gadermaier 2 , Christophe Dunand 1 and Elisabeth Jamet 1,* 1 Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, 31320 Auzeville Tolosane, France; [email protected] (H.N-K.); [email protected] (H.S.C.); [email protected] (C.D.) 2 Paris-Lodron-University of Salzburg, Department of Biosciences, 5020 Salzburg, Austria; [email protected] (J.L.); [email protected] (P.L.); [email protected] (G.G.) * Correspondence: [email protected]; Tel.: +33-(0)5-3432-3830 These two authors equally contributed to the work. y Received: 17 January 2020; Accepted: 1 April 2020; Published: 3 April 2020 Abstract: Plant cell wall proteins play major roles during plant development and in response to environmental cues. A bioinformatic search for functional domains has allowed identifying the PAC domain (Proline-rich, Arabinogalactan proteins, conserved Cysteines) in several proteins (PDPs) identified in cell wall proteomes. This domain is assumed to interact with pectic polysaccharides and O-glycans and to contribute to non-covalent molecular scaffolds facilitating the remodeling of polysaccharidic networks during rapid cell expansion. In this work, the characteristics of the PAC domain are described in detail, including six conserved Cys residues, their spacing, and the predicted secondary structures. Modeling has been performed based on the crystal structure of a Plantago lanceolata PAC domain.
    [Show full text]
  • Arabinogalactan Proteins in Arabidopsis Thaliana Pollen Development
    16 Arabinogalactan Proteins in Arabidopsis thaliana Pollen Development Sílvia Coimbra and Luís Gustavo Pereira University of Porto, Faculty of Sciences, Biology Department and BioFIG Portugal 1. Introduction Pollen ontogeny is an attractive model to study cell division and differentiation. The progression from proliferating microspores to terminally differentiated pollen is characterized by large-scale repression of early program genes and the activation of a unique late gene-expression program in mature pollen. Among the genes, or gene families that conform to the transition from a sporophytic type of development to a gametophytic program are the arabinogalactan protein (AGP) genes. AGPs are a class of plant proteoglycans, virtually present in all plant cells and in all plant species, from Algae to Angiosperms. They are predominantly located at the periphery of cells, i.e. on the plasma membrane and in the apoplast. Such ubiquitous presence insinuates that AGPs are vital components of the plant cell. Indeed, many studies have implicated AGPs in important biological phenomena, such as cell expansion, cell division, cell death, seed germination, pollen tube growth and guidance, resistance to infection, etc. (Seifert & Roberts, 2007). Evidences implicating AGPs in sexual reproduction have been obtained in our group, for several plant species (Coimbra & Duarte, 2003; Coimbra & Salema 1997; Coimbra et al., 2005) but how these molecules exert their function or how they interact with other cell components is yet to be defined. Only then the fragmentary knowledge that we have today about the function of these proteins may become pieces of a puzzle. Following studies of pollen and pistil development in Arabidopsis with anti-AGP monoclonal antibodies (Coimbra et al., 2007; Pereira et al., 2006), it became clear that some AGPs may be suitable as molecular markers for gametophytic cell differentiation.
    [Show full text]
  • BRUTUS-LIKE Proteins Moderate the Transcriptional Response to Iron Deficiency in Roots
    bioRxiv preprint doi: https://doi.org/10.1101/231365; this version posted December 8, 2017. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. BRUTUS-LIKE proteins moderate the transcriptional response to iron deficiency in roots Authors: Jorge Rodríguez-Celma1,2, Robert T. Green1, James M. Connorton1,2, Inga Kruse1, Yan Cui3, Hong Qing Ling3, Janneke Balk*1,2 1 John Innes Centre, Department of Biological Chemistry, NR4 7UH, United Kingdom 2 University of East Anglia, School of Biological Sciences, NR4 7TJ, United Kingdom 3 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China *corresponding author: Janneke Balk, [email protected] Short title: BRUTUS-LIKE proteins target FIT for degradation The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantcell.org) is: Janneke Balk ([email protected]). 1 bioRxiv preprint doi: https://doi.org/10.1101/231365; this version posted December 8, 2017. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. ABSTRACT Iron is an essential micronutrient but in excess is toxic inside cells. Under iron deficiency, the expression of iron uptake genes is increased, but it is not known how the transcriptional response is controlled to avoid uptake of too much iron.
    [Show full text]
  • Characterization of a Yariv Precipitated Arabinogalactan-Protein from Fruits of Rye (Secale Cereale L.)
    ORIGINAL ARTICLES Pharmaceutical Institute, Department of Pharmaceutical Biology, Christian-Albrechts-University of Kiel, Germany Characterization of a Yariv precipitated arabinogalactan-protein from fruits of rye (Secale cereale L.) E. M. Goellner, W. Blaschek, B. Classen Received November 28, 2012, accepted December 13, 2012 Dr. Esther Marie Göllner, Pharmaceutical Institute, Department of Pharmaceutical Biology, Christian-Albrechts- University of Kiel, Gutenbergstraße 76, 24118 Kiel, Germany [email protected] Dedicated to Prof. Dr. Theo Dingermann, Frankfurt, on the occasion of his 65th birthday. Pharmazie 68: 631–635 (2013) doi: 10.1691/ph.2013.6519 An arabinogalactan-protein (AGP) with a molecular mass of 110 kDa was isolated from whole grain of rye (Secale cereale L.) by double precipitation with (␤-D-Glc)3-Yariv-phenylglycoside (␤GlcY) and its structure was analyzed. The AGP consists of a hydroxyproline-rich protein backbone of about 7 % and an arabino- galactan moiety of about 93%. By alkaline hydrolysis, hydroxyproline was identified as the main amino acid responsible for the binding between the protein and the carbohydrate subunits via an O-glycosidic linkage. The arabinogalactan moieties are highly branched consisting of 1,3-linked Galp residues, some of them linked in position 6 to 1,6-Galp side chains, terminating in Araf residues. With regard to its structure, the rye AGP is comparable to other cereal AGPs like those from oat or wheat grain. 1. Introduction structural characterization of these interesting constituents of In Europe rye is cultivated widely and serves as one of the our daily food. main bread cereals. Together with a great variety of other food, this leads to a healthy, balanced nutrition.
    [Show full text]