The known ubiquitous presence of glycans fulfils an essential prerequisite for fundamental roles in cell sociology. Since carbohydrates are chemically predestined to form biochemical messages of a maximum of structural diversity in a minimum of space, coding of biological information by sugars is the reason for the broad occurrence of cellular glycoconjugates. Their glycans originate from sophisticated enzymatic assembly and dynamically adaptable remodelling. These signals are read and translated into effects by receptors (lectins). The functional pairing between lectins and their counterreceptor(s) is highly specific, often orchestrated by intimate co-regulation of the receptor, the cognate glycan and the bioactive scaffold (e.g., an integrin). Bottom-up approaches, teaming up synthetic and supramolecular chemistry to prepare fully programmable nanoparticles as binding partners with systematic network analysis of lectins and rational design of variants, enable us to delineate the rules of the sugar code.
- MeSH
- Lectins metabolism MeSH
- Humans MeSH
- Polysaccharides metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
BACKGROUND: The most demanding challenge in research on molecular aspects within the flow of biological information is posed by the complex carbohydrates (glycan part of cellular glycoconjugates). How the 'message' encoded in carbohydrate 'letters' is 'read' and 'translated' can only be unraveled by interdisciplinary efforts. SCOPE OF REVIEW: This review provides a didactic step-by-step survey of the concept of the sugar code and the way strategic combination of experimental approaches characterizes structure-function relationships, with resources for teaching. MAJOR CONCLUSIONS: The unsurpassed coding capacity of glycans is an ideal platform for generating a broad range of molecular 'messages'. Structural and functional analyses of complex carbohydrates have been made possible by advances in chemical synthesis, rendering production of oligosaccharides, glycoclusters and neoglycoconjugates possible. This availability facilitates to test the glycans as ligands for natural sugar receptors (lectins). Their interaction is a means to turn sugar-encoded information into cellular effects. Glycan/lectin structures and their spatial modes of presentation underlie the exquisite specificity of the endogenous lectins in counterreceptor selection, that is, to home in on certain cellular glycoproteins or glycolipids. GENERAL SIGNIFICANCE: Understanding how sugar-encoded 'messages' are 'read' and 'translated' by lectins provides insights into fundamental mechanisms of life, with potential for medical applications.
- MeSH
- Glycoproteins chemistry MeSH
- Protein Conformation MeSH
- Carbohydrate Conformation MeSH
- Models, Molecular MeSH
- Molecular Sequence Data MeSH
- Oligosaccharides chemistry MeSH
- Polysaccharides chemistry MeSH
- Carbohydrate Sequence MeSH
- Carbohydrates chemistry MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
BACKGROUND: Mal de Río Cuarto virus (MRCV) infects several monocotyledonous species including maize and wheat. Infected plants show shortened internodes, partial sterility, increased tillering and reduced root length. To better understand the molecular basis of the plant-virus interactions leading to these symptoms, we combined RNA sequencing with metabolite and hormone measurements. RESULTS: More than 3000 differentially accumulated transcripts (DATs) were detected in MRCV-infected wheat plants at 21 days post inoculation compared to mock-inoculated plants. Infected plants exhibited decreased levels of TaSWEET13 transcripts, which are involved in sucrose phloem loading. Soluble sugars, starch, trehalose 6-phosphate (Tre6P), and organic and amino acids were all higher in MRCV-infected plants. In addition, several transcripts related to plant hormone metabolism, transport and signalling were increased upon MRCV infection. Transcripts coding for GA20ox, D14, MAX2 and SMAX1-like proteins involved in gibberellin biosynthesis and strigolactone signalling, were reduced. Transcripts involved in jasmonic acid, ethylene and brassinosteroid biosynthesis, perception and signalling and in auxin transport were also altered. Hormone measurements showed that jasmonic acid, brassinosteroids, abscisic acid and indole-3-acetic acid were significantly higher in infected leaves. CONCLUSIONS: Our results indicate that MRCV causes a profound hormonal imbalance that, together with alterations in sugar partitioning, could account for the symptoms observed in MRCV-infected plants.
- MeSH
- Brassinosteroids metabolism MeSH
- Sugars metabolism MeSH
- Cytokinins metabolism MeSH
- Gibberellins metabolism MeSH
- Host-Pathogen Interactions physiology MeSH
- Indoleacetic Acids metabolism MeSH
- Plant Leaves metabolism virology MeSH
- Plant Diseases virology MeSH
- Triticum genetics metabolism virology MeSH
- Gene Expression Regulation, Plant MeSH
- Plant Growth Regulators metabolism MeSH
- Reoviridae pathogenicity MeSH
- Gene Expression Profiling MeSH
- Publication type
- Journal Article MeSH
elektronický časopis
Cytokinins are plant hormones with biological functions ranging from coordination of plant growth and development to the regulation of senescence. A series of 2-chloro-N(6)-(halogenobenzylamino)purine ribosides was prepared and tested for cytokinin activity in detached wheat leaf senescence, tobacco callus and Amaranthus bioassays. The synthetic compounds showed significant activity, especially in delaying senescence in detached wheat leaves. They were also tested in bacterial receptor bioassays using both monocot and dicot members of the cytokinin receptor family. Most of the derivatives did not trigger cytokinin signaling via the AHK3 and AHK4 receptors from Arabidopsis thaliana in the bacterial assay, but some of them specifically activated the ZmHK1 receptor from Zea mays and were also more active than the aromatic cytokinin BAP in an ARR5::GUS cytokinin bioassay using transgenic Arabidopsis plants. Whole transcript expression analysis was performed using an Arabidopsis model to gather information about the reprogramming of gene transcription when senescent leaves were treated with selected C2-substituted aromatic cytokinin ribosides. Genome-wide expression profiling revealed that the synthetic halogenated derivatives induced the expression of genes related to cytokinin signaling and metabolism. They also prompted both up- and down-regulation of a unique combination of genes coding for components of the photosystem II (PSII) reaction center, light-harvesting complex II (LHCII), and the oxygen-evolving complex, as well as several stress factors responsible for regulating photosynthesis and chlorophyll degradation. Chlorophyll content and fluorescence analyses demonstrated that treatment with the halogenated derivatives increased the efficiency of PSII photochemistry and the abundance of LHCII relative to DMSO- and BAP-treated controls. These findings demonstrate that it is possible to manipulate and fine-tune leaf longevity using synthetic aromatic cytokinin analogs.
- MeSH
- Amaranthus metabolism MeSH
- Arabidopsis metabolism MeSH
- Cytokinins metabolism MeSH
- Photosynthetic Reaction Center Complex Proteins physiology MeSH
- Plant Leaves metabolism MeSH
- Carbohydrate Metabolism physiology MeSH
- Triticum metabolism MeSH
- Purine Nucleosides chemical synthesis chemistry MeSH
- Ribonucleosides chemical synthesis chemistry MeSH
- Aging drug effects physiology MeSH
- Nicotiana metabolism MeSH
- Plant Development drug effects MeSH
- Structure-Activity Relationship MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Biotransformation has accompanied mankind since the Neolithic community, when people settled down and began to engage in agriculture [...].
- MeSH
- Bacteria enzymology MeSH
- Biocatalysis * MeSH
- Biosensing Techniques MeSH
- Biotransformation MeSH
- Glycomics MeSH
- Fungi enzymology MeSH
- Humans MeSH
- Agriculture MeSH
- Check Tag
- Humans MeSH
- Publication type
- Introductory Journal Article MeSH
- Editorial MeSH
Glykomika se zabývá detekcí a charakterizací glykanů přítomných v biologických vzorcích. Je známo, že glykanové struktury dodávají biomolekulám vysoký stupeň strukturní diverzity a tím i mnohostranné biologické funkce, jako jsou buněčné rozpoznávání, adheze nebo zapojení v buněčných signálních drahách. Významně se také účastní onkogeneze, např. ve fázích invaze, metastazování a angiogeneze. Analýza glykanových struktur přítomných v nádorových tkáních nebo tělních tekutinách pacientů je tedy slibným nástrojem pro hledání potenciálních nádorových biomarkerů nezbytných pro časnou diagnostiku nádorových onemocnění. V předložené práci je popsán proces glykosylace a vznik N a O glykanů, současně jsou zmíněny příklady glykanového profilování u rakoviny slinivky břišní, prostaty a vaječníku.
Glycomics is concerned with detection and characterization of glycans present in biological samples. It is well‑known that glycan structures impart high degree of structural diversity to biomolecules and thus add wide‑ranging biological functions, such as cellular recognition, adhesion or involvement in cellular signaling pathways. They substantially participate in oncogenesis, e. g. in phases of invasion, metastasis and angiogenesis. Therefore, analysis of glycan structures in tumor tissues or body liquids is a promising tool for searching for potential tumor biomarkers essential for an early diagnosis of the neoplastic disease. The presented review describes the process of glycosylation and the origination of N and O glycans, presenting examples of glycan profiling in pancreatic, prostate and ovarian cancer. Key words: glycomics – tumor biomarker – pancreatic cancer – prostate cancer – ovarian cancer This study was supported by IGA MH CR NT/13794-4/2012, by the European Regional Development Fund and the State Budget of the Czech Republic (RECAMO, CZ.1.05/2.1.00/03.0101), MEYS – NPS I – LO1413, by MH CZ – DRO (MMCI, 00209805) and by BBMRI_CZ (LM2010004). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers. Submitted: 10. 4. 2015 Accepted: 25. 6. 2015
- MeSH
- Fucose metabolism MeSH
- Glycomics * MeSH
- Glycoproteins blood metabolism MeSH
- Glycosylation * MeSH
- Humans MeSH
- Biomarkers, Tumor * blood metabolism MeSH
- Prostatic Neoplasms blood metabolism MeSH
- Pancreatic Neoplasms blood metabolism MeSH
- Ovarian Neoplasms blood metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Pythium oligandrum is a soil born free living oomycete able to parasitize fungi and oomycetes prey, including important plant and animals pathogens. Pythium oligandrum can colonize endophytically the root tissues of diverse plants where it induces plant defenses. Here we report the first long-read genome sequencing of a P. oligandrum strain sequenced by PacBio technology. Sequencing of genomic DNA loaded onto six SMRT cells permitted the acquisition of 913,728 total reads resulting in 112X genome coverage. The assembly and polishing of the genome sequence yielded180 contigs (N50 = 1.3 Mb; L50 = 12). The size of the genome assembly is 41.9 Mb with a longest contig of 2.7 Mb and 15,007 predicted protein-coding genes among which 95.25% were supported by RNAseq data, thus constituting a new Pythium genome reference. This data will facilitate genomic comparisons of Pythium species that are commensal, beneficial or pathogenic on plant, or parasitic on fungi and oomycete to identify key genetic determinants underpinning their diverse lifestyles. In addition comparison with plant pathogenic or zoopathogenic species will illuminate genomic adaptations for pathogenesis toward widely diverse hosts.
