386 research outputs found
Membrane-Bound Methyltransferase Complex VapA-VipC-VapB Guides Epigenetic Control of Fungal Development
Epigenetic and transcriptional control of gene
expression must be coordinated in response to
external signals to promote alternative multicellular
developmental programs. The membrane-associated
trimeric complex VapA-VipC-VapB controls a
signal transduction pathway for fungal differentiation.
The VipC-VapB methyltransferases are tethered
to the membrane by the FYVE-like zinc finger protein
VapA, allowing the nuclear VelB-VeA-LaeA complex
to activate transcription for sexual development.
Once the release from VapA is triggered, VipCVapB
is transported into the nucleus. VipC-VapB
physically interacts with VeA and reduces its nuclear
import and protein stability, thereby reducing the
nuclear VelB-VeA-LaeA complex. Nuclear VapB
methyltransferase diminishes the establishment of
facultative heterochromatin by decreasing histone 3
lysine 9 trimethylation (H3K9me3). This favors activation
of the regulatory genes brlA and abaA, which
promote the asexual program. The VapA-VipCVapB
methyltransferase pathway combines control
of nuclear import and stability of transcription factors
with histone modification to foster appropriate differentiation
responses
Lipid mediators from pollen act as chemoattractants and activators of polymorphonuclear granulocytes
String amplitudes in arbitrary dimensions
We calculate gravitational dressed tachyon correlators in non critcal
dimensions. The 2D gravity part of our theory is constrained to constant
curvature. Then scaling dimensions of gravitational dressed vertex operators
are equal to their bare conformal dimensions. Considering the model as d+2
dimensional critical string we calculate poles of generalized Shapiro-Virasoro
amplitudes.Comment: 14 page
Lolium perenne apoplast metabolomics for identification of novel metabolites produced by the symbiotic fungus Epichlo festucae
Epichloe festucae is an endophytic fungus that forms a symbiotic association with Lolium perenne. Here we analysed how the metabolome of the ryegrass apoplast changed upon infection of this host with sexual and asexual isolates of E. festucae. A metabolite fingerprinting approach was used to analyse the metabolite composition of apoplastic wash fluid from uninfected and infected L. perenne. Metabolites enriched or depleted in one or both of these treatments were identified using a set of interactive tools. A genetic approach in combination with tandem MS was used to identify a novel product of a secondary metabolite gene cluster. Metabolites likely to be present in the apoplast were identified using MarVis in combination with the BioCyc and KEGG databases, and an in‐house Epichloe metabolite database. We were able to identify the known endophyte‐specific metabolites, peramine and epichloecyclins, as well as a large number of unknown markers. To determine whether these methods can be applied to the identification of novel Epichloe‐derived metabolites, we deleted a gene encoding a NRPS (lgsA) that is highly expressed in planta. Comparative MS analysis of apoplastic wash fluid from wild‐type‐ vs mutant‐infected plants identified a novel Leu/Ile glycoside metabolite present in the former.This research was supported by a grant from the Tertiary Education Commission to the Bio-Protection Research Centre and by Massey University. BS was supported by an Alexander von Humboldt Research Award. IF was supported by the Deutsche Forschungsgemeinschaft (ZUK 45/2010)
Differential Induction of Lipoxygenase Isoforms in Wheat upon Treatment with Rust Fungus Elicitor, Chitin Oligosaccharides, Chitosan, and Methyl Jasmonate
Оценка экономической эффективности инновационного проекта в IT-сфере
Цель работы - разработка комплекса мероприятий по совершенствованию проектной деятельности в IT-сфере (на примере IT-проекта "UMKA").
В процессе исследования проводились изучения теоретических основ проектной деятельности компании, особенности реализации инновационных проектов в IT-сфере, анализировались модели, методы и показатели оценки эффективности IT-проекта, выявлялись особенности оценки эффективности проектов в IT-сфере. В практической части проводилась оценка эффективности IT-проекта "UMKA", разработанная и реализуемая ООО "I-link".The work purpose - development of complex of measures on improvement of project activities in the IT sphere (on the example of an IT project "UMKA").
In the process of research was conducted to study the theoretical basics of project activities of the company, peculiarities of realization of innovative projects in the IT field, we have analyzed the models, methods and indicators to measure the effectiveness of an IT project and identified the features of estimation of efficiency of projects in the IT sphere. In the practical part of the evaluation of the effectiveness of IT-project "UMKA", developed and implemented by "I-link"
A seed-like proteome in oil-rich tubers
There are numerous examples of plant organs or developmental stages that are desiccation-tolerant and can withstand extended periods of severe water loss. One prime example are seeds and pollen of many spermatophytes. However, in some plants, also vegetative organs can be desiccation-tolerant. One example are the tubers of yellow nutsedge (Cyperus esculentus), which also store large amounts of lipids similar to seeds. Interestingly, the closest known relative, purple nutsedge (Cyperus rotundus), generates tubers that do not accumulate oil and are not desiccation-tolerant. We generated nanoLC-MS/MS-based proteomes of yellow nutsedge in five replicates of four stages of tuber development and compared them to the proteomes of roots and leaves, yielding 2257 distinct protein groups. Our data reveal a striking upregulation of hallmark proteins of seeds in the tubers. A deeper comparison to the tuber proteome of the close relative purple nutsedge (C. rotundus) and a previously published proteome of Arabidopsis seeds and seedlings indicates that indeed a seed-like proteome was found in yellow but not purple nutsedge. This was further supported by an analysis of the proteome of a lipid droplet-enriched fraction of yellow nutsedge, which also displayed seed-like characteristics. One reason for the differences between the two nutsedge species might be the expression of certain transcription factors homologous to ABSCISIC ACID INSENSITIVE3, WRINKLED1, and LEAFY COTYLEDON1 that drive gene expression in Arabidopsis seed embryos
Update on LIPID MAPS classification, nomenclature, and shorthand notation for MS-derived lipid structures
A comprehensive and standardized system to report lipid structures analyzed by mass spectrometry is essentialfor the communication and storage of lipidomics data. Herein, an update on both the LIPID MAPSclassification system and shorthand notation of lipid structures is presented for lipid categories Fatty Acyls(FA), Glycerolipids (GL), Glycerophospholipids (GP), Sphingolipids (SP), and Sterols (ST). With its majorchanges, i.e. annotation of ring double bond equivalents and number of oxygens, the updated shorthandnotation facilitates reporting of newly delineated oxygenated lipid species as well. For standardized reportingin lipidomics, the hierarchical architecture of shorthand notation reflects the diverse structural resolutionpowers provided by mass spectrometric assays. Moreover, shorthand notation is expanded beyond mammalianphyla to lipids from plant and yeast phyla. Finally, annotation of atoms is included for the use of stableisotope-labelled compounds in metabolic labelling experiments or as internal standards
Arabidopsis CPR5 Independently Regulates Seed Germination and Postgermination Arrest of Development through LOX Pathway and ABA Signaling
The phytohormone abscisic acid (ABA) and the lipoxygenases (LOXs) pathway play important roles in seed germination and seedling growth and development. Here, we reported on the functional characterization of Arabidopsis CPR5 in the ABA signaling and LOX pathways. The cpr5 mutant was hypersensitive to ABA in the seed germination, cotyledon greening and root growth, whereas transgenic plants overexpressing CPR5 were insensitive. Genetic analysis demonstrated that CPR5 gene may be located downstream of the ABI1 in the ABA signaling pathway. However, the cpr5 mutant showed an ABA independent drought-resistant phenotype. It was also found that the cpr5 mutant was hypersensitive to NDGA and NDGA treatment aggravated the ABA-induced delay in the seed germination and cotyledon greening. Taken together, these results suggest that the CPR5 plays a regulatory role in the regulation of seed germination and early seedling growth through ABA and LOX pathways independently
Metabolite-based clustering and visualization of mass spectrometry data using one-dimensional self-organizing maps
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