40 research outputs found
The dynamics of root cap sloughing in Arabidopsis is regulated by peptide signalling
The root cap protects the stem cell niche of angiosperm roots from damage. In Arabidopsis, lateral root cap (LRC) cells covering the meristematic zone are regularly lost through programmed cell death, while the outermost layer of the root cap covering the tip is repeatedly sloughed. Efficient coordination with stem cells producing new layers is needed to maintain a constant size of the cap. We present a signalling pair, the peptide IDA-LIKE1 (IDL1) and its receptor HAESA-LIKE2 (HSL2), mediating such communication. Live imaging over several days characterized this process from initial fractures in LRC cell files to full separation of a layer. Enhanced expression of IDL1 in the separating root cap layers resulted in increased frequency of sloughing, balanced with generation of new layers in a HSL2-dependent manner. Transcriptome analyses linked IDL1-HSL2 signalling to the transcription factors BEARSKIN1/2 and genes associated with programmed cell death. Mutations in either IDL1 or HSL2 slowed down cell division, maturation and separation. Thus, IDL1-HSL2 signalling potentiates dynamic regulation of the homeostatic balance between stem cell division and sloughing activity
Risk-based maintenance and rehabilitation decisions for transportation infrastructure networks
A method for determining optimal risk-based maintenance and rehabilitation (M&R) policies for transportation infrastructure is presented. The proposed policies guarantee a certain performance level across the network under a predefined level of risk. The long-term model is formulated in the Markov Decision Process framework with risk-averse actions and transitional probabilities describing the uncertainty in the deterioration process. The well known Conditional Value at Risk (CVaR) is used as the measure of risk. The steady-state risk-averse M&R policies are modeled assuming no budget restriction. To address the short-term resource allocation problem, two linear programming models are presented to generate network-level polices with different objectives. While the proposed methodology is general and can be used with any performance indicator, pavement roughness is used for numerical studies and an analytical expression for computing CVaR is derived.Maintenance Rehabilitation Risk CVaR Resource allocation
The Organizational and Economic Policy of the state Administration of Development of Railway Transport of Ukraine
The article deals with the main directions of the organizational and economic policy of the state administration of the development of railway transport and provides suggestions for improving the management mechanism of the railway industry, to ensure the competitiveness of railway transport enterprises. Conceptual aspects of state administration of railway transport development are defined. Components of the organizational and economic policy of management development are provided. The necessity of reforming such components as an innovative renewal of production, overcoming structural deformations in industry, investment in the real sector is substantiated. the general mechanism of organizational and economic support of reform is provided
Peptidome profiling dataset of ovarian cancer and non-cancer proximal fluids: Ascites and blood sera
Despite a large number of proteomic studies of biological fluids from ovarian cancer patients, there is a lack of sensitive screening methods in clinical practice (Kim et al., 2016) (DOI:https://doi.org/10.1111/cas.12987 [1]). Low molecular weight endogenous peptides more easily diffuse across endothelial barriers than proteins and can be more relevant biomarker candidates (Meo et al., 2016) (DOI:https://doi.org/10.18632/oncotarget.8931 [2], (Bery et al., 2014) DOI:https://doi.org/10.1186/1559-0275-11-13 [3], (Huang et al., 2018) DOI:https://doi.org/10.1097/IGC.0000000000001166 [4]). Detailed peptidomic analysis of 26 ovarian cancer and 15 non-cancer samples of biological fluids (ascites and sera) were performed using TripleTOF 5600+ mass-spectrometer. Prior to LC-MS/MS analysis, peptides were extracted from biological fluids using anion exchange sorbent with subsequent peptide desorption from the surface of highly abundant proteins. In total, we identified 4874 peptides; 3123 peptides were specific for the ovarian cancer samples. The mass-spectrometry peptidomics data presented in this data article have been deposited to the ProteomeXchange Consortium (Deutsch et al., 2017) (DOI:https://doi.org/10.1093/nar/gkw936 [5]) via the PRIDE partner repository with the dataset identifier PXD009382 and https://doi.org/10.6019/PXD009382, http://www.ebi.ac.uk/pride/archive/projects/PXD009382
Data-independent proteome profile of Mycoplasma gallisepticum under normal conditions and heat stress
The data reported is a large-scale untargeted proteome profile for Mycoplasma gallisepticum – a model organism for studying both regulation in genome-reduced bacteria and intracellular infection (Mazin et al., 2014) [1,2]. While seminal whole-proteome studies were performed on Mycoplasma genitalium [3] and a few proteome datasets are available for Mycoplasma pneumoniae, no data-independent (DIA) proteome profiling has been published for bacteria of Mycoplasma genus. Since DIA-based proteome profiling allows to extract evidence on presence and quantity of any protein of interest in a post-acquisition manner and the data presented is describing a model which is suitable to study both proteome regulation in general and details of mycoplasma infection process [4], the proteome profiling data presented here is of value for deep annotation. The data was deposited to the PRIDE repository (PXD008198)
β-N-Methylamino-L-Alanine (BMAA) Causes Severe Stress in Nostoc sp. PCC 7120 Cells under Diazotrophic Conditions: A Proteomic Study
Non-proteinogenic neurotoxic amino acid β-N-methylamino-L-alanine (BMAA) is synthesized by cyanobacteria, diatoms, and dinoflagellates, and is known to be a causative agent of human neurodegenerative diseases. Different phytoplankton organisms’ ability to synthesize BMAA could indicate the importance of this molecule in the interactions between microalgae in nature. We were interested in the following: what kinds of mechanisms underline BMAA’s action on cyanobacterial cells in different nitrogen supply conditions. Herein, we present a proteomic analysis of filamentous cyanobacteria Nostoc sp. PCC 7120 cells that underwent BMAA treatment in diazotrophic conditions. In diazotrophic growth conditions, to survive, cyanobacteria can use only biological nitrogen fixation to obtain nitrogen for life. Note that nitrogen fixation is an energy-consuming process. In total, 1567 different proteins of Nostoc sp. PCC 7120 were identified by using LC-MS/MS spectrometry. Among them, 123 proteins belonging to different functional categories were selected—due to their notable expression differences—for further functional analysis and discussion. The presented proteomic data evidences that BMAA treatment leads to very strong (up to 80%) downregulation of α (NifD) and β (NifK) subunits of molybdenum-iron protein, which is known to be a part of nitrogenase. This enzyme is responsible for catalyzing nitrogen fixation. The genes nifD and nifK are under transcriptional control of a global nitrogen regulator NtcA. In this study, we have found that BMAA impacts in a total of 22 proteins that are under the control of NtcA. Moreover, BMAA downregulates 18 proteins that belong to photosystems I or II and light-harvesting complexes; BMAA treatment under diazotrophic conditions also downregulates five subunits of ATP synthase and enzyme NAD(P)H-quinone oxidoreductase. Therefore, we can conclude that the disbalance in energy and metabolite amounts leads to severe intracellular stress that induces the upregulation of stress-activated proteins, such as starvation-inducible DNA-binding protein, four SOS-response enzymes, and DNA repair enzymes, nine stress-response enzymes, and four proteases. The presented data provide new leads into the ecological impact of BMAA on microalgal communities that can be used in future investigations
Proteomic Insights into Starvation of Nitrogen-Replete Cells of Nostoc sp. PCC 7120 under β-N-Methylamino-L-Alanine (BMAA) Treatment
All cyanobacteria produce a neurotoxic non-protein amino acid β-N-methylamino-L-alanine (BMAA). However, the biological function of BMAA in the regulation of cyanobacteria metabolism still remains undetermined. It is known that BMAA suppresses the formation of heterocysts in diazotrophic cyanobacteria under nitrogen starvation conditions, and BMAA induces the formation of heterocyst-like cells under nitrogen excess conditions, by causing the expression of heterocyst-specific genes that are usually “silent” under nitrogen-replete conditions, as if these bacteria receive a nitrogen deficiency intracellular molecular signal. In order to find out the molecular mechanisms underlying this unexpected BMAA effect, we studied the proteome of cyanobacterium Nostoc sp. PCC 7120 grown under BMAA treatment in nitrogen-replete medium. Experiments were performed in two experimental settings: (1) in control samples consisted of cells grown without the BMAA treatment and (2) the treated samples consisted of cells grown with addition of an aqueous solution of BMAA (20 µM). In total, 1567 different proteins of Nostoc sp. PCC 7120 were identified by LC-MS/MS spectrometry. Among them, 80 proteins belonging to different functional categories were chosen for further functional analysis and interpretation of obtained proteomic data. Here, we provide the evidence that a pleiotropic regulatory effect of BMAA on the proteome of cyanobacterium was largely different under conditions of nitrogen-excess compared to its effect under nitrogen starvation conditions (that was studied in our previous work). The most significant difference in proteome expression between the BMAA-treated and untreated samples under different growth conditions was detected in key regulatory protein PII (GlnB). BMAA downregulates protein PII in nitrogen-starved cells and upregulates this protein in nitrogen-replete conditions. PII protein is a key signal transduction protein and the change in its regulation leads to the change of many other regulatory proteins, including different transcriptional factors, enzymes and transporters. Complex changes in key metabolic and regulatory proteins (RbcL, RbcS, Rca, CmpA, GltS, NodM, thioredoxin 1, RpbD, ClpP, MinD, RecA, etc.), detected in this experimental study, could be a reason for the appearance of the “starvation” state in nitrogen-replete conditions in the presence of BMAA. In addition, 15 proteins identified in this study are encoded by genes, which are under the control of NtcA—a global transcriptional regulator—one of the main protein partners and transcriptional regulators of PII protein. Thereby, this proteomic study gives a possible explanation of cyanobacterium starvation under nitrogen-replete conditions and BMAA treatment. It allows to take a closer look at the regulation of cyanobacteria metabolism affected by this cyanotoxin
Ecological and Technological Evaluation of the Nutrition of Perennial Legumes and their Effectiveness for Animals
Main task of feed production is to provide farm animals with nutrients. Insufficient or excessive intake of these elements can lead to undesirable consequences. For instance, a deficiency in mineral elements reduces the protective function of the animal's body against various diseases and disrupts the functional activity of organs. Conversely, an excess of any element contributes to the expenditure of a significant amount of energy for its removal and, in some cases, leads to poisoning. Imbalanced animal feeding results in decreased productivity and a deterioration in the quality of products, leading to the production of non-viable offspring and a disruption of reproductive capacity. Our calculations have shown that increasing the energy concentration in the diet from 490 to 600 EFU/kg DM, combined with an increase in feed intake by 4.4 kg, ensures proportional energy consumption based on their productivity difference. In our research, we concluded that it is economically advantageous to use the planned norms of the nutrient requirements for cattle in feed planning