187 research outputs found

    Two contrasting late embryogenesis abounded protein family groups of Ramonda serbica Panc.

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    Ramonda serbica Panc. is an ancient resurrection plant, that survives a long desiccation period and fully recovers metabolic functions upon watering. The main characteristic of desiccationtolerant plant species is their ability to accumulate protective late embryogenesis abounded protein (LEAPs). To propose their role in R. serbica desiccation tolerance we structurally analysed LEAPs in hydrated and desiccated leaves. According to transcriptomics, 318 LEAPs were identified and classified into seven family groups based on protein BLAST analysis and conserved motifs (Pfam). The largest LEAPs belonged to the LEA2 and LEA4 protein family groups. We employed online tools to analyse physicochemical characteristics (Expasy, ProtParam, BioPython, GRAVY calculator), disorder propensity, and characterization protein structures (FELLS, JPred, SOPMA, PsiPred, Phyre2, Espritz-DisProt, Espritz-X, Iupred, TMHMM, +Heliquest). The most abundant, atypical LEA2 group containing 127, mostly hydrophobic proteins, was divided into five subgroups. Members of this group were predicted to fold into globular domains, Ī²-barrel at the C-terminus, followed by transmembrane hydrophobic-helices and disordered N-terminal regions. Results indicated the possible involvement in the protection of the chloroplastic membranes. The LEA4 group exhibited an exceptionally high tendency to form amphipathic Ī±-helices and simultaneously had a high disorder propensity. This group is made of 96 proteins, classified into 3 subgroups. The high content of polar and charged amino acids (lysine, glutamate, and aspartate) is characteristic of this group. Motifs corresponding to the R. serbica LEA4 protein family group folded into A-type Ī±-helices that contained positive, negative, and hydrophobic surfaces. Based on previous knowledge, the possible functions of the LEA2 and LEA4 groups are discussed with significant implications on cell preservation technology and the improvement of crop drought tolerance

    Late embryogenesis abundant (LEA) proteins in Ramonda serbica Panc identification, classification and structural characterization

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    An ancient resurrection plant Ramonda serbica Panc. is able to survive a long desiccation period and reestablish metabolic activity upon watering. A hallmark of desiccation tolerance in the resurrection species is the accumulation of protective late embryogenesis abundant proteins (LEAPs). These intrinsically disordered proteins (IDPs) may stabilize the correct structure of proteins and membranes during cellular dehydration. The aim of our study was to assess LEA genesā€™ expression levels in hydrated (HL) and desiccated leaves (DL) and to identify, characterise, and estimate the potential role of R. serbica LEAPs in desiccation tolerance. In total, 318 LEAPs from HL and DL were identified and classified into the seven LEA protein family groups ranging from LEA1-LEA5, seed maturation proteins (SMPs), and dehydrins (DEH). Analysis of the physicochemical properties, motif architecture, secondary structure, homology, and phylogenetic relationships demonstrated that R. serbica LEAPs greatly differed among the LEA family groups. The most abundant LEA2 proteins (mostly downregulated upon desiccation) exhibited lower hydrophilicity and propensity to fold into organised globular domains. Oppositely, hydrophilic LEA4 proteins tended to form amphipathic, A-type, Ī±-helices. Most of desiccation-upregulated LEA genes encoded highly disordered DEH1, LEA1, LEA4.2, and LEA4.3 proteins. While dehydrins might chelate metals and bind DNA under water deficit, other ID LEAPs (e.g. LEA1, LEA3, LEA4) might participate in forming intracellular proteinaceous condensates or adopt amphipathic Ī±-helical conformation, enabling them to stabilise desiccation-sensitive proteins and membranes. Taken together, possible functions of LEAPs are discussed with significant implications on drought tolerance improvement of crops grown in arid areas

    Characterization of the late embryogenesis abundant (LEA) proteins family in hydrated and desiccated Ramonda serbica Panc. leaves

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    Endemic plant species, Ramonda serbica is a resurrection plant that can tolerate extreme dehydration (desiccation, loss of 95% of cellular water) even over months. The accumulation of late embryogenesis abundant proteins (LEAPs) is a crucial step in the mechanism of desiccation tolerance. The role of LEAPs is not completely resolved, but they are accepted as intrinsically disordered proteins (IDPs). Based on previously established de novo transcriptome database of R. serbica leaves we identify around 160 members of LEA gene family. Identified LEAPs were classified into six groups: LEA 1-5 and seed maturation proteins (SMPs) according to protein family (Pfam) database. Based on multiple sequence alignment, secondary structure prediction and 3D structure modeling, we conducted LEA protein structure analysis. We showed that more than 50% of identified LEAPs exhibited a high propensity to form Ī±-helices. As predicted by several bioinformatic tools, more than 70% of identified LEAPs were found to be highly disordered. Thus, these proteins are predicted to be disordered in solution, but they acquire a secondary, predominantly Ī±-helical structure during drying, in contrast to globular proteins, which most often causes the loss of structure upon dehydration. By using molecular dynamic simulations, we identified the most favorable conformations of representative LEAPs and we have studied conformational transitions driven by the water scarcity. Structural characterization of LEAPs is a key to understand their function and regulation of their intrinsic structural disorder-to-order transition during desiccation as a requirement for biological function, in order to promote development of new therapeutic strategies in neurodegenerative disorders, cell preservation technology and the improvement of crop drought tolerance.Serbian Biochemical Society, 10th Conference, Kragujevac, Serbia, 24.09.202

    Error estimation in multitemporal InSAR deformation time series, with application to Lanzarote, Canary Islands

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    Interferometric Synthetic Aperture Radar (InSAR) is a reliable technique for measuring crustal deformation. However, despite its long application in geophysical problems, its error estimation has been largely overlooked. Currently, the largest problem with InSAR is still the atmospheric propagation errors, which is why multitemporal interferometric techniques have been successfully developed using a series of interferograms. However, none of the standard multitemporal interferometric techniques, namely PS or SB (Persistent Scatterers and Small Baselines, respectively) provide an estimate of their precision. Here, we present a method to compute reliable estimates of the precision of the deformation time series. We implement it for the SB multitemporal interferometric technique (a favorable technique for natural terrains, the most usual target of geophysical applications). We describe the method that uses a properly weighted scheme that allows us to compute estimates for all interferogram pixels, enhanced by a Montecarlo resampling technique that properly propagates the interferogram errors (variance-covariances) into the unknown parameters (estimated errors for the displacements). We apply the multitemporal error estimation method to Lanzarote Island (Canary Islands), where no active magmatic activity has been reported in the last decades. We detect deformation around Timanfaya volcano (lengthening of line-of-sight āˆ¼ subsidence), where the last eruption in 1730ā€“1736 occurred. Deformation closely follows the surface temperature anomalies indicating that magma crystallization (cooling and contraction) of the 300-year shallow magmatic body under Timanfaya volcano is still ongoing.Peer reviewe

    Peptide microarrays for the profiling of cytotoxic T-lymphocyte activity using minimum numbers of cells

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    The identification of epitopes that elicit cytotoxic T-lymphocyte activity is a prerequisite for the development of cancer-specific immunotherapies. However, especially the parallel characterization of several epitopes is limited by the availability of T cells. Microarrays have enabled an unprecedented miniaturization and parallelization in biological assays. Here, we developed peptide microarrays for the detection of CTL activity. MHC class I-binding peptide epitopes were pipetted onto polymer-coated glass slides. Target cells, loaded with the cell-impermeant dye calcein, were incubated on these arrays, followed by incubation with antigen-expanded CTLs. Cytotoxic activity was detected by release of calcein and detachment of target cells. With only 200,000 cells per microarray, CTLs could be detected at a frequency of 0.5% corresponding to 1,000 antigen-specific T cells. Target cells and CTLs only settled on peptide spots enabling a clear separation of individual epitopes. Even though no physical boundaries were present between the individual spots, peptide loading only occurred locally and cytolytic activity was confined to the spots carrying the specific epitope. The peptide microarrays provide a robust platform that implements the whole process from antigen presentation to the detection of CTL activity in a miniaturized format. The method surpasses all established methods in the minimum numbers of cells required. With antigen uptake occurring on the microarray, further applications are foreseen in the testing of antigen precursors that require uptake and processing prior to presentation

    UCRAID (Ukrainian Citizen and refugee electronic support in Respiratory diseases, Allergy, Immunology and Dermatology) action plan.

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    Eight million Ukrainians have taken refuge in the European Union. Many have asthma and/or allergic rhinitis and/or urticaria, and around 100,000 may have a severe disease. Cultural and language barriers are a major obstacle to appropriate management. Two widely available mHealth apps, MASK-airĀ® (Mobile Airways Sentinel NetworK) for the management of rhinitis and asthma and CRUSEĀ® (Chronic Urticaria Self Evaluation) for patients with chronic spontaneous urticaria, were updated to include Ukrainian versions that make the documented information available to treating physicians in their own language. The Ukrainian patients fill in the questionnaires and daily symptom-medication scores for asthma, rhinitis (MASK-air) or urticaria (CRUSE) in Ukrainian. Then, following the GDPR, patients grant their physician access to the app by scanning a QR code displayed on the physician's computer enabling the physician to read the app contents in his/her own language. This service is available freely. It takes less than a minute to show patient data to the physician in the physician's web browser. UCRAID-developed by ARIA (Allergic Rhinitis and its Impact on Asthma) and UCARE (Urticaria Centers of Reference and Excellence)-is under the auspices of the Ukraine Ministry of Health as well as European (European Academy of Allergy and Clinical immunology, EAACI, European Respiratory Society, ERS, European Society of Dermatologic Research, ESDR) and national societies
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