The Experts below are selected from a list of 1446 Experts worldwide ranked by ideXlab platform
Johannes M F G Aerts - One of the best experts on this subject based on the ideXlab platform.
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hepes activates a mit tfe dependent lysosomal autophagic gene network in cultured cells a call for caution
Autophagy, 2018Co-Authors: Martijn J C Van Der Lienden, Tanit L Gabriel, Jacob Hagen, Saskia Scheij, Tineke Veenendaal, Judith Klumperman, Wilma E Donkerkoopman, Arthur J Verhoeven, Hermen S Overkleeft, Johannes M F G AertsAbstract:ABSTRACTIn recent years, the lysosome has emerged as a highly dynamic, transcriptionally regulated organelle that is integral to nutrient-sensing and metabolic rewiring. This is coordinated by a lysosome-to-nucleus signaling nexus in which MTORC1 controls the subcellular distribution of the microphthalmia-transcription factor E (MiT/TFE) family of “master lysosomal regulators”. Yet, despite the importance of the lysosome in cellular metabolism, the impact of traditional in vitro culture media on lysosomal dynamics and/or MiT/TFE localization has not been fully appreciated. Here, we identify HEPES, a chemical Buffering Agent that is broadly applied in cell culture, as a potent inducer of lysosome biogenesis. Supplementation of HEPES to cell growth media is sufficient to decouple the MiT/TFE family members–TFEB, TFE3 and MITF–from regulatory mechanisms that control their cytosolic retention. Increased MiT/TFE nuclear import in turn drives the expression of a global network of lysosomal-autophagic and innate...
Michel Genard - One of the best experts on this subject based on the ideXlab platform.
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improvement of the enhanced phloem exudation technique to estimate phloem concentration and turgor pressure in tomato
Plant Science, 2010Co-Authors: Safaa Najlas Najla, Gilles Vercambre, Michel GenardAbstract:Abstract A critical appraisal of the EDTA-enhanced exudation technique was performed and improvements for this technique were proposed. Two buffer solutions were used (HEPES and EDTA) at a concentration of 20 mM. HEPES is a Buffering Agent widely used in cell culture. Exudation from cut-ends of petioles and peduncles of tomato was allowed to occur over a period of 7 h. Variations of the buffer solution volume, carbohydrates and potassium concentrations, as well as osmotic pressure, were measured in the exudates. The use of HEPES buffer solution alone is proof of the large uptake of the buffer solution by the plant through the xylem. The effect of this uptake on the classical estimation of the carbohydrate flow and concentration of phloem is presented. An improvement of the technique is proposed in order to correctly estimate: (i) the phloem flow; (ii) its composition (carbohydrates and others solutes); and (iii) the turgor pressure of the phloem. The improved EDTA-enhanced exudation technique was applied to investigate the effect of water stress on the driving variables involved in the carbohydrate allocation within the plant. Phloem composition varied with the date and was affected by water stress as well as turgor pressure, which decreased. Furthermore, differences arose in the turgor pressure at the petiole and peduncle sites. Results showed that the exudation technique could be a useful tool to estimate local phloem composition and turgor pressure and to infer resource allocation within the plant.
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improvement of the enhanced phloem exudation technique to estimate phloem concentration and turgor pressure in tomato
Plant Science, 2010Co-Authors: Safaa Najlas Najla, Gilles Vercambre, Michel GenardAbstract:Abstract A critical appraisal of the EDTA-enhanced exudation technique was performed and improvements for this technique were proposed. Two buffer solutions were used (HEPES and EDTA) at a concentration of 20 mM. HEPES is a Buffering Agent widely used in cell culture. Exudation from cut-ends of petioles and peduncles of tomato was allowed to occur over a period of 7 h. Variations of the buffer solution volume, carbohydrates and potassium concentrations, as well as osmotic pressure, were measured in the exudates. The use of HEPES buffer solution alone is proof of the large uptake of the buffer solution by the plant through the xylem. The effect of this uptake on the classical estimation of the carbohydrate flow and concentration of phloem is presented. An improvement of the technique is proposed in order to correctly estimate: (i) the phloem flow; (ii) its composition (carbohydrates and others solutes); and (iii) the turgor pressure of the phloem. The improved EDTA-enhanced exudation technique was applied to investigate the effect of water stress on the driving variables involved in the carbohydrate allocation within the plant. Phloem composition varied with the date and was affected by water stress as well as turgor pressure, which decreased. Furthermore, differences arose in the turgor pressure at the petiole and peduncle sites. Results showed that the exudation technique could be a useful tool to estimate local phloem composition and turgor pressure and to infer resource allocation within the plant.
Sirma Yegin - One of the best experts on this subject based on the ideXlab platform.
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valorization of egg shell as a detoxifying and Buffering Agent for efficient polymalic acid production by aureobasidium pullulans nrrl y 2311 1 from barley straw hydrolysate
Bioresource Technology, 2019Co-Authors: Sirma Yegin, Badal C Saha, Gregory J Kennedy, Timothy D LeathersAbstract:Abstract Stepwise formulation of a versatile and cost-effective medium based on barley straw hydrolysate and egg shell for efficient polymalic acid production by A. pullulans NRRL Y-2311-1 was carried out for the first time. The strain did not grow and produce polymalic acid when dilute acid pretreated barley straw hydrolysate (total fermentable sugars: 94.60 g/L; furfural: 1.01 g/L; hydroxymethylfurfural: 0.55 g/L; acetic acid: 5.06 g/L) was directly used in medium formulation without detoxification (e.g. charcoal pretreatment). When CaCO3 in the medium formulation was substituted with egg shell powder, efficient production of polymalic acid was achieved without a detoxification step. Utilization of 40 g/L of egg shell powder led to 43.54 g polymalic acid production per L with the productivity of 0.30 g/L/h and yield of 0.48 g/g. The bioprocess strategy used in this study can also be utilized for mass production of several other industrially important microbial organic acids and biomaterials.
Xiao-jun Wang - One of the best experts on this subject based on the ideXlab platform.
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Get phases from arsenic anomalous scattering: de novo SAD phasing of two protein structures crystallized in cacodylate buffer.
PloS one, 2011Co-Authors: Xiang Liu, Heng Zhang, Xiao-jun WangAbstract:The crystal structures of two proteins, a putative pyrazinamidase/nicotinamidase from the dental pathogen Streptococcus mutans (SmPncA) and the human caspase-6 (Casp6), were solved by de novo arsenic single-wavelength anomalous diffraction (As-SAD) phasing method. Arsenic (As), an uncommonly used element in SAD phasing, was covalently introduced into proteins by cacodylic acid, the Buffering Agent in the crystallization reservoirs. In SmPncA, the only cysteine was bound to dimethylarsinoyl, which is a pentavalent arsenic group (As (V)). This arsenic atom and a protein-bound zinc atom both generated anomalous signals. The predominant contribution, however, was from the As anomalous signals, which were sufficient to phase the SmPncA structure alone. In Casp6, four cysteines were found to bind cacodyl, a trivalent arsenic group (As (III)), in the presence of the reducing Agent, dithiothreitol (DTT), and arsenic atoms were the only anomalous scatterers for SAD phasing. Analyses and discussion of these two As-SAD phasing examples and comparison of As with other traditional heavy atoms that generate anomalous signals, together with a few arsenic-based de novo phasing cases reported previously strongly suggest that As is an ideal anomalous scatterer for SAD phasing in protein crystallography.
Su Xiao-dong - One of the best experts on this subject based on the ideXlab platform.
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Get Phases from Arsenic Anomalous Scattering: de novo SAD Phasing of Two Protein Structures Crystallized in Cacodylate Buffer
plos one, 2011Co-Authors: Liu Xiang, Zhang Heng, Wang Xiao-jun, Li Lan-fen, Su Xiao-dongAbstract:The crystal structures of two proteins, a putative pyrazinamidase/nicotinamidase from the dental pathogen Streptococcus mutans (SmPncA) and the human caspase-6 (Casp6), were solved by de novo arsenic single-wavelength anomalous diffraction (As-SAD) phasing method. Arsenic (As), an uncommonly used element in SAD phasing, was covalently introduced into proteins by cacodylic acid, the Buffering Agent in the crystallization reservoirs. In SmPncA, the only cysteine was bound to dimethylarsinoyl, which is a pentavalent arsenic group (As (V)). This arsenic atom and a protein-bound zinc atom both generated anomalous signals. The predominant contribution, however, was from the As anomalous signals, which were sufficient to phase the SmPncA structure alone. In Casp6, four cysteines were found to bind cacodyl, a trivalent arsenic group (As (III)), in the presence of the reducing Agent, dithiothreitol (DTT), and arsenic atoms were the only anomalous scatterers for SAD phasing. Analyses and discussion of these two As-SAD phasing examples and comparison of As with other traditional heavy atoms that generate anomalous signals, together with a few arsenic-based de novo phasing cases reported previously strongly suggest that As is an ideal anomalous scatterer for SAD phasing in protein crystallography.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000294686100025&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Multidisciplinary SciencesSCI(E)PubMed6ARTICLE9e24227
