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131.
Luciferase-dependent assays, important for biochemical analyses of cytotoxicity and reporter genes, may be perturbed by compounds interfering with the luciferase reaction. We analyzed the impact of different aluminum (Al) species on a luciferase-based assay for determination of cellular adenosine triphosphate. Al0 nanoparticles (Al0–NPs) but not Al2O3–NPs decreased luminescence, correlated to high absorbance of Al0–NPs. By contrast, Al ions increased the luminescent signal. Data demonstrate that luciferase-dependent assays can be reciprocally disturbed by Al–NPs or Al ions in a specific manner, depending on the particular Al species. Careful interpretation of data from such experiments is essential in order to obtain conclusive results. 相似文献
132.
Marie J. Zwetsloot Johannes Lehmann Taryn Bauerle Steven Vanek Rachel Hestrin Abebe Nigussie 《Plant and Soil》2016,408(1-2):95-105
Aims
The objectives of this study were to evaluate (1) the fertilizer potential of bone char, (2) the effects of wood biochar on plant-available phosphorus (P), and (3) the role of root-mycorrhizae-biochar interactions in plant P acquisition from a P-fixing soil.Methods
Incubation and pot experiments were conducted with a P-fixing soil and maize with or without root hairs and arbuscular mycorrhizae (AM) inoculation. Olsen-, resin-P and plant P accumulation were used to estimate P availability from bone char, co-pyrolyzed bone char-wood biochar, and separate bone char and wood biochar additions produced at 60, 350 and 750 °C, and Triple Superphosphate (TSP).Results
Maize inoculated with AM showed similar P accumulation when fertilized with either 750 °C bone char or TSP. Pyrolyzing bone did not increase extractable P in soil in comparison to unpyrolyzed bone, apart from a 67 % increase in resin-extractable P after additions of bone char pyrolyzed at 350 °C. Despite greater Olsen-P extractability, co-pyrolysis of bone with wood reduced maize P uptake. Wood biochars reduced resin-P from bone char by 14–26 %, whereas oven-dried wood increased resin-P by 23 %.Conclusions
Bone char is an effective P fertilizer, especially if root-AM interactions are simultaneously considered. Biochar influences plant access to soil P and requires careful management to improve P availability.133.
134.
The Toxoplasma gondii rhoptry protein ROP18 is an Irga6‐specific kinase and regulated by the dense granule protein GRA7 下载免费PDF全文
Thomas Hermanns Urs B. Müller Stephanie Könen‐Waisman Jonathan C. Howard Tobias Steinfeldt 《Cellular microbiology》2016,18(2):244-259
In mice, avirulent strains (e.g. types II and III) of the protozoan parasite Toxoplasma gondii are restricted by the immunity‐related GTPase (IRG) resistance system. Loading of IRG proteins onto the parasitophorous vacuolar membrane (PVM) is required for vacuolar rupture resulting in parasite clearance. In virulent strain (e.g. type I) infections, polymorphic effector proteins ROP5 and ROP18 cooperate to phosphorylate and thereby inactivate mouse IRG proteins to preserve PVM integrity. In this study, we confirmed the dense granule protein GRA7 as an additional component of the ROP5/ROP18 kinase complex and identified GRA7 association with the PVM by direct binding to ROP5. The absence of GRA7 results in reduced phosphorylation of Irga6 correlated with increased vacuolar IRG protein amounts and attenuated virulence. Earlier work identified additional IRG proteins as targets of T. gondii ROP18 kinase. We show that the only specific target of ROP18 among IRG proteins is in fact Irga6. Similarly, we demonstrate that GRA7 is strictly an Irga6‐specific virulence effector. This identifies T. gondii GRA7 as a regulator for ROP18‐specific inactivation of Irga6. The structural diversity of the IRG proteins implies that certain family members constitute additional specific targets for other yet unknown T. gondii virulence effectors. 相似文献
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Thomas Simonson Shixin Ye‐Lehmann Zoltan Palmai Najette Amara Sandra Wydau‐Dematteis Erwan Bigan Karen Druart Clara Moch Pierre Plateau 《Proteins》2016,84(2):240-253
d ‐Amino acids are largely excluded from protein synthesis, yet they are of great interest in biotechnology. Unnatural amino acids have been introduced into proteins using engineered aminoacyl‐tRNA synthetases (aaRSs), and this strategy might be applicable to d ‐amino acids. Several aaRSs can aminoacylate their tRNA with a d ‐amino acid; of these, tyrosyl‐tRNA synthetase (TyrRS) has the weakest stereospecificity. We use computational protein design to suggest active site mutations in Escherichia coli TyrRS that could increase its d ‐Tyr binding further, relative to l ‐Tyr. The mutations selected all modify one or more sidechain charges in the Tyr binding pocket. We test their effect by probing the aminoacyl‐adenylation reaction through pyrophosphate exchange experiments. We also perform extensive alchemical free energy simulations to obtain l ‐Tyr/d ‐Tyr binding free energy differences. Agreement with experiment is good, validating the structural models and detailed thermodynamic predictions the simulations provide. The TyrRS stereospecificity proves hard to engineer through charge‐altering mutations in the first and second coordination shells of the Tyr ammonium group. Of six mutants tested, two are active towards d ‐Tyr; one of these has an inverted stereospecificity, with a large preference for d ‐Tyr. However, its activity is low. Evidently, the TyrRS stereospecificity is robust towards charge rearrangements near the ligand. Future design may have to consider more distant and/or electrically neutral target mutations, and possibly design for binding of the transition state, whose structure however can only be modeled. Proteins 2016; 84:240–253. © 2015 Wiley Periodicals, Inc. 相似文献
137.
Robert Lehmann Damien J. Lightfoot Celia Schunter Craig T. Michell Hajime Ohyanagi Katsuhiko Mineta Sylvain Foret Michael L. Berumen David J. Miller Manuel Aranda Takashi Gojobori Philip L. Munday Timothy Ravasi 《Molecular ecology resources》2019,19(3):570-585
The iconic orange clownfish, Amphiprion percula, is a model organism for studying the ecology and evolution of reef fishes, including patterns of population connectivity, sex change, social organization, habitat selection and adaptation to climate change. Notably, the orange clownfish is the only reef fish for which a complete larval dispersal kernel has been established and was the first fish species for which it was demonstrated that antipredator responses of reef fishes could be impaired by ocean acidification. Despite its importance, molecular resources for this species remain scarce and until now it lacked a reference genome assembly. Here, we present a de novo chromosome‐scale assembly of the genome of the orange clownfish Amphiprion percula. We utilized single‐molecule real‐time sequencing technology from Pacific Biosciences to produce an initial polished assembly comprised of 1,414 contigs, with a contig N50 length of 1.86 Mb. Using Hi‐C‐based chromatin contact maps, 98% of the genome assembly were placed into 24 chromosomes, resulting in a final assembly of 908.8 Mb in length with contig and scaffold N50s of 3.12 and 38.4 Mb, respectively. This makes it one of the most contiguous and complete fish genome assemblies currently available. The genome was annotated with 26,597 protein‐coding genes and contains 96% of the core set of conserved actinopterygian orthologs. The availability of this reference genome assembly as a community resource will further strengthen the role of the orange clownfish as a model species for research on the ecology and evolution of reef fishes. 相似文献
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140.
Salah E. EI-Hendawy Yuncai Hu Urs Schmidhalter 《植物学报(英文版)》2007,49(9):1352-1360
Success of improving the salt tolerance of genotypes requires effective and reliable screening traits in breeding programs. The objective was to assess the suitability of various physiological traits to screen wheat genotypes for salt tolerance. Thirteen wheat genotypes from Egypt, Germany, Australia and India were grown in soil with two salinity levels (control and 150 mmol/L NaCI) in a greenhouse. The physiological traits (ion contents in leaves and stems, i.e. Na^+, Cl^-, K^+, Ca^2+), the ratios of K^+/Na^+ and Ca^+/Na^+ in the leaves and stems, net photosynthesis rate, stomatal conductance, transpiration rate, chlorophyll content (SPAD value), and leaf water relations, were measured at different growth stages. The physiological traits except for Na^+ and Cl^- in stems and the leaf transpiration rate at 150 mmol/L NaCI showed a significant genotypic variation, indicating that the traits that have a significant genotypic variation may be possibly used as screening criteria. According to the analysis of linear regression of the scores of the physiological traits against those of grain yield, however, the physiological traits of Ca^2+ and Ca2^+/Na^+ at 45 d and final harvest with the greatest genotypic variation were ranked at the top. From a practical and economic point of view, SPAD value should be considered to be used as screening criteria and/or there is a need to develop a quick and practical approach to determine Ca^2+ in plant tissues. 相似文献