Differences in relative air humidity affect responses to soil salinity in freshwater and salt marsh populations of the dominant grass species Phragmites australis

Hydrobiologia - Soil salinity diminishes the dominance of species and affects their distribution. Phragmites australis is a dominant ecosystem engineer with broad distribution, high intraspecific...     

Intraspecific differences of Asian/Australian Phragmites australis subgroups reveal no potentially invasive traits

Hydrobiologia - Phragmites australis is a cosmopolitan plant species with high intraspecific diversity and phenotypic plasticity. Due to its variability and large ecological niche breadth,...     

Expression and functional analysis of two NhaD type antiporters from the halotolerant and alkaliphilic <Emphasis Type="Italic">Halomonas</Emphasis> sp. Y2

Na⁺/H⁺ antiporters play important roles in ion and pH homeostasis. In this study, two NhaD homologues that effectively catalyze Na⁺/H⁺ antiporter were identified from Halomonas sp. Y2, a halotolerant and alkaliphilic strain isolated from sodium enriched black liquor. They exhibited high sequence identity of 72 % and similar binding affinities for Na⁺ and Li⁺ translocation, while having different pH profiles. Ha-NhaD1 was active at pH 6.0 and most active at pH 8.0–8.5, whereas Ha-NhaD2 lacked activity at pH 6.0 but exhibited maximum activity at pH 9.5 or higher. Based on multiple alignments, 11 partially conserved residues were selected and corresponding mutants were generated for Ha-NhaD1. As expected, replacement of most of the hydrophobic residues abolished the cation exchange activities. Three serine residues at positions 200, 282 and 353 in Ha-NhaD1 were replaceable by alanines with partial retention of activity. The S353A mutant exhibited significantly reduced binding affinity for Na⁺ and Li⁺, while S282 mutant exhibited an alkaline shift of about 1.5 pH units, as compared to the wild type Ha-NhaD1. Serine at position 282 was predicted to be located in transmembrane segment VIII and was found to be important in regulating pH sensitivity in concert with flanking residues.     

Functional characterization of four allelic variants of human cytochrome P450 1A2

Human cytochrome P450 1A2 catalyzes important reactions in xenobiotic metabolism, including the N-hydroxylation of carcinogenic aromatic amines. In 2001, Chevalier et al. reported four new P450 1A2 sequence variants in the human population. We have now expressed these variants in Escherichia coli and measured protein expression (optical spectroscopy of holoenzyme and immunoblotting) and bioactivation of IQ (2-amino-3-methylimidazo[4,5-f]quinoline) and MeIQ (2-amino-2,4-dimethylimidazo[4,5-f]quinoline) in the lacZ reversion mutagenicity test. Enzyme kinetic analyses were performed for N-hydroxylation of five heterocyclic amine substrates and for O-deethylation of phenacetin. The most drastic effect was that of the R431W substitution: no holoenzyme was detectable. This residue is located in the "meander" peptide region and earlier site-directed mutagenesis studies demonstrated that it is critical for maintenance of protein tertiary structure. The other three variants had subtly different catalytic activities compared to the wild-type enzyme.     

Design, synthesis and biological evaluation of novel acrylamide analogues as inhibitors of BCR-ABL kinase

A series of acrylamide analogues were designed and synthesized from Imatinib and Nilotinib as novel BCR-ABL inhibitors by application of the principle of nonclassical electronic isostere. All new compounds were evaluated for their inhibitory effects on the activity of BCR-ABL kinase and the proliferation of K562 leukemia cancer cells in vitro. The acrylamide analogues in which the substituent in C ring was trifluoromethyl group were identified as highly potent BCR-ABL kinase inhibitors. Compound 13f exhibited an IC(50) value as low as 20.6nM in ABL kinase inhibition and an IC(50) value of 32.3nM for antiproliferative activity, about 10.5-fold and 12-fold lower than those of Imatinib respectively. These results suggest that compound 13f is a promising candidate as a novel BCR-ABL kinase inhibitor for further development.     

High alkaline activity of a thermostable α-amylase (cyclomaltodextrinase) from thermoacidophilic <Emphasis Type="Italic">Alicyclobacillus</Emphasis> isolate

It is well demonstrated that glycosyl hydrolases from Alicyclobacillus strains are general thermoacidophilic enzymes and are ideal proteins for industrial applications. In this study, a thermophilic Alicyclobacillus α-amylase of glycoside hydrolases 13_20 subfamily, AMY1, was identified from an Alicyclobacillus strain and efficiently expressed in the host Escherichia coli BL21 CodonPlus. In agreement with other reported Alicyclobacillus hydrolases, the purified AmyY1 had an optimal pH of 6.0–6.5 in phosphate or citrate/Na₂HPO₄ buffers, and a remarkably decreased activity at pH 8.0. Differently, much higher activity was detected in the alkaline glycine/NaOH reaction mixtures. Compared to the highest amylolytic activity at pH 6.0, AmyY1 exhibited 230 and 116% activities at pH 8.0 and 9.0, respectively. This glycine-activation was further confirmed by a supplementation of glycine into the assay mixtures. During the digestions of various raw starches, AmyY1 also exhibited high hydrolysis efficiency under acidic or alkaline conditions. Findings in this study not only endow AMY1 with much broad applications, but also may provide a novel field for the application potentials of some other Alicyclobacillus hydrolases.     

Feeling the Insight: Uncovering Somatic Markers of the “aha” Experience

Whether internal insight can be recognized by experiencing (somatic feeling) remains an unexplored problem. This study investigated the issue by examining potential somatic markers of the “aha” experience occurring at the moment of sudden insight. Participants were required to solve a set of compound remote associates (CRA) problems and were simultaneously monitored via electrodermal and cardiovascular recordings. The “aha”-related psychological components and somatic markers were determined by contrasting insightful solutions with non-insightful solutions. Results showed that the “aha” experience was an amalgam entailing positive affects and approached cognition accompanied by a greater mean skin conductance response (mSCR) amplitude and a marginally accelerated heart rate than the “no-aha” one. These results confirm and extend findings of the multidimensionality of the “aha” feeling and offer the first direct evidence of somatic markers, particularly an electrodermal signature of an “aha” feeling, which suggests a sudden insight could likely be experienced by individuals’ external soma.     

Nitrogen and α-Ketoglutaric Acid Application Modulate Grain Yield,Aroma, Nutrient Uptake and Physiological Attributes in Fragrant Rice

Journal of Plant Growth Regulation - The present study was conducted to assess the effects of nitrogen (N) and α-ketoglutaric acid application morpho-physiological attributes, aroma...     

Dechorionation of Medaka Embryos and Cell Transplantation for the Generation of Chimeras

Medaka is a small egg-laying freshwater fish that allows both genetic and embryological analyses and is one of the three vertebrate model organisms in which genome-wide phenotype-driven mutant screens were carried out ¹. Divergence of functional overlap of related genes between medaka and zebrafish allows identification of novel phenotypes that are unidentifiable in a single species ², thus medaka and zebrafish are complementary for genetic dissection of the vertebrate genome functions. Manipulation of medaka embryos, such as dechorionation, mounting embryos for imaging and cell transplantation, are key procedures to work on both medaka and zebrafish in a laboratory. Cell transplantation examines cell autonomy of medaka mutations. Chimeras are generated by transplanting labeled cells from donor embryos into unlabeled recipient embryos. Donor cells can be transplanted to specific areas of the recipient embryos based on the fate maps ³ so that clones from transplanted cells can be integrated in the tissue of interest during development. Due to the hard chorion and soft embryos, manipulation of medaka embryos is more involved than in zebrafish. In this video, we show detailed procedures to manipulate medaka embryos.Download video file.^{(55M, mov)}