CsACO4, an ACC oxidase gene regulating male differentiation in cucumber

Ethylene has been implicated as a sex-determining hormone in cucumber: Its exogenous application increases femaleness and gynoecious genotypes were reported to produce more ethylene. 1- aminocyclopropane-1-carboxylate (ACC) oxidase (ACO) is the key enzyme in ethylene biosynthesis. In this study, a 1,188 base pair (bp) fragment was amplified from cucumber (Jinyan-4) genome with degenerated primers derived from the ACO amino acid consensus sequence among different plant species. The putative new gene was analyzed by bioinformatic tools. Phylogenic analysis result of the new gene (CsACO4, GenBank accession number AY450356) was in accordance with the evolution relationship of genetics among various plant species. The result of BLAST showed the sequence presented a very high match with the ACO genes from other plants; the homologue was from 80 to 99%. Using the sequence, a RNA interference (RNAi) transformation vector was constructed through the way of BP cloning. Eleven transgenic plants were obtained. The transgene integrated into cucumber genome was proved with PCR and southern blotting. The morphological exploration showed that the inserted RNAi target fragments could inhibit the endogenous CsACO4 gene expression and that it could regulate male differentiation in the lower nodes in cucumber.Keywords: Cucumber, ACC oxidase gene, RNAi, male differentiatio

An endoglucanase, GsCelA, from Geobacilus sp. undergoes an intriguing self- truncation process for enhancing activity and thermostability

An endoglucanase, GsCelA, was isolated and cloned from a thermophilic Geobacillus sp. 70PC53 grown in a rice straw compost in southern Taiwan. It was observed that highly purified GsCelA was able to self-truncate, removing a segment of 53 amino acid residues from its C-terminus. The purified GsCelA does not possess any protease activity and this self-truncation process is insensitive to standard protease inhibitors except EDTA and EGTA. This unique self-truncation process takes place at a temperature higher than 10C with an optimal pH between 6-7, and can be further enhanced with certain divalent ions such as Ca+2 and Mg+2. Crystal structure of GsCelA has a typical TIM-barrel configuration with 8 alpha-helices and 8 beta-strands, but with the presence of a divalent ion. Mutations of amino acids residues surrounding this metal ion do not affect the self-truncation process, but some of these mutants have enhanced enzymatic activities. Mutation of the cleavage site between K315 and G316 does not affect the self-truncation process. However, a deletion of ten amino acids near the cleavage site, i.e. from amino acid 310 to 320, slows down the truncation process but does not block it, and a truncated form around 315 amino acids in length eventually appears. This intriguing observation indicates that the self-truncation process is not site specific, but capable of measuring 315 amino acids from the N-terminus as the cleavage site. This self-truncation process also occurs in the native host of this enzyme, Geobacillus sp. 70PC53, with almost all secreted form of this enzyme being self-truncated. The 53 amino-acid-long C-terminal segment removed by this self-truncation process has binding affinity toward both crystal and amorphous cellulose as well as the s cell walls, yet its sequence bears no apparent homology to any known carbohydrate binding motifs. Various other mutation analyses and the structure-based recombination process, SCHEMA, have been carried out, and both the activity and thermostabilty of this enzyme are further improved. The truncated and improved GsCelA has almost twice the activity as the un-truncated form, and its thermostability is also further enhanced with T50 reaching 86C and TA50 higher than 100C, making this enzyme extremely useful in industrial processes carried out at high temperatures, such as the pre-treatment of cellulosic animal feeds during the final drying step. This research was supported by grants from Taiwan Ministry of Science and Technology and from Academia Sinica

A chalcone derivative reactivates latent HIV-1 transcription through activating P-TEFb and promoting Tat-SEC interaction on viral promoter.

The principal barrier to the eradication of HIV/AIDS is the existence of latent viral reservoirs. One strategy to overcome this barrier is to use latency-reversing agents (LRAs) to reactivate the latent proviruses, which can then be eliminated by effective anti-retroviral therapy. Although a number of LRAs have been found to reactivate latent HIV, they have not been used clinically due to high toxicity and poor efficacy. In this study, we report the identification of a chalcone analogue called Amt-87 that can significantly reactivate the transcription of latent HIV provirses and act synergistically with known LRAs such as prostratin and JQ1 to reverse latency. Amt-87 works by activating the human transcriptional elongation factor P-TEFb, a CDK9-cyclin T1 heterodimer that is part of the super elongation complex (SEC) used by the viral encoded Tat protein to activate HIV transcription. Amt-87 does so by promoting the phosphorylation of CDK9 at the T-loop, liberating P-TEFb from the inactive 7SK snRNP, and inducing the formation of the Tat-SEC complex at the viral promoter. Together, our data reveal chalcones as a promising category of compounds that should be further explored to identify effective LRAs for targeted reversal of HIV latency

Cultural Differences in the Study of Public Administration

This is a revised version of a paper given at the international conference Public Admininstration and Governance in a Time of Global Economic Turbulence: Searching for New Paradigms, organized by the Korea Institute of Public Administration(KIPA), in Seoul on October 9, 2009.There are two kinds of truth: extensional (objective) and intentional (subjective). Western culture has traditionally foregrounded extensional truth, while Chinese culture has focused on intentional truth. This paper focuses on intentional truth, which has not been given sufficient attention in the study of public administration. Action knowledge is more valuable than a science of administration, and we need to develop it. All learning takes place inside individuals, so all organizational learning is individual learning. Meanwhile, tacit knowledge must be made explicitly before it can be gainfully deployed. An organizations competitiveness depends on its tacit knowledge, not its explicit knowledge, and the same is true of public administration. This paper uses hermeneutical methods to analyze the meaning of administrative action in organizations from different cultural viewpoints. To deal with the global economic crisis, it is important to develop action knowledge to support theories of how financial crises develop and how they could be avoided, so as to reform the institutionalized paradigm of public administration and governance and to cooperate in dealing with the economic crisis

Synthesis of Aminoalkyl Sclareolide Derivatives and Antifungal Activity Studies

Sclareolide was developed as an efficient C-nucleophilic reagent for an asymmetric Mannich addition reaction with a series of N-tert-butylsulfinyl aldimines. The Mannich reaction was carried out under mild conditions, affording the corresponding aminoalkyl sclareolide derivatives with up to 98% yield and 98:2:0:0 diastereoselectivity. Furthermore, the reaction could be performed on a gram scale without any reduction in yield and diastereoselectivity. Additionally, deprotection of the obtained Mannich addition products to give the target sclareolide derivatives bearing a free N-H group was demonstrated. In addition, target compounds 4–6 were subjected to an antifungal assay in vitro, which showed considerable antifungal activity against forest pathogenic fungi.Financial support from the National Natural Science Foundation of China (Nos. 21761132021 and 21606133) and IKERBASQUE, Basque Foundation for Science

Enhancement of activity and thermostability of a Geobacillus endoglucanase via a unique self-truncation process

The complete utilization of lignocellulosic biomass requires the hydrolysis of cellulose fibers via the synergistic action of three enzymes: exoglucanase, endoglucanase and beta-glucosidase. GsCelA is a 368-amino-acid endoglucanase secreted from a thermophilic Geobacillus sp. 70PC53 that was isolated form a rice straw compost in south Taiwan. GsCelA belongs to the glycosyl hydrolase family 5 and has a typical TIM barrel structure. This enzyme has excellent lignocellulolytic activity and high thermostability, with optimal temperature at 60℃ and pH at 5.0. The purified GsCelA is capable of carrying out a unique self-truncation process at temperature higher than 10 ℃ with optimal pH at 6-7. This self-truncation process is not due to the action of contaminating proteases and it can be suppressed by EDTA and EGTA, and enhanced by divalent metal ions. This self-truncation process also takes place in vivo in Geobacillus sp. 70PC53. The spontaneous or engineered C-terminal truncation up to 60 amino acids from the C-terminus improves GsCelA specific activity and renders the enzyme more thermostable. To investigate the importance of specific amino acids on the enzymatic activity of GsCelA, site-directed mutagenesis and protein engineering approach were employed to alter amino acid residues unique to this enzyme. It was demonstrated that point mutations Y195T , D55S, G288T and D289L replacements increase the activity of this enzyme by 30%

Depletion of OLFM4 gene inhibits cell growth and increases sensitization to hydrogen peroxide and tumor necrosis factor-alpha induced-apoptosis in gastric cancer cells

<p>Abstract</p> <p>Background</p> <p>Human olfactomedin 4 (OLFM4) gene is a secreted glycoprotein more commonly known as the anti-apoptotic molecule GW112. OLFM4 is found to be frequently up-regulated in many types of human tumors including gastric cancer and it was believed to play significant role in the progression of gastric cancer. Although the function of OLFM4 has been indicated in many studies, recent evidence strongly suggests a cell or tissue type-dependent role of OLFM4 in cell growth and apoptosis. The aim of this study is to examine the role of gastric cancer-specific expression of OLFM4 in cell growth and apoptosis resistance.</p> <p>Methods</p> <p>OLFM4 expression was eliminated by RNA interference in SGC-7901 and MKN45 cells. Cell proliferation, anchorage-independent growth, cell cycle and apoptosis were characterized in vitro. Tumorigenicity was analyzed in vivo. The apoptosis and caspase-3 activation in response to hydrogen peroxide (H₂O₂) or tumor necrosis factor-alpha (TNF α) were assessed in the presence or absence of caspase inhibitor Z-VAD-fmk.</p> <p>Results</p> <p>The elimination of OLFM4 protein by RNA interference in SGC-7901 and MKN45 cells significantly inhibits tumorigenicity both in vitro and in vivo by induction of cell G1 arrest (all P < 0.01). OLFM4 knockdown did not trigger obvious cell apoptosis but increased H₂O₂or TNF α-induced apoptosis and caspase-3 activity (all P < 0.01). Treatment of Z-VAD-fmk attenuated caspase-3 activity and significantly reversed the H₂O₂or TNF α-induced apoptosis in OLFM4 knockdown cells (all P < 0.01).</p> <p>Conclusion</p> <p>Our study suggests that depletion of OLFM4 significantly inhibits tumorigenicity of the gastric cancer SGC-7901 and MKN45 cells. Blocking OLFM4 expression can sensitize gastric cancer cells to H₂O₂or TNF α treatment by increasing caspase-3 dependent apoptosis. A combination strategy based on OLFM4 inhibition and anticancer drugs treatment may provide therapeutic potential in gastric cancer intervention.</p

Multidetector CT Findings of a Congenital Coronary Sinus Anomaly: a Report of Two Cases

Congenital coronary sinus anomalies are extremely rare, and they have received relatively little attention. This is probably due to the lack of both clinical symptoms and significant cardiac functional disturbance. We present two cases of a coronary sinus anomaly and briefly review the literature. Recognizing and being familiar with the variations of a congenital coronary sinus anomaly in congenital heart disease may avoid a misinterpretation of cardiac catheterization findings and the troublesome disruption of coronary sinus blood return during the surgical management of cardiac lesions

Television Meets Facebook: The Correlation between TV Ratings and Social Media

Abstract This study examines the relationship between social media site Facebook and TV ratings drawing from audience factors of integration model of audience behavior. Based on context of Taiwan television network programs, this study collected measures for Facebook likes, shares, comments, posts for three genres of television shows and their Nielsen ratings over a period of eleven weeks, resulting in the size of sample more than 130 observations. This study applied multiple regression models and determined that the key social media measures correlate with TV ratings. In essence, TV shows with higher number of posts and engagement are likely to relate to higher ratings, special in drama shows. Subsequently, this study constructed the TV prediction models with measures for Facebook via SVR. The results suggested that prediction models are a good forecasting of which MAPE was between 10% -20%, even less than 10%. This implies that TV network should be motivated to invest in social media and engage their audience and analysts can use social media as a mechanism of exante forecasting