Abstract:Transcription factor is a key trans-acting factor to mediate stress response by regulating gene expression. Plants have developed a series of mechanisms to modulate development, stress response, signaling and disease resistance at transcription level. DNA binding with one finger (DOF), containing one C2-C2 zinc finger domain, is a special plant transcription factor. Specifically, the conserved domain at N-terminus of DOF has multiple functions, including interacting with DNA and protein, which could be involved in plant development and stress response. Although many DOF family genes are characterized in plant stress response, it is not clear if DOF genes have functions in cereal plants. In the present paper, the role of DOF family genes on cereal plants were discussed based on a comprehensive phylogenetic relationship analysis, expression profiles in different tissues and various environmental conditions. The results obtained here will provide an important reference for further understanding the mechanism of gramineous crops in stress resistance.

Abstract:Taxol is a secondary metabolite with prominent anti-tumor activity, but the yield cannot meet the growing clinical demand due to lower content in yew. Now, most enzyme genes involved in taxol biosynthesis have been cloned and identified, so that obtaining this drug by using synthetic biology method has become a hotspot in recent years. However, most hydroxylases involved in taxol biosynthetic pathway have not been explored. Here, we reviewed the progress on the biosynthesis pathway of taxol, especially concerning hydroxylase. The future research areas of taxol biosynthesis through synthetic biology were also discussed to provide basis for the discovery of uncharacterized hydroxylase genes and the mass taxol production by synthetic biology technology.

Abstract:Tumor is a neoplasm formed by the abnormal proliferation of local tissue cells under the effects of different tumorigenic factors. Tumor-therapy has always been a difficult clinical issue, while regular cancer treatments, such as radiotherapy, chemotherapy and surgery, have obvious limitations. Earlier studies have shown that some obligate anaerobes or facultative anaerobes have anti-tumor effects, for example, Salmonella typhymurium as facultative anaerobic bacteria can selectively colonize tumors and inhibit their growth. Besides, Salmonella has many advantages in tumor-therapy. In the past decade or two, many researchers have carried out genetic manipulation to attenuate the virulence of Salmonella, to improve their specificity of tumor colonization and specially to use attenuated Salmonella as carriers to deliver a variety of anti-tumor therapeutic molecules, and these genetically modified Salmonella have shown good anti-tumor effects in many animal experiments. Along with further research of Salmonella-mediated antitumor treatment, applications of genetically modified Salmonella for more effective tumor-therapy are promising. We reviewed the anti-tumor mechanisms of Salmonella, the research progress in tumor-therapy using genetically modified Salmonella, and current problems and possible solutions.

Abstract:To analyze the immunogenicity and protective ability of recombinant IgG-binding protein (EAG) of Streptococcus equi subspecies equi and to evaluate its value when used as equine vaccine antigen, EAG gene was amplified by PCR and inserted into pET-28a vector. The EAG recombinant proteins were expressed and purified to immune mice. The serum antibody and challenge protection were tested. The purified recombinant protein of EAG was 26 kDa, and the protein reacted specifically with positive serum of Streptococcus equi subspecies equi. The mice antibody level for EAG immunization group was 1∶8 100. The immunological protection result showed that the protection rate of the EAG recombinant protein was 90%. The results suggested that the EAG protein has good immunogenicity and immunological protection, and it can effectively increase the humoral immune response and immunological protection of mice.

Abstract:Effective expression of pIFN-α in recombinant Pichia pastoris was conducted in a 5 L fermentor. Ethanol accumulation during the late glycerol feeding period inhibited heterologous protein expression. Comparative transcriptome analysis was thus performed to compare the gene transcription profiles of Pichia pastoris KM71H in high and low ethanol concentration environments. The results showed that during the glycerol cultivation stage, 545 genes (265 up-regulated and 280 down-regulated) were differentially expressed with ethanol stress. These genes were mainly involved in protein synthesis, energy metabolism, cell cycle and peroxisome metabolism. During the methanol induction stage, 294 genes (171 up-regulated and 123 down-regulated) were differentially expressed, which were mainly related to methanol metabolism, amino acid metabolism and protein synthesis. Ethanol stress increased protein misfolding and reduced structural integrity of ribosome and mitochondria during cultivation stage, and led to the failure of endoplasmic reticulum stress removal and damaged amino acid metabolism during induction stage in Pichia pastoris.

Abstract:We isolated and identified the symbiotic and adnascent microorganisms from an unidentified sponge collected from 10-meter-deep seawater of the Paracel Islands in China. A total of 16 strains were obtained and identified. Through bacteriostatic activity assay, one of the strains, Dermacoccus sp. X4, was found to effectively inhibit the growth of Staphylococcus aureus. Subsequently, its secondary metabolites were purified by silica gel partition, octadecylsilane (ODS) reverse phase, SephadexTMLH-20 size exclusion, and C18 reverse phase chromatography. Using liquid chromatography, mass spectrometry, and nuclear magnetic resonance, three of the purified compounds were structurally characterized to be one 3-(4-hydroxybenzyl) hexahydropyrrolo [1,2-a]pyrazine-1,4-dione and two indole acid glycerides. This is the first report about indole acid glyceride isolated from microbial secondary metabolites, enriching marine drug candidate resources.

Abstract:To construct soluble TNF related apoptosis inducing ligand (TRAIL) expression system and investigate the effect of the expression product on tumor cell. It may provide valuable information for research into the immune system of the finless porpoise. The full-length cDNA of TRAIL (designated fTRAIL) was cloned from the total RNA of the finless porpoises blood using RT–PCR techniques and then the extracellular soluble fragments of fTRAIL (designated fsTRAIL) was ligated into pET43.1a. Recombinant soluble fTRAIL (pET43.1a-fsTRAIL) fused with Nus-his tag was efficiently expressed in Escherichia coli BL21 (DE3) and the Nus-His-fsTRAIL protein was purified. The expression of Nus-His-fsTRAIL was verified by Western blotting. In vitro, the effects of the purified Nus-His-fsTRAIL protein on Jurkat and HeLa cells were etected by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide (MTT) assay, TrypanBlue and Flow Cytometry analysis. The expression system pET43.1a-fsTRAIL was constructed and Nus-His-fsTRAIL protein was expressed successfully. In vitro, the Nus-His-fsTRAIL protein was able to inhibit the proliferation and induce apoptosis of Jurkat and HeLa cells in a dose-dependent manner. The Nus-His-fsTRAIL protein has anti-tumor activity against Jurkat and HeLa cells in vitro.

Abstract:We isolated and enriched mixed microorganisms SWA1 from landfill cover soils supplemented with trichloroethylene (TCE). The microbial mixture could degrade TCE effectively under aerobic conditions. Then, we investigated the effect of copper ion (0 to 15 μmol/L) on TCE biodegradation. Results show that the maximum TCE degradation speed was 29.60 nmol/min with 95.75% degradation when copper ion was at 0.03 μmol/L. In addition, genes encoding key enzymes during biodegradation were analyzed by Real-time quantitative reverse transcription PCR (RT-qPCR). The relative expression abundance of pmoA gene (4.22E-03) and mmoX gene (9.30E-06) was the highest when copper ion was at 0.03 μmol/L. Finally, we also used MiSeq pyrosequencing to investigate the diversity of microbial community. Methylocystaceae that can co-metabolic degrade TCE were the dominant microorganisms; other microorganisms with the function of direct oxidation of TCE were also included in SWA1 and the microbial diversity decreased significantly along with increasing of copper ion concentration. Based on the above results, variation of copper ion concentration affected the composition of SWA1 and degradation mechanism of TCE. The degradation mechanism of TCE included co-metabolism degradation of methanotrophs and oxidation metabolism directly at copper ion of 0.03 μmol/L. When copper ion at 5 μmol/L (biodegradation was 84.75%), the degradation mechanism of TCE included direct-degradation and co-metabolism degradation of methanotrophs and microorganisms containing phenol hydroxylase. Therefore, biodegradation of TCE by microorganisms was a complicated process, the degradation mechanism included co-metabolism degradation of methanotrophs and bio-oxidation of non-methanotrophs.

Abstract:The heterochronic genes regulate cell proliferation and switch development stage transitions. Heterochronic genes might also play important roles in regulating the development of silkworm, but very few of their expression profiles, functions and their relationship with microRNAs are available so far. Firstly, in this work, the primers for cloning Bmlin-41 were designed based on the homologous sequence of known Drosophila melanogaster lin-41, which was used as the query to blast against SilkDB. The obtained full CDS (2 166 bp) of Bmlin-41 encodes 721 amino acids and contains B-box and NHL domains. Then, the spatiotemporal expression patterns of Bmlin-41 were characterized by RT-PCR, quantitative real time PCR as well as our lab’s previous silkworm genome microarray data. Bmlin-41 was increasingly expressed from embryonic to adult stage. In diverse tissues of day-3 fifth instar, Bmlin-41 showed the highest accumulation in ovary, secondly in testis and midgut, but very low expression was observed in other tissues. Finally, 3′UTR of Bmlin-41 1 434 bp was cloned by rapid-amplification of cDNA ends (3'RACE) and was predicted to bare two binding sites of bmo-let-7 by using online RNAhybrid. To verify the binding effect, 3′UTR was cloned into psi-CHECK-2 vector and submitted to dual luciferase assay in the S2 cells in vitro. The dual luciferase assay demonstrated that Bmlin-41 was down-regulated by bmo-let-7 mimics and upregulated by bmo-let-7 antagomir, thus confirming the Bmlin-41 is negatively regulated by bmo-let-7. Our work might help further study on the roles of Bmlin-41 and bmo-let-7 and their regulation relationship involved in controlling metamorphosis of silkworm.

Abstract:We aimed at analyzing the structure of extracellular polysaccharide A from Grifola frondosa (EXGFP-A) and testing its immunomodulatory activity. Structural analysis shows that EXGFP-A was a contained α-D-glucoside bond and pyranose ring. GC analysis reveals that EXGFP-A was mainly composed of rhamnose, arabinose, xylose, mannose, glucose, galactose, by the molar ratio of 0.28:0.31:0.30:0.06:7.98:0.61. The results of MTT(3-(4,5-Dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) assay indicates when EXGFP-A was at a concentration of 80 μg/mL and treatment time of 48 h, RAW264.7 cells proliferation index reached a maximum of 137.5%. Meanwhile, the AO staining showed that EXGFP-A activated RAW264.7 cells and improved the level of intracellular nucleic acid metabolism. In addition, in a certain range of concentration, EXGFP-A was able to increase the release of NO in RAW264.7 cells, and upregulate the mRNA expression of immunological factor TNF-α, IL-1β, IL-6, IL-12, IFN-γ and iNOS of RAW264.7 cells. Our results confirm that EXGFP-A had immunomodulatory activity. Our findings provided scientific basis for the structural analysis and application of Grifola frondosa polysaccharide.

Abstract:Metabolism and deposition of exogenous gene and protein from transgenic glyphosate herbicide-tolerant soybean meal in SD rats were studied in the experiment. The transgenic soybean GTS40-3-2 meal and its non-transgenic counterpart (parent A5403) were fed to the generation and the second generation Sprague-Dawley (SD) rats (Rattus norvegicus). The study added the genetically modified (GM) soybean meal and its non-transgenic control soybean meal (parent A5403) in a ratio of 20% respectively to the feeds. By using qualitative, quantitative PCR and ELISA methods to detect transgenic soybean residues of metabolism ingredients in rats, the safety and influence of GM soybean were evaluated. The results showed that the intestinal fecal and cecum contents of rats were detected with residues of GM ingredients, intestinal flora and organs were not found related genes and protein. These results indicated that transgenic glyphosate herbicide-tolerant soybean GTS40-3-2 meal was as safe as its non-GM soybean meal in long-term feeding study.

Abstract:Faldaprevir analogue molecule (FAM) has been reported to effectively inhibit the catalytic activity of HCV NS3/4A protease, making it a potential lead compound against HCV. A series of HCV NS3/4A protease crystal structures were analyzed by bioinformatics methods, and the FAM-HCV NS3/4A protease crystal structure was chosen for this study. A 20.4 ns molecular dynamics simulation of the complex consists of HCV NS3/4A protease and FAM was conducted. The key amino acid residues for interaction and the binding driving force for the molecular recognition between the protease and FAM were identified from the hydrogen bonds and binding free energy analyses. With the driving force of hydrogen bonds and van der Waals, FAM specifically bind to the active pocket of HCV NS3/4A protease, including V130?S137, F152?D166, D77?D79 and V55, which agreed with the experimental data. The effect of R155K, D168E/V and V170T site-directed mutagenesis on FAM molecular recognition was analyzed for their effect on drug resistance, which provided the possible molecular explanation of FAM resistance. Finally, the system conformational change was explored by using free energy landscape and conformational cluster. The result showed four kinds of dominant conformation, which provides theoretical basis for subsequent design of Faldaprevir analogue inhibitors based on the structure of HCV NS3/4A protease.

Abstract:Listeria monocytogenes (L. monocytogenes, LM) is an excellent tumor vaccine vector. In this study, recombinant LM vaccine candidate expressing human papillomavirus type 16 (HPV16) E7 protein was constructed and its charactericts were determined. Through homologous recombination, E7 gene was cloned in frame with the LM4 Phly promoter-signal sequence, and introduced into the chromosome of LM4. The recombinant strain named LM4△hly::E7 with the plasmid-free and antibiotic-resistant gene-free was constructed. LM4△hly::E7 could express and secrete E7-LLO fusion protein; its size is 66 kDa and has immunological activity. Furthermore, LM4△hly::E7 could multiply in RAW264.7 macrophages by confocal laser scanning microscope. Additionally, LM4△hly::E7 could induce specific antibodies against E7 in immunized mice in ELISA. Also, the 50% lethal dose (LD50) of LM4△hly::E7 strain was 3.863×109 CFU (Colony-Forming Units) in C57BL/6 mice with intraperitoneal immunization, which was more attenuated than wild type LM4. Mice immunized with LM4△hly::E7 did not show obvious pathological change. These data show that LM4△hly::E7 expressing E7-LLO fusion protein has good safety, which may provide the materials for research of antitumor effect and would be a promising vaccine candidate for cervical cancer.

Abstract:The length of IGF1R 3’UTR is greater than 7 kb. The structure of IGF1R 3’UTR is complex, with multiple binding sites of miRNAs. IGF1R is involved in the regulation of MAPK and PI3K/AKT signaling pathways and the formation and development of tumors. Bioinformatics analysis can reveal the structure features of IGF1R, which provides ideas for further research. The analysis shows that the binding sites between IGF1R and miRNAs have the highest mutation rate in Neuroblastoma. We analyzed the structure of 3'UTR, miRNAs binding sites, physical and chemical properties, hydrophilic-hydrophobic property, glycosylation and phosphorylation sites, secondary structure and tertiary structure modeling of IGF1R. The locations and names of amino acids interacting in IGF1R and IGF1 were obtained by molecular docking. Therefore, if IGF1R 3'UTR is mutated, the capacity of IGF1R combined with miRNAs will reduce and the IGF1R expression will be up-regulated, and the function of miRNAs will be repressed. We can change the sites of IGF1R to combine with IGF1 to repress the function of IGF1R and IGF1. Then the function of IGF1R will be repressed.