Advances of phage receptor binding proteins / 生物工程学报

Bacteriophages bind to the bacteria receptor through the receptor binding proteins (RBPs), a process that requires the involvement of complex atomic structures and conformational changes. In response to bacteriophage infection, bacteria have developed a variety of resistance mechanisms, while bacteriophages have also evolved multiple antagonistic mechanisms to escape host resistance. The exploration of the "adsorption-anti adsorption-escape process" between bacteriophages and bacteria helps us better understand the co-evolution process of bacteriophages and bacteria, which is important for the development of phage therapeutic technologies and phage-based biotechnologies. This review summarizes the bacteriophage adsorption related proteins, how bacteriophages escape host resistance based on the RBP alternations, and the recent progress of RBP-related biotechnologies.

MiR-1246 Promotes Metastasis and Invasion of A549 cells by Targeting GSK-3β‒Mediated Wnt/β-Catenin Pathway / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: MicroRNAs (miRNAs) are a group of small non-coding RNAs involved in different cancers, including lung cancer. Here, we aim to investigate the expression profiles of circulating miRNAs and their roles contributed to the progress of lung cancer. MATERIALS AND METHODS: The levels of circulating miRNA in lung cancer patients were investigated by miRNAs assay. Then we predicted the target genes of aberrantly expressing miRNAs by searching genetic databases. Based on the A549 cells transfected with miR-1246 mimics or miR-1246 inhibitor,we further measured the roles of miR-1246 involving in the epithelial-mesenchymal transition (EMT), migration and invasion capacities of lung cancer cells in vitro. Finally, we detected the effects of miR-1246 on glycogen synthase kinase-3β (GSK-3β)/β-catenin pathway by immunofluorescence and Western blot, respectively. RESULTS: We identified that 14 miRNAs were aberrantly expressed in the serum of lung cancer patients. Among them, miR-1246 was the most up-regulated. The cell assays indicated that miR-1246 significantly increased the migration and invasion capabilities of A549 lung cancer cells. Meanwhile, immunofluorescence analysis revealed that miR-1246 promoted EMT process of A549 cells accompanying with decreasing E-cadherin expression, while increasing vimentin and transforming growth factor β (TGF-β) expression. Furthermore, an online tool predicated that miR-1246 might bind to 3′-untranslated region of GSK-3β, which was confirmed by overexpression and knockdown of miR-1246 assays. CONCLUSION: Taken together, the study illustrates that miR-1246 regulates Wnt/β-catenin pathway through targeting GSK-3β/β-catenin, which partly contributing to tumor metastasis. MiR-1246 may play an essential role in the diagnosis and therapeutic of lung cancer.

Comparison of Signal Peptides for Two Hemicellulase Secretory Expression / 中国生物工程杂志

Xylanase and mannanase are two hemicellulases,which are widely used in many fields.To improve the expression of thermostable xylanase DSB and thermostable mannanase ManA in Pichia pastoris,three endogenous signal peptides of Pichia pastoris(Scw1 1,Dse4 and Exg1) were chosed.Their capability to mediate the secretion of DSB and ManA with that of the Saccharomyces cerevisiae α-factor were compared.In shake-flask cultivation,three endogenous signal peptides and α-factor efficiently mediated the secretion of DSB and ManA,but the secretion efficiency has obvious difference.As for DSB,the expression efficiency of α-factor was much higher than three endogenous signal peptides.But as for ManA,the expression efficiency of Dse4 was equal to α-factor and much higher than Scw11 and Exg1.Therefore,α-factoris the most efficient signal peptide for DSB expression and Dse4 or α-factor are the most efficient signal peptide for ManA expression in Pichia pastoris X33.Moreover,the intracellular activities of DSB and ManA by α-factor are higher than Scw1 1,Dse4 and Exg1,and the intracellular activity of ManA was higher than DSB (the molecular weight of ManA was larger than DSB).Thus,when ManA were expressed in Pichia pastoris,different signal peptide,such as Dse4,could be used for improving the secretion efficiency.A basis for identifying more available signal peptides and screening for the optimal signal peptide for the target protein was provided.