Retromer-Mediated Protein Sorting and Vesicular Trafficking

Retromer is an evolutionarily conserved multimeric protein complex that mediates intracellular transport of various vesicular cargoes and functions in a wide variety of cellular processes including polarized trafficking,developmental signaling and lysosome biogenesis.Through its interaction with the Rab GTPases and their effectors,membrane lipids,molecular motors,the endocytic machinery and actin nucleation promoting factors,retromer regulates sorting and trafficking of transmembrane proteins from endosomes to the trans-Golgi network(TGN) and the plasma membrane.In this review.I highlight recent progress in the understanding of relromer-medialed protein sorting and vesicle trafficking and discuss how retromer contributes to a diverse set of developmental,physiological and pathological processes.     

Anti-Hepatitis B surface Antigen monoclonal antibody IgM production in suspension and immobilized cell bioreactors

Summary We have cultivated a hybridoma cell-line H505AC in suspension and alginate immobilized cell bioreactors to produce anti-Hepatitis B surface Antigen (anti-HBsAg) monoclonal antibody IgM. The specific IgM production rates correlate linearly with the specific glucose consumption rate in suspension culture with a maximum production rate of 300 g/10⁶ cells/day. In alginate-cell immobilized airlift bioreactor, a total of 1143 milligrams IgM was produced in 9 days operation with a volumetric productivity 44.1 mg/day.L     

投喂低聚木糖对草鱼肠道菌群的影响

投喂添加0.1%、0.2%、0.4%和0.6%低聚木糖的基础饲料56 d, 对草鱼(Ctenopharyngodon idellus)肠道菌群进行了研究。分别在投喂前(0 d)和投喂后的第14、28、42 和56 天取样, 对草鱼肠道大肠杆菌(E. coli)、气单胞菌(Aeromonas)和双歧杆菌(Bifidobacterium)数量进行了分析。结果表明: 基础饲料中添加不同浓度的低聚木糖对草鱼肠道菌群有一定影响, 大肠杆菌数量在28 d 达最低值, 其中0.4%组减少的幅度最大, 与对照组比较显著减少(P<0.05); 气单胞菌数量均有减少但与对照组比较差异并不显著; 双歧杆菌数量均有增加, 其中0.4%组在第14 天时差异显著(P<0.05)。因此, 饲料中添加0.4%低聚木糖效果最佳, 有利于草鱼肠道菌群保持健康的状态。     

濒危珍稀植物半枫荷的转录组分析

为加强中国特有濒危植物半枫荷资源的保护与利用工作,采用高通量测序平台Illumina HiSeq 2500对其进行转录组测序,将得到的数据过滤后进行de novo组装并聚类去冗余,获得77 629个Unigenes,通过九大功能数据库比对、分析、注释,最终有45 293个Unigenes获得注释信息;其中在KOG按功能分为25个子类,获得25 253个功能注释信息;GO功能注释可分为细胞组分、生物学过程、分子功能3大类、分别可细分为22、26、17亚类（共65个亚类）;与KEGG数据库对比,共发现286条代谢通路,其中发现可能与半枫荷药用活性成分相关的次生代谢产物生物合成的177条途径;根据组装结果预测出88个基因家族共1 547个编码转录因子的Unigenes,发现控制药效合成的转录因子家族。另外,根据注释结果检测到12 579个SNP多态位点和预测出57 671个CDS位点。本研究首次对半枫荷转录组进行分析,为深入开展半枫荷分子生物学研究提供基础数据来源。     

一株硝化反硝化菌的筛选鉴定及反硝化特性研究

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Down-regulation of MSH2 expression by an Hsp90 inhibitor enhances pemetrexed-induced cytotoxicity in human non-small-cell lung cancer cells

Elevated heat shock protein 90 (Hsp90) expression has been linked to poor prognosis in patients with non-small cell lung cancer (NSCLC). The multitargeted antifolate pemetrexed has demonstrated certain clinical activities against NSCLC. However, the efficacy of the combination of pemtrexed and Hsp90 inhibitor to prolong the survival of patients with NSCLC still remains unclear. Human MutS homolog 2 (MSH2), a crucial element of the highly conserved DNA mismatch repair system, and defects or polymorphisms of MSH2 have been found in lung cancer. In this study, we evaluated the effects of pemetrexed on NSCLC cell lines (H520 and H1703) and found that treatment with this drug at 20–50 µM increased the MSH2 mRNA and protein levels in a MKK3/6–p38 MAPK signal activation-dependent manner. Furthermore, the knockdown of MSH2 expression by transfection with small interfering RNA of MSH2 or the blockage of p38 MAPK activation by SB202190 enhanced the cytotoxicity of pemetrexed. Combining the drug treatment with an Hsp90 inhibitor resulted in an enhanced pemetrexed-induced cytotoxic effect, accompanied with the reduction of MSH2 protein and mRNA levels. The expression of constitutively active MKK6 (MKK6E) or HA-p38 MAPK vectors significantly rescued the decreased p38 MAPK activity, and restored the MSH2 protein levels and cell survival in NSCLC cells co-treated with pemetrexed and Hsp90 inhibitor. In this study, we have demonstrated that down-regulation of the MKK3/6–p38 MAPK signal with the subsequent reduction of MSH2 enhanced the cytotoxic effect of pemetrexed in H520 and H1703 cells. The results suggest a potential future benefit of combining pemetrexed and the Hsp90 inhibitor to treat lung cancer.     

Epitopes of Escherichia coli ribosomal protein S13

To analyze the immunochemical structure ofEscherichia coli ribosomal protein S13 and its organizationin situ, we have generated and characterized 22 S13-specific monoclonal antibodies. We used a competitive enzyme-linked immunosorbent assay to divide them into groups based on their ability to inhibit binding of one another. The discovery of five groups with distinct binding properties suggested that a minimum of five distinct determinants on S13 are recognized by our monoclonal antibodies. The locations of the epitopes detected by these monoclonal antibodies have been mapped on S13 peptides. Three monoclonal antibodies bind a S13 C-terminal 34-residue segment. All the other 19 monoclonal antibodies bind a S13N-terminal segment of about 80 residues. The binding sites of these 19 monoclonal antibodies have been further mapped to subfragments of peptides. Two monoclonal antibodies recognized S13_1–22; three monoclonal antibodies bound to S13_1–40; the binding sites of three other antibodies have been located in S13_23–80, with epitopes possibly associated with residues 40–80. The remaining 11 monoclonal antibodies did not bind to these subfragments. These data provide molecular basis to the structure of S13 epitopes, whosein situ accessibility may reveal the S13 organization on the ribosome.     

Design, synthesis and biological evaluation of novel chalcone derivatives as antitubulin agents

A series of novel chalcone derivatives have been designed and synthesized, and their biological activities were also evaluated as potential inhibitors of tubulin. These compounds were assayed for growth-inhibitory activity against MCF-7 and A549 cell lines in vitro. Compound 3d showed the most potent antiproliferative activity against MCF-7 and A549 cell lines with IC(50) values of 0.03 and 0.95 μg/mL and exhibited the most potent tubulin inhibitory activity with IC(50) of 1.42 μg/mL. Docking simulation was performed to insert compound 3d into the crystal structure of tubulin at colchicines binding site to determine the probable binding model. Based on the preliminary results, compound 3d with potent inhibitory activity in tumor growth may be a potential anticancer agent.