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排序方式: 共有911条查询结果,搜索用时 531 毫秒
191.
Kristine M. Frizzell Matthew J. Gamble Jhoanna G. Berrocal Tong Zhang Raga Krishnakumar Yana Cen Anthony A. Sauve W. Lee Kraus 《The Journal of biological chemistry》2009,284(49):33926-33938
Poly(ADP-ribose) polymerase-1 (PARP-1) and poly(ADP-ribose) glycohydrolase (PARG) are enzymes that modify target proteins by the addition and removal, respectively, of ADP-ribose polymers. Although a role for PARP-1 in gene regulation has been well established, the role of PARG is less clear. To investigate how PARP-1 and PARG coordinately regulate global patterns of gene expression, we used short hairpin RNAs to stably knock down PARP-1 or PARG in MCF-7 cells followed by expression microarray analyses. Correlation analyses showed that the majority of genes affected by the knockdown of one factor were similarly affected by the knockdown of the other factor. The most robustly regulated common genes were enriched for stress-response and metabolic functions. In chromatin immunoprecipitation assays, PARP-1 and PARG localized to the promoters of positively and negatively regulated target genes. The levels of chromatin-bound PARG at a given promoter generally correlated with the levels of PARP-1 across the subset of promoters tested. For about half of the genes tested, the binding of PARP-1 at the promoter was dependent on the binding of PARG. Experiments using stable re-expression of short hairpin RNA-resistant catalytic mutants showed that PARP-1 and PARG enzymatic activities are required for some, but not all, target genes. Collectively, our results indicate that PARP-1 and PARG, nuclear enzymes with opposing enzymatic activities, localize to target promoters and act in a similar, rather than antagonistic, manner to regulate gene expression. 相似文献
192.
Avermectin B1a is an important macrolide antibiotic with potent anthlemintic and insecticidal activity. The objective of this study was to enhance productivity of avermectin B1a by optimizing culture medium and glucose feeding fermentation. Results showed that B1a concentration was increased by 48.6% through optimization of nitrogen, carbon sources as well as supplement of 0.2 mM Co2+. It was found that a maximum B1a concentration of 826 mg/l was attained by glucose-feeding in a laboratory scale fermentor, which was two-fold higher than that in the control fermentation. Meanwhile, the proportion of B1a in the total products was increased by 6% with respect to the control process. These results would be very useful for maximizing productivity of avermectin B1a in an up-scaled fermentation. 相似文献
193.
194.
Meng-Er Cen Feng Wang Ying Su Wang-Jun Zhang Bei Sun Gang Wang 《Apoptosis : an international journal on programmed cell death》2018,23(7-8):377-387
In the early stage of acute pancreatitis (AP), abundant cytokines induced by local pancreatic inflammation enter the bloodstream, further cause systemic inflammatory response syndrome (SIRS) by “trigger effect”, which eventually leads to multiple organ dysfunction syndrome (MODS). During SIRS and MODS, the intestinal barrier function was seriously damaged accompanied by the occurrence of gut-derived infection which forms a “second hit summit” by inflammatory overabundance. Gastrointestinal microecology, namely the biologic barrier, could be transformed into a pathogenic state, which is called microflora dysbiosis when interfered by the inflammatory stress during AP. More and more evidences indicate that gastrointestinal microflora dysbiosis plays a key role in “the second hit” induced by AP gut-derived infection. Therefore, the maintenance of gastrointestinal microecology balance is likely to provide an effective method in modulating systemic infection of AP. This article reviewed the progress of gastrointestinal microecology in AP to provide a reference for deeply understanding the pathogenic mechanisms of AP and identifying new therapeutic targets. 相似文献
195.
196.
Ou Li Ang Li Chujun Zhang Jingyu Huang Yongli Meng Shenjing Yuan Junhua Huang Xu Gao Yulong Yao Rui Yin Jinpan Hu Bin Ding Xiufang Hu 《Applied microbiology and biotechnology》2018,102(3):1357-1366
Applied Microbiology and Biotechnology - Paenibacillus elgii B69 produces a new xylose-containing exopolysaccharide (EPS) that effectively removes the pollutants from wastewater through... 相似文献
197.
Respiratory burst oxidase homologue‐dependent H2O2 and chloroplast H2O2 are essential for the maintenance of acquired thermotolerance during recovery after acclimation 下载免费PDF全文
Mintao Sun Fangling Jiang Benjian Cen Junqin Wen Yanzhao Zhou Zhen Wu 《Plant, cell & environment》2018,41(10):2373-2389
Thermotolerance is improved by heat stress (HS) acclimation, and the thermotolerance level is “remembered” by plants. However, the underlying signalling mechanisms remain largely unknown. Here, we showed NADPH oxidase‐mediated H2O2 (NADPH‐H2O2), and chloroplast‐H2O2 promoted the sustained expression of HS‐responsive genes and programmed cell death (PCD) genes, respectively, during recovery after HS acclimation. When spraying the NADPH oxidase inhibitor, diphenylene iodonium, after HS acclimation, the NADPH‐H2O2 level significantly decreased, resulting in a decrease in the expression of HS‐responsive genes and the loss of maintenance of acquired thermotolerance (MAT). In contrast, compared with HS acclimation, NADPH‐H2O2 declined but chloroplast‐H2O2 further enhanced during recovery after HS over‐acclimation, resulting in the reduced expression of HS‐responsive genes and substantial production of PCD. Notably, the further inhibition of NADPH‐H2O2 after HS over‐acclimation also inhibited chloroplast‐H2O2, alleviating the severe PCD and surpassing the MAT of HS over‐acclimation treatment. Due to the change in subcellular H2O2 after HS acclimation, the tomato seedlings maintained a constant H2O2 level during recovery, resulting in stable and lower total H2O2 levels during a tester HS challenge conducted after recovery. We conclude that tomato seedlings increase their MAT by enhancing NADPH‐H2O2 content and controlling chloroplast‐H2O2 production during recovery, which enhances the expression of HS‐responsive genes and balances PCD levels, respectively. 相似文献
198.
Shaoyi Cai Gengzheng Zhu Xiaohong Cen Jingjie Bi Jingru Zhang Xiaoshan Tang Kun Chen Kui Cheng 《Bioorganic & medicinal chemistry》2018,26(8):2041-2050
Toll-like receptor 2 (TLR2) can recognize pathogen-associated molecular patterns to defense against invading organisms and has been represents an attractive therapeutic target. Until today, none TLR2 small molecule antagonist have been developed in clinical trial. Herein, we designed and synthesized 50?N-benzylideneaniline compounds with the help of CADD. And subsequent in vitro studies leading to the optimized compound SMU-A0B13 with most potent inhibitory activity to TLR2 (IC50=18.21?±?0.87?μM). Preliminary mechanism studies indicated that this TLR2 inhibitor can work through the NF-κB signaling pathway with high specificity and low toxicity, and can also efficiently downregulate inflammatory cytokines, such as SEAP, TNF-α and NO in HEK-Blue hTLR2, human PBMC and Raw 264.7 cell lines. Additionally, the docking situation also indicate SMU-A0B13 can well bind to the TLR2-TIR (PDB: 1FYW) active domain, which probably explains the bioactivity. 相似文献
199.
三相流化床L-乳酸发酵及与离子交换分离耦合 总被引:6,自引:0,他引:6
L—乳酸因其能被人体代谢而将在食品、医药工业中代替DL—乳酸。另外均聚和共聚L—乳酸在医学及生产可生物降解的包装材料、农膜等方面有巨大的潜在市场。L—乳酸一般采用米根霉 相似文献
200.
中国婪步甲属一新亚属二新种(鞘翅目:步甲科) 总被引:1,自引:1,他引:0
本文记载了分布在四川地区的婪步甲属新亚属;云纹婪步甲亚属及2新种;云纹婪步甲和拟粘毛婪步甲。模式标本保存于西南农业大学昆虫标本馆内。 相似文献