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81.
Elevated GAPDH expression is associated with the proliferation and invasion of lung and esophageal squamous cell carcinomas
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Lihong Hao Xin Zhou Shuqing Liu Mingzhong Sun Yang Song Sha Du Bing Sun Chunmei Guo Linlin Gong Jun Hu Shujuan Shao 《Proteomics》2015,15(17):3087-3100
Glyceraldehyde‐3‐phosphate dehydrogenase, is one of the most investigated housekeeping genes and widely used as an internal control in analysis of gene expression levels. The present study was designed to assess whether GAPDH is associated with cancer cell growth and progression and, therefore may not be a good internal control in cancer research. Our results from clinical tissue studies showed that the levels of GAPDH protein were significantly up‐regulated in lung squamous cell carcinoma tissues, compared with the adjacent normal lung tissues, and this was confirmed by western blotting and immunohistochemistry. GAPDH knockdown by siRNA resulted in significant reductions in proliferation, migration, and invasion of lung squamous carcinoma cells in vitro. In a nude mouse cancer xenograft model, GAPDH knockdown significantly inhibited the cell proliferation and migration/invasion in vivo. In summary, GAPDH may not be an appropriate internal control for gene expression studies, especially in cancer research. The role of GAPDH in cancer development and progression should be further examined in pre‐clinical and clinical studies. 相似文献
82.
Structural analysis of the N- and C-termini in a peptide with consensus sequence. 总被引:1,自引:2,他引:1
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Y. Gong H. X. Zhou M. Guo N. R. Kallenbach 《Protein science : a publication of the Protein Society》1995,4(8):1446-1456
We present a structural analysis of a peptide, the sequence of which includes amino acids that show preferences for specific positions near the N- and C-termini in protein helices. This peptide has the sequence ac-YMSEDELKAAEAAFKRHGVP-amide, which includes a strong version of an N-terminal Harper-Rose capping box structure as well as a Gly located close to the C-terminus designed to elucidate its role in C-terminal capping. The sequence of five residues at the middle is inserted to separate effects at the two ends via a helix-stabilizing linker. Application of a simulated annealing procedure using interproton distance constraints derived from 1H NOESY experiments in water reveals the presence of a C-terminal structure in this model. The C-terminus forms a folded back structure in a significant fraction of structures generated by the annealing, in most of which Gly assumes an alpha L conformation. This structure occurs within a highly flexible region of the molecule and hence is occupied only a fraction of the time. 相似文献
83.
蛋白的糖基化对蛋白的活性、高级结构及功能都有重要的影响。酵母表达的糖蛋白不同于哺乳动物表达的杂合型或复杂型糖蛋白,而是高甘露糖型或过度甘露糖化糖蛋白。在前期成功敲除毕赤酵母α-1,6-甘露糖转移酶(Och1p)基因、阻断毕赤酵母过度糖基化,获得毕赤酵母过度糖基化缺陷菌株GJK01 (ura3、och1) 的基础上,通过表达不同物种来源的α-1,2-甘露糖苷酶I (MDSI) 的活性区与酵母自身定位信号的融合蛋白,并通过DSA-FACE (基于DNA测序仪的荧光辅助糖电泳) 分析筛选报告蛋白HSA/GM-CSF (人血清白蛋白与粒细胞-巨噬细胞集落刺激因子融合蛋白) 的糖基结构,发现当编码酿酒酵母α-1,2-甘露糖苷酶 (MnsI) 基因的内质网定位信号与带有完整C-端催化区的拟南芥MDSI基因融合表达时,毕赤酵母工程菌株能够合成Man5GlcNAc2哺乳动物甘露糖型糖蛋白。这为在酵母体内合成类似于哺乳动物杂合型或复杂型糖基化修饰的糖蛋白奠定了基础。 相似文献
84.
γ-氨基丁酸对低氧胁迫下甜瓜幼苗多胺代谢的影响 总被引:1,自引:0,他引:1
以‘西域一号’甜瓜为试验材料,采用营养液水培法,研究了低氧胁迫下外源添加γ-氨基丁酸(GABA)对甜瓜幼苗多胺代谢的影响.结果表明:与通气对照相比,低氧胁迫处理的甜瓜幼苗谷氨酸脱羧酶(GAD)活性和GABA含量显著提高,同时多胺合成酶活性提高诱导多胺含量显著增加,但二胺氧化酶(DAO)和多胺氧化酶(PAO)活性也显著提高;根系精氨酸脱羧酶(ADC)活性提高幅度较大,导致根系游离态腐胺含量较高,而叶片乌氨酸脱羧酶(ODC)和S-腺苷甲硫氨酸脱羧酶(SAMDC)活性提高幅度较大,导致叶片游离态亚精胺(Spd)含量较高;根系游离态DAO和PAO活性显著低于叶片,其细胞壁结合态PAO活性显著高于叶片.与低氧胁迫处理相比,低氧胁迫下外源添加GABA处理的甜瓜幼苗叶片和根系中GABA和谷氨酸含量均显著提高,而GAD活性显著降低;精氨酸、鸟氨酸、甲硫氨酸含量的提高促使多胺合成酶活性显著提高,从而诱导多胺含量显著增加,DAO和PAO活性显著降低. 相似文献
85.
云南高黎贡山蚤类的生态区系 总被引:14,自引:2,他引:14
本文报道了1985年以来对我甸横断山南端高黎贡山东、西坡蚤类生态区系的调查及研究结果。共发现蚤类5科23属47种(亚种)。文中对该山脉蚤类在不同森林植物带的群落结构、种的多样性及均匀度,各种蚤的栖境幅度、宿主多样性进行了陈述和比较,并对蚤类的区系特征、特有种的区系划分等问题进行了讨论。 相似文献
86.
Constance Mehlgarten Daniel Jablonowski Uta Wrackmeyer Susan Tschitschmann David Sondermann Gunilla Jäger Zhizhong Gong Anders S. Byström Raffael Schaffrath Karin D. Breunig 《Molecular microbiology》2010,76(5):1082-1094
Based on studies in yeast and mammalian cells the Elongator complex has been implicated in functions as diverse as histone acetylation, polarized protein trafficking and tRNA modification. Here we show that Arabidopsis mutants lacking the Elongator subunit AtELP3/ELO3 have a defect in tRNA wobble uridine modification. Moreover, we demonstrate that yeast elp3 and elp1 mutants expressing the respective Arabidopsis Elongator homologues AtELP3/ELO3 and AtELP1/ELO2 assemble integer Elongator complexes indicating a high degree of structural conservation. Surprisingly, in vivo complementation studies based on Elongator‐dependent tRNA nonsense suppression and zymocin tRNase toxin assays indicated that while AtELP1 rescued defects of a yeast elp1 mutant, the most conserved Elongator gene AtELP3, failed to complement an elp3 mutant. This lack of complementation is due to incompatibility with yeast ELP1 as coexpression of both plant genes in an elp1 elp3 yeast mutant restored Elongator's tRNA modification function in vivo. Similarly, AtELP1, not ScELP1 also supported partial complementation by yeast–plant Elp3 hybrids suggesting that AtElp1 has less stringent sequence requirements for Elp3 than ScElp1. We conclude that yeast and plant Elongator share tRNA modification roles and propose that this function might be conserved in Elongator from all eukaryotic kingdoms of life. 相似文献
87.
Molecular dynamics (MD) simulation is an important tool for understanding bio-molecules in microscopic temporal/spatial scales. Besides the demand in improving simulation techniques to approach experimental scales, it becomes more and more crucial to develop robust methodology for precisely and objectively interpreting massive MD simulation data. In our previous work [J Phys Chem B 114, 10266 (2010)], the trajectory mapping (TM) method was presented to analyze simulation trajectories then to construct a kinetic transition network of metastable states. In this work, we further present a top-down implementation of TM to systematically detect complicate features of conformational space. We first look at longer MD trajectory pieces to get a coarse picture of transition network at larger time scale, and then we gradually cut the trajectory pieces in shorter for more details. A robust clustering algorithm is designed to more effectively identify the metastable states and transition events. We applied this TM method to detect the hierarchical structure in the conformational space of alanine-dodeca-peptide from microsecond to nanosecond time scales. The results show a downhill folding process of the peptide through multiple pathways. Even in this simple system, we found that single common-used order parameter is not sufficient either in distinguishing the metastable states or predicting the transition kinetics among these states. 相似文献
88.
In this study, the anammox consortium was found to adapt to the wastewater containing dissolved oxygen (DO), as the DO was gradually increased. Batch tests indicated the maximum aerobic ammonium oxidizing activity of the consortium was 1.38mmolNH(4)(+)-N(gVSS)(-1)day(-1), which played key roles in the oxygen consumption process; the maximum anaerobic ammonium oxidizing activity was slightly decreased after long-term oxygen exposure, but only from 21.23mmolNH(4)(+)-N(gVSS)(-1)day(-1) to 20.23mmolNH(4)(+)-N(gVSS)(-1)day(-1). Microbiological community analysis identified two strains similar to Nitrosomonas eutropha were responsible for oxygen consumption, which were able to exist in the autotrophic anaerobic condition for long periods and protect anammox bacteria Planctomycetales from the influence of oxygen. Microbiological composition analysis showed Nitrosomonas and Planctomycetales approximately accounted for 10% and 70% of the bacteria, respectively. The possibility of cultivation anammox consortium in presence of DO will lead to substantial savings of energy and resource in the industrial application. 相似文献
89.
90.