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31.
磷酸化是蛋白质翻译后的主要修饰,可分为激酶特异性和非激酶特异性两种类型.以非激酶特异性磷酸化位点Dou数据集为基础,本文发展了一种基于位置的卡方差表特征χ2-pos,融合伪氨基酸序列进化信息PsePSSM表征序列,构建正负样本均衡的支持向量机分类器,S, T, Y独立测试Matthew相关系数、ROC曲线下面积分及准确率分别达到了(0.59、0.87、79.74%),(0.55、0.85、77.68%)和(0.50、0.81、75.22%),明显优于文献报道结果. χ2-pos、PsePSSM两种特征的融合在蛋白质磷酸化位点预测中有广泛应用前景. 相似文献
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肝癌先天性多表达多药耐药基因,严重影响肝癌的化疗效果,筛选肝癌细胞中的耐药基因,研究其耐药机制有助于提高肝癌化疗效果,提高肝癌的治愈率。首先构建肝癌细胞逆转录病毒的cDNA文库,感染成纤维细胞,使得逆转录病毒基因整合进细胞,加药筛选,存活细胞中的基因再次包装成病毒,用于下一轮筛选。采用循环包装回收(Cyclical packaging rescue,CPR)技术进行肝癌细胞耐药基因的筛选即是通过病毒包装将基因从细胞中钓取出来,相比于常规筛选方法,仅通过一轮筛选可能会出现很多假阳性基因,采用CPR技术则是通过多轮筛选,很大程度减少了假阳性细胞的出现。通过该方法经过四轮筛选获得核糖体蛋白S11(RPS11)、核糖体蛋白L6(RPL6)、核糖体蛋白L11(RPL11)、核糖体蛋白L24(RPL24)等几种基因,经初步检测,增加了细胞的耐药性。 相似文献
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Immunohistochemical expression of pi class glutathione S-transferase and alpha-fetoprotein in hepatocellular carcinoma and chronic liver disease 总被引:6,自引:0,他引:6
Yusof YA Yan KL Hussain SN 《Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology》2003,25(6):332-338
OBJECTIVE: To determine whether tumor marker pi glutathione transferase (GST-pi) is expressed in hepatocellular carcinoma (HCC) and other chronic liver diseases and to compare its expression with that of alpha-fetoprotein (AFP). STUDY DESIGN: Samples used were formalin-fixed, paraffin-embedded liver tissues: normal (n = 3), chronic hepatitis B (n = 15), cirrhosis (n = 15) and HCC (n = 30). The expression of AFP and GST-pi was detected by using immunohistochemistry with the peroxidase-antiperoxidase method. AFP immunoreactivity was based on the cytoplasm of the hepatocytes, while GST-pi immunoreactivity was based on the nuclei of hepatocytes. RESULTS: In normal liver tissues, AFP was not expressed. However, there was strong staining of GST-pi in bile duct epithelium cells and weak staining in hepatocytes. Our results showed higher AFP immunoreactivity in cases of HCC (36.7%) as compared to cirrhosis (6.7%) and hepatitis B (0%), whereas GST-pi immunoreactivity was lower in cases of HCC (53.3%) as compared to cases of cirrhosis (100.0%) and hepatitis B (93.3%). Percent sensitivity of AFP determination for HCC was 36.7% as compared to 53.3% for GST-pi, thus making GST-pi a more sensitive marker for detection of HCC. This study showed a significant relationship between the intensity and percentage of cells stained in hepatitis B, cirrhosis and HCC for GST-pi immunoreactivity (P < .001, .001 and .05, respectively) but not for AFP (P > .05). Statistical analysis showed that there was no significant relationship between expression of AFP and GST-pi in cirrhosis and HCC cases. Hepatitis B virus infection in HCC cases showed a positive rate of 46.7%, with AFP staining positively in 42.9% of tissues and GST-pi staining positively in 57.1% of tissues. CONCLUSION: AFP is a diagnostic but rather insensitive tissue marker for HCC. However, the absence of AFP in benign chronic liver disease makes this marker useful in differentiating between HCC and other chronic liver diseases, whereas GST-pi can be used as a diagnostic marker for HCC as well as in detecting other chronic liver diseases. 相似文献
36.
水稻幼芽细胞生物膜上的赤霉素结合蛋白的结合特性 总被引:1,自引:0,他引:1
在水稻 (Oryza sativa)幼芽中存在膜结合的赤霉素结合蛋白 ,其与 GA3 结合的平衡解离常数(Kd)为 6.5× 1 0 -8mol/ L,总浓度为 0 .3 pmol· mg-1 蛋白质。结合蛋白与 GA3 结合活力在 0℃时比 2 5℃时高 1 4 0 %。它与 GA3 结合的最适 p H为 5。 GA3 与此结合蛋白的结合量随反应时间延长而增加 ,1 h达最大值 ,以后又逐渐下降。 IAA、ABA可与 GA3 竞争赤霉素结合蛋白。 相似文献
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HongYuan Wei YuXuan Ye HaiJian Huang MingShun Chen ZiXiang Yang XiaoMing Chen ChuanXi Zhang 《Ecology and evolution》2022,12(4)
The aphid Schlechtendalia chinensis is an economically important insect that can induce horned galls, which are valuable for the medicinal and chemical industries. Up to now, more than twenty aphid genomes have been reported. Most of the sequenced genomes are derived from free‐living aphids. Here, we generated a high‐quality genome assembly from a galling aphid. The final genome assembly is 271.52 Mb, representing one of the smallest sequenced genomes of aphids. The genome assembly is based on contig and scaffold N50 values of the genome sequence are 3.77 Mb and 20.41 Mb, respectively. Nine‐seven percent of the assembled sequences was anchored onto 13 chromosomes. Based on BUSCO analysis, the assembly involved 96.9% of conserved arthropod and 98.5% of the conserved Hemiptera single‐copy orthologous genes. A total of 14,089 protein‐coding genes were predicted. Phylogenetic analysis revealed that S. chinensis diverged from the common ancestor of Eriosoma lanigerum approximately 57 million years ago (MYA). In addition, 35 genes encoding salivary gland proteins showed differentially when S. chinensis forms a gall, suggesting they have potential roles in gall formation and plant defense suppression. Taken together, this high‐quality S. chinensis genome assembly and annotation provide a solid genetic foundation for future research to reveal the mechanism of gall formation and to explore the interaction between aphids and their host plants. 相似文献
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Xiao‐Yan Xu Zhong‐Jie Ding Lei Chen Jin‐Ying Yan Gui‐Xin Li Shao‐Jian Zheng 《植物学报(英文版)》2015,57(10):848-858
Cadmium (Cd) is one of the most toxic elements and can be accumulated in plants easily; meanwhile, eIF5A is a highly conserved protein in all eukaryotic organisms. The present work tried to investigate whether eIF5A is involved in Cd accumulation and sensitivity in Arabidopsis (Arabidopsis thaliana L.) by comparing the wild‐type Columbia‐0 (Col‐0) with a knockdown mutant of AteIF5A‐2, fbr12‐3 under Cd stress conditions. The results showed that the mutant fbr12‐3 accumulated more Cd in roots and shoots and had significantly lower chlorophyll content, shorter root length, and smaller biomass, suggesting that downregulation of AteIF5A‐2 makes the mutant more Cd sensitive. Real‐time polymerase chain reaction revealed that the expressions of metal transporters involved in Cd uptake and translocation including IRT1, ZIP1, AtNramp3, and AtHMA4 were significantly increased but the expressions of PCS1 and PCS2 related to Cd detoxification were decreased notably in fbr12‐3 compared with Col‐0. As a result, an increase in MDA and H2O2 content but decrease in root trolox, glutathione and proline content under Cd stress was observed, indicating that a severer oxidative stress occurs in the mutant. All these results demonstrated for the first time that AteIF5A influences Cd sensitivity by affecting Cd uptake, accumulation, and detoxification in Arabidopsis. 相似文献