目的:初步研究78 k D的葡萄糖调节蛋白(the 78 k D glucose-regulated protein,GRP78)与乙型肝炎病毒(hepatitis B virus,HBV)的前S1蛋白(Pre S1)的相互作用位点。方法:利用PCR技术扩增GRP78的基因,将扩增的目的基因克隆至p W28载体质粒...目的:初步研究78 k D的葡萄糖调节蛋白(the 78 k D glucose-regulated protein,GRP78)与乙型肝炎病毒(hepatitis B virus,HBV)的前S1蛋白(Pre S1)的相互作用位点。方法:利用PCR技术扩增GRP78的基因,将扩增的目的基因克隆至p W28载体质粒,在大肠杆菌(Escherichia coli,E.coli)B834中表达,经过镍离子亲和层析柱纯化GRP78蛋白;将Pre S1 3个截短片段的重组质粒(p GST-Pre S1-X1/X2/X3)在B834中表达后,经过GST亲和层析柱纯化相应蛋白;利用蛋白质体外结合实验(pull down)、微量热泳动(microscale thermophoresis,MST)检测GRP78与Pre S1 3个截短片段的相互作用。结果:成功构建重组质粒p W28-GRP78;获得GRP78蛋白及Pre S1 3个截短片段的融合蛋白;pull down及MST实验验证了GRP78可以与Pre S1的3个片段结合,且GRP78与GST-Pre S1-X1结合效果最好。结论:利用分子克隆技术及蛋白质表达纯化技术,获得GRP78蛋白及Pre S1截短片段的融合蛋白,并初步筛选了Pre S1与GRP78的相互作用位点,为后续研究打基础。展开更多
Plant WRKY transcription factors are involved in various physiological processes, including biotic and abiotic stress responses, as well as developmental processes. In this study, the expression patterns of the WRKY68...Plant WRKY transcription factors are involved in various physiological processes, including biotic and abiotic stress responses, as well as developmental processes. In this study, the expression patterns of the WRKY68 protein during interactions between rice 4021 containing the bacterial blight resistance gene Xa21 and Xanthomonas oryzae pv. oryzae（Xoo） were investigated. A possible modified form of the WRKY68 protein appeared in the Xa21-mediated disease resistance response, and its expression levels were similar in compatible and incompatible responses, but differed significantly from that of the mock control treatment, suggesting that WRKY68 may be involved in the bacterial blight response in rice. To further understand WRKY68＇s roles in the resistance signaling pathway, WRKY68 recombinant protein was expressed in Escherichia coli and a microscale thermophoresis analysis was performed to investigate the interactions between WRKY68 and cis-elements in crucial pathogenesis-related（PR） genes. The results showed that the WRKY68 protein binds to W-boxes in the PR1 b promoter region, with an apparent dissociation constant of 25 nmol L–1, while the binding between WRKY68 and PR10 a was W-box independent. The results suggested that a possible modified form of the WRKY68 protein was induced during the interaction between rice and Xoo, which then regulated the activity of the downstream PR genes by binding with the W-boxes in the PR1 b gene＇s promoter region. Moreover, the constitutive transcription of the WRKY68 gene in dozens of rice tissues and the expression of the WRKY68 protein in leaves during all growth stages suggests that WRKY68 plays important roles in rice during normal growth processes.展开更多
Bisphenol A(BPA)is one of the environmental endocrine disruptors(EDCs),and BPA contamination in environment can cause high risks to human health.Rapid determination of BPA on sites is in high demand in environmental a...Bisphenol A(BPA)is one of the environmental endocrine disruptors(EDCs),and BPA contamination in environment can cause high risks to human health.Rapid determination of BPA on sites is in high demand in environmental analysis.Taking advantage of aptamers as affinity ligands and fluorescence anisotropy(FA)analysis,we developed a simple and rapid FA assay for BPA by employing a single tetramethylrhodamine(TMR)labeled short 35-mer DNA aptamer against BPA.The assay is based on the BPA-binding induced conformation change of TMR-labeled aptamer and alteration of interaction between TMR and guanine bases,resulting in change of FA signals.We screened the FA change of aptamer probes having TMR label on a specific site of the aptamer upon BPA addition.The aptamer with a TMR label on the 22nd T base showed large FA-decreasing response to BPA and maintained good binding affinity to BPA.By using this TMR-labeled aptamer,we achieved FA detection of BPA with a detection limit of 0.5μmol/L under the optimized conditions.This assay was selective towards BPA and enabled the detection of BPA spiked in tap water sample,showing the potential applications on water samples.展开更多
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China(20131302110006)
文摘Plant WRKY transcription factors are involved in various physiological processes, including biotic and abiotic stress responses, as well as developmental processes. In this study, the expression patterns of the WRKY68 protein during interactions between rice 4021 containing the bacterial blight resistance gene Xa21 and Xanthomonas oryzae pv. oryzae（Xoo） were investigated. A possible modified form of the WRKY68 protein appeared in the Xa21-mediated disease resistance response, and its expression levels were similar in compatible and incompatible responses, but differed significantly from that of the mock control treatment, suggesting that WRKY68 may be involved in the bacterial blight response in rice. To further understand WRKY68＇s roles in the resistance signaling pathway, WRKY68 recombinant protein was expressed in Escherichia coli and a microscale thermophoresis analysis was performed to investigate the interactions between WRKY68 and cis-elements in crucial pathogenesis-related（PR） genes. The results showed that the WRKY68 protein binds to W-boxes in the PR1 b promoter region, with an apparent dissociation constant of 25 nmol L–1, while the binding between WRKY68 and PR10 a was W-box independent. The results suggested that a possible modified form of the WRKY68 protein was induced during the interaction between rice and Xoo, which then regulated the activity of the downstream PR genes by binding with the W-boxes in the PR1 b gene＇s promoter region. Moreover, the constitutive transcription of the WRKY68 gene in dozens of rice tissues and the expression of the WRKY68 protein in leaves during all growth stages suggests that WRKY68 plays important roles in rice during normal growth processes.
基金supported by the National Natural Science Foundation of China(Nos.21874146,21575153,21435008)。
文摘Bisphenol A(BPA)is one of the environmental endocrine disruptors(EDCs),and BPA contamination in environment can cause high risks to human health.Rapid determination of BPA on sites is in high demand in environmental analysis.Taking advantage of aptamers as affinity ligands and fluorescence anisotropy(FA)analysis,we developed a simple and rapid FA assay for BPA by employing a single tetramethylrhodamine(TMR)labeled short 35-mer DNA aptamer against BPA.The assay is based on the BPA-binding induced conformation change of TMR-labeled aptamer and alteration of interaction between TMR and guanine bases,resulting in change of FA signals.We screened the FA change of aptamer probes having TMR label on a specific site of the aptamer upon BPA addition.The aptamer with a TMR label on the 22nd T base showed large FA-decreasing response to BPA and maintained good binding affinity to BPA.By using this TMR-labeled aptamer,we achieved FA detection of BPA with a detection limit of 0.5μmol/L under the optimized conditions.This assay was selective towards BPA and enabled the detection of BPA spiked in tap water sample,showing the potential applications on water samples.
