拟南芥丝氨酸/苏氨酸蛋白激酶基因AtSTK的过量表达可以明显提高拟南芥的耐盐性。为进一步研究AtSTK基因表达的调控机制,以拟南芥基因组DNA为模板设计引物,扩增获得AtSTK基因的启动子序列,并构建到报告载体pAbAi,将重组报告载体质粒pAbAi...拟南芥丝氨酸/苏氨酸蛋白激酶基因AtSTK的过量表达可以明显提高拟南芥的耐盐性。为进一步研究AtSTK基因表达的调控机制,以拟南芥基因组DNA为模板设计引物,扩增获得AtSTK基因的启动子序列,并构建到报告载体pAbAi,将重组报告载体质粒pAbAi-HYT利用BstbⅠ进行单酶切线性化,转化酵母菌株Y1H Gold,线性化的pAbAi-HYT整合到基因组中。然后,将纯化的拟南芥双链cDNA、pGADT7-Rec载体共转化含有报告载体pAbAi-HYT的酵母菌,将菌液涂布到含有100 ng/m L Ab A的SD/-Leu培养基上进行阳性克隆的酵母单杂交筛选。通过回复鉴定、序列测定,最终筛选获得了可能参与AtSTK基因表达调控的4个拟南芥基因。测序结果表明,酵母单杂交筛选获得的拟南芥基因AT3G32090含有WRKY转录因子保守结构域,为WRKY类转录因子的一员。因此,AtSTK基因的表达很可能接受MAPK信号传导途径中AT3G32090基因编码的WRKY类转录因子的调控,从而影响拟南芥植株的耐盐性。展开更多
The epigenetic regulation of gene expression is critical for ensuring the proper deployment and stability of defined genome transcription programs at specific developmental stages. The cellular memory of stable gene e...The epigenetic regulation of gene expression is critical for ensuring the proper deployment and stability of defined genome transcription programs at specific developmental stages. The cellular memory of stable gene expression states during animal and plant development is mediated by the opposing activities of Polycomb group （PcG） factors and trithorax group （trxG） factors. Yet, despite their importance, only a few trxG factors have been characterized in plants and their rotes in regulating plant development are poorly defined. In this work, we report that the closely related Arabidopsis trxG genes ULTRAPETALA1 （ULT1） and ULT2 have overlapping functions in regulating shoot and floral stem cell accumula- tion, with ULT1 playing a major role but ULT2 also making a minor contribution. The two genes also have a novel, redun- dant activity in establishing the apical-basal polarity axis of the gynoecium, indicating that they function in differentiating tissues. Like ULT1 proteins, ULT2 proteins have a dual nuclear and cytoplasmic localization, and the two proteins physically associate in planta. Finally, we demonstrate that ULT1 and ULT2 have very similar overexpression phenotypes and regulate a common set of key development target genes, including floral MADS-box genes and class I KNOX genes. Our results reveal that chromatin remodeling mediated by the ULT1 and ULT2 proteins is necessary to control the development of mer- istems and reproductive organs. They also suggest that, like their animal counterparts, plant trxG proteins may function in multi-protein complexes to up-regulate the expression of key stage- and tissue-specific developmental regulatory genes.展开更多
Maintenance of homeostasis is pivotal to all forms of life. In the case of plants, homeostasis is constantly threatened by the inability to escape environmental fluctuations, and therefore sensitive mechanisms must ha...Maintenance of homeostasis is pivotal to all forms of life. In the case of plants, homeostasis is constantly threatened by the inability to escape environmental fluctuations, and therefore sensitive mechanisms must have evolved to allow rapid perception of environmental cues and concomitant modification of growth and developmental patterns for adaptation and survival. Re-establishment of homeostasis in response to environmental perturbations requires reprog- ramming of metabolism and gene expression to shunt energy sources from growth-related biosynthetic processes to defense, acclimation, and, ultimately, adaptation. Failure to mount an initial ＇emergency＇ response may result in nutrient deprivation and irreversible senescence and cell death. Early signaling events largely determine the capacity of plants to orchestrate a successful adaptive response. Early events, on the other hand, are likely to be shared by different conditions through the generation of similar signals and before more specific responses are elaborated. Recent studies lend credence to this hypothesis, underpinning the importance of a shared energy signal in the transcriptional response to various types of stress. Energy deficiency is associated with most environmental perturbations due to their direct or indirect deleterious impact on photosynthesis and/or respiration. Several systems are known to have evolved for monitoring the available resources and triggering metabolic, growth, and developmental decisions accordingly. In doing so, energy-sensing systems regulate gene expression at multiple levels to allow flexibility in the diversity and the kinetics of the stress response.展开更多
目的:研究PDGF-BB和AP-1在肺动脉中表达改变,探讨肺动脉高压发病机制。方法:体外分离PASMCs进行缺氧,采用real timePCR技术和免疫印迹技术检测AP-1和PDGFR-BB的表达,比较缺氧前后AP-1和PDGFR-BB表达改变。结果:western blot和real time ...目的:研究PDGF-BB和AP-1在肺动脉中表达改变,探讨肺动脉高压发病机制。方法:体外分离PASMCs进行缺氧,采用real timePCR技术和免疫印迹技术检测AP-1和PDGFR-BB的表达,比较缺氧前后AP-1和PDGFR-BB表达改变。结果:western blot和real time PCR结果显示PASMCs中AP-1和PDGFR-BB的表达增加。结论:缺氧PASMCs中AP-1和PDGFR-BB的表达上调,可能是肺动脉高压发病机制之一。展开更多
文摘拟南芥丝氨酸/苏氨酸蛋白激酶基因AtSTK的过量表达可以明显提高拟南芥的耐盐性。为进一步研究AtSTK基因表达的调控机制,以拟南芥基因组DNA为模板设计引物,扩增获得AtSTK基因的启动子序列,并构建到报告载体pAbAi,将重组报告载体质粒pAbAi-HYT利用BstbⅠ进行单酶切线性化,转化酵母菌株Y1H Gold,线性化的pAbAi-HYT整合到基因组中。然后,将纯化的拟南芥双链cDNA、pGADT7-Rec载体共转化含有报告载体pAbAi-HYT的酵母菌,将菌液涂布到含有100 ng/m L Ab A的SD/-Leu培养基上进行阳性克隆的酵母单杂交筛选。通过回复鉴定、序列测定,最终筛选获得了可能参与AtSTK基因表达调控的4个拟南芥基因。测序结果表明,酵母单杂交筛选获得的拟南芥基因AT3G32090含有WRKY转录因子保守结构域,为WRKY类转录因子的一员。因此,AtSTK基因的表达很可能接受MAPK信号传导途径中AT3G32090基因编码的WRKY类转录因子的调控,从而影响拟南芥植株的耐盐性。
基金This work is supported by the Portuguese Foundation for Science and Technology （SFRH/BD/22517/2005 - Ph.D fellow- ship to H.R.R） and the National Science Foundation （IOS- 1052050 to J.C.F.）.We thank Patricia Zambryski, Jennifer Nemhauser, Chris Day, David Ehrhardt, and Robert Blanvillain for providing materi- als, Ludmila Tyler for assistance developing the ult2 alleles, Minna Mahonen, and Paul Hussey and Lilyana Chandra for technical assistance. No conflict of interest declared.
文摘The epigenetic regulation of gene expression is critical for ensuring the proper deployment and stability of defined genome transcription programs at specific developmental stages. The cellular memory of stable gene expression states during animal and plant development is mediated by the opposing activities of Polycomb group （PcG） factors and trithorax group （trxG） factors. Yet, despite their importance, only a few trxG factors have been characterized in plants and their rotes in regulating plant development are poorly defined. In this work, we report that the closely related Arabidopsis trxG genes ULTRAPETALA1 （ULT1） and ULT2 have overlapping functions in regulating shoot and floral stem cell accumula- tion, with ULT1 playing a major role but ULT2 also making a minor contribution. The two genes also have a novel, redun- dant activity in establishing the apical-basal polarity axis of the gynoecium, indicating that they function in differentiating tissues. Like ULT1 proteins, ULT2 proteins have a dual nuclear and cytoplasmic localization, and the two proteins physically associate in planta. Finally, we demonstrate that ULT1 and ULT2 have very similar overexpression phenotypes and regulate a common set of key development target genes, including floral MADS-box genes and class I KNOX genes. Our results reveal that chromatin remodeling mediated by the ULT1 and ULT2 proteins is necessary to control the development of mer- istems and reproductive organs. They also suggest that, like their animal counterparts, plant trxG proteins may function in multi-protein complexes to up-regulate the expression of key stage- and tissue-specific developmental regulatory genes.
文摘Maintenance of homeostasis is pivotal to all forms of life. In the case of plants, homeostasis is constantly threatened by the inability to escape environmental fluctuations, and therefore sensitive mechanisms must have evolved to allow rapid perception of environmental cues and concomitant modification of growth and developmental patterns for adaptation and survival. Re-establishment of homeostasis in response to environmental perturbations requires reprog- ramming of metabolism and gene expression to shunt energy sources from growth-related biosynthetic processes to defense, acclimation, and, ultimately, adaptation. Failure to mount an initial ＇emergency＇ response may result in nutrient deprivation and irreversible senescence and cell death. Early signaling events largely determine the capacity of plants to orchestrate a successful adaptive response. Early events, on the other hand, are likely to be shared by different conditions through the generation of similar signals and before more specific responses are elaborated. Recent studies lend credence to this hypothesis, underpinning the importance of a shared energy signal in the transcriptional response to various types of stress. Energy deficiency is associated with most environmental perturbations due to their direct or indirect deleterious impact on photosynthesis and/or respiration. Several systems are known to have evolved for monitoring the available resources and triggering metabolic, growth, and developmental decisions accordingly. In doing so, energy-sensing systems regulate gene expression at multiple levels to allow flexibility in the diversity and the kinetics of the stress response.
文摘目的:研究PDGF-BB和AP-1在肺动脉中表达改变,探讨肺动脉高压发病机制。方法:体外分离PASMCs进行缺氧,采用real timePCR技术和免疫印迹技术检测AP-1和PDGFR-BB的表达,比较缺氧前后AP-1和PDGFR-BB表达改变。结果:western blot和real time PCR结果显示PASMCs中AP-1和PDGFR-BB的表达增加。结论:缺氧PASMCs中AP-1和PDGFR-BB的表达上调,可能是肺动脉高压发病机制之一。
