Filamentous fungi employ conserved eukaryotic signaling pathway to detect and respond to environmental signals, including the presence of the host. Genetic experiment in which a particular signaling protein is lost, o...Filamentous fungi employ conserved eukaryotic signaling pathway to detect and respond to environmental signals, including the presence of the host. Genetic experiment in which a particular signaling protein is lost, or its activity enhanced, have defined some of the function of heterotrimeric G proteins and MAP kinases in development and virulence. A hallmark of these studies is that orthologs in different species may have different functions. Antagonistic fungal-fungal interactions form the basis for biological control of plant disease. These interactions may employ novel modes of regulation by conserved signaling elements. Tag1, a G protein α subunit of Trichoderma. atroviride belonging to fungal Gi class, is involved in repression of sporulation and hyphal coiling(1). Deletion of ortholog of this gene, TgaA, in Trichoderma (Gliocladium) virens, however, did not affect sporulation and growth, yet tgaA mutants are unable to parasitize S. rolfsii sclerotia(2). Mutation of a second G α subunit gene is now under study. TmkA, a MAPK gene of T. virens, is involved in biocontrol properties and repression of conidiation(3). Using suppression-subtraction hybridization and other approaches, we are beginning to identify additional elements of the signaling cascades and their downsteam targets. The role of G protein and MAPK genes are sometimes specific to a particular host fungus or to parasitism of mycelia or sclerotia(2,3). Also of relevance to biocontrol, signal transduction pathway provide a means to alter the balance between sporulation, mycelial growth and hyphal coiling.展开更多
目的:探讨β1整合素功能性过表达对角膜上皮细胞凋亡的影响及机制,为角膜细胞移植提供理论依据。方法:构建β1整合素-绿色荧光蛋白(GFP)融合基因并转染兔角膜上皮细胞。观察融合基因在角膜上皮细胞的表达及对各细胞外基质蛋白的黏附能...目的:探讨β1整合素功能性过表达对角膜上皮细胞凋亡的影响及机制,为角膜细胞移植提供理论依据。方法:构建β1整合素-绿色荧光蛋白(GFP)融合基因并转染兔角膜上皮细胞。观察融合基因在角膜上皮细胞的表达及对各细胞外基质蛋白的黏附能力。检测β1整合素功能性转染对角膜上皮细胞凋亡及丝裂素活化蛋白激酶(mitogen-activated protein kinase,MAP激酶)磷酸化的影响。结果:β1整合素-GFP融合基因成功转染至兔角膜上皮细胞并过表达;β1整合素过表达能够明显增加角膜上皮细胞对各细胞外基质蛋白的黏附力并抑制角膜上皮细胞凋亡及促使MAP激酶磷酸化。结论:β1整合素过表达能有效抑制角膜上皮细胞凋亡,MAP激酶磷酸化可能在这一过程中起重要作用。展开更多
Numerous Trichoderma spp. are mycoparasites and commercially applied as biological control agents against a large number of plant pathogenic fungi. The mycoparasitic interaction is host-specific and several research s...Numerous Trichoderma spp. are mycoparasites and commercially applied as biological control agents against a large number of plant pathogenic fungi. The mycoparasitic interaction is host-specific and several research strategies have been applied to identify the main genes and compounds involved in the antagonist-plant-pathogen three-way interaction. During mycoparasitism, signals from the host fungus are recognised by Trichoderma, stimulating antifungal activities that are accompanied by morphological changes and the secretion of hydrolytic enzymes and antibiotics. Interestingly some morphological changes appeared highly conserved in the strategy of pathogenicity within the fungal world, i.e. the formation of appressoria as well as the secretion of hydrolytic enzymes seem to be general mechanisms of attack both for plant pathogens and mycoparasitic antagonists. This knowledge is being used to identify receptors and key components of signalling pathways involved in fungus-fungus interaction. For this purpose we have cloned the first genes (tmk1, tga1, tga3) from T. atroviride showing a high similarity to MAP kinase and G protein subunits (see abstract by Zeilinger et al.), which have been found to have an important role in pathogenicity by Magnaporthe grisea. To identify the function and involvement of these factors in mycoparasitism by T. atroviride, tmk1, tga1, tga3 disruptant strains were produced. The knock-out mutants were tested by in vivo biocontrol assays for their ability to inhibit soil and foliar plant pathogens such as Rhizoctonia solani, Pythium ultimum and Botrytis cinerea . Disruption of these genes corresponded to a complete loss of biocontrol ability, suggesting a significant role in mycoparasitism. In particular, it has been suggested that tga3 regulates the expression of chitinase-encoding genes, the secretion of the corresponding enzymes and the process of conidiation. Comparative proteome analysis of wild type and disruptants supported this hypothesis, and indicated many changes in the protein profiles of T. atroviride in different interaction conditions with plants and pathogenic hosts.展开更多
目的探讨细胞外信号调节激酶(ERK)信号通路对间歇低氧早期大鼠海马CA1区神经元凋亡及凋亡相关蛋白P53表达的影响.方法选择雄性Wistar大鼠135只,采用随机数字法分为对照组、间歇低氧组、U0126组,每组45只,每组又分为1、3、7、10、14d共5...目的探讨细胞外信号调节激酶(ERK)信号通路对间歇低氧早期大鼠海马CA1区神经元凋亡及凋亡相关蛋白P53表达的影响.方法选择雄性Wistar大鼠135只,采用随机数字法分为对照组、间歇低氧组、U0126组,每组45只,每组又分为1、3、7、10、14d共5个时间点,每个时间点9只.各组大鼠采用免疫组织化学法及蛋白免疫印迹法检测海马CA1区ERK1/2、P53表达;TUNEL法检测海马CA1区神经细胞凋亡情况.结果与间歇低氧组比较,U0126组海马CA1区神经细胞1、3、7、10、14 d ERK1/2蛋白和P53蛋白表达明显降低(P<0.05).与对照组比较,间歇低氧组和U0126组海马CA1区3、7、10、14d神经细胞凋亡指数明显升高(P<0.05).与间歇低氧组比较,U0126组海马CA1区3、7、10、14d神经细胞凋亡指数明显降低(0).100±0.021 vs 0.133±0.015,0.160±0.017 vs0.253±0.019,0.239±0.027 vs 0.351±0.024,0.332±0.033 vs 0.500±0.048,P<0.05).结论 ERK抑制剂U0126通过阻断ERK信号通路减少间歇低氧早期神经细胞的凋亡,可能与其降低P53表达有关.展开更多
目的探讨细胞外信号调节激酶(ERK)抑制剂对间歇低氧大鼠海马CA1区神经细胞自噬相关蛋白表达及认知功能的影响。方法成年雄性Wistar大鼠96只,采用随机数字法分为正常对照组(UC组)、5%间歇低氧组(5%IH组)、ERK抑制剂组(U0126组),每组又分...目的探讨细胞外信号调节激酶(ERK)抑制剂对间歇低氧大鼠海马CA1区神经细胞自噬相关蛋白表达及认知功能的影响。方法成年雄性Wistar大鼠96只,采用随机数字法分为正常对照组(UC组)、5%间歇低氧组(5%IH组)、ERK抑制剂组(U0126组),每组又分为7、14、21、28 d 4个时间点,每个时间点8只大鼠。应用透射电镜观察大鼠海马CA1区神经细胞线粒体、自噬体等超微结构的改变;免疫组织化学法检测海马CA1区ERK1/2、Beclin-1、微管相关蛋白1轻链3(LC3)蛋白表达;TUNEL检测海马CA1区神经细胞凋亡情况;Morris水迷宫检测各组大鼠学习记忆功能。结果与UC组比较,5%IH组7、14、21、28 d海马CAl区神经细胞ERK1/2蛋白表达明显增加(P<0.05);与5%IH组比较,U0126组7、14、21、28 d海马CAl区神经细胞ERK1/2蛋白表达明显降低(15.48±2.00 vs 27.91±2.15,15.51±1.93 vs 35.86±2.58,15.57±2.09 vs 47.04±3.96,15.43±1.97 vs 59.03±4.09,P<0.05)。与UC组比较,5%IH组和U0126组7、14、21、28 d海马CAl区神经细胞Beclin-1和LC3蛋白表达及神经元凋亡指数明显增加(P<0.05);与5%IH组比较,U0126组7、14、21、28 d海马CAl区神经细胞Beclin-1和LC3蛋白表达及神经元凋亡指数明显降低(P<0.05)。与UC组比较,5%IH组和U0126组大鼠7、14、21、28 d逃避潜伏期明显延长,跨越目标象限时间明显缩短(P<0.05);与5%IH组比较,U0126组大鼠7、14、21、28 d逃避潜伏期明显缩短,跨越目标象限时间明显延长(P<0.05)。结论ERK抑制剂U0126通过阻断ERK信号通路抑制大鼠海马神经细胞自噬的激活,进而减轻神经细胞损伤,改善认知功能。展开更多
文摘Filamentous fungi employ conserved eukaryotic signaling pathway to detect and respond to environmental signals, including the presence of the host. Genetic experiment in which a particular signaling protein is lost, or its activity enhanced, have defined some of the function of heterotrimeric G proteins and MAP kinases in development and virulence. A hallmark of these studies is that orthologs in different species may have different functions. Antagonistic fungal-fungal interactions form the basis for biological control of plant disease. These interactions may employ novel modes of regulation by conserved signaling elements. Tag1, a G protein α subunit of Trichoderma. atroviride belonging to fungal Gi class, is involved in repression of sporulation and hyphal coiling(1). Deletion of ortholog of this gene, TgaA, in Trichoderma (Gliocladium) virens, however, did not affect sporulation and growth, yet tgaA mutants are unable to parasitize S. rolfsii sclerotia(2). Mutation of a second G α subunit gene is now under study. TmkA, a MAPK gene of T. virens, is involved in biocontrol properties and repression of conidiation(3). Using suppression-subtraction hybridization and other approaches, we are beginning to identify additional elements of the signaling cascades and their downsteam targets. The role of G protein and MAPK genes are sometimes specific to a particular host fungus or to parasitism of mycelia or sclerotia(2,3). Also of relevance to biocontrol, signal transduction pathway provide a means to alter the balance between sporulation, mycelial growth and hyphal coiling.
基金Supported by S&T Research Project of Liaoning Provincial Department of Education(No.20061000)~~
文摘目的:探讨β1整合素功能性过表达对角膜上皮细胞凋亡的影响及机制,为角膜细胞移植提供理论依据。方法:构建β1整合素-绿色荧光蛋白(GFP)融合基因并转染兔角膜上皮细胞。观察融合基因在角膜上皮细胞的表达及对各细胞外基质蛋白的黏附能力。检测β1整合素功能性转染对角膜上皮细胞凋亡及丝裂素活化蛋白激酶(mitogen-activated protein kinase,MAP激酶)磷酸化的影响。结果:β1整合素-GFP融合基因成功转染至兔角膜上皮细胞并过表达;β1整合素过表达能够明显增加角膜上皮细胞对各细胞外基质蛋白的黏附力并抑制角膜上皮细胞凋亡及促使MAP激酶磷酸化。结论:β1整合素过表达能有效抑制角膜上皮细胞凋亡,MAP激酶磷酸化可能在这一过程中起重要作用。
文摘Numerous Trichoderma spp. are mycoparasites and commercially applied as biological control agents against a large number of plant pathogenic fungi. The mycoparasitic interaction is host-specific and several research strategies have been applied to identify the main genes and compounds involved in the antagonist-plant-pathogen three-way interaction. During mycoparasitism, signals from the host fungus are recognised by Trichoderma, stimulating antifungal activities that are accompanied by morphological changes and the secretion of hydrolytic enzymes and antibiotics. Interestingly some morphological changes appeared highly conserved in the strategy of pathogenicity within the fungal world, i.e. the formation of appressoria as well as the secretion of hydrolytic enzymes seem to be general mechanisms of attack both for plant pathogens and mycoparasitic antagonists. This knowledge is being used to identify receptors and key components of signalling pathways involved in fungus-fungus interaction. For this purpose we have cloned the first genes (tmk1, tga1, tga3) from T. atroviride showing a high similarity to MAP kinase and G protein subunits (see abstract by Zeilinger et al.), which have been found to have an important role in pathogenicity by Magnaporthe grisea. To identify the function and involvement of these factors in mycoparasitism by T. atroviride, tmk1, tga1, tga3 disruptant strains were produced. The knock-out mutants were tested by in vivo biocontrol assays for their ability to inhibit soil and foliar plant pathogens such as Rhizoctonia solani, Pythium ultimum and Botrytis cinerea . Disruption of these genes corresponded to a complete loss of biocontrol ability, suggesting a significant role in mycoparasitism. In particular, it has been suggested that tga3 regulates the expression of chitinase-encoding genes, the secretion of the corresponding enzymes and the process of conidiation. Comparative proteome analysis of wild type and disruptants supported this hypothesis, and indicated many changes in the protein profiles of T. atroviride in different interaction conditions with plants and pathogenic hosts.
文摘目的探讨细胞外信号调节激酶(ERK)信号通路对间歇低氧早期大鼠海马CA1区神经元凋亡及凋亡相关蛋白P53表达的影响.方法选择雄性Wistar大鼠135只,采用随机数字法分为对照组、间歇低氧组、U0126组,每组45只,每组又分为1、3、7、10、14d共5个时间点,每个时间点9只.各组大鼠采用免疫组织化学法及蛋白免疫印迹法检测海马CA1区ERK1/2、P53表达;TUNEL法检测海马CA1区神经细胞凋亡情况.结果与间歇低氧组比较,U0126组海马CA1区神经细胞1、3、7、10、14 d ERK1/2蛋白和P53蛋白表达明显降低(P<0.05).与对照组比较,间歇低氧组和U0126组海马CA1区3、7、10、14d神经细胞凋亡指数明显升高(P<0.05).与间歇低氧组比较,U0126组海马CA1区3、7、10、14d神经细胞凋亡指数明显降低(0).100±0.021 vs 0.133±0.015,0.160±0.017 vs0.253±0.019,0.239±0.027 vs 0.351±0.024,0.332±0.033 vs 0.500±0.048,P<0.05).结论 ERK抑制剂U0126通过阻断ERK信号通路减少间歇低氧早期神经细胞的凋亡,可能与其降低P53表达有关.
文摘目的探讨细胞外信号调节激酶(ERK)抑制剂对间歇低氧大鼠海马CA1区神经细胞自噬相关蛋白表达及认知功能的影响。方法成年雄性Wistar大鼠96只,采用随机数字法分为正常对照组(UC组)、5%间歇低氧组(5%IH组)、ERK抑制剂组(U0126组),每组又分为7、14、21、28 d 4个时间点,每个时间点8只大鼠。应用透射电镜观察大鼠海马CA1区神经细胞线粒体、自噬体等超微结构的改变;免疫组织化学法检测海马CA1区ERK1/2、Beclin-1、微管相关蛋白1轻链3(LC3)蛋白表达;TUNEL检测海马CA1区神经细胞凋亡情况;Morris水迷宫检测各组大鼠学习记忆功能。结果与UC组比较,5%IH组7、14、21、28 d海马CAl区神经细胞ERK1/2蛋白表达明显增加(P<0.05);与5%IH组比较,U0126组7、14、21、28 d海马CAl区神经细胞ERK1/2蛋白表达明显降低(15.48±2.00 vs 27.91±2.15,15.51±1.93 vs 35.86±2.58,15.57±2.09 vs 47.04±3.96,15.43±1.97 vs 59.03±4.09,P<0.05)。与UC组比较,5%IH组和U0126组7、14、21、28 d海马CAl区神经细胞Beclin-1和LC3蛋白表达及神经元凋亡指数明显增加(P<0.05);与5%IH组比较,U0126组7、14、21、28 d海马CAl区神经细胞Beclin-1和LC3蛋白表达及神经元凋亡指数明显降低(P<0.05)。与UC组比较,5%IH组和U0126组大鼠7、14、21、28 d逃避潜伏期明显延长,跨越目标象限时间明显缩短(P<0.05);与5%IH组比较,U0126组大鼠7、14、21、28 d逃避潜伏期明显缩短,跨越目标象限时间明显延长(P<0.05)。结论ERK抑制剂U0126通过阻断ERK信号通路抑制大鼠海马神经细胞自噬的激活,进而减轻神经细胞损伤,改善认知功能。
