The rice false smut disease, caused by Ustilaginoidea virens, has emerged as a significantglobal threat to rice production. The mechanism of carbon catabolite repression plays a crucial role in theefficient utilizatio...The rice false smut disease, caused by Ustilaginoidea virens, has emerged as a significantglobal threat to rice production. The mechanism of carbon catabolite repression plays a crucial role in theefficient utilization of carbon nutrients and enzyme regulation in the presence of complex nutritionalconditions. Although significant progress has been made in understanding carbon catabolite repression infungi such as Aspergillus nidulans and Magnaporthe oryzae, its role in U. virens remains unclear. Toaddress this knowledge gap, we identified UvCreA, a pivotal component of carbon catabolite repression,in U. virens. Our investigation revealed that UvCreA localized to the nucleus. Deletion of UvCreA resultedin decreased growth and pathogenicity in U. virens. Through RNA-seq analysis, it was found that theknockout of UvCreA led to the up-regulation of 514 genes and down-regulation of 640 genes. Moreover,UvCreA was found to be involved in the transcriptional regulation of pathogenic genes and genesassociated with carbon metabolism in U. virens. In summary, our findings indicated that UvCreA isimportant in fungal development, virulence, and the utilization of carbon sources through transcriptionalregulation, thus making it a critical element of carbon catabolite repression.展开更多
The influence of high temperature repressing treatment on the segregation of phosphorus in the 93W alloy was carefully investigated by means of Auger electron spectroscope,EPMA, TEM and SEM.The segregation of phosphor...The influence of high temperature repressing treatment on the segregation of phosphorus in the 93W alloy was carefully investigated by means of Auger electron spectroscope,EPMA, TEM and SEM.The segregation of phosphorus has been observed at the tungsten-tungsten grain boundaries,particularly at the tungsten-matrix interphases when the specimens were kept at the temperature in the range of 1200—1500℃ ,followed by furnace cooling.However, no segregation of phosphorus was observed at the interfaces after the specimens were re- pressed at the range of temperature,followed by furnace cooling.After investigation,the dis- locations in the matrix phase of as-repressed specimens directly influenced the phosphorus segregation to the interfaces.After annealing,the mechanical properties were reduced because of the phosphorus segregation at the interface boundaries.展开更多
Aiming at the corrosion issue of oil extraction equipments caused by sulfate-reducing bacteria （SRB） reproducing in oil field affusion system, we studied the dominant strains in the SRB community and the impact of f...Aiming at the corrosion issue of oil extraction equipments caused by sulfate-reducing bacteria （SRB） reproducing in oil field affusion system, we studied the dominant strains in the SRB community and the impact of four ecological factors on the growth of the dominant strains：temperature, pH, mineralization degree and concentration of PAM （Polyacrylamine）. The feasibility of repressing the growth of SRB by changing ecological factors was also discussed. The results indicate that Desutfobacter （one genus of SRB） is the preponderant strains of the system, and the order of the effect of four ecological factors is pH 〉 temperature 〉 the concentrations of PAM 〉 mineralization degree. The optimal pH for the highest growth rate of SRB is 8.0. No growth of SRB was observed when pH 〈 4 or pH 〉 12. The optimal temperature for the growth of SRB is 40 ℃ and the ecological amplitude is 20 -50 ℃. The appropriate concentration values of PAM is 400 -800 mg/L, beyond of which the multiplication rate and growth quantity 6f cell decrease obviously. The effect of mineralization degree of SO4^2- , HCO^3- and Na^＋ on the growth of SRB has reached an extremely remarkable level, and the change of three ions＇ concentration in water obviously effects SRB： The optimum values on the main ions in the system are Cl- of 200mg/L, HCO^3- of 900 mg/L,SO4^2- of 400 mg/L, Mg^2＋ of 60 mg/L and Na^＋ of 900 mg/L. Our results indicate that it is possible to repress the growth of SRB by changing the ecological factors in nil field affusion system.展开更多
LSD1 （KDM1 under the new nomenclature） was the first identified lysine-specific histone demethylase belonging to the flavin-dependent amine oxidase family. Here, we report that AOF1 （KDM1B under the new nomenclatur...LSD1 （KDM1 under the new nomenclature） was the first identified lysine-specific histone demethylase belonging to the flavin-dependent amine oxidase family. Here, we report that AOF1 （KDM1B under the new nomenclature）, a mammalian protein related to LSD1, also possesses histone demethylase activity with specificity for H3K4mel and H3K4me2. Like LSD1, the highly conserved SWIRM domain is required for its enzymatic activity. However, AOF1 differs from LSD1 in several aspects. First, AOF1 does not appear to form stable protein complexes containing histone deacetylases. Second, AOF1 is found to localize to chromosomes during the mitotic phase of the cell cycle, whereas LSD1 does not. Third, AOF1 represses transcription when tethered to DNA and this repression activity is independent of its demethylase activity. Structural and functional analyses identified its unique N-terminal Zf-CW domain as essential for the demethylase activity-independent repression function. Collectively, our study identifies AOF1 as the second histone demethylase in the family of flavin-dependent amine oxidases and reveals a demethylase-independent repression function of AOF1.展开更多
Interferon-gamma （IFN-γ） is a major proinflammatory effector and regulatory cytokine produced by activated T cells and NK cells. IFN-γ has been shown to play pivotal roles in fundamental immunological processes su...Interferon-gamma （IFN-γ） is a major proinflammatory effector and regulatory cytokine produced by activated T cells and NK cells. IFN-γ has been shown to play pivotal roles in fundamental immunological processes such as inflammatory reactions, cell-mediated immunity and autoimmunity. A variety of human disorders have now been linked to irregular IFN-γ expression. In order to achieve proper IFN-γ-mediated immunological effects, IFN-γ expression in T cells is subject to both positive and negative regulation. In this study, we report for the first time the negative regulation of IFN-γ expression by Prospero-related Homeobox （Proxl）. In Jurkat T cells and primary human CD4＋ T cells, Proxl expression decreases quickly upon T cell activation, concurrent with a dramatic increase in IFN-γ expression. Reporter analysis and chromatin immunoprecipitation （CHIP） revealed that Proxl associates with and inhibits the transcription activity of IFN-γ promoter in activated Jurkat T cells. Co-immunoprecipitation and GST pull-down assay demonstrated a direct binding between Proxl and the nuclear receptor peroxisome proliferator-activated receptor gamma （PPARγ）, which is also an IFN-γ repressor in T cells. By introducing deletions and mutations into Proxl, we show that the repression of IFN-γ promoter by Proxl is largely dependent upon the physical interaction between Proxl and PPARγ. Furthermore, PPARγ antagonist treatment removes Proxl from IFN-γ promoter and attenuates repression of IFN-γ expression by Proxl. These findings establish Proxl as a new negative regulator of IFN-γ expression in T cells and will aid in the understanding of IFN-γ transcription regulation mechanisms.展开更多
Polycomb repressive complex 2(PRC2)contributes to catalyze the methylation of histone H3 at lysine 27 and plays vital roles in transcriptional silencing and growth development in various organisms.In Magnaporthe oryza...Polycomb repressive complex 2(PRC2)contributes to catalyze the methylation of histone H3 at lysine 27 and plays vital roles in transcriptional silencing and growth development in various organisms.In Magnaporthe oryzae,histone H3K27 is found to associate with altered transcription of in planta induced genes.However,it is still unknown whether and how H3K27me3 modification is involved in pathogenicity to rice and stress response.In this study,we found that core subunits of PRC2,Kmt6-Suz12-Eed,were required for fungal pathogenicity to rice in M.oryzae.Kmt6-Suz12-Eed localized in the nuclei and was necessary for the establishment of H3K27me3 modification.With ChIP-seq analysis,9.0%of genome regions enriched with H3K27me3 occupancy,which corresponded to 1033 genes in M.oryzae.Furthermore,deletion of Kmt6,Suz12 or Eed altered genome-wide transcriptional expression,while the de-repression genes in theΔkmt6 strain were highly associated with H3K27me3 occupancy.Notably,plenty of genes which encode effectors and secreted enzymes,secondary metabolite synthesis genes,and cell wall stress-responsive genes were directly occupied with H3K27me3 modification and de-repression in theΔkmt6 strain.These results elaborately explained how PRC2 was required for pathogenicity,which is closely related to effector modulated host immunity and host environment adaption.展开更多
基金the Key Projects of Zhejiang Provincial Natural Science Foundation,China(Grant No.LZ23C130002)the National Natural Science Foundation of China(Grant No.32100161)+3 种基金the Zhejiang Science and Technology Major Program on Rice New Variety Breeding,China(Grant No.2021C02063)the Key R&D Project of China National Rice Research Institute(Grant No.CNRRI-2020-04)the Chinese Academy of Agricultural Sciences under the Agricultural Sciences and Technologies Innovation Program,the Youth innovation Program of Chinese Academy of Agricultural Sciences(Grant No.Y2023QC22)the Joint Open Competitive Project of the Yazhou Bay Seed Laboratory and China National Seed Company Limited(Grant Nos.B23YQ1514 and B23CQ15EP).
文摘The rice false smut disease, caused by Ustilaginoidea virens, has emerged as a significantglobal threat to rice production. The mechanism of carbon catabolite repression plays a crucial role in theefficient utilization of carbon nutrients and enzyme regulation in the presence of complex nutritionalconditions. Although significant progress has been made in understanding carbon catabolite repression infungi such as Aspergillus nidulans and Magnaporthe oryzae, its role in U. virens remains unclear. Toaddress this knowledge gap, we identified UvCreA, a pivotal component of carbon catabolite repression,in U. virens. Our investigation revealed that UvCreA localized to the nucleus. Deletion of UvCreA resultedin decreased growth and pathogenicity in U. virens. Through RNA-seq analysis, it was found that theknockout of UvCreA led to the up-regulation of 514 genes and down-regulation of 640 genes. Moreover,UvCreA was found to be involved in the transcriptional regulation of pathogenic genes and genesassociated with carbon metabolism in U. virens. In summary, our findings indicated that UvCreA isimportant in fungal development, virulence, and the utilization of carbon sources through transcriptionalregulation, thus making it a critical element of carbon catabolite repression.
文摘The influence of high temperature repressing treatment on the segregation of phosphorus in the 93W alloy was carefully investigated by means of Auger electron spectroscope,EPMA, TEM and SEM.The segregation of phosphorus has been observed at the tungsten-tungsten grain boundaries,particularly at the tungsten-matrix interphases when the specimens were kept at the temperature in the range of 1200—1500℃ ,followed by furnace cooling.However, no segregation of phosphorus was observed at the interfaces after the specimens were re- pressed at the range of temperature,followed by furnace cooling.After investigation,the dis- locations in the matrix phase of as-repressed specimens directly influenced the phosphorus segregation to the interfaces.After annealing,the mechanical properties were reduced because of the phosphorus segregation at the interface boundaries.
文摘Aiming at the corrosion issue of oil extraction equipments caused by sulfate-reducing bacteria （SRB） reproducing in oil field affusion system, we studied the dominant strains in the SRB community and the impact of four ecological factors on the growth of the dominant strains：temperature, pH, mineralization degree and concentration of PAM （Polyacrylamine）. The feasibility of repressing the growth of SRB by changing ecological factors was also discussed. The results indicate that Desutfobacter （one genus of SRB） is the preponderant strains of the system, and the order of the effect of four ecological factors is pH 〉 temperature 〉 the concentrations of PAM 〉 mineralization degree. The optimal pH for the highest growth rate of SRB is 8.0. No growth of SRB was observed when pH 〈 4 or pH 〉 12. The optimal temperature for the growth of SRB is 40 ℃ and the ecological amplitude is 20 -50 ℃. The appropriate concentration values of PAM is 400 -800 mg/L, beyond of which the multiplication rate and growth quantity 6f cell decrease obviously. The effect of mineralization degree of SO4^2- , HCO^3- and Na^＋ on the growth of SRB has reached an extremely remarkable level, and the change of three ions＇ concentration in water obviously effects SRB： The optimum values on the main ions in the system are Cl- of 200mg/L, HCO^3- of 900 mg/L,SO4^2- of 400 mg/L, Mg^2＋ of 60 mg/L and Na^＋ of 900 mg/L. Our results indicate that it is possible to repress the growth of SRB by changing the ecological factors in nil field affusion system.
基金We thank Dr Ramin Shiekhattar （Wistar Institute, USA） for the baculoviruses expressing Flag-LSD1 and Drs Jianguo Song and Degui Chen （Shanghai Institute of Biochemistry and Cell Biol- ogy, China） for anti-HDAC1 antibody and H3K36me2 antibody, respectively. This study was partially supported by grants from the National Natural Science Foundation of China （90919025, 30871381）, the Ministry of Science and Technology of China （2009CB918402, 2009CB825601） and the Research Platform for Cell Signaling Networks from the Science and Technology Com- mission of Shanghai Municipality （06DZ22923）.
文摘LSD1 （KDM1 under the new nomenclature） was the first identified lysine-specific histone demethylase belonging to the flavin-dependent amine oxidase family. Here, we report that AOF1 （KDM1B under the new nomenclature）, a mammalian protein related to LSD1, also possesses histone demethylase activity with specificity for H3K4mel and H3K4me2. Like LSD1, the highly conserved SWIRM domain is required for its enzymatic activity. However, AOF1 differs from LSD1 in several aspects. First, AOF1 does not appear to form stable protein complexes containing histone deacetylases. Second, AOF1 is found to localize to chromosomes during the mitotic phase of the cell cycle, whereas LSD1 does not. Third, AOF1 represses transcription when tethered to DNA and this repression activity is independent of its demethylase activity. Structural and functional analyses identified its unique N-terminal Zf-CW domain as essential for the demethylase activity-independent repression function. Collectively, our study identifies AOF1 as the second histone demethylase in the family of flavin-dependent amine oxidases and reveals a demethylase-independent repression function of AOF1.
文摘Interferon-gamma （IFN-γ） is a major proinflammatory effector and regulatory cytokine produced by activated T cells and NK cells. IFN-γ has been shown to play pivotal roles in fundamental immunological processes such as inflammatory reactions, cell-mediated immunity and autoimmunity. A variety of human disorders have now been linked to irregular IFN-γ expression. In order to achieve proper IFN-γ-mediated immunological effects, IFN-γ expression in T cells is subject to both positive and negative regulation. In this study, we report for the first time the negative regulation of IFN-γ expression by Prospero-related Homeobox （Proxl）. In Jurkat T cells and primary human CD4＋ T cells, Proxl expression decreases quickly upon T cell activation, concurrent with a dramatic increase in IFN-γ expression. Reporter analysis and chromatin immunoprecipitation （CHIP） revealed that Proxl associates with and inhibits the transcription activity of IFN-γ promoter in activated Jurkat T cells. Co-immunoprecipitation and GST pull-down assay demonstrated a direct binding between Proxl and the nuclear receptor peroxisome proliferator-activated receptor gamma （PPARγ）, which is also an IFN-γ repressor in T cells. By introducing deletions and mutations into Proxl, we show that the repression of IFN-γ promoter by Proxl is largely dependent upon the physical interaction between Proxl and PPARγ. Furthermore, PPARγ antagonist treatment removes Proxl from IFN-γ promoter and attenuates repression of IFN-γ expression by Proxl. These findings establish Proxl as a new negative regulator of IFN-γ expression in T cells and will aid in the understanding of IFN-γ transcription regulation mechanisms.
基金the National Natural Science Foundation of China(Grant Nos.32170192 and 32000103)Zhejiang Science and Technology Major Program on Agricultural New Variety Breeding(Grant No.2021C02064)+1 种基金Key Research and Development Project of China National Rice Research Institute(Grant No.CNRRI-2020-04)the Chinese Academy of Agricultural Sciences under the‘Elite Youth’Program and the Agricultural Sciences and Technologies Innovation Program.
文摘Polycomb repressive complex 2(PRC2)contributes to catalyze the methylation of histone H3 at lysine 27 and plays vital roles in transcriptional silencing and growth development in various organisms.In Magnaporthe oryzae,histone H3K27 is found to associate with altered transcription of in planta induced genes.However,it is still unknown whether and how H3K27me3 modification is involved in pathogenicity to rice and stress response.In this study,we found that core subunits of PRC2,Kmt6-Suz12-Eed,were required for fungal pathogenicity to rice in M.oryzae.Kmt6-Suz12-Eed localized in the nuclei and was necessary for the establishment of H3K27me3 modification.With ChIP-seq analysis,9.0%of genome regions enriched with H3K27me3 occupancy,which corresponded to 1033 genes in M.oryzae.Furthermore,deletion of Kmt6,Suz12 or Eed altered genome-wide transcriptional expression,while the de-repression genes in theΔkmt6 strain were highly associated with H3K27me3 occupancy.Notably,plenty of genes which encode effectors and secreted enzymes,secondary metabolite synthesis genes,and cell wall stress-responsive genes were directly occupied with H3K27me3 modification and de-repression in theΔkmt6 strain.These results elaborately explained how PRC2 was required for pathogenicity,which is closely related to effector modulated host immunity and host environment adaption.
