The Dof (DNA-binding with one finger) proteins are a class of plant-specific transcription factors that can trigger several processes involved in plant growth and development, as well as in stress responses. Here, we ...The Dof (DNA-binding with one finger) proteins are a class of plant-specific transcription factors that can trigger several processes involved in plant growth and development, as well as in stress responses. Here, we performed a systematic bioinformatics analysis to characterize all Dof genes in common bean, which included analysis of the genome sequence, conserved protein domains, chromosomal locations, subcellular locations, phylogenetic relationships, gene duplications, and gene expression profiles in different tissues. Bioinformatics analysis revealed 36 putative genes related to PvDof that were classified into seven subfamilies (A, B1, B2, C1, C2, D1, and, D2) by comparative phylogenetic analysis. Based on our genome duplication analysis, a total of 36 genes were found to be distributed on all 11 chromosomes, and they expanded through gene duplication in tandem, suggesting the involvement of segmental duplication events in the evolutionary process. Synteny events and phylogenetic comparisons of the Dof proteins of common bean with those of A. thaliana, O. sativa, and G. max L. led to the identification of several orthologous and paralogous genes, which provided further insight into the diversity of the evolutionary characteristics of genes of this family in other plant species. Expression profiles revealed that most of the PvDof genes were expressed in different tissues, indicating that PvDof genes may be involved in various physiological functions during plant development. The results of this study provide additional information and potential biotechnological resources for further understanding the molecular basis of this gene family and consequently improvement of common bean crops.展开更多
In complex, constantly changing environments, plants have developed astonishing survival strategies. These elaborated strategies rely on rapid and precise gene regulation mediated by transcription factors （TFs）. TFs...In complex, constantly changing environments, plants have developed astonishing survival strategies. These elaborated strategies rely on rapid and precise gene regulation mediated by transcription factors （TFs）. TFs represent a large fraction of plant genomes and among them, MYBs and basic helix-loop-helix （bHLHs） have unique inherent properties specific to plants. Proteins of these two TF families can act as homo- or heterodimers, associate with proteins from other protein families, or form MYB/bHLH complexes to regulate distinct cellular processes. The ability of MYBs and bHLHs to interact with multiple protein part- ners has evolved to keep up with the increased metabolic complexity of multi-cellular organisms. Associ- ation and disassociation of dynamic TF complexes in response to developmental and environmental cues are controlled through a plethora of regulatory mechanisms specifically modulating TF activity. Regulation of TFs at the protein level is critical for efficient and precise control of their activity, and thus provides the mechanistic basis for a rapid on-and-off switch of TF activity. In this review, examples of post-translational modifications, protein-protein interactions, and subcellular mobilization of TFs are discussed with regard to the relevance of these regulatory mechanisms for the specific activation of MYBs and bHLHs in response to a given environmental stimulus.展开更多
Activating transcription factor 5(ATF5) is a member of the activating transcription factor/cA MP response element binding protein(ATF/CREB) family, and is highly expressed in liver and adipose tissue. Previous reports...Activating transcription factor 5(ATF5) is a member of the activating transcription factor/cA MP response element binding protein(ATF/CREB) family, and is highly expressed in liver and adipose tissue. Previous reports have shown that ATF5 promoted 3T3-L1 preadipocytes differentiation. In this study, we found that ATF5 was highly expressed in mature adipocytes, suggesting a potential role of ATF5 in mature adipocytes, which has not been reported previously. To understand the function of ATF5 in mature adipocytes, we knocked down the expression of ATF5 in 3T3-L1 mature adipocytes and observed decreased lipid droplets. Consistent with the in vitro experiment, the knockdown of ATF5 in white adipose tissue led to less adipose tissue and smaller adipocytes size. Further research revealed that the inhibition of ATF5 diminished the adipocytes size via the inhibition of fatty acid synthetase, stearyl coenzyme A desaturation enzyme 1, and the induction of carnitine palmitoyl transferase 1, one key enzyme of lipid metabolism. In addition, ATF5 knockdown in inguinal white adipose tissue improved whole body insulin sensitivity.Our work provides a new understanding of ATF5 function in mature adipocytes and a potential therapeutic target of diabetes.展开更多
目的探讨细胞因子信号转导抑制因子3(suppressors of cytokine signaling 3,SOCS3)过表达对实验性自身免疫性心肌炎(experimental autoimmune myocarditis,EAM)大鼠CD4^(+)T细胞失衡的影响及机制。方法从30只雄性Lewis大鼠中随机选取10...目的探讨细胞因子信号转导抑制因子3(suppressors of cytokine signaling 3,SOCS3)过表达对实验性自身免疫性心肌炎(experimental autoimmune myocarditis,EAM)大鼠CD4^(+)T细胞失衡的影响及机制。方法从30只雄性Lewis大鼠中随机选取10只作为对照组,其余20只大鼠在实验第0天和第7天注射猪心肌肌球蛋白,建立EAM大鼠模型。将20只大鼠随机分为EAM组和EAM+SOCS3组。EAM+SOCS3组尾静脉注射过表达SOCS3慢病毒,EAM组尾静脉注射等量空载体慢病毒。实验第21天对所有大鼠进行超声心动图检查,评估其心脏功能后实施安乐死。采用酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)法检测血清心肌肌钙蛋白T、肌酸激酶同工酶、B型利钠肽和血清细胞因子水平。采用苏木精-伊红(hematoxylin-eosin,HE)染色法评估心肌组织炎症浸润和心肌病理积分,流式细胞仪检测大鼠脾脏中CD4^(+)T细胞亚群水平。采用实时荧光定量聚合酶链反应(real time fluorescent quantitative polymerase chain reaction,RT-qPCR)法和蛋白质印迹(Western blot,WB)法检测SOCS3、Janus激酶2(Janus kinase 2,JAK2)、信号转导和转录激活因子3(signal transducer and activator of transcription 3,STAT3)和CD4^(+)T细胞特异性转录因子的表达。结果EAM组血清心肌肌钙蛋白T、肌酸激酶同工酶、B型利钠肽的表达水平较对照组上升(P<0.05),心肌病理积分较对照组上升(P<0.05);EAM组心肌组织中T细胞转录因子(T-box expressed in T cells,T-bet)、维甲酸相关孤核受体γt(retinoid-related orphan receptorγt,RORγt)mRNA和蛋白表达水平较对照组上升(P<0.05),叉状头转录因子P3(forkhead box P3,Foxp3)表达水平下降(P<0.05);EAM组脾脏中辅助性T细胞1(helper T cell 1,Th1)、辅助性T细胞17(helper T cell 17,Th17)百分比较对照组上升(P<0.05),调节性T细胞(regulatory T cell,Treg)百分比下降(P<0.05);EAM组心肌组织中JAK2、STAT3mRNA和蛋白的表达水平较对照组上升(P<0.05)。EAM+SOCS3组这些指标较EAM均有不同程度的恢复(P<0.05)。结论SOCS3过表达可改善EAM大鼠CD4^(+)T细胞失衡,减轻心肌损害,其机制可能与下调JAK2/STAT3信号通路有关。展开更多
文摘The Dof (DNA-binding with one finger) proteins are a class of plant-specific transcription factors that can trigger several processes involved in plant growth and development, as well as in stress responses. Here, we performed a systematic bioinformatics analysis to characterize all Dof genes in common bean, which included analysis of the genome sequence, conserved protein domains, chromosomal locations, subcellular locations, phylogenetic relationships, gene duplications, and gene expression profiles in different tissues. Bioinformatics analysis revealed 36 putative genes related to PvDof that were classified into seven subfamilies (A, B1, B2, C1, C2, D1, and, D2) by comparative phylogenetic analysis. Based on our genome duplication analysis, a total of 36 genes were found to be distributed on all 11 chromosomes, and they expanded through gene duplication in tandem, suggesting the involvement of segmental duplication events in the evolutionary process. Synteny events and phylogenetic comparisons of the Dof proteins of common bean with those of A. thaliana, O. sativa, and G. max L. led to the identification of several orthologous and paralogous genes, which provided further insight into the diversity of the evolutionary characteristics of genes of this family in other plant species. Expression profiles revealed that most of the PvDof genes were expressed in different tissues, indicating that PvDof genes may be involved in various physiological functions during plant development. The results of this study provide additional information and potential biotechnological resources for further understanding the molecular basis of this gene family and consequently improvement of common bean crops.
文摘In complex, constantly changing environments, plants have developed astonishing survival strategies. These elaborated strategies rely on rapid and precise gene regulation mediated by transcription factors （TFs）. TFs represent a large fraction of plant genomes and among them, MYBs and basic helix-loop-helix （bHLHs） have unique inherent properties specific to plants. Proteins of these two TF families can act as homo- or heterodimers, associate with proteins from other protein families, or form MYB/bHLH complexes to regulate distinct cellular processes. The ability of MYBs and bHLHs to interact with multiple protein part- ners has evolved to keep up with the increased metabolic complexity of multi-cellular organisms. Associ- ation and disassociation of dynamic TF complexes in response to developmental and environmental cues are controlled through a plethora of regulatory mechanisms specifically modulating TF activity. Regulation of TFs at the protein level is critical for efficient and precise control of their activity, and thus provides the mechanistic basis for a rapid on-and-off switch of TF activity. In this review, examples of post-translational modifications, protein-protein interactions, and subcellular mobilization of TFs are discussed with regard to the relevance of these regulatory mechanisms for the specific activation of MYBs and bHLHs in response to a given environmental stimulus.
基金supported by the National Key Basic Research Project (2013CB530601 to X. Li)the National Natural Science Foundation of China (81270954, 31571401 to X. Li)
文摘Activating transcription factor 5(ATF5) is a member of the activating transcription factor/cA MP response element binding protein(ATF/CREB) family, and is highly expressed in liver and adipose tissue. Previous reports have shown that ATF5 promoted 3T3-L1 preadipocytes differentiation. In this study, we found that ATF5 was highly expressed in mature adipocytes, suggesting a potential role of ATF5 in mature adipocytes, which has not been reported previously. To understand the function of ATF5 in mature adipocytes, we knocked down the expression of ATF5 in 3T3-L1 mature adipocytes and observed decreased lipid droplets. Consistent with the in vitro experiment, the knockdown of ATF5 in white adipose tissue led to less adipose tissue and smaller adipocytes size. Further research revealed that the inhibition of ATF5 diminished the adipocytes size via the inhibition of fatty acid synthetase, stearyl coenzyme A desaturation enzyme 1, and the induction of carnitine palmitoyl transferase 1, one key enzyme of lipid metabolism. In addition, ATF5 knockdown in inguinal white adipose tissue improved whole body insulin sensitivity.Our work provides a new understanding of ATF5 function in mature adipocytes and a potential therapeutic target of diabetes.
文摘目的探讨细胞因子信号转导抑制因子3(suppressors of cytokine signaling 3,SOCS3)过表达对实验性自身免疫性心肌炎(experimental autoimmune myocarditis,EAM)大鼠CD4^(+)T细胞失衡的影响及机制。方法从30只雄性Lewis大鼠中随机选取10只作为对照组,其余20只大鼠在实验第0天和第7天注射猪心肌肌球蛋白,建立EAM大鼠模型。将20只大鼠随机分为EAM组和EAM+SOCS3组。EAM+SOCS3组尾静脉注射过表达SOCS3慢病毒,EAM组尾静脉注射等量空载体慢病毒。实验第21天对所有大鼠进行超声心动图检查,评估其心脏功能后实施安乐死。采用酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)法检测血清心肌肌钙蛋白T、肌酸激酶同工酶、B型利钠肽和血清细胞因子水平。采用苏木精-伊红(hematoxylin-eosin,HE)染色法评估心肌组织炎症浸润和心肌病理积分,流式细胞仪检测大鼠脾脏中CD4^(+)T细胞亚群水平。采用实时荧光定量聚合酶链反应(real time fluorescent quantitative polymerase chain reaction,RT-qPCR)法和蛋白质印迹(Western blot,WB)法检测SOCS3、Janus激酶2(Janus kinase 2,JAK2)、信号转导和转录激活因子3(signal transducer and activator of transcription 3,STAT3)和CD4^(+)T细胞特异性转录因子的表达。结果EAM组血清心肌肌钙蛋白T、肌酸激酶同工酶、B型利钠肽的表达水平较对照组上升(P<0.05),心肌病理积分较对照组上升(P<0.05);EAM组心肌组织中T细胞转录因子(T-box expressed in T cells,T-bet)、维甲酸相关孤核受体γt(retinoid-related orphan receptorγt,RORγt)mRNA和蛋白表达水平较对照组上升(P<0.05),叉状头转录因子P3(forkhead box P3,Foxp3)表达水平下降(P<0.05);EAM组脾脏中辅助性T细胞1(helper T cell 1,Th1)、辅助性T细胞17(helper T cell 17,Th17)百分比较对照组上升(P<0.05),调节性T细胞(regulatory T cell,Treg)百分比下降(P<0.05);EAM组心肌组织中JAK2、STAT3mRNA和蛋白的表达水平较对照组上升(P<0.05)。EAM+SOCS3组这些指标较EAM均有不同程度的恢复(P<0.05)。结论SOCS3过表达可改善EAM大鼠CD4^(+)T细胞失衡,减轻心肌损害,其机制可能与下调JAK2/STAT3信号通路有关。
