Xylanase 1 (Xyn1) is one of the two major representatives of the xylanase system of T. reesei; the mechanisms governing its expression were analysed throughout this study. All factors and regulatory motifs responsible...Xylanase 1 (Xyn1) is one of the two major representatives of the xylanase system of T. reesei; the mechanisms governing its expression were analysed throughout this study. All factors and regulatory motifs responsible for transcriptional regulation and the model of their interplay in induction and repression will be presented. Using in vivo foot printing analysis of xylan-induced and glucose repressed mycelia, we detected three adjacent nucleotide sequences contacted by DNA-binding proteins. Protection within the inverted repeat of the Cre1 (SYGGRG) consensus sequence on the non coding strand under repressing conditions is in perfect agreement with the previously reported Cre1 dependent glucose repression of xyn1. Constitutive protein binding could be observed to a CCAAT-box and an inverted repeat of a 5′ GGCTAA 3′ sequence. EMSA with crude extracts from induced and repressed mycelia revealed that the latter motifs are sufficient for formation of the basal transcriptional complex under all conditions. The inverted repeat of GGCTAA closely resembles the consensus sequences of the cellulase and xylanase regulators Ace1, Ace2 and, Xyr1 (encoded by xyr1, cloned and characterised in this study) EMSA with heterologously expressed components of each factor and of the T. reesei Hap2/3/5 protein complex revealed that the basal transcriptional complex is formed by Xyr1 and the Hap2/3/5. Additionally to the Cre1 mediated carbon catabolite repression a yet unknown mechanism antagonizing induction of xyn1 expression could be elucidated. Latter occurs through competition of the repressor Ace1 and Xyr1 for the GGCTAA motif. In vivo proof for the relevance of identified motifs could be given through analysis of T. reesei transformants containing correspondingly mutated versions of the xyn1 promoter fused to the A. niger goxA gene. The results indicated that the basal as well as the induction level of xyn1 gene transcription is dependent on an interaction of Xyr1 with the GGCTAA motif while formation of the CCAAT-Hap2/3/5 complex slightly reduces induction. It can be concluded that mutations impairing protein binding in vitro lead to a loss of distinct regulatory functions in xyn1 gene expression in vivo. A respective model of gene regulation will be presented.展开更多
The paper presented an implement method for a dynamic gene expression display software based on the GTK. This method established the dynamic presentation system of gene expression which according to gene expression da...The paper presented an implement method for a dynamic gene expression display software based on the GTK. This method established the dynamic presentation system of gene expression which according to gene expression data from gene chip hybridize at different time, adopted a linearity combination model and Pearson correlation coefficient algorithm. The system described the gene expression changes in graphic form, the gene expression changes with time and the changes in characteristics of the gene expression, also the changes in relations of the gene expression and regulation relationships among genes. The system also provided an integrated platform for analysis on gene chips data, especially for the research on the network ofgene regulation.展开更多
The regulating axillary branch gene was cloned and named as CsCCD7.Using a series bioinformatic computer softwares,database and online programes,CsCCD7 nucleotide sequence and CsCCD7 amino acid sequence were analyzed ...The regulating axillary branch gene was cloned and named as CsCCD7.Using a series bioinformatic computer softwares,database and online programes,CsCCD7 nucleotide sequence and CsCCD7 amino acid sequence were analyzed and CsCCD7 function was predicted.The results showed that CsCCD7 cDNA full length sequence was 2 136 bp,and included a 1 665 bp ORF which encoded a 554 AA protein;there were 32 kinds of cis-acting regulating element in 2 136 bp cDNA sequence;CsCCD7 was an unstable protein（the unstable coefficient：40.77）,including many phosphorylation sites related with CsCCD7 function;CsCCD7 had no transmembrane domain,and its subcellular localization was in chloroplast.CsCCD7 secondary structure contained four conformations including α-helix,β-sheet,β-turn and random coil.CsCCD7 protein had no signal peptide,so was non-secretory protein and hydrophilicity protein（grand average of hydropathicity：-0.401）.Both CsCCD7 secondary and tertiary structure prediction results showed that it was classified as carotenoid oxygenase family.Phylogenetic tree drew by Geneious showed that CsCCD7 was more closely related to AtCCD7 than any other Arabidopsis CCD protein.展开更多
文摘Xylanase 1 (Xyn1) is one of the two major representatives of the xylanase system of T. reesei; the mechanisms governing its expression were analysed throughout this study. All factors and regulatory motifs responsible for transcriptional regulation and the model of their interplay in induction and repression will be presented. Using in vivo foot printing analysis of xylan-induced and glucose repressed mycelia, we detected three adjacent nucleotide sequences contacted by DNA-binding proteins. Protection within the inverted repeat of the Cre1 (SYGGRG) consensus sequence on the non coding strand under repressing conditions is in perfect agreement with the previously reported Cre1 dependent glucose repression of xyn1. Constitutive protein binding could be observed to a CCAAT-box and an inverted repeat of a 5′ GGCTAA 3′ sequence. EMSA with crude extracts from induced and repressed mycelia revealed that the latter motifs are sufficient for formation of the basal transcriptional complex under all conditions. The inverted repeat of GGCTAA closely resembles the consensus sequences of the cellulase and xylanase regulators Ace1, Ace2 and, Xyr1 (encoded by xyr1, cloned and characterised in this study) EMSA with heterologously expressed components of each factor and of the T. reesei Hap2/3/5 protein complex revealed that the basal transcriptional complex is formed by Xyr1 and the Hap2/3/5. Additionally to the Cre1 mediated carbon catabolite repression a yet unknown mechanism antagonizing induction of xyn1 expression could be elucidated. Latter occurs through competition of the repressor Ace1 and Xyr1 for the GGCTAA motif. In vivo proof for the relevance of identified motifs could be given through analysis of T. reesei transformants containing correspondingly mutated versions of the xyn1 promoter fused to the A. niger goxA gene. The results indicated that the basal as well as the induction level of xyn1 gene transcription is dependent on an interaction of Xyr1 with the GGCTAA motif while formation of the CCAAT-Hap2/3/5 complex slightly reduces induction. It can be concluded that mutations impairing protein binding in vitro lead to a loss of distinct regulatory functions in xyn1 gene expression in vivo. A respective model of gene regulation will be presented.
文摘The paper presented an implement method for a dynamic gene expression display software based on the GTK. This method established the dynamic presentation system of gene expression which according to gene expression data from gene chip hybridize at different time, adopted a linearity combination model and Pearson correlation coefficient algorithm. The system described the gene expression changes in graphic form, the gene expression changes with time and the changes in characteristics of the gene expression, also the changes in relations of the gene expression and regulation relationships among genes. The system also provided an integrated platform for analysis on gene chips data, especially for the research on the network ofgene regulation.
基金Supported by Doctoral Fund of Ministry of Education of China (200802240008)National 863 Project (2007AA10Z177)
文摘The regulating axillary branch gene was cloned and named as CsCCD7.Using a series bioinformatic computer softwares,database and online programes,CsCCD7 nucleotide sequence and CsCCD7 amino acid sequence were analyzed and CsCCD7 function was predicted.The results showed that CsCCD7 cDNA full length sequence was 2 136 bp,and included a 1 665 bp ORF which encoded a 554 AA protein;there were 32 kinds of cis-acting regulating element in 2 136 bp cDNA sequence;CsCCD7 was an unstable protein（the unstable coefficient：40.77）,including many phosphorylation sites related with CsCCD7 function;CsCCD7 had no transmembrane domain,and its subcellular localization was in chloroplast.CsCCD7 secondary structure contained four conformations including α-helix,β-sheet,β-turn and random coil.CsCCD7 protein had no signal peptide,so was non-secretory protein and hydrophilicity protein（grand average of hydropathicity：-0.401）.Both CsCCD7 secondary and tertiary structure prediction results showed that it was classified as carotenoid oxygenase family.Phylogenetic tree drew by Geneious showed that CsCCD7 was more closely related to AtCCD7 than any other Arabidopsis CCD protein.
