In filamentous fungi,nitrogen metabolism is repressed by GATA-type zinc finger transcription factors.Nitrogen metabolite repression has been found to affect antibiotic production,but the mechanism is still poorly unde...In filamentous fungi,nitrogen metabolism is repressed by GATA-type zinc finger transcription factors.Nitrogen metabolite repression has been found to affect antibiotic production,but the mechanism is still poorly understood.AcareB,encoding a homologue of fungal GATA-type regulatory protein,was cloned from Acremonium chrysogenum.Gene disruption and genetic complementation demonstrated that AcareB plays a key role in utilization of ammonium,glutamine and urea.In addition,significant reduction of cephalosporin production in the AcareB disruption mutant indicated that AcareB is important for cephalosporin production.In consistence with it,the transcriptional level of cephalosporin biosynthetic genes was significantly decreased in the AcareB disruption mutant.Electrophoretic mobility shift assay showed that AcAREB directly bound to the intergenic regions of pcbAB-pcbC,cefD1-cefD2 and cefEF-cefG.Sequence analysis showed that all the AcAREB binding sites contained the consensus GATA elements.AcareB is negatively autoregulated during cephalosporin production.Moreover,another GATA zinc-finger protein encoded by AcareA positively regulates the transcription of AcareB.However,AcareB does not regulate the transcription of AcareA.These results indicated that AcAREB plays an important role in both regulation of nitrogen metabolism and cephalosporin production in A.chrysogenum.展开更多
The transcriptional factor GATA-6 gene produces two translational isoforms from a single mRNA through ribosomal leaky scanning. L-type GATA-6 has an extension of 146 amino acid residues at its amino terminus. In the e...The transcriptional factor GATA-6 gene produces two translational isoforms from a single mRNA through ribosomal leaky scanning. L-type GATA-6 has an extension of 146 amino acid residues at its amino terminus. In the extension, there is a unique PEST sequence (Glu31-Cys46), which is composed of an amino terminal Pro-rich segment and a carboxyl terminal Ser-cluster. Substitution of either half of the PEST sequence with Ala residues by cassette mutagenesis reduced the apparent molecular size of L-type GATA-6 on SDS-polyacrylamide gel-electrophoresis. However, the effect of substitution of the Pro-rich segment was much more significant;the mobility increase of the Pro-rich segment on the gel was 13% while that of the Ser-cluster was 8%. Substitution of each amino acid residue demonstrated that the effect of Pro substitution is greater than that of the Ser and Thr residues. Such increased mobility of L-type GATA-6 in the presence of a detergent may apparently correlate with the decrease in transcription activity in vivo as determined by means of luciferase reporter gene assay. The activity of ΔAla (with Ala residues instead of the PEST sequence) was reduced to one fifth of that of ΔA (with the PEST sequence). These results suggest that the PEST sequence of L-type GATA-6 does not function as a constitutive protein degradation signal, but rather plays structural and functional roles in the activation of gene expression on the GATA responsive promoter.展开更多
目的探讨GATA结合蛋白3(GATA binding protein 3,GATA-3)在非特殊型浸润性乳腺癌患者癌组织中的表达及与患者预后的关系。方法收集北京市垂杨柳医院2013年1月至2017年12月收治的98例非特殊型浸润性乳腺癌患者的临床资料进行回顾性分析,...目的探讨GATA结合蛋白3(GATA binding protein 3,GATA-3)在非特殊型浸润性乳腺癌患者癌组织中的表达及与患者预后的关系。方法收集北京市垂杨柳医院2013年1月至2017年12月收治的98例非特殊型浸润性乳腺癌患者的临床资料进行回顾性分析,采用病例对照研究,收集癌旁正常组织作为对照。采用免疫组织化学法检测非特殊型浸润性乳腺癌癌组织和癌旁正常组织中GATA-3的表达情况,分析GATA-3不同表达与非特殊型浸润性乳腺癌患者临床病理特征的关系及对患者预后的影响,并分析对GATA-3表达的影响因素。本研究采用的统计方法:计数资料采用χ^(2)检验。生存率采用Kaplan-Meier法进行分析,Long-rank法进行组间比较。采用Logistic回归进行多因素分析。结果非特殊型浸润性乳腺癌患者癌组织中GATA-3阳性表达率为61.2%(60/98),癌旁组织为86.7%(85/98),两者比较差异有统计学意义(χ^(2)=16.57,P<0.001)。非特殊型浸润性乳腺癌患者的年龄、肿瘤直径对GATA-3的表达比较差异均无统计学意义(均P>0.05),组织学分级、TNM分期、淋巴结转移、雌激素受体、孕激素受体、人表皮生长因子受体2对GATA-3表达比较差异均有统计学意义(均P<0.05)。Logistic回归分析结果表明,淋巴结转移情况(OR=2.628,95%CI为1.180~5.812,P=0.018)、TNM分期(OR=3.419,95%CI为1.067~7.565,P=0.041)、组织学分级(OR=1.540,95%CI为1.026~2.361,P=0.044)及人表皮生长因子受体2表达(OR=1.801,95%CI为1.067~3.221,P=0.048)为GATA-3表达的独立影响因素。GATA-3阳性表达患者3年无病生存率为80.0%,阴性表达者为57.9%,两组比较差异有统计学意义(χ^(2)=4.30,P=0.045)。GATA-3阳性表达患者3年生存率(86.7%)高于阴性表达患者(68.4%),两组比较差异有统计学意义(χ^(2)=3.99,P=0.046)。结论在非特殊型浸润性乳腺癌患者中癌组织与癌旁正常组织相比较,GATA-3的表达缺失,TNM分期、组织学分级、淋巴结转移、雌激素受体、孕激素受体、人表皮生长因子受体2与GATA-3的表达有关,GATA-3阳性表达提示患者预后较好,淋巴结转移、组织学分级、TNM分期及人表皮生长因子受体2表达为GATA-3表达的独立影响因素。展开更多
基金supported by the National Natural Science Foundation of China(31670091 and 31470177)
文摘In filamentous fungi,nitrogen metabolism is repressed by GATA-type zinc finger transcription factors.Nitrogen metabolite repression has been found to affect antibiotic production,but the mechanism is still poorly understood.AcareB,encoding a homologue of fungal GATA-type regulatory protein,was cloned from Acremonium chrysogenum.Gene disruption and genetic complementation demonstrated that AcareB plays a key role in utilization of ammonium,glutamine and urea.In addition,significant reduction of cephalosporin production in the AcareB disruption mutant indicated that AcareB is important for cephalosporin production.In consistence with it,the transcriptional level of cephalosporin biosynthetic genes was significantly decreased in the AcareB disruption mutant.Electrophoretic mobility shift assay showed that AcAREB directly bound to the intergenic regions of pcbAB-pcbC,cefD1-cefD2 and cefEF-cefG.Sequence analysis showed that all the AcAREB binding sites contained the consensus GATA elements.AcareB is negatively autoregulated during cephalosporin production.Moreover,another GATA zinc-finger protein encoded by AcareA positively regulates the transcription of AcareB.However,AcareB does not regulate the transcription of AcareA.These results indicated that AcAREB plays an important role in both regulation of nitrogen metabolism and cephalosporin production in A.chrysogenum.
文摘The transcriptional factor GATA-6 gene produces two translational isoforms from a single mRNA through ribosomal leaky scanning. L-type GATA-6 has an extension of 146 amino acid residues at its amino terminus. In the extension, there is a unique PEST sequence (Glu31-Cys46), which is composed of an amino terminal Pro-rich segment and a carboxyl terminal Ser-cluster. Substitution of either half of the PEST sequence with Ala residues by cassette mutagenesis reduced the apparent molecular size of L-type GATA-6 on SDS-polyacrylamide gel-electrophoresis. However, the effect of substitution of the Pro-rich segment was much more significant;the mobility increase of the Pro-rich segment on the gel was 13% while that of the Ser-cluster was 8%. Substitution of each amino acid residue demonstrated that the effect of Pro substitution is greater than that of the Ser and Thr residues. Such increased mobility of L-type GATA-6 in the presence of a detergent may apparently correlate with the decrease in transcription activity in vivo as determined by means of luciferase reporter gene assay. The activity of ΔAla (with Ala residues instead of the PEST sequence) was reduced to one fifth of that of ΔA (with the PEST sequence). These results suggest that the PEST sequence of L-type GATA-6 does not function as a constitutive protein degradation signal, but rather plays structural and functional roles in the activation of gene expression on the GATA responsive promoter.
文摘目的探讨GATA结合蛋白3(GATA binding protein 3,GATA-3)在非特殊型浸润性乳腺癌患者癌组织中的表达及与患者预后的关系。方法收集北京市垂杨柳医院2013年1月至2017年12月收治的98例非特殊型浸润性乳腺癌患者的临床资料进行回顾性分析,采用病例对照研究,收集癌旁正常组织作为对照。采用免疫组织化学法检测非特殊型浸润性乳腺癌癌组织和癌旁正常组织中GATA-3的表达情况,分析GATA-3不同表达与非特殊型浸润性乳腺癌患者临床病理特征的关系及对患者预后的影响,并分析对GATA-3表达的影响因素。本研究采用的统计方法:计数资料采用χ^(2)检验。生存率采用Kaplan-Meier法进行分析,Long-rank法进行组间比较。采用Logistic回归进行多因素分析。结果非特殊型浸润性乳腺癌患者癌组织中GATA-3阳性表达率为61.2%(60/98),癌旁组织为86.7%(85/98),两者比较差异有统计学意义(χ^(2)=16.57,P<0.001)。非特殊型浸润性乳腺癌患者的年龄、肿瘤直径对GATA-3的表达比较差异均无统计学意义(均P>0.05),组织学分级、TNM分期、淋巴结转移、雌激素受体、孕激素受体、人表皮生长因子受体2对GATA-3表达比较差异均有统计学意义(均P<0.05)。Logistic回归分析结果表明,淋巴结转移情况(OR=2.628,95%CI为1.180~5.812,P=0.018)、TNM分期(OR=3.419,95%CI为1.067~7.565,P=0.041)、组织学分级(OR=1.540,95%CI为1.026~2.361,P=0.044)及人表皮生长因子受体2表达(OR=1.801,95%CI为1.067~3.221,P=0.048)为GATA-3表达的独立影响因素。GATA-3阳性表达患者3年无病生存率为80.0%,阴性表达者为57.9%,两组比较差异有统计学意义(χ^(2)=4.30,P=0.045)。GATA-3阳性表达患者3年生存率(86.7%)高于阴性表达患者(68.4%),两组比较差异有统计学意义(χ^(2)=3.99,P=0.046)。结论在非特殊型浸润性乳腺癌患者中癌组织与癌旁正常组织相比较,GATA-3的表达缺失,TNM分期、组织学分级、淋巴结转移、雌激素受体、孕激素受体、人表皮生长因子受体2与GATA-3的表达有关,GATA-3阳性表达提示患者预后较好,淋巴结转移、组织学分级、TNM分期及人表皮生长因子受体2表达为GATA-3表达的独立影响因素。
