粘细菌转录因子FruA的表达、纯化及调控作用

ＦｒｕＡ是粘细菌（Ｍｙｘｏｃｏｃｃｕｓ ｘａｎｔｈｕｓ）发育所必需的转录因子,影响着一系列发育特异性基因的表达,在大肠杆菌中表达了带组氨酸标记的ＦｒｕＡ,并用镍离子层析进行快速分离纯化。凝胶阻滞试验提示ＦｒｕＡ对靶基因的调控可能需要其它因子的参与。     

A novel regulation on developmental gene expression of fruiting body formation in Myxobacteria

Myxobacteria are Gram-negative soil microorganisms that prey on other microorganisms. Myxobacteria have significant potential for applications in biotechnology because of their extraordinary ability to produce natural products such as secondary metabolites. Myxobacteria also stand out as model organisms for the study of cell–cell interactions and multicellular development during their complex life cycle. Cellular morphogenesis during multicellular development in myxobacteria is very similar to that in the eukaryotic soil amoebae. Recent studies have started uncovering molecular mechanisms directing the myxobacterial life cycle. We describe recent studies on signal transduction and gene expression during multicellular development in the myxobacterium Myxococcus xanthus. We provide our current model for signal transduction pathways mediated by a two-component His–Asp phosphorelay system and a Ser/Thr kinase cascade.     

粘细菌转录因子FruA与结合蛋白FruB协同参与发育基因的调控

粘细菌中一系列发育相关基因受到转录因子ＦｒｕＡ的调节。用亲和层析法从粘细菌分离出另一种与ＦｒｕＡ结合的蛋白因子ＦｒｕＢ。实验表明,ＦｒｕＢ可以被粘细菌细胞膜上的蛋白激酶磷酸化,磷酸化后的ＦｒｕＢ与ＦｒｕＡ形成复合物,此复合物通过与靶基因顺式元件的结合来调节基因的表达。有助于深入理解ＦｒｕＡ对发育相关基因的调节作用机制。     

粘细菌转录因子FruA的表达、纯化及调控作用

FruA是粘细菌(Myxocoxccusxanthus)发育所必需的转录因子,影响着一系列发育特异性基因的表达。在大肠杆菌中表达了带组氨酸标记的FruA,并用镍离子层析进行快速分离纯化。凝胶阻滞试验提示FruA对靶基因的调控可能需要其它因子的参与。     

黄色黏细菌转录因子FruA对自身基因的表达不具自调节作用

 粘细菌是研究多细胞结构形态发生机制的良好模型.FruA是粘细菌发育所必需的一种 关键性转录因子, 调节一系列发育相关基因的表达,本文研究FruA对自身基因是否存在反馈调节从而导致发育后期fruA表达水平的下调.以野生型粘细菌模式菌株DK1622为基础构建fruA基因敲除突变株DK1622ΔfruA,再将fruA-lacZ转录融合载体pMF1A整合入fruA突变株染色体attB, 获得重组菌株DK1622ΔfruA/pMF1A,通过检测β-半乳糖苷酶活性来确认FruA对自身基因的表达水平是否有影响. 结果表明fruA调控序列完整的fruA-lacZ转录融合体β-半乳糖苷酶活性在DK1622/pMF1A和DK1622ΔfruA/pMF1A之间无明显差异, 即fruA表达产物作为一种转录因子对自身基因的转录没有调节作用,黏细菌发育后期fruA表达水平的下降存在其它调节机制.