The wide-domain carbon catabolite repressor CreA indirectly controls expression of the Aspergillus nidulans xlnB gene, encoding the acidic endo-β-(1,4)-xylanase X24
The wide-domain carbon catabolite repressor CreA indirectly controls expression of the Aspergillus nidulans xlnB gene, encoding the acidic endo-β-(1,4)-xylanase X24
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DOI：
10.1128/jb.183.5.1517-1523.2001
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发表时间：
2001-03-01
影响因子：
3.2
通讯作者：
Ramón, D
中科院分区：
文献类型：
--
作者：
Orejas, M;MacCabe, AP;Ramón, D
构巢曲霉的xlnB基因编码酸性内切 -β-(1,4)-木聚糖酶X - 24，当木糖作为唯一碳源时该基因表达，而在葡萄糖存在时被抑制。creA(d)30突变导致xlnB mRNA水平显著升高，这表明广域阻遏物CreA在抑制xlnB启动子（xlnBp）活性中起作用。对xlnBp::goxC报告基因构建体的功能分析表明，在xlnBp中鉴定出的四个CreA共有靶位点在体内均无功能。因此，CreA阻遏物可能通过间接机制施加碳代谢物阻遏，而不是通过直接作用于xlnB来影响其表达。
The Aspergillus nidulans xlnB gene, which encodes the acidic endo-beta-(1,4)-xylanase X-24, is expressed when xylose is present as the sole carbon source and repressed in the presence of glucose. That the mutation creA(d)30 results in considerably elevated levels of xlnB mRNA indicates a role for the wide-domain repressor CreA in the repression of xlnB promoter (xlnBp) activity. Functional analyses of xlnBp::goxC reporter constructs show that none of the four CreA consensus target sites identified in xlnBp are functional in vivo. The CreA repressor is thus likely to exert carbon catabolite repression via an indirect mechanism rather than to influence xlnB expression by acting directly on xlnB.