Carbon regulation of ribosomal genes in Neurospora crassa occurs by a mechanism which does not require Cre-1, the homologue of the Aspergillus carbon catabolite repressor, CreA
Carbon regulation of ribosomal genes in Neurospora crassa occurs by a mechanism which does not require Cre-1, the homologue of the Aspergillus carbon catabolite repressor, CreA
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DOI：
10.1006/fgbi.1999.1121
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发表时间：
1999-04-01
影响因子：
3
通讯作者：
Tyler, BM
中科院分区：
文献类型：
--
作者：
de la Serna, I;Ng, D;Tyler, BM
在粗糙脉孢菌的稳态生长和碳源转换过程中，核糖体蛋白和40S rRNA基因的转录受到协同调控。构巢曲霉碳代谢物阻遏蛋白CreA的识别序列与一个40S rRNA基因和crp - 2核糖体蛋白基因的转录元件重叠。它们也出现在其他几个核糖体蛋白基因启动子的相似位置。在crp - 2启动子中包含 - 74和 - 167 CreA共有序列的替换会导致转录减少。编码粗糙脉孢菌CreA同源物的cDNA被克隆并命名为Cre - 1。Cre - 1蛋白与构巢曲霉的CreA有45%的同一性，在大肠杆菌中产生的Cre - 1蛋白与40S rRNA和crp - 2基因启动子中的CreA位点结合。从组氨酸（92）到苏氨酸的氨基酸变化使Cre - 1结合特异性从（（5）'（G）/（C）（C）/（T）GG（G）/（A）G（3）'）变为（（5）'（G）/（C）（C）/（T）GGCG（3）'）。crp - 2启动子中Cre - 1结合位点的碱基替换破坏了野生型Cre - 1在体外的结合，但在稳态生长或碳源转换过程中对转录没有影响，这表明碳源对核糖体基因的调控不是由Cre - 1介导的，而是通过结合Cre - 1位点和Dde盒的不同蛋白质介导的。（C）1999学术出版社
Transcription of the ribosomal protein and 40S rRNA genes is coordinately regulated during steady state growth and carbon shifts in Neurospora crassa, Recognition sequences for the Aspergillus nidulans carbon catabolite repressor, CreA, overlap transcriptional elements of a 40S rRNA gene and the crp-2 ribosomal protein gene. They also occur in similar locations in the promoters of several other ribosomal protein genes. Substitutions encompassing the -74 and -167 CreA consensus sequences in the crp-2 promoter result in a decrease in transcription. A cDNA encoding the N, crassa homologue of CreA was cloned and designated Cre-1,The Cre-l protein is 45% identical to CreA from A. nidulans, Cre-l protein produced in Escherichia coli binds to the CreA sites in the promoters of the 40S rRNA and crp-2 genes. An amino acid change from histidine (92) to threonine changed the Cre-l binding specificity from ((5)'(G)/(C)(C)/(T)GG(G)/(A)G(3)') to ((5)'(G)/(C)(C)/(T)GGCG(3)'). Base substitutions in the Cre-l binding sites of the crp-2 promoter disrupted binding of wildtype Cre-l in vitro but had no effect on transcription during steady state growth or carbon shifts, indicating that regulation of ribosomal genes by carbon source is not mediated by Cre-l, but via different proteins binding the Cre-l sites and the Dde boxes, (C) 1999 Academic Press.