Refining the pH response in Aspergillus nidulans: a modulatory triad involving PacX, a novel zinc binuclear cluster protein.
Refining the pH response in Aspergillus nidulans: a modulatory triad involving PacX, a novel zinc binuclear cluster protein.
复制标题
DOI：
10.1111/mmi.13173
复制
发表时间：
2015-12
影响因子：
3.6
通讯作者：
Tilburn J
中科院分区：
文献类型：
--
作者：
Bussink HJ;Bignell EM;Múnera-Huertas T;Lucena-Agell D;Scazzocchio C;Espeso EA;Bertuzzi M;Rudnicka J;Negrete-Urtasun S;Peñas-Parilla MM;Rainbow L;Peñalva MÁ;Arst HN Jr;Tilburn J
构巢曲霉PacC转录因子介导基因调节，以响应碱性环境pH，其通过PacC途径发出信号，导致PacC 72通过PacC 53加工为PacC 27。在这里，我们调查两个水平的pH调节系统是转录调节的pH值和识别和识别的pH调节机制，PacX的一个新的组成部分。转录水平分析和过表达研究表明，可能通过PacC 27和/或PacC 53抑制酸表达的pal F（指定Pal F途径抑制蛋白），可防止碱性pH反应的升级。使用报告基因和组成型表达的pac C反式等位基因进行的转录分析表明，pac C优先碱性表达是通过消耗酸优势的PacC 72形式来解除阻遏的结果。 我们还表明，PAC C抑制需要PacX。pac X突变抑制PacC加工抑制突变，部分是通过去抑制PacC水平，导致pH非依赖性蛋白水解形成痕量PacC 27。通过黑斑羚转座子诱变克隆pac X。PacX与Leotiomyceta内的同源物具有不寻常的结构，具有氨基末端卷曲螺旋和羧基末端锌双核簇。pacX突变表明这些区域的重要性。一个突变，一个前所未有的发现在A。nidulans遗传学，由内源性Fot 1样转座子的插入引起。
The A spergillus nidulans PacC transcription factor mediates gene regulation in response to alkaline ambient pH which, signalled by the Pal pathway, results in the processing of PacC72 to PacC27 via PacC53. Here we investigate two levels at which the pH regulatory system is transcriptionally moderated by pH and identify and characterise a new component of the pH regulatory machinery, PacX. Transcript level analysis and overexpression studies demonstrate that repression of acid‐expressed pal F, specifying the Pal pathway arrestin, probably by PacC27 and/or PacC53, prevents an escalating alkaline pH response. Transcript analyses using a reporter and constitutively expressed pac C trans‐alleles show that pac C preferential alkaline‐expression results from derepression by depletion of the acid‐prevalent PacC72 form. We additionally show that pac C repression requires PacX. pac X mutations suppress PacC processing recalcitrant mutations, in part, through derepressed PacC levels resulting in traces of PacC27 formed by pH‐independent proteolysis. pac X was cloned by impala transposon mutagenesis. PacX, with homologues within the Leotiomyceta, has an unusual structure with an amino‐terminal coiled‐coil and a carboxy‐terminal zinc binuclear cluster. pacX mutations indicate the importance of these regions. One mutation, an unprecedented finding in A . nidulans genetics, resulted from an insertion of an endogenous Fot1‐like transposon.