Functions and regulation of the Nox family in the filamentous fungus Podospora anserina: a new role in cellulose degradation
Functions and regulation of the Nox family in the filamentous fungus Podospora anserina: a new role in cellulose degradation
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DOI：
10.1111/j.1365-2958.2009.06878.x
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发表时间：
2009-10-01
影响因子：
3.6
通讯作者：
Silar, Philippe
中科院分区：
文献类型：
--
作者：
Brun, Sylvain;Malagnac, Fabienne;Silar, Philippe
NADPH氧化酶是产生活性氧的酶。在哺乳动物、植物和真菌中的研究表明，它们在分化、防御、宿主/病原体相互作用以及互利共生中发挥重要作用。在本文中，我们鉴定了一株粗糙脉孢菌（Podospora anserina）突变株，其在由PaNox1和PaNox2控制的过程中存在缺陷，这两种Nox异构体是在这种模式子囊菌中所特有的。我们表明突变的基因是PaNoxR，它是编码调节亚基p67phox的基因的同源物，在哺乳动物和真菌中是保守的，并且PaNoxR调节PaNox1和PaNox2。粗糙脉孢菌的基因组序列分析显示，这种真菌具有第三种Nox异构体PaNox3，它与人Nox5/Duox和植物Rboh相关。我们已经构建了PaNox3的敲除突变体，并报道如果PaNox3在粗糙脉孢菌中有作用的话，也是很次要的。我们表明PaNox1和PaNox2在纤维素降解中起拮抗作用。最后，我们首次报道一种腐生真菌——粗糙脉孢菌形成了专门用于突破和利用固体纤维素底物（玻璃纸）的特殊细胞结构。重要的是，对于一些植物病原体中存在的类似结构，它们的正常分化需要PaNox1、PaNox2、PaNoxR和四跨膜蛋白PaPls1。
P>NADPH oxidases are enzymes that produce reactive oxygen species. Studies in mammals, plants and fungi have shown that they play important roles in differentiation, defence, host/pathogen interaction and mutualistic symbiosis. In this paper, we have identified a Podospora anserina mutant strain impaired for processes controlled by PaNox1 and PaNox2, the two Nox isoforms characterized in this model ascomycete. We show that the gene mutated is PaNoxR, the homologue of the gene encoding the regulatory subunit p67phox, conserved in mammals and fungi, and that PaNoxR regulates both PaNox1 and PaNox2. Genome sequence analysis of P. anserina reveals that this fungus posses a third Nox isoform, PaNox3, related to human Nox5/Duox and plant Rboh. We have generated a knock-out mutant of PaNox3 and report that PaNox3 plays a minor role in P. anserina, if any. We show that PaNox1 and PaNox2 play antagonist roles in cellulose degradation. Finally, we report for the first time that a saprobic fungus, P. anserina, develops special cell structures dedicated to breach and to exploit a solid cellulosic substrate, cellophane. Importantly, as for similar structures present in some plant pathogens, their proper differentiation requires PaNox1, PaNox2, PaNoxR and the tetraspanin PaPls1.