Analysis of regulation of pentose utilisation in Aspergillus niger reveals evolutionary adaptations in Eurotiales.
Analysis of regulation of pentose utilisation in Aspergillus niger reveals evolutionary adaptations in Eurotiales.
复制标题
DOI：
10.3114/sim.2011.69.03
复制
发表时间：
2011-06-30
影响因子：
16.5
通讯作者：
de Vries RP
中科院分区：
文献类型：
--
作者：
Battaglia E;Visser L;Nijssen A;van Veluw GJ;Wösten HA;de Vries RP
曲霉常见于土壤和腐烂的植物材料中。 D-木糖和L-阿拉伯糖是植物生物质中含量丰富的成分。它们是真菌使用一组胞外酶从多糖中释放出来的，随后通过戊糖分解代谢途径（PCP）在细胞内转化。在这项研究中，在黑曲霉中鉴定出 L-阿拉伯糖反应性转录激活剂 (AraR)，并显示其控制 L-阿拉伯糖分解代谢途径以及编码细胞外 L-阿拉伯糖释放酶的基因的表达。 AraR 在戊糖分解代谢途径的调节中与 D-木糖反应性转录激活剂 XlnR 相互作用，但与 L-阿拉伯糖和 D-木糖的释放无关。 AraR 仅在 Eurotiales 中发现，更具体地说是在 Trichocomaceae 科中发现，并且似乎起源于该目或科从其他丝状子囊菌分裂后的基因复制事件（来自 XlnR）。 XlnR 存在于除 Onygenales 成员之外的所有丝状子囊菌中。由于 Onygenales 和 Eurotiales 都是 Eurotiomycetidae 亚纲的一部分，这表明在这个进化节点上发生了对戊糖利用调节的强烈适应。在 Eurotiales 中，已经进化出一种独特的用于戊糖释放和代谢的双组分调节系统，而 Onygenales 中则丢失了该调节系统。观察到的进化变化（在 Eurotiomycetidae 中）主要影响调节系统，相反，L-阿拉伯糖/D-木糖分解代谢途径的大多数基因的同源物存在于所有丝状真菌中，无论是否存在 XlnR 和/或 AraR。
Aspergilli are commonly found in soil and on decaying plant material. D-xylose and L-arabinose are highly abundant components of plant biomass. They are released from polysaccharides by fungi using a set of extracellular enzymes and subsequently converted intracellularly through the pentose catabolic pathway (PCP). In this study, the L-arabinose responsive transcriptional activator (AraR) is identified in Aspergillus niger and was shown to control the L-arabinose catabolic pathway as well as expression of genes encoding extracellular L-arabinose releasing enzymes. AraR interacts with the D-xylose-responsive transcriptional activator XlnR in the regulation of the pentose catabolic pathway, but not with respect to release of L-arabinose and D-xylose. AraR was only identified in the Eurotiales, more specifically in the family Trichocomaceae and appears to have originated from a gene duplication event (from XlnR) after this order or family split from the other filamentous ascomycetes. XlnR is present in all filamentous ascomycetes with the exception of members of the Onygenales. Since the Onygenales and Eurotiales are both part of the subclass Eurotiomycetidae, this indicates that strong adaptation of the regulation of pentose utilisation has occurred at this evolutionary node. In Eurotiales a unique two-component regulatory system for pentose release and metabolism has evolved, while the regulatory system was lost in the Onygenales. The observed evolutionary changes (in Eurotiomycetidae) mainly affect the regulatory system as in contrast, homologues for most genes of the L-arabinose/D-xylose catabolic pathway are present in all the filamentous fungi, irrespective of the presence of XlnR and/or AraR.