Insights into enzyme secretion by filamentous fungi: Comparative proteome analysis of Trichoderma reesei grown on different carbon sources
Insights into enzyme secretion by filamentous fungi: Comparative proteome analysis of Trichoderma reesei grown on different carbon sources
复制标题
丝状真菌酶分泌的见解：在不同碳源上生长的里氏木霉的比较蛋白质组分析
DOI：
10.1016/j.jprot.2013.06.014
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发表时间：
2013-08-26
影响因子：
3.3
通讯作者：
Chen Daiwen
中科院分区：
文献类型：
--
作者：
He Jun;Han Guangye;Chen Daiwen
里氏木霉（Trichoderma reesei）是木质纤维素分解酶的主要工业生产者，其分泌行为强烈依赖于碳源。为了深入了解T. reesei适应各种碳并调节酶的产生，T.研究了在以乳糖或木糖作为碳源的成分确定的培养基中生长的里氏杆菌。结果表明，胞外蛋白质组的组成有很大的差异，这取决于碳。主要的纤维二糖水解酶，即Cel 7a/Cel 6是在两种培养基中鉴定的最丰富的纤维素分解酶，并且发现在乳糖生长的培养物中更丰富。与乳糖相比，木糖可作为木聚糖分解酶的有效诱导剂。有趣的是，大多数鉴定的细胞内蛋白质参与碳代谢。参与木糖利用的酶，如n-木糖还原酶（Xyl 1 p）和n-木糖脱氢酶（Xyl 2 p），在木糖上生长的培养物中以升高的水平存在，但在乳糖培养物中仅以少量存在。但是，乳糖诱导显著激活了参与糖酵解途径和柠檬酸循环的关键酶的表达。重要的是，参与乳糖和木糖催化的蛋白质Xyl 1 p被证实是T. reesei.生物学意义本研究不仅概述了两种常规碳底物诱导的细胞内普遍存在的变化，而且为理解T. reesei。此外，本研究还提供了一个潜在的靶点（Xyl 1 p），可用于T. reesei用于成本有效的纤维素酶生产。(C)2013爱思唯尔有限公司版权所有。
Trichoderma reesei is the main industrial producer of lignocellulolytic enzymes, and the secretory behavior of this fungus strongly depends on the carbon sources. To gain insights into how the T. reesei adapts to various carbons and regulates enzyme production, the extra-and intracellular proteomes of T. reesei grown in defined medium with lactose or xylose as the carbon source were investigated. Results indicated that the composition of extracellular proteome differed considerably depending on the carbons. The main cellobiohydrolases, i.e. Cel7a/Cel6 were the most abundant cellulolytic enzymes identified in both media, and found to be more abundant in lactose-grown culture. As compared to lactose, xylose can serve as a potent inducer of xylanolytic enzymes. Interestingly, most identified intracellular proteins are involved in carbon metabolism. Enzymes involved in utilization of xylose, such as n-xylose reductase (Xyl1p) and n-xylose dehydrogenase (Xyl2p), were present at elevated levels in the culture growing on xylose but only in minor amounts in the lactose culture. However, lactose induction significantly activated the expression of key enzymes involved in glycolysis pathway and citrate cycle. Importantly, the protein Xyl1p which participates both in the lactose and the xylose catabolism was verified as a potential regulator for cellulase formation in T. reesei.Biological significanceThis study not only gives an overview of the ubiquitous cellular changes induced by the two conventional carbon substrates, but offers the framework for understanding the mechanisms behind the carbon-dependent induction of extracellular enzymes in T. reesei. Moreover, this study provides a potential target (Xyl1p) that could be tentatively used for metabolic engineering of T. reesei for cost-effective cellulase production. (C) 2013 Elsevier B.V. All rights reserved.