Parallel proteomic and phosphoproteomic analyses reveal cellobiose-dependent regulation of lignocellulase secretion in the filamentous fungus Neurospora crassa
Parallel proteomic and phosphoproteomic analyses reveal cellobiose-dependent regulation of lignocellulase secretion in the filamentous fungus Neurospora crassa
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平行蛋白质组和磷酸蛋白质组分析揭示丝状真菌粗糙脉孢菌中木质纤维素酶分泌的纤维二糖依赖性调节
DOI：
10.1111/gcbb.12862
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Shaolin Chen
中科院分区：
文献类型：
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作者：
Bentao Xiong;Linfang Wei;Yifan Wang;Jinyu Li;Xin Liu;Yunheng Zhou;Panpan Du;Hao Fang;Johannes Liesche;Yahong Wei;Jisheng Li;Shaolin Chen
木质纤维素酶的高成本限制了由木质纤维素生物质生产生物燃料和生物产品的商业化。组成型表达的木质纤维素酶被认为降解纤维素以释放少量可溶性纤维糊精如纤维二糖用于进一步大规模生产木质纤维素酶;然而，潜在的机制仍有待阐明。在这里，模式真菌粗糙脉孢菌的三重β-葡萄糖苷酶突变体，其阻止纤维二糖的快速周转，从而允许二糖诱导木质纤维素酶，被应用于响应纤维二糖和Avicel纤维素的蛋白质组和磷酸化蛋白质组变化的平行分析。结果显示，共享的蛋白质组和磷酸化蛋白质组的纤维二糖和Avicel的反应，证实了纤维二糖介导的木质纤维素酶的表达和分泌的调节的想法。结果进一步表明，这种调节是在多个水平上实现的，包括表观遗传、转录、转录后、翻译和翻译后。蛋白质组分析显示，纤维二糖和Avicel上调的蛋白质在纤维素降解和降解产物转运途径中过度表达。磷酸化蛋白质组分析显示，被纤维二糖和Avicel差异磷酸化的蛋白质在转录控制、蛋白质加工和输出、细胞壁生物合成和细胞信号传导等途径中过度表达。缺失突变分析进一步表明，ER伴侣蛋白Hsp 70 - 6、易位复合物亚基Sec 66/Sec 71和信号肽酶亚基Spc 2参与木质纤维素酶分泌，特别是跨内质网的易位。这些结果为纤维二糖调控纤维素酶的表达和分泌提供了新的思路，为工程菌株提高纤维素酶产量提供了可能的策略。
High cost of lignocellulases restricts the commercialization of biofuel and bio‐product production from lignocellulosic biomass. Constitutively expressed lignocellulases are considered to degrade cellulose to release small amount of soluble cellodextrins such as cellobiose for further large‐scale production of lignocellulases; however, the underlying mechanism remains to be elucidated. Here, a triple β‐glucosidase mutant of the model fungusNeurospora crassa, which prevents rapid turnover of cellobiose and thus allows the disaccharide to induce lignocellulases, was applied to perform parallel analyses of proteome and phosphoproteome changes in response to cellobiose and Avicel cellulose. The results revealed shared proteome and phosphoproteome responses to cellobiose and Avicel, corroborating the idea that cellobiose mediates the regulation of lignocellulase expression and secretion. The results further suggest that this regulation is achieved at multiple levels, including epigenetic, transcription, post‐transcription, translation, and post‐translation. Proteome profiling revealed that the proteins upregulated by cellobiose and Avicel were over‐represented in cellulose degradation and degradation product transport pathways. Phosphoproteome profiling revealed that the proteins differentially phosphorylated by cellobiose and Avicel were over‐represented by the pathways such as transcriptional control, protein processing and export, cell wall biogenesis, and cellular signaling. Deletion mutation analysis further suggests that the ER chaperon protein Hsp70‐6, the translocation complex subunit Sec66/Sec71, and the signal peptidase subunit Spc2 are involved in lignocellulase secretion, particularly translocation across the endoplasmic reticulum. Altogether, the results offer a new insight into how cellobiose mediates the regulation of lignocellulase expression and secretion, providing a potential strategy for the strain engineering to improve lignocellulase production.