Austrian Institute of Technology GmbH, Health & Environment, Bioresources, Konrad-Lorenz-Straße 24, 3430, Tulln, Austria.
Sci Rep. 2019 Jul 29;9(1):10995. doi: 10.1038/s41598-019-47421-z.
Trichoderma reesei represents one of the most prolific producers of plant cell wall degrading enzymes. Recent research showed broad regulation by phosphorylation in T. reesei, including important transcription factors involved in cellulase regulation. To evaluate factors crucial for changes in these phosphorylation events, we studied non-essential protein phosphatases (PPs) of T. reesei. Viable deletion strains were tested for growth on different carbon sources, osmotic and oxidative stress response, asexual and sexual development, cellulase and protease production as well as secondary metabolism. Six PPs were found to be positive or negative regulators for cellulase production. A correlation of the effects of PPs on protease activities and cellulase activities was not detected. Hierarchical clustering of regulation patterns and phenotypes of deletion indicated functional specialization within PP classes and common as well as variable effects. Our results confirmed the central role of catalytic and regulatory subunits of PP2A which regulates several aspects of cell growth and metabolism. Moreover we show that the additional homologue of PPH5 in Trichoderma spp., PPH5-2 assumes distinct functions in metabolism, development and stress response, different from PPH5. The influence of PPs on both cellulase gene expression and secondary metabolite production support an interrelationship in the underlying regulation mechanisms.
里氏木霉是植物细胞壁降解酶的最主要生产者之一。最近的研究表明，在里氏木霉中，磷酸化广泛调节，包括参与纤维素酶调节的重要转录因子。为了评估这些磷酸化事件变化的关键因素，我们研究了里氏木霉的非必需蛋白磷酸酶（PP）。对可行的缺失菌株进行了在不同碳源、渗透和氧化应激反应、无性和有性发育、纤维素酶和蛋白酶产生以及次生代谢方面的生长测试。发现 6 个 PP 对纤维素酶的产生具有正或负的调节作用。未检测到 PP 对蛋白酶活性和纤维素酶活性的影响之间存在相关性。缺失的调控模式和表型的层次聚类表明 PP 类内的功能专业化以及共同和可变的影响。我们的结果证实了 PP2A 的催化和调节亚基在细胞生长和代谢的几个方面的核心作用。此外，我们还表明，在木霉属中，PPH5 的另一个同源物 PPH5-2 在代谢、发育和应激反应方面具有不同的功能，与 PPH5 不同。PP 对纤维素酶基因表达和次生代谢产物产生的影响支持了潜在调控机制之间的相互关系。
