Murry Reyna, Traxler Lea, Pötschner Jessica, Krüger Thomas, Kniemeyer Olaf, Krause Katrin, Kothe Erika
Institute of Microbiology, Friedrich Schiller University Jena, Microbial Communication, Neugasse 25, 07743 Jena, Germany.
Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Molecular and Applied Microbiology, Adolf-Reichwein-Straße 23, 07745 Jena, Germany.
J Fungi (Basel). 2021 Jun 10;7(6):470. doi: 10.3390/jof7060470.
Intracellular signaling is conserved in eukaryotes to allow for response to extracellular signals and to regulate development and cellular functions. In fungi, inositol phosphate signaling has been shown to be involved in growth, sexual reproduction, and metabolic adaptation. However, reports on mushroom-forming fungi are lacking so far. In , an inositol monophosphatase has been found up-regulated during sexual development. The enzyme is crucial for inositol cycling, where it catalyzes the last step of inositol phosphate metabolism, restoring the inositol pool from the monophosphorylated inositol monophosphate. We overexpressed the gene in this model basidiomycete and verified its involvement in cell wall integrity and intracellular trafficking. Strong phenotypes in mushroom formation and cell metabolism were evidenced by proteome analyses. In addition, altered inositol signaling was shown to be involved in tolerance towards cesium and zinc, and increased metal tolerance towards cadmium, associated with induced expression of kinases and repression of phosphatases within the inositol cycle. The presence of the heavy metals Sr, Cs, Cd, and Zn lowered intracellular calcium levels. We could develop a model integrating inositol signaling in the known signal transduction pathways governed by Ras, G-protein coupled receptors, and cAMP, and elucidate their different roles in development.
细胞内信号传导在真核生物中是保守的，以允许对细胞外信号作出反应并调节发育和细胞功能。在真菌中，肌醇磷酸信号传导已被证明参与生长、有性生殖和代谢适应。然而，迄今为止，关于形成蘑菇的真菌的报道还很缺乏。在[具体研究中]，一种肌醇单磷酸酶在有性发育过程中被发现上调。该酶对于肌醇循环至关重要，它催化肌醇磷酸代谢的最后一步，从单磷酸化的肌醇单磷酸中恢复肌醇池。我们在这种模式担子菌中过表达了该基因，并验证了其参与细胞壁完整性和细胞内运输。蛋白质组分析证明了在蘑菇形成和细胞代谢中出现的强烈表型。此外，改变的肌醇信号传导被证明与对铯和锌的耐受性有关，以及对镉的金属耐受性增加，这与肌醇循环内激酶的诱导表达和磷酸酶的抑制有关。重金属锶、铯、镉和锌的存在降低了细胞内钙水平。我们可以建立一个模型，将肌醇信号传导整合到由Ras、G蛋白偶联受体和cAMP控制的已知信号转导途径中，并阐明它们在发育中的不同作用。
