Santos Ronaldo Silva, Martins-Silva Gabriel, Padilla Adrián Adolfo Álvarez, Possari Mateus, Degello Sérgio Donnantuoni, Bernardes Brustolini Otávio J, Vasconcelos Ana Tereza Ribeiro, Vallim Marcelo Afonso, Pascon Renata C
Universidade Federal de São Paulo, Campus Diadema, Rua São Nicolau, 210, Diadema 09913-030, SP, Brazil.
Laboratório Nacional de Computação Científica-LNCC, Labinfo-Laboratório de Bioinformática, Petrópolis 25651-075, RJ, Brazil.
J Fungi (Basel). 2024 Jul 30;10(8):531. doi: 10.3390/jof10080531.
Stress management is an adaptive advantage for survival in adverse environments. Pathogens face this challenge during host colonization, requiring an appropriate stress response to establish infection. The fungal pathogen undergoes thermal, oxidative, and osmotic stresses in the environment and animal host. Signaling systems controlled by Ras1, Hog1, and calcineurin respond to high temperatures and osmotic stress. Cationic stress caused by Na, K, and Li can be overcome with glycerol, the preferred osmolyte. Deleting the glycerol phosphate phosphatase gene (2) prevents cells from accumulating glycerol due to a block in the last step of its biosynthetic pathway. Gpp2 accumulates in a phosphorylated form in a 1Δ strain, and a physical interaction between Gpp2 and Cna1 was found; moreover, the 2Δ strain undergoes slow growth and has attenuated virulence in animal models of infection. We provide biochemical evidence that growth in 1 M NaCl increases glycerol content in the wild type, whereas 2Δ, 1Δ, and 1Δ mutants fail to accumulate it. The deletion of 1Δ or 1Δ renders yeast cells sensitive to cationic stress, and the Gfp-Gpp2 protein assumes an abnormal localization. We suggest a mechanism in which calcineurin controls Gpp2 at the post-translational level, affecting its localization and activity, leading to glycerol biosynthesis. Also, we showed the transcriptional profile of glycerol-deficient mutants and established the cationic stress response mediated by calcineurin; among the biological processes differentially expressed are carbon utilization, translation, transmembrane transport, glutathione metabolism, oxidative stress response, and transcription regulation. To our knowledge, this is the first time that this transcriptional profile has been described. These results have implications for pathogen stress adaptability.
应激管理是在不利环境中生存的一种适应性优势。病原体在宿主定殖过程中面临这一挑战，需要适当的应激反应来建立感染。真菌病原体在环境和动物宿主中会经历热、氧化和渗透应激。由Ras1、Hog1和钙调神经磷酸酶控制的信号系统对高温和渗透应激作出反应。由钠、钾和锂引起的阳离子应激可以通过甘油（首选的渗透溶质）来克服。删除甘油磷酸磷酸酶基因（GPP2）会阻止细胞因甘油生物合成途径的最后一步受阻而积累甘油。Gpp2在GPP2Δ菌株中以磷酸化形式积累，并且发现Gpp2与Cna1之间存在物理相互作用；此外，GPP2Δ菌株生长缓慢，在感染动物模型中的毒力减弱。我们提供了生化证据，表明在1 M NaCl中生长会增加野生型中的甘油含量，而GPP2Δ、RAS1Δ和CNB1Δ突变体则无法积累甘油。删除RAS1Δ或CNB1Δ会使酵母细胞对阳离子应激敏感，并且Gfp-Gpp2蛋白呈现异常定位。我们提出了一种机制，其中钙调神经磷酸酶在翻译后水平控制Gpp2，影响其定位和活性，从而导致甘油生物合成。此外，我们展示了甘油缺陷型突变体的转录谱，并建立了由钙调神经磷酸酶介导的阳离子应激反应；在差异表达的生物学过程中包括碳利用、翻译、跨膜运输、谷胱甘肽代谢、氧化应激反应和转录调控。据我们所知，这是首次描述这种转录谱。这些结果对病原体应激适应性具有重要意义。
