PDF(Pubmed)
Abstract：
Cla4, an orthologous p21-activated kinase crucial for non-entomopathogenic fungal lifestyles, has two paralogs (Cla4A/B) functionally unknown in hypocrealean entomopathogens. Here, we report a regulatory role of Cla4A in gene expression networks of Beauveria bassiana required for asexual and entomopathogenic lifecycles while Cla4B is functionally redundant. The deletion of cla4A resulted in severe growth defects, reduced stress tolerance, delayed conidiation, altered conidiation mode, impaired conidial quality, and abolished pathogenicity through cuticular penetration, contrasting with no phenotype affected by cla4B deletion. In ∆cla4A, 5288 dysregulated genes were associated with phenotypic defects, which were restored by targeted gene complementation. Among those, 3699 genes were downregulated, including more than 1300 abolished at the transcriptomic level. Hundreds of those downregulated genes were involved in the regulation of transcription, translation, and post-translational modifications and the organization and function of the nuclear chromosome, chromatin, and protein-DNA complex. DNA-binding elements in promoter regions of 130 dysregulated genes were predicted to be targeted by Cla4A domains. Samples of purified Cla4A extract were proven to bind promoter DNAs of 12 predicted genes involved in multiple stress-responsive pathways. Therefore, Cla4A acts as a novel regulator of genomic expression and stability and mediates gene expression networks required for insect-pathogenic fungal adaptations to the host and environment.
摘要：
Cla4，一种对非昆虫病原真菌生活方式至关重要的直系同源p21激活激酶，在低胰虫昆虫病原体中有两个功能未知的旁系同源物（Cla4A/B）。这里,我们报道了Cla4A在无性和昆虫病原生命周期所需的球孢白僵菌基因表达网络中的调节作用,而Cla4B在功能上是多余的.cla4A的缺失导致严重的生长缺陷，降低应力耐受性，延迟分生孢子，改变分生孢子模式，分生孢子质量受损，并通过角质层穿透消除了致病性，与没有受cla4B缺失影响的表型形成对比。在Δcla4A中，5288个失调基因与表型缺陷相关，通过靶向基因互补恢复。其中,3699个基因下调，包括在转录组水平上废除的1300多个。数以百计的下调基因参与了转录的调节，翻译,以及翻译后修饰和核染色体的组织和功能，染色质,和蛋白质-DNA复合物。预测130个失调基因的启动子区域中的DNA结合元件被Cla4A结构域靶向。纯化的Cla4A提取物的样品被证明与参与多种应激反应途径的12个预测基因的启动子DNA结合。因此,Cla4A充当基因组表达和稳定性的新型调节剂，并介导昆虫病原真菌适应宿主和环境所需的基因表达网络。
