Elucidation of the calcineurin-Crz1 stress response transcriptional network in the human fungal pathogen Cryptococcus neoformans.
Elucidation of the calcineurin-Crz1 stress response transcriptional network in the human fungal pathogen Cryptococcus neoformans.
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DOI：
10.1371/journal.pgen.1006667
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发表时间：
2017-04
期刊：
影响因子：
4.5
通讯作者：
Heitman J
中科院分区：
文献类型：
--
作者：
Chow EW;Clancey SA;Billmyre RB;Averette AF;Granek JA;Mieczkowski P;Cardenas ME;Heitman J
钙调神经磷酸酶是一种高度保守的钙/钙调蛋白依赖性丝氨酸/苏氨酸特异性蛋白磷酸酶，其协调细胞的钙信号应答。在新生隐球菌中，钙调神经磷酸酶被包括高温在内的多种胁迫激活，并且是胁迫适应和毒力所必需的。转录因子Crz 1是酿酒酵母和其他真菌中的主要钙调神经磷酸酶效应子。钙调磷酸酶使Crz 1去磷酸化，从而使Crz 1核转位和靶基因转录成为可能。在这里，我们表明，Crz 1的损失赋予野生型和钙调磷酸酶突变体之间的中间表型，并证明，缺失的钙调磷酸酶对接结构域的结果在Crz 1不能易位到细胞核中的热应力。RNA测序揭示了102个基因在37°C下以钙调神经磷酸酶-Crz 1依赖性方式调节。在cna 1 Δ和crz 1 Δ突变体中，大多数基因表达下调，表明这些基因在高温下通常由钙调神经磷酸酶-Crz 1途径激活。大约58%的calcineurin-Crz 1靶基因具有未知的功能，而已知或预测功能的基因参与细胞壁重塑、钙转运和信息素产生。我们确定了三个钙调神经磷酸酶依赖性的响应元件图案内的启动子区域的钙调神经磷酸酶-Crz 1的靶基因，并表明，Crz 1结合靶基因启动子增加后，热应力的钙调神经磷酸酶依赖的方式。此外，我们还发现了大量由钙调神经磷酸酶独立调控的基因，Crz 1独立于钙调神经磷酸酶调控了59个基因。考虑到中间crz 1 Δ突变表型，以及我们最近的证据表明钙调磷酸酶调控网络影响P体和应激颗粒中的mRNA，而不依赖于Crz 1，钙调磷酸酶可能作用于Crz 1以外的因子，这些因子控制mRNA表达/稳定性，以操作真菌毒力所必需的分支转录/转录后应激反应网络。综上所述，我们的研究结果揭示了核心calcineurin-Crz 1应激反应级联反应是从子囊菌到致病性担子菌真菌维持的，但它在C.新变型似乎适于促进真菌毒力。丝氨酸/苏氨酸特异性蛋白磷酸酶钙调神经磷酸酶是几种机会致病性人类真菌病原体，包括白色念珠菌，烟曲霉，和新型隐球菌的毒力的关键。我们发现Crz 1作用于钙调磷酸酶下游，1）控制涉及细胞壁完整性、钙离子和小分子转运的基因表达，2）有助于C.新人类我们的研究表明，钙调神经磷酸酶也控制其他基因的mRNA表达水平独立的Crz 1。我们建议，钙调神经磷酸酶在一个分支的信号转导级联控制目标在转录和转录后水平。
Calcineurin is a highly conserved Ca2+/calmodulin-dependent serine/threonine-specific protein phosphatase that orchestrates cellular Ca2+ signaling responses. In Cryptococcus neoformans, calcineurin is activated by multiple stresses including high temperature, and is essential for stress adaptation and virulence. The transcription factor Crz1 is a major calcineurin effector in Saccharomyces cerevisiae and other fungi. Calcineurin dephosphorylates Crz1, thereby enabling Crz1 nuclear translocation and transcription of target genes. Here we show that loss of Crz1 confers phenotypes intermediate between wild-type and calcineurin mutants, and demonstrate that deletion of the calcineurin docking domain results in the inability of Crz1 to translocate into the nucleus under thermal stress. RNA-sequencing revealed 102 genes that are regulated in a calcineurin-Crz1-dependent manner at 37°C. The majority of genes were down-regulated in cna1Δ and crz1Δ mutants, indicating these genes are normally activated by the calcineurin-Crz1 pathway at high temperature. About 58% of calcineurin-Crz1 target genes have unknown functions, while genes with known or predicted functions are involved in cell wall remodeling, calcium transport, and pheromone production. We identified three calcineurin-dependent response element motifs within the promoter regions of calcineurin-Crz1 target genes, and show that Crz1 binding to target gene promoters is increased upon thermal stress in a calcineurin-dependent fashion. Additionally, we found a large set of genes independently regulated by calcineurin, and Crz1 regulates 59 genes independently of calcineurin. Given the intermediate crz1Δ mutant phenotype, and our recent evidence for a calcineurin regulatory network impacting mRNA in P-bodies and stress granules independently of Crz1, calcineurin likely acts on factors beyond Crz1 that govern mRNA expression/stability to operate a branched transcriptional/post-transcriptional stress response network necessary for fungal virulence. Taken together, our findings reveal the core calcineurin-Crz1 stress response cascade is maintained from ascomycetes to a pathogenic basidiomycete fungus, but its output in C. neoformans appears to be adapted to promote fungal virulence. The ubquitiously conserved serine/threonine-specific protein phosphatase calcineurin is crucial for virulence of several opportunistic human fungal pathogens including Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans. We show that Crz1 acts downstream of calcineurin, to 1) govern expression of genes involved in cell wall integrity, and calcium and small molecule transport, and 2) contribute to stress survival and virulence of C. neoformans. Our studies reveal that calcineurin also controls mRNA expression levels of other genes independently of Crz1. We propose that calcineurin operates in a branched signal transduction cascade controlling targets at both the transcriptional and post-transcriptional levels.