Basic Leucine Zipper (bZIP) Domain Transcription Factor MBZ1 Regulates Cell Wall Integrity, Spore Adherence, and Virulence in Metarhizium robertsii
Basic Leucine Zipper (bZIP) Domain Transcription Factor MBZ1 Regulates Cell Wall Integrity, Spore Adherence, and Virulence in Metarhizium robertsii
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DOI：
10.1074/jbc.m114.630939
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发表时间：
2015-03-27
影响因子：
4.8
通讯作者：
Wang, Chengshu
中科院分区：
文献类型：
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作者：
Huang, Wei;Shang, Yanfang;Wang, Chengshu
含有碱性亮氨酸拉链（bZIP）结构域的转录因子（TF）广泛分布于真核生物中，并显示出一系列不同的功能。在这项研究中，bZIP型TF基因（MBZ1）的删除和功能的特点，在昆虫病原真菌绿僵菌罗伯茨。缺失突变体（三角洲MBZ1）表现出缺陷的细胞壁完整性，粘附到疏水表面，和局部感染的昆虫。相对于WT，Delta MBZ1的生长和分生孢子发生也受损。推定的靶基因表达的检查表明，参与几丁质生物合成的基因在Delta MBZ1中与WT相比差异转录，这导致了更高水平的几丁质在突变体细胞壁中的积累。MBZ1表现出枯草杆菌蛋白酶的负调节，但粘附素基因的正控制，这与观察到的对细胞自溶的影响和在Δ MBZ1中孢子粘附到疏水表面的减少一致。启动子结合实验表明MBZ1可以与不同的靶基因结合，并提示异源二聚体的形成可能增加MBZ1调控网络的多样性。本研究的结果推进了我们对bZIP型转录因子在种内和种间水平上的分歧的理解。
Transcription factors (TFs) containing the basic leucine zipper (bZIP) domain are widely distributed in eukaryotes and display an array of distinct functions. In this study, a bZIP-type TF gene (MBZ1) was deleted and functionally characterized in the insect pathogenic fungus Metarhizium robertsii. The deletion mutant (Delta MBZ1) showed defects in cell wall integrity, adhesion to hydrophobic surfaces, and topical infection of insects. Relative to the WT, Delta MBZ1 was also impaired in growth and conidiogenesis. Examination of putative target gene expression indicated that the genes involved in chitin biosynthesis were differentially transcribed in Delta MBZ1 compared with the WT, which led to the accumulation of a higher level of chitin in mutant cell walls. MBZ1 exhibited negative regulation of subtilisin proteases, but positive control of an adhesin gene, which is consistent with the observation of effects on cell autolysis and a reduction in spore adherence to hydrophobic surfaces in Delta MBZ1. Promoter binding assays indicated thatMBZ1can bind to different target genes and suggested the possibility of heterodimer formation to increase the diversity of the MBZ1 regulatory network. The results of this study advance our understanding of the divergence of bZIP-type TFs at both intra-and interspecific levels.