The tetrameric pheromone module SteC-MkkB-MpkB-SteD regulates asexual sporulation, sclerotia formation and aflatoxin production in Aspergillus flavus
The tetrameric pheromone module SteC-MkkB-MpkB-SteD regulates asexual sporulation, sclerotia formation and aflatoxin production in Aspergillus flavus
复制标题
四聚体信息素模块STEC-MkkB-MpkB-STED调节黄曲霉无性孢子形成、菌核形成和黄曲霉毒素的产生
DOI：
10.1111/cmi.13192
复制
发表时间：
2020-03-03
影响因子：
3.4
通讯作者：
Bayram, Ozgur
中科院分区：
文献类型：
--
作者：
Frawley, Dean;Greco, Claudio;Bayram, Ozgur
对于真核生物如真菌来调节对环境刺激的生物反应，利用各种信号传导级联，如高度保守的促分裂原活化蛋白激酶（MAPK）途径。在模式真菌构巢曲霉中，被称为信息素模块的MAPK途径调节发育和次级代谢产物（SM）的产生。该途径由五种蛋白质组成，三种激酶SteC、MkkB和MpkB，接头SteD和支架HamE。在这项研究中，这五个信息素模块蛋白的同源物已被确定在植物和人类病原真菌黄曲霉。我们已经表明，由三种激酶和SteD适配器组成的四聚体复合物在该物种中组装。观察到该复合物在细胞质中组装，并且MpkB易位到细胞核中。steC、mkkB、mpkB或steD的缺失导致无性孢子形成和菌核产生两者的消除。这种复合物是必需的黄曲霉毒素的生产和各种SM，包括兔孔蛋白B和cyclopiazonic酸（CPA），可能通过Mpk B在细胞核中的相互作用的正调节和负调节。这些数据突出了曲霉属物种中信息素模块的保守性，表明该途径在调节真菌发育和次生代谢中的重要性。
For eukaryotes like fungi to regulate biological responses to environmental stimuli, various signalling cascades are utilized, like the highly conserved mitogen-activated protein kinase (MAPK) pathways. In the model fungus Aspergillus nidulans, a MAPK pathway known as the pheromone module regulates development and the production of secondary metabolites (SMs). This pathway consists five proteins, the three kinases SteC, MkkB and MpkB, the adaptor SteD and the scaffold HamE. In this study, homologs of these five pheromone module proteins have been identified in the plant and human pathogenic fungus Aspergillus flavus. We have shown that a tetrameric complex consisting of the three kinases and the SteD adaptor is assembled in this species. It was observed that this complex assembles in the cytoplasm and that MpkB translocates into the nucleus. Deletion of steC, mkkB, mpkB or steD results in abolishment of both asexual sporulation and sclerotia production. This complex is required for the positive regulation of aflatoxin production and negative regulation of various SMs, including leporin B and cyclopiazonic acid (CPA), likely via MpkB interactions in the nucleus. These data highlight the conservation of the pheromone module in Aspergillus species, signifying the importance of this pathway in regulating fungal development and secondary metabolism.