BcIqg1, a fungal IQGAP homolog, interacts with NADPH oxidase, MAP kinase and calcium signaling proteins and regulates virulence and development in Botrytis cinerea
BcIqg1, a fungal IQGAP homolog, interacts with NADPH oxidase, MAP kinase and calcium signaling proteins and regulates virulence and development in Botrytis cinerea
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DOI：
10.1111/mmi.13391
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发表时间：
2016-07-01
影响因子：
3.6
通讯作者：
Tudzynski, Paul
中科院分区：
文献类型：
--
作者：
Marschall, Robert;Tudzynski, Paul
NADPH氧化酶（Nox）在多细胞真核生物中产生活性氧（ROS）。它们在吞噬细胞和植物细胞中引发防御反应（氧化爆发），并参与广泛的分化过程。真菌Nox复合物在植物生长、有性繁殖和致病过程中起着重要作用。与哺乳动物系统相反，知识是有限的组成，定位和连接到真菌中的主要信号级联。在这里，我们表征了RasGAP支架蛋白IQGAP的真菌同源物，其连接几个主要的信号传导过程，包括哺乳动物细胞系中的Nox。我们发现，BcIqg 1直接与胞质，调节成分（BcRac）和膜相关的亚基（BcNoxD）的一个Nox-复合体中的病原体灰葡萄孢相互作用。因此，这种蛋白质可能是介导催化亚基与调节剂BcNoxR相互作用的支架。该蛋白质与MAP激酶和钙依赖性信号通路的模块相互作用。BcIqg 1的功能分析证实了其参与不同的信号通路。介导Ca 2+触发的BcCRZ 1和MAP激酶BcBmp 1的核转位。BcIqg 1参与抗氧化和膜胁迫，是几个发育过程所需的，包括形成菌核，分生孢子吻合管和感染垫以及毒力。
NADPH oxidases (Nox) produce reactive oxygen species (ROS) in multicellular eukaryotic organisms. They trigger defense reactions (oxidative burst') - in phagocytes and plant cells -, and are involved in a broad range of differentiation processes. Fungal Nox-complexes play a central role in vegetative, sexual and pathogenic processes. In contrast to mammalian systems, knowledge is limited about composition, localisation and connection to major signaling cascades in fungi. Here, we characterize a fungal homolog of the RasGAP scaffold protein IQGAP, which links several major signaling processes, including Nox in mammalian cell lines. We show that BcIqg1 interacts directly with a cytosolic, regulatory component (BcRac) and a membrane-associated subunit (BcNoxD) of a Nox-complex in the pathogen Botrytis cinerea. Thus, this protein may be a scaffold that mediates interaction of the catalytic subunits with the regulator BcNoxR. The protein interacts with modules of the MAP kinase- and calcium-dependent signaling pathways. Functional analysis of BcIqg1 substantiated its involvement in different signaling pathways. It mediates the Ca2+-triggered nuclear translocation of-BcCRZ1 and the MAP kinase BcBmp1. BcIqg1 is involved in resistance against oxidative and membrane stress and is required for several developmental processes including formation of sclerotia, conidial anastomosis tubes and infection cushions as well as for virulence.