CsmA, a class V chitin synthase with a myosin motor-like domain, is localized through direct interaction with the actin cytoskeleton in Aspergillus nidulans
CsmA, a class V chitin synthase with a myosin motor-like domain, is localized through direct interaction with the actin cytoskeleton in Aspergillus nidulans
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DOI：
10.1091/mbc.e04-09-0761
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发表时间：
2005-04-01
影响因子：
3.3
通讯作者：
Horiuchi, H
中科院分区：
文献类型：
--
作者：
Takeshita, N;Ohta, A;Horiuchi, H
真菌形态发生的基本特征之一是细胞壁成分（如几丁质）的极化合成。肌动蛋白细胞骨架为细粒曲霉以及大多数其他真核生物的细胞极性提供了结构基础。V类几丁质合成酶CsmA含有肌凝蛋白运动样结构域（MMD），在大多数丝状真菌中是保守的。Delta csmA零突变体在细胞壁完整性和极性建立方面表现出明显的异常。在这项研究中，我们证明了CsmA标记了9个HA表位，这些表位位于菌丝尖端和分裂位点的肌动蛋白结构附近，并且其MMD能够与肌动蛋白结合。MMD中携带点突变或缺失的突变体的特征表明，MMD和肌动蛋白之间的相互作用不仅对CsmA的正确定位是必要的，而且对CsmA的功能也是必要的。因此，发现几丁质合成酶和肌动蛋白细胞骨架之间的直接相互作用为研究极化细胞壁合成和真菌形态发生的机制提供了新的见解。
One of the essential features of fungal morphogenesis is the polarized synthesis of cell wall components such as chitin. The actin cytoskeleton provides the structural basis for cell polarity in Aspergillus nidulans, as well as in most other eukaryotes. A class V chitin synthase, CsmA, which contains a myosin motor-like domain (MMD), is conserved among most filamentous fungi. The Delta csmA null mutant showed remarkable abnormalities with respect to cell wall integrity and the establishment of polarity. In this study, we demonstrated that CsmA tagged with 9 x HA epitopes localized near actin structures at the hyphal tips and septation sites and that its MMD was able to bind to actin. Characterization of mutants bearing a point mutation or deletion in the MMD suggests that the interaction between the MMD and actin is not only necessary for the proper localization of CsmA, but also for CsmA function. Thus, the finding of a direct interaction between the chitin synthase and the actin cytoskeleton provides new insight into the mechanisms of polarized cell wall synthesis and fungal morphogenesis.