FgSpa2 recruits FgMsb3, a Rab8 GAP, to the polarisome to regulate polarized trafficking, growth and pathogenicity in Fusarium graminearum
FgSpa2 recruits FgMsb3, a Rab8 GAP, to the polarisome to regulate polarized trafficking, growth and pathogenicity in Fusarium graminearum
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FgSpa2 将 FgMsb3（一种 Rab8 GAP）招募至极化体，以调节禾谷镰刀菌的极化运输、生长和致病性
DOI：
10.1111/nph.16935
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Zheng Wenhui
中科院分区：
文献类型：
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作者：
Zheng Huawei;Li Lingping;Yu Zhi;Yuan Yanping;Zheng Qiaojia;Xie Qiurong;Li Guangpu;Abubakar Yakubu Saddeeq;Zhou Jie;Wang Zonghua;Zheng Wenhui
在丝状真菌中，菌丝的生长依赖于囊泡向生长尖端的连续递送。目前尚不清楚快速生长的菌丝如何协调尖端细胞中同时的细胞延伸和扩张。我们对禾谷镰刀菌中12个含有TBC（Tre 2/Bub 2/Cdc 16）结构域的蛋白进行了功能表征。其中，FgMsb 3被发现调节菌丝顶端的扩展和致病性所需的。FgMsb 3蛋白定位于极性体和菌丝顶端圆顶（HAD），在那里它作为FgRab 8的GT β激活蛋白，而FgRab 8是顶端分泌介导的生长和致病所必需的。FgMSB 3的缺失导致过度极化运输，但阻断FgSnc 1相关囊泡与质膜的融合。此外，我们确定FgSpa 2与FgMsb 3相互作用，使FgMsb 3能够与极化体连接。FgSpa 2或其他极性体组分（FgBud 6和FgPea 2）的缺失导致FgMsb 3完全转移到HAD，这影响了真菌的极性生长和致病性。综上所述，我们得出结论，FgSpa 2调节FgMsb 3-FgRab 8级联，这对于建立稳态平衡至关重要，该平衡维持连续的极性生长并有助于F的致病性。禾谷早熟禾
In filamentous fungi, hyphal growth depends on the continuous delivery of vesicles to the growing tips. It is unclear how fast‐growing hyphae coordinate simultaneous cell extension and expansion in the tip cells.We have functionally characterized 12 TBC (Tre‐2/Bub2/Cdc16) domain‐containing proteins inFusarium graminearum. Among them, FgMsb3 is found to regulate hyphal tip expansion and to be required for pathogenicity. The regulatory mechanism of FgMsb3 has been further investigated by genetic, high‐resolution microscopy and high‐throughput co‐immunoprecipitation strategies.The FgMsb3 protein localizes at the polarisome and the hyphal apical dome (HAD) where it acts as a GTPase‐activating protein for FgRab8 which is required for apical secretion‐mediated growth and pathogenicity. Deletion ofFgMSB3causes excessive polarized trafficking but blocks the fusion of FgSnc1‐associated vesicles to the plasma membrane. Moreover, we establish that FgSpa2 interacts with FgMsb3, enabling FgMsb3 tethering to the polarisome. Loss of FgSpa2 or other polarisome components (FgBud6 and FgPea2) causes complete shifting of FgMsb3 to the HAD and this affects the polarized growth and pathogenicity of the fungus.In summary, we conclude that FgSpa2 regulates FgMsb3–FgRab8 cascade and this is crucial for creating a steady‐state equilibrium that maintains continuous polarized growth and contributes to the pathogenicity ofF. graminearum.