MgAtg9 trafficking in Magnaporthe oryzae
MgAtg9 trafficking in Magnaporthe oryzae
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MgAtg9 在稻瘟病中的贩运
DOI：
10.4161/auto.5.7.9161
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发表时间：
2009-10-01
期刊：
影响因子：
13.3
通讯作者：
Lin, Fu-Cheng
中科院分区：
文献类型：
--
作者：
Dong, Bo;Liu, Xiao-Hong;Lin, Fu-Cheng
自噬是真核细胞中的液泡/溶酶体细胞质回收系统。 ScATG9 对于酿酒酵母的自噬是不可或缺的。在这里，我们通过在植物病原丝状真菌 Magnaporthe oryzae 中进行靶向基因替换，删除了 ScATG9 的直系同源物 MgATG9，然后分析了 Mgatg9 Delta 突变体中 EGFP-MgAtg9 的细胞分布模式。我们在接种于丰富培养基中的分生孢子细胞和与水中分生孢子分化的附着胞中检测到多个绿点的表达谱。在打点的同时，我们发现一些荧光信号位于富培养基中培养的分生孢子的沉没菌丝的中央液泡上。接下来，我们将 DsRed2-MgAtg8 引入表达 EGFP-MgAtg9 的 Mgatg9 Delta 突变体中，并观察到分生孢子细胞中多个位点的部分重叠，这让人想起哺乳动物系统中的情况。我们的发现进一步得出这样的假设：两个融合共定位的多个位点倾向于合并为分生孢子细胞的中心结构。最后，我们分别测试了 MgATG1、2、13 和 18 无效突变体中 EGFP-MgAtg9 的表达。我们推测 MgAtg1、2 和 18，而不是 MgAtg13，是 MgAtg9 通过多个共定位位点循环到其在米霉分生孢子细胞中的存储池所必需的，并且这些共定位位点融合到中心结构中可以通过其他未识别的机制来控制。
Autophagy is a vacuolar/lysosomal cytoplasmic recycling system in eukaryotic cells. ScATG9 is indispensable for autophagy in Saccharomyces cerevisiae. Here, we deleted MgATG9, the orthologue of ScATG9, via targeted gene replacement in the phytopathogenic filamentous fungus Magnaporthe oryzae, and then analyzed the cellular distribution pattern of EGFP-MgAtg9 in the Mgatg9 Delta mutant. We detected an expression profile of multiple green dots in the conidial cell inoculated in rich media and in the appressoria differentiated from the conidia in H2O. Concurrent with the punctation, we found some fluorescent signals localized on the central vacuole of the submerged hyphae from the conidia cultured in rich media. Next, we introduced DsRed2-MgAtg8 into the Mgatg9 Delta mutant expressing EGFP-MgAtg9 and observed partial overlap at multiple sites in the conidial cell, reminiscent of that in the mammalian system. Our findings further led to the postulation that the multiple sites where the two fusions colocalized tend to merge as a central structure in the conidial cell. Finally, we tested the expression of EGFP-MgAtg9 in null mutants of MgATG1, 2, 13 and 18, respectively. We speculate that MgAtg1, 2 and 18, but not MgAtg13, is required for MgAtg9 cycling through the multiple colocalization sites to its storage pools in the conidial cell of M. oryzae, and fusion of these colocalization sites into a central structure could be governed through other unidentified mechanisms.