Autophagy-related (ATG) 11, ATG9 and the phosphatidylinositol 3-kinase control ATG2-mediated formation of autophagosomes in Arabidopsis
Autophagy-related (ATG) 11, ATG9 and the phosphatidylinositol 3-kinase control ATG2-mediated formation of autophagosomes in Arabidopsis
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DOI：
10.1007/s00299-018-2258-9
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发表时间：
2018-04-01
影响因子：
6.2
通讯作者：
Chung, Taijoon
中科院分区：
文献类型：
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作者：
Kang, Sangwoo;Shin, Kwang Deok;Chung, Taijoon
利用自噬的定量分析方法，我们分析了4类atg突变体，发现了新的atg 2表型和ATG基因间的相互作用，并提出了植物自噬体形成的模型。自噬是由一组保守的蛋白质调控和执行的，称为自噬相关蛋白（ATG）。在拟南芥中，几组ATG蛋白已经使用遗传方法进行了表征。然而，ATG基因之间的遗传相互作用尚未建立，植物中不同ATG组之间的关系仍然不清楚。在这里，我们分析了atg 2，atg 7，atg 9和atg 11突变体及其双突变体在生理，生化和亚细胞水平。磷脂酰肌醇3-激酶（PI 3 K）在自噬中的参与也使用渥曼青霉素（一种PI 3 K抑制剂）进行了测试。我们使用自噬标记的突变体分析表明atg 7和atg 2表型比atg 11和atg 9更严重。与其他突变体不同，atg 2细胞积累了几个自噬小泡，不能被交付到液泡。atg双突变体的分析，结合渥曼青霉素治疗，表明ATG 11，PI 3 K，和ATG 9作用于ATG 2的上游。我们的数据支持一种模型，其中植物ATG 1和PI 3 K复合物在自噬的启动中发挥作用，而ATG 2参与自噬囊泡的生物发生过程中的后续步骤。
Using quantitative assays for autophagy, we analyzed 4 classes of atg mutants, discovered new atg2 phenotypes and ATG gene interactions, and proposed a model of autophagosome formation in plants.Plant and other eukaryotic cells use autophagy to target cytoplasmic constituents for degradation in the vacuole. Autophagy is regulated and executed by a conserved set of proteins called autophagy-related (ATG). In Arabidopsis, several groups of ATG proteins have been characterized using genetic approaches. However, the genetic interactions between ATG genes have not been established and the relationship between different ATG groups in plants remains unclear. Here we analyzed atg2, atg7, atg9, and atg11 mutants and their double mutants at the physiological, biochemical, and subcellular levels. Involvement of phosphatidylinositol 3-kinase (PI3K) in autophagy was also tested using wortmannin, a PI3K inhibitor. Our mutant analysis using autophagy markers showed that atg7 and atg2 phenotypes are more severe than those of atg11 and atg9. Unlike other mutants, atg2 cells accumulated several autophagic vesicles that could not be delivered to the vacuole. Analysis of atg double mutants, combined with wortmannin treatment, indicated that ATG11, PI3K, and ATG9 act upstream of ATG2. Our data support a model in which plant ATG1 and PI3K complexes play a role in the initiation of autophagy, whereas ATG2 is involved in a later step during the biogenesis of autophagic vesicles.