Noncanonical ATG8-ABS3 interaction controls senescence in plants
Noncanonical ATG8-ABS3 interaction controls senescence in plants
复制标题
非经典 ATG8-ABS3 相互作用控制植物衰老。
DOI：
10.1038/s41477-018-0348-x
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发表时间：
2019-02-01
期刊：
影响因子：
18
通讯作者：
Yu, Fei
中科院分区：
文献类型：
--
作者：
Jia, Min;Liu, Xiayan;Yu, Fei
蛋白质稳态对细胞功能和寿命至关重要，而蛋白质稳态的丧失是衰老的标志之一。自噬是一种进化保守的细胞降解途径，对维持蛋白质稳态至关重要。矛盾的是，自噬缺陷会通过未知的机制导致蛋白质的加速损失。我们发现拟南芥多药和有毒化合物挤压转运蛋白的异常SHOOT3 （ABS3）亚家族在自然和碳剥夺条件下促进衰老。促进衰老的ABS3通路与促进长寿的自噬并行发挥作用，平衡植物的衰老和生存。令人惊讶的是，ABS3亚家族多药和有毒化合物挤出蛋白在内核体晚期与自噬相关蛋白8 （AUTOPHAGY-RELATED PROTEIN 8, ATG8）相互作用，促进衰老和蛋白质降解，而不发生ATG8的典型裂解和脂化。这种非自噬的ATG8-ABS3相互作用模式可能在双子体和单子体中保守。我们的研究结果揭示了ATG8先前未知的非自噬功能和ATG8 - abs3介导的蛋白质停滞控制的未被识别的衰老调控途径。自噬控制蛋白质稳态。自噬相关蛋白8和异常SHOOT3相互作用，促进核内体运输，并在衰老过程中独立于标准的自噬机制调节蛋白质降解。
Protein homeostasis is essential for cellular functions and longevity, and the loss of proteostasis is one of the hallmarks of senescence. Autophagy is an evolutionarily conserved cellular degradation pathway that is critical for the maintenance of proteostasis. Paradoxically, autophagy deficiency leads to accelerated protein loss by unknown mechanisms. We discover that the ABNORMAL SHOOT3 (ABS3) subfamily of multidrug and toxic compound extrusion transporters promote senescence under natural and carbon-deprivation conditions in Arabidopsis thaliana. The senescence-promoting ABS3 pathway functions in parallel with the longevity-promoting autophagy to balance plant senescence and survival. Surprisingly, ABS3 subfamily multidrug and toxic compound extrusion proteins interact with AUTOPHAGY-RELATED PROTEIN 8 (ATG8) at the late endosome to promote senescence and protein degradation without canonical cleavage and lipidation of ATG8. This non-autophagic ATG8–ABS3 interaction paradigm is probably conserved among dicots and monocots. Our findings uncover a previously unknown non-autophagic function of ATG8 and an unrecognized senescence regulatory pathway controlled by ATG8–ABS3-mediated proteostasis. Autophagy controls protein homeostasis. AUTOPHAGY-RELATED PROTEIN 8 and ABNORMAL SHOOT3 interact to promote endosome trafficking, as well as to regulate protein degradation during senescence independently from the canonical autophagy machinery.