Arabidopsis ATG8-INTERACTING PROTEIN1 Is Involved in Autophagy-Dependent Vesicular Trafficking of Plastid Proteins to the Vacuole
Arabidopsis ATG8-INTERACTING PROTEIN1 Is Involved in Autophagy-Dependent Vesicular Trafficking of Plastid Proteins to the Vacuole
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DOI：
10.1105/tpc.114.129999
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发表时间：
2014-10-01
期刊：
影响因子：
11.6
通讯作者：
Galili, Gad
中科院分区：
文献类型：
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作者：
Michaeli, Simon;Honig, Arik;Galili, Gad
选择性自噬已经在各种生物中被广泛研究，但关于其在植物中的功能，特别是在细胞器周转中的知识有限。我们最近从拟南芥中发现了ATG8相互作用蛋白1（ATI1），并表明在碳饥饿后，ATI1定位于内质网（ER）相关体，随后被转运到液泡。在这里，我们表明，碳饥饿后，ATI 1也位于与质体相关的体上，这与ER ATI体不同，并且主要在表现出质体降解的衰老细胞中检测到。此外，这些质体定位的机构含有基质蛋白标记物作为货物，并观察到出芽和脱离质体。ATI 1与质体定位的蛋白质相互作用，并进一步显示为其中一种蛋白质的周转所需。质体上的ATI 1也与ATG8f相互作用，这显然导致质体通过需要功能性自噬的过程靶向液泡。最后，我们表明ATI 1参与了拟南芥盐胁迫耐受性。总之，我们的研究结果表明ATI 1通过其与核心自噬机制的质体蛋白和ATG 8相互作用的能力参与自噬质体到液泡的运输。
Selective autophagy has been extensively studied in various organisms, but knowledge regarding its functions in plants, particularly in organelle turnover, is limited. We have recently discovered ATG8-INTERACTING PROTEIN1 (ATI1) from Arabidopsis thaliana and showed that following carbon starvation it is localized on endoplasmic reticulum (ER)-associated bodies that are subsequently transported to the vacuole. Here, we show that following carbon starvation ATI1 is also located on bodies associating with plastids, which are distinct from the ER ATI bodies and are detected mainly in senescing cells that exhibit plastid degradation. Additionally, these plastid-localized bodies contain a stroma protein marker as cargo and were observed budding and detaching from plastids. ATI1 interacts with plastid-localized proteins and was further shown to be required for the turnover of one of them, as a representative. ATI1 on the plastid bodies also interacts with ATG8f, which apparently leads to the targeting of the plastid bodies to the vacuole by a process that requires functional autophagy. Finally, we show that ATI1 is involved in Arabidopsis salt stress tolerance. Taken together, our results implicate ATI1 in autophagic plastid-to-vacuole trafficking through its ability to interact with both plastid proteins and ATG8 of the core autophagy machinery.