Dehydrin MtCAS31 promotes autophagic degradation under drought stress
Dehydrin MtCAS31 promotes autophagic degradation under drought stress
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脱水蛋白 MtCAS31 促进干旱胁迫下的自噬降解
DOI：
10.1080/15548627.2019.1643656
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发表时间：
2019-08-02
期刊：
影响因子：
13.3
通讯作者：
Wang, Tao
中科院分区：
文献类型：
--
作者：
Li, Xin;Liu, Qianwen;Wang, Tao
摘要干旱胁迫严重影响作物产量，植物通过自噬/巨自噬来抵抗干旱胁迫的机制尚不清楚。在这里，我们表明，一种自噬蛋白，蒺藜苜蓿MtCAS 31（冷驯化特异性31），干旱反应的正调节剂，在自噬降解中起着关键作用。GFP切割测定和用自噬特异性抑制剂处理表明，MtCAS 31参与自噬降解途径，并且过表达MtCAS 31促进干旱胁迫下的自噬。此外，我们发现MtCAS 31与自噬相关蛋白ATG 8a在AIM样基序YXXXI中相互作用，支持其在自噬降解中的功能。此外，我们通过筛选M.蒺藜cDNA文库。我们发现MtPIP 2;7作为干旱反应的负调节因子发挥作用。在干旱胁迫下，MtCAS 31促进了MtPIP 2;7的自噬降解，降低了根系导水率，从而减少了水分损失，提高了耐旱性。总之，我们的研究结果揭示了一种新的功能，促进自噬降解的蛋白质，这扩展了我们的知识的自噬蛋白的功能。缩略语：目的：ATG 8相互作用基序; ATG：自噬相关; ATI 1：ATG 8相互作用蛋白1; BiFC：生物分子荧光互补; CAS 31：冷适应特异性31; ConcA：康卡霉素A; DSK 2：KAR 2的显性抑制因子; ER：内质网; ERAD：ER相关降解; NBR 1：BRCA 1基因1旁; PM：质膜; PIP：质膜内在蛋白; TALEN：转录激活因子样效应物核酸酶; TSPO：富含寡核苷酸的感觉蛋白/转运蛋白; UPR：未折叠蛋白反应; VC：载体对照
ABSTRACT Drought stress seriously affects crop yield, and the mechanism underlying plant resistance to drought stress via macroautophagy/autophagy is not clear. Here, we show that a dehydrin, Medicago truncatula MtCAS31 (cold acclimation-specific 31), a positive regulator of drought response, plays a key role in autophagic degradation. A GFP cleavage assay and treatment with an autophagy-specific inhibitor indicated that MtCAS31 participates in the autophagic degradation pathway and that overexpressing MtCAS31 promotes autophagy under drought stress. Furthermore, we discovered that MtCAS31 interacts with the autophagy-related protein ATG8a in the AIM-like motif YXXXI, supporting its function in autophagic degradation. In addition, we identified a cargo protein of MtCAS31, the aquaporin MtPIP2;7, by screening an M. truncatula cDNA library. We found that MtPIP2;7 functions as a negative regulator of drought response. Under drought stress, MtCAS31 facilitated the autophagic degradation of MtPIP2;7 and reduced root hydraulic conductivity, thus reducing water loss and improving drought tolerance. Taken together, our results reveal a novel function of dehydrins in promoting the autophagic degradation of proteins, which extends our knowledge of the function of dehydrins. Abbreviations: AIM: ATG8-interacting motif; ATG: autophagy-related; ATI1: ATG8-interacting protein1; BiFC: Biomolecular fluorescence complementation; CAS31: cold acclimation-specific 31; ConcA: concanamycin A; DSK2: dominant suppressor of KAR2; ER: endoplasmic reticulum; ERAD: ER-associated degradation; NBR1: next to BRCA1 gene 1; PM: plasma membrane; PIPs: plasma membrane intrinsic proteins; TALEN: transcription activator-like effector nuclease; TSPO: tryptophan-rich sensory protein/translocator; UPR: unfolded protein response; VC: vector control