The lumen-facing domain is important for the biological function and organelle-to-organelle movement of bZIP28 during ER stress in Arabidopsis.
The lumen-facing domain is important for the biological function and organelle-to-organelle movement of bZIP28 during ER stress in Arabidopsis.
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DOI：
10.1093/mp/sst059
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发表时间：
2013-09
期刊：
影响因子：
27.5
通讯作者：
Le Sun;Sun-Jie Lu;Shuang-Shuang Zhang-Shuang;Shun-Fan Zhou;Ling Sun;Jian-Xiang Liu
中科院分区：
文献类型：
--
作者：
Le Sun;Sun-Jie Lu;Shuang-Shuang Zhang-Shuang;Shun-Fan Zhou;Ling Sun;Jian-Xiang Liu
膜相关转录因子bZIP28在拟南芥中响应内质网应激时从内质网（ER）重新定位到高尔基体，并通过两种蛋白酶S1P和S2P介导从膜上蛋白水解释放。激活的N-末端结构域募集核因子Y（NF-Y）亚基在细胞核中调节ER应激下游基因。关于bZIP28 C-末端腔面结构域的功能知之甚少。在这里，我们提供了新的见解如何ER腔面对域影响的生物功能和细胞器到细胞器的运动bZIP28在ER应激反应。首先，我们通过bZIP28和bZIP60双突变体zip28zip60的产生和分析证明了bZIP28和bZIP60的功能冗余。随后在zip28zip60背景下进行的bZIP 28腔面结构域缺失的遗传互补实验突出了腔面结构域对于bZIP 28在ER应激反应中的体内功能的重要性。蛋白质亚细胞定位和蛋白质印迹结果进一步揭示了bZIP28面向内腔的结构域包含ER保留信号，其对于bZIP28的蛋白水解活化是重要的。因此，bZIP28内腔的C-末端在bZIP28的ER到高尔基体的运动中起重要作用，这可能有助于ER应激的感知。
The membrane-associated transcription factor, bZIP28, is relocated from the endoplasmic reticulum (ER) to the Golgi and proteolytically released from the membrane mediated by two proteases, S1P and S2P, in response to ER stress in Arabidopsis. The activated N-terminal domain recruits nuclear factor Y (NF-Y) subunits in the nucleus to regulate ER stress downstream genes. Little is known about the functions of the bZIP28 C-terminal lumen-facing domain. Here, we provide novel insights into how the ER lumen-facing domain affects the biological function and organelle-to-organelle movement of bZIP28 in the ER stress response. First, we demonstrated the functional redundancy of bZIP28 and bZIP60 by generation and analysis of the bZIP28 and bZIP60 double mutant zip28zip60. Subsequent genetic complementation experiments in zip28zip60 background with deletions on bZIP28 lumen-facing domain highlighted the importance of lumen-facing domain for its in vivo function of bZIP28 in the ER stress response. The protein subcellular localization and Western blotting results further revealed that the bZIP28 lumen-facing domain contains ER retention signal which is important for the proteolytic activation of bZIP28. Thus, the bZIP28 lumen-facing C-terminus plays important roles in the ER-to-Golgi movement of bZIP28, which may contribute to the sensing of the ER stress.