Identification of an Arabidopsis transmembrane bZIP transcription factor involved in the endoplasmic reticulum stress response
Identification of an Arabidopsis transmembrane bZIP transcription factor involved in the endoplasmic reticulum stress response
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DOI：
10.1016/j.bbrc.2008.07.021
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发表时间：
2008-09-19
影响因子：
3.1
通讯作者：
Koizumi, Nozomu
中科院分区：
文献类型：
--
作者：
Tajima, Hiromi;Iwata, Yuji;Koizumi, Nozomu
在拟南芥中鉴定的 75 个 bZIP 转录因子中，除了先前已表征的 AtbZIP60 之外，还有 3 个（AtbZIP17、AtbZIP28 和 AtbZIP49）还具有假定的跨膜结构域 (TMD)。在本研究中，分离了AtbZIP17和AtbZIP28的cDNA。缺少包括 TMD 在内的 C 端结构域的 AtbZIP17 和 AtbZIP28 的截短形式被检查为假定的活性形式。其中之一，AtbZIP28 Delta C，通过负责 ER 应激反应的顺式元件 P-UPRE 和 ERSE 激活 BiP1 和 BiP3 启动子。随后，绿色荧光蛋白（GFP）和AtbZIP28的融合蛋白在拟南芥培养细胞中表达。在非应激条件下，GFP荧光定位几乎与ER标记重叠；然而，衣霉素和二硫苏糖醇处理明显增加了细胞核中的 GFP 荧光，表明 AtbZIP28 的 N 末端片段响应 ER 应激而易位至细胞核。 (C) 2008 Elsevier Inc. 保留所有权利。
Among 75 bZIP transcription factors identified in Arabidopsis, 3 (AtbZIP17, AtbZIP28, and AtbZIP49) possess a putative transmembrane domain (TMD) in addition to AtbZIP60, which was characterized previously. In the present study, cDNAs of AtbZIP17 and AtbZIP28 were isolated. Truncated forms of AtbZIP17 and AtbZIP28 lacking the C-terminal domain including TMD were examined as putative active forms. One of them, AtbZIP28 Delta C, activated BiP1 and BiP3 promoters through the cis-elements P-UPRE and ERSE responsible for the ER stress response. Subsequently, a fusion protein of green fluorescent protein (GFP) and AtbZIP28 was expressed in Arabidopsis cultured cells. Under non-stress conditions, GFP fluorescence localization almost overlapped with an ER marker; however, tunicamycin and dithiothreitol treatment clearly increased GFP fluorescence in the nucleus suggesting that the N-terminal fragment of AtbZIP28 translocates to the nucleus in response to ER stress. (C) 2008 Elsevier Inc. All rights reserved.