14-3-3 proteins regulate intracellular localization of the bZIP transcriptional activator RSG
14-3-3 proteins regulate intracellular localization of the bZIP transcriptional activator RSG
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DOI：
10.1105/tpc.13.11.2483
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发表时间：
2001-11-01
期刊：
影响因子：
11.6
通讯作者：
Takahashi, Y
中科院分区：
文献类型：
--
作者：
Igarashi, D;Ishida, S;Takahashi, Y
赤霉素（GAs）是植物生长发育的重要调节因子，包括茎伸长、种子萌发和开花。RSG是具有碱性亮氨酸拉链结构域的转录激活因子，其通过控制GA生物合成酶来调节内源性GA量。RSG在植物器官中的普遍表达表明转录因子的转录后和/或翻译后修饰的参与。在这里，我们确定14-3-3信号蛋白作为RSG结合伙伴。不能与14-3-3蛋白结合的RSG突变体比野生型RSG表现出更高的转录活性。与该观察结果一致，不能结合14-3-3蛋白的突变体RSG主要位于细胞核中，而野生型RSG分布在整个细胞中。使用核输出抑制剂来普霉素B，我们还表明，RSG，显然静态定位在细胞质中，是能够穿梭进出细胞核。这些结果表明，14-3-3蛋白负调节RSG，这是参与调节内源性的GAs量，通过控制其细胞内定位。
Gibberellins (GAs) are essential regulators of many aspects of plant development, including stem elongation, seed germination, and flowering. RSG is a transcriptional activator with a basic leucine zipper domain that regulates endogenous amounts of GAs through the control of a GA biosynthetic enzyme. The ubiquitous expression of RSG in plant organs suggests an involvement of post-transcriptional and/or post-translational modifications of the transcription factor. Here, we identify the 14-3-3 signaling proteins as RSG binding partners. The mutant version of RSG that could not bind to 14-3-3 proteins exhibited a higher transcriptional activity than did wild-type RSG. Consistent with this observation, the mutant RSG that could not bind to 14-3-3 proteins was localized predominantly in the nucleus, whereas wild-type RSG was distributed throughout the cell. Using the nuclear export inhibitor leptomycin B, we also showed that RSG, apparently statically localized in the cytoplasm, is capable of shuttling in and out of the nucleus. These results suggest that 14-3-3 proteins negatively modulate RSG, which is involved in the regulation of endogenous amounts of GAs, by controlling its intracellular localization.