Zinc finger domain of Snail functions as a nuclear localization signal for importin β-mediated nuclear import pathway
Zinc finger domain of Snail functions as a nuclear localization signal for importin β-mediated nuclear import pathway
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DOI：
10.1111/j.1365-2443.2005.00850.x
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发表时间：
2005-05-01
期刊：
影响因子：
2.1
通讯作者：
Yoneda, Y
中科院分区：
文献类型：
--
作者：
Yamasaki, H;Sekimoto, T;Yoneda, Y
Snail是一种与DNA结合的锌指蛋白，在肿瘤细胞的生长发育和侵袭过程中，它是包括E-钙粘蛋白在内的基因的转录抑制因子。人Snail是一种由264个氨基酸组成的核蛋白，其氨基端有一个富含碱性氨基酸的结构域（SNAG结构域），羧基端有一个DNA结合结构域（锌指结构域）。制备了一系列由绿色荧光蛋白（GFP）和Snail蛋白部分组成的融合蛋白，并检测了它们的亚细胞定位。四个锌指与GFP的融合导致GFP靶向细胞核，表明锌指结构域足以用于核定位。使用体外转运系统，在Ran和NTF 2的存在下，通过输入蛋白（核转运蛋白）β重建Snail的核输入。我们进一步证明了Snail以锌指结构域依赖的方式直接结合importin beta。这些结果表明Snail的锌指结构域具有核定位信号的功能，Snail可以通过importin β介导的方式进入细胞核。
Snail, a DNA-binding zinc finger protein, functions as a transcriptional repressor for genes including E-cadherin during development and the acquisition of tumor cell invasiveness. Human Snail is a 264-amino acid nuclear protein with an amino-terminal basic amino acid-rich domain (SNAG domain) and a carboxyl-terminal DNA-binding domain (zinc finger domain). A series of fusion proteins composed of green fluorescent protein (GFP) and portions of the Snail protein were generated, and their subcellular localization was examined. Fusion of the four zinc fingers to GFP led to the targeting of GFP to the nucleus, demonstrating that the zinc finger domain is sufficient for nuclear localization. Using an in vitro transport system, the nuclear import of Snail was reconstituted by importin (karyopherin) beta in the presence of Ran and NTF2. We further demonstrated that Snail binds directly to importin beta in a zinc finger domain-dependent manner. These results indicate that zinc finger domain of Snail functions as a nuclear localization signal and Snail can be transported into the nucleus in an importin beta-mediated manner.