The nuclear import of RNA helicase A is mediated by importin-alpha3.
The nuclear import of RNA helicase A is mediated by importin-alpha3.
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DOI：
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发表时间：
2006
影响因子：
3.1
通讯作者：
S. Aratani;T. Oishi;Hidetoshi Fujita;M. Nakazawa;R. Fujii;N. Imamoto;Y. Yoneda;A. Fukamizu;
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文献类型：
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作者：
S. Aratani;T. Oishi;Hidetoshi Fujita;M. Nakazawa;R. Fujii;N. Imamoto;Y. Yoneda;A. Fukamizu;
RNA 解旋酶 A (RHA) 是一种 ATP 酶/解旋酶，在转录激活和 RNA 加工等各个步骤中调节基因表达。已知 RHA 在细胞核和细胞质之间穿梭。我们鉴定了 RHA 的核定位信号（NLS）并分析了核输入机制。 RHA 的 NLS (RHA-NLS) 由 19 个氨基酸残基组成，在物种间高度保守，并且不具有共有的经典 NLS。体外核输入测定表明，RHA 的核输入是 Ran 依赖性的，并由经典的输入蛋白-α/β 依赖性途径介导。结合测定表明RHA-NLS中的碱性残基用于与导入蛋白-α相互作用。此外，RHA-NLS 的核导入得到 importin-alpha1 和优先 importin-alpha3 的支持。我们的结果表明，RHA 的核输入是由 importin-alpha3/importin-beta 依赖性途径介导的，并表明 importin 的特异性可能调节货物蛋白的功能。
RNA helicase A (RHA), an ATPase/helicase, regulates the gene expression at various steps including transcriptional activation and RNA processing. RHA is known to shuttle between the nucleus and cytoplasm. We identified the nuclear localization signal (NLS) of RHA and analyzed the nuclear import mechanisms. The NLS of RHA (RHA-NLS) consisting of 19 amino acid residues is highly conserved through species and does not have the consensus classical NLS. In vitro nuclear import assays revealed that the nuclear import of RHA was Ran-dependent and mediated with the classical importin-alpha/beta-dependent pathway. The binding assay indicated that the basic residues in RHA-NLS were used for interaction with importin-alpha. Furthermore, the nuclear import of RHA-NLS was supported by importin-alpha1 and preferentially importin-alpha3. Our results indicate that the nuclear import of RHA is mediated by the importin-alpha3/importin-beta-dependent pathway and suggest that the specificity for importin may regulate the functions of cargo proteins.