Transportin-mediated nuclear import of heterogeneous nuclear RNP proteins.
Transportin-mediated nuclear import of heterogeneous nuclear RNP proteins.
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DOI：
10.1083/jcb.138.6.1181
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发表时间：
1997-09-22
影响因子：
7.8
通讯作者：
Dreyfuss, G
中科院分区：
文献类型：
--
作者：
Siomi, MC;Eder, PS;Kataoka, N;Wan, LL;Liu, Q;Dreyfuss, G
异质核核糖核蛋白（hnRNP）A1是一种丰富的核蛋白，在前mRNA加工和mRNA从核输出中起重要作用。A1在细胞核和细胞质之间快速穿梭，38个氨基酸的结构域M9作为A1的双向转运信号。最近，一个90 kD的蛋白，转运蛋白，被确定为A1核输入的介质。在这项研究中，我们发现转运蛋白介导了额外的hnRNP蛋白，包括hnRNP F的核输入。我们还分离并测序了一种新的转运蛋白同源物，转运蛋白2，这可能不同于转运蛋白1在其底物特异性。免疫组织化学染色显示，转运蛋白1定位于细胞质和核质，并观察到核边缘染色。A1的核定位依赖于正在进行的RNA聚合酶II转录。有趣的是，丙酮酸激酶-M9融合，通常定位在细胞核中，也积累在细胞质中时，RNA聚合酶II被抑制。因此，M9本身是转录依赖性核转运的特异性传感器。转运蛋白1-A1复合物可以从细胞质和核质中分离，但在hnRNP复合物中检测不到转运蛋白1。RanGTP在体外引起A1-转运蛋白1复合物的解离。因此，这是可能的，核输入后，A1从转运蛋白1的RanGTP解离，并成为纳入hnRNP复合物，其中A1在前mRNA加工功能。
Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is an abundant nuclear protein that plays an important role in pre-mRNA processing and mRNA export from the nucleus. A1 shuttles rapidly between the nucleus and the cytoplasm, and a 38-amino acid domain, M9, serves as the bidirectional transport signal of A1. Recently, a 90-kD protein, transportin, was identified as the mediator of A1 nuclear import. In this study, we show that transportin mediates the nuclear import of additional hnRNP proteins, including hnRNP F. We have also isolated and sequenced a novel transportin homolog, transportin2, which may differ from transportin1 in its substrate specificity. Immunostaining shows that transportin1 is localized both in the cytoplasm and the nucleoplasm, and nuclear rim staining is also observed. The nuclear localization of A1 is dependent on ongoing RNA polymerase II transcription. Interestingly, a pyruvate kinase–M9 fusion, which normally localizes in the nucleus, also accumulates in the cytoplasm when RNA polymerase II is inhibited. Thus, M9 itself is a specific sensor for transcription-dependent nuclear transport. Transportin1–A1 complexes can be isolated from the cytoplasm and the nucleoplasm, but transportin1 is not detectable in hnRNP complexes. RanGTP causes dissociation of A1-transportin1 complexes in vitro. Thus, it is likely that after nuclear import, A1 dissociates from transportin1 by RanGTP and becomes incorporated into hnRNP complexes, where A1 functions in pre-mRNA processing.
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影响因子：
7.8
作者：
Chi, NC;Adam, EJH;Visser, GD;Adam, SA
通讯作者：
Adam, SA
影响因子：
56.9
作者：
CACERES, JF;STAMM, S;KRAINER, AR
通讯作者：
KRAINER, AR
影响因子：
4.8
作者：
IMAMOTO, N;TACHIBANA, T;YONEDA, Y
通讯作者：
YONEDA, Y
DOI：
10.1073/pnas.81.23.7471
发表时间：
1984-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
CHOI, YD;DREYFUSS, G
通讯作者：
DREYFUSS, G
影响因子：
64.5
作者：
GORLICH, D;PREHN, S;HARTMANN, E
通讯作者：
HARTMANN, E