Distinct association of the nuclear pore protein Nup153 with A- and B-type lamins
Distinct association of the nuclear pore protein Nup153 with A- and B-type lamins
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DOI：
10.4161/nucl.2.5.17913
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发表时间：
2011-09-01
期刊：
影响因子：
3.7
通讯作者：
Fahrenkrog, Birthe
中科院分区：
文献类型：
--
作者：
Al-Haboubi, Teiba;Shumaker, Dale K.;Fahrenkrog, Birthe
核膜是细胞核与细胞质之间的双层物理屏障。NE的下面是核纤层蛋白，其与内核膜蛋白结合形成纤层。层对于维持核的结构完整性和对于在NE内定位核孔复合物（NPC）是至关重要的。核孔蛋白Nup153以前曾被报道与B型核纤层蛋白结合。然而，这种相互作用的特异性还没有很好地确定。在这里，我们表明，Nup153具有多个结合位点的A-和B-型核纤层蛋白。利用GST-pull down分析，我们发现Nup153的N-末端结构域和C-末端都与A-和B-型核纤层蛋白的Ig-折叠结构域相关联。通过采用纯化的Nup153和核纤层蛋白在印迹重叠测定中，我们揭示了Nup153的N-末端和C-末端结构域都直接与核纤层蛋白相互作用。此外，我们提供的证据表明，核纤层蛋白A Ig折叠结构域的突变选择性地影响Nup153结合，这表明Nup153可能在核纤层蛋白相关疾病（称为核纤层蛋白病）中发挥作用。总之，我们的研究结果表明，Nup153和核纤层之间的相互作用比以前接受的要复杂得多。
The nuclear envelope (NE) is a double membrane physical barrier, which separates the nucleus from the cytoplasm. Underlying the NE are the nuclear lamins, which in combination with inner nuclear membrane proteins form the lamina. The lamina is crucial for maintaining the structural integrity of the nucleus and for positioning of nuclear pore complexes (NPCs) within the NE. The nucleoporin Nup153 has previously been reported to bind to B-type lamins. However, the specificity of this interaction is not well established. Here we show that Nup153 exhibits multiple binding sites for A- and B-type lamins. Using GST-pull down assays, we found that both the N-terminal domain of Nup153 and its C terminus associate with the Ig-fold domain of A-and B-type lamins. By employing purified Nup153 and lamin proteins in blot overlay assays we revealed that both the N-terminal and the C-terminal domain of Nup153 are directly interacting with the lamins. Moreover, we provide evidence that mutations in the lamin A Ig-fold domain selectively affect Nup153-binding, suggesting that Nup153 may play a role in lamin-associated diseases, known as laminopathies. Together our results indicate a far more intricate interplay between Nup153 and nuclear lamins than previously accepted.