Identification and characterization of Gemin7, a novel component of the survival of motor neuron complex
Identification and characterization of Gemin7, a novel component of the survival of motor neuron complex
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DOI：
10.1074/jbc.m203478200
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发表时间：
2002-08-30
影响因子：
4.8
通讯作者：
Dreyfuss, G
中科院分区：
文献类型：
--
作者：
Baccon, J;Pellizzoni, L;Dreyfuss, G
运动神经元存活（SMN）蛋白是神经退行性疾病脊髓性肌萎缩症中基因突变或缺失的产物。SMN是一个大分子复合物的一部分，该复合物还含有Gemin2，Gemin3，Gemin4，Gemin5和Gemin6。SMN复合物在剪接体小核核糖核蛋白和可能的其他核糖核蛋白颗粒的组装中起作用。我们已经确定了一种新的蛋白质组成部分的SMN复合物称为Gemin7使用天然纯化的SMN复合物和肽测序质谱。免疫共沉淀和免疫定位实验表明，Gemin7是SMN复合物的一个组成部分，并与SMN共定位在细胞质和宝石。结合实验表明，Gemin7直接与SMN和Gemin6相互作用，并介导Gemin6与SMN复合物的缔合。Gemin7的氨基酸序列不包含任何可识别的基序，除了几个精氨酸和甘氨酸重复序列，这是其与SMN相互作用所必需的。此外，Gemin7与剪接体小核核糖核蛋白的几种Sm蛋白相互作用，特别是与SmE相互作用。随着Gemin7的鉴定，SMN复合体核心成分的清单基本上完成了。
The survival of motor neurons (SMN) protein is the product of the gene mutated or deleted in the neurodegenerative disease, spinal muscular atrophy. SMN is part of a large macromolecular complex that also contains Gemin2, Gemin3, Gemin4, Gemin5, and Gemin6. The SMN complex functions in the assembly of spliceosomal small nuclear ribonucleoproteins and probably other ribonucleoprotein particles. We have identified a novel protein component of the SMN complex termed Gemin7 using native purified SMN complexes and peptide sequencing by mass spectrometry. Coimmunoprecipitation and immunolocalization experiments demonstrate that Gemin7 is a component of the SMN complex and colocalizes with SMN in the cytoplasm and in gems. Binding experiments show that Gemin7 interacts directly with SMN and Gemin6 and mediates the association of Gemin6 with the SMN complex. The amino acid sequence of Gemin7 does not contain any recognizable motifs with the exception of several arginine and glycine repeats that are necessary for its interaction with SMN. Moreover, Gemin7 interacts with several Sm proteins of spliceosomal small nuclear ribonucleoproteins, in particular, with SmE. With the identification of Gemin7, the inventory of the core components of the SMN complex appears essentially complete.