Functional characterization of naturally occurring genetic variations of the human guanine-rich RNA sequence binding factor 1 (GRSF1).
Functional characterization of naturally occurring genetic variations of the human guanine-rich RNA sequence binding factor 1 (GRSF1).
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DOI：
10.1016/j.bbagen.2017.12.008
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发表时间：
2018-04
期刊：
影响因子：
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通讯作者：
S. Sofi;J. Fitzgerald;Désirée Jähn;Bernhard Dumoulin;Sabine Stehling;H. Kuhn;C. Ufer
中科院分区：
文献类型：
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作者：
S. Sofi;J. Fitzgerald;Désirée Jähn;Bernhard Dumoulin;Sabine Stehling;H. Kuhn;C. Ufer
富含鸟嘌呤的RNA序列结合因子1(GRSF1)是一种普遍存在的RNA结合蛋白(RBP)，属于异质性核糖核蛋白F/H(hnRNP F/H)家族。它与核、胞质和线粒体的RNA代谢有关。虽然GRSF1同源物的晶体结构尚未解决，但与相似RNA结合蛋白的氨基酸序列比对表明，存在三个被称为准RNA识别基序(QRRM)的RNA结合域。在这里，我们根据hnRNP F的核磁共振结构建立了人GRSF1的三个qRRMs的3D模型，并确定了推测的RNA与氨基酸的相互作用。接下来，我们通过搜索基因组数据库来探索人类GRSF1的三个qRRMs的遗传变异性，并测试自然发生的突变的功能后果。为此，通过定量RNA凝胶迁移率改变分析评估了野生型和突变型重组GRSF1蛋白的RNA结合能力。我们发现，一些自然产生的GRSF1突变体表现出强烈的RNA结合活性降低，尽管一般的蛋白质结构几乎没有受到影响。这些数据表明，这些特定突变体的纯合子等位基因携带者表达功能失调的GRSF1，因此可能显示GRSF1信号缺陷。
The guanine-rich RNA sequence binding factor 1 (GRSF1) constitutes an ubiquitously occurring RNA-binding protein (RBP), which belongs to the family of heterogeneous nuclear ribonucleoprotein F/H (hnRNP F/H). It has been implicated in nuclear, cytosolic and mitochondrial RNA metabolism. Although the crystal structures of GRSF1 orthologs have not been solved, amino acid alignments with similar RNA-binding proteins suggested the existence of three RNA-binding domains designated quasi-RNA recognition motifs (qRRMs). Here we established 3D–models for the three qRRMs of human GRSF1 on the basis of the NMR structure of hnRNP F and identified the putative RNA interacting amino acids. Next, we explored the genetic variability of the three qRRMs of human GRSF1 by searching genomic databases and tested the functional consequences of naturally occurring mutants. For this purpose the RNA-binding capacity of wild-type and mutant recombinant GRSF1 protein species was assessed by quantitative RNA electrophoretic mobility shift assays. We found that some of the naturally occurring GRSF1 mutants exhibited a strongly reduced RNA-binding activity although the general protein structure was hardly affected. These data suggested that homozygous allele carriers of these particular mutants express dysfunctional GRSF1 and thus may show defective GRSF1 signaling.