Departamento de Biología Molecular y Celular, Centro Nacional de Biotecnología (CSIC), C/Darwin 3, Campus Cantoblanco, 28049 Madrid, Spain, Ciber de Enfermedades Respiratorias (ISCIII), Mallorca, Spain, Servicio de Genómica Computacional, Centro Nacional de Biotecnología (CSIC), C/Darwin 3, Campus Cantoblanco, 28049 Madrid, Spain and Bioinformática de Sistemas, Centro Nacional de Biotecnología (CSIC), C/Darwin 3, Campus Cantoblanco, 28049 Madrid, Spain.
Nucleic Acids Res. 2014 Apr;42(7):4516-26. doi: 10.1093/nar/gku073. Epub 2014 Jan 26.
Cellular messenger RNAs (mRNAs) are associated to proteins in the form of ribonucleoprotein particles. The double-stranded RNA-binding (DRB) proteins play important roles in mRNA synthesis, modification, activity and decay. Staufen is a DRB protein involved in the localized translation of specific mRNAs during Drosophila early development. The human Staufen1 (hStau1) forms RNA granules that contain translation regulation proteins as well as cytoskeleton and motor proteins to allow the movement of the granule on microtubules, but the mechanisms of hStau1-RNA recognition are still unclear. Here we used a combination of affinity chromatography, RNAse-protection, deep-sequencing and bioinformatic analyses to identify mRNAs differentially associated to hStau1 or a mutant protein unable to bind RNA and, in this way, defined a collection of mRNAs specifically associated to wt hStau1. A common sequence signature consisting of two opposite-polarity Alu motifs was present in the hStau1-associated mRNAs and was shown to be sufficient for binding to hStau1 and hStau1-dependent stimulation of protein expression. Our results unravel how hStau1 identifies a wide spectrum of cellular target mRNAs to control their localization, expression and fate.
细胞信使 RNA（mRNA）与蛋白质以核糖核蛋白颗粒的形式相关联。双链 RNA 结合（DRB）蛋白在 mRNA 的合成、修饰、活性和降解中发挥着重要作用。Staufen 是一种 DRB 蛋白，参与果蝇早期发育过程中特定 mRNA 的局部翻译。人类 Staufen1（hStau1）形成 RNA 颗粒，其中包含翻译调节蛋白以及细胞骨架和运动蛋白，以使颗粒能够在微管上移动，但 hStau1-RNA 识别的机制仍不清楚。在这里，我们使用亲和层析、RNA 酶保护、深度测序和生物信息学分析的组合，来鉴定与 hStau1 或不能结合 RNA 的突变蛋白差异相关的 mRNA，从而定义了一组与 wt hStau1 特异性相关的 mRNA。在 hStau1 相关的 mRNA 中存在由两个相反极性的 Alu 基序组成的共同序列特征，该特征足以与 hStau1 结合，并刺激 hStau1 依赖性的蛋白质表达。我们的研究结果揭示了 hStau1 如何识别广泛的细胞靶 mRNA，以控制它们的定位、表达和命运。
