Plante Isabelle, Davidovic Laetitia, Ouellet Dominique L, Gobeil Lise-Andrée, Tremblay Sandra, Khandjian Edouard W, Provost Patrick
Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du CHUL-CHUQ, Sainte-Foy, QC, Canada.
J Biomed Biotechnol. 2006;2006(4):64347. doi: 10.1155/JBB/2006/64347.
In mammalian cells, fragile X mental retardation protein (FMRP) has been reported to be part of a microRNA (miRNA)-containing effector ribonucleoprotien (RNP) complex believed to mediate translational control of specific mRNAs. Here, using recombinant proteins, we demonstrate that human FMRP can act as a miRNA acceptor protein for the ribonuclease Dicer and facilitate the assembly of miRNAs on specific target RNA sequences. The miRNA assembler property of FMRP was abrogated upon deletion of its single-stranded (ss) RNA binding K-homology domains. The requirement of FMRP for efficient RNA interference (RNAi) in vivo was unveiled by reporter gene silencing assays using various small RNA inducers, which also supports its involvement in an ss small interfering RNA (siRNA)-containing RNP (siRNP) effector complex in mammalian cells. Our results define a possible role for FMRP in RNA silencing and may provide further insight into the molecular defects in patients with the fragile X syndrome.
在哺乳动物细胞中，脆性X智力低下蛋白（FMRP）据报道是一种含微小RNA（miRNA）的效应核糖核蛋白（RNP）复合物的一部分，该复合物被认为介导特定mRNA的翻译控制。在此，我们使用重组蛋白证明，人FMRP可作为核糖核酸酶Dicer的miRNA受体蛋白，并促进miRNA在特定靶RNA序列上的组装。FMRP的miRNA组装特性在其单链（ss）RNA结合K-同源结构域缺失后被消除。通过使用各种小RNA诱导剂的报告基因沉默试验揭示了FMRP在体内对有效RNA干扰（RNAi）的需求，这也支持其参与哺乳动物细胞中含ss小干扰RNA（siRNA）的RNP（siRNP）效应复合物。我们的结果确定了FMRP在RNA沉默中的可能作用，并可能为脆性X综合征患者的分子缺陷提供进一步的见解。
