报告人简介：Hervé LE HIR，1998年获得巴黎七大的分子生物学博士学位😼。随后在美国的布兰迪斯大学（Brandeis University）做博士后☝️，从事pre-mRNA和核糖体复合物功能的研究🚂。2009年起在法国巴黎高师的生物研究所担任“真核细胞mRNA表达”研究组组长🪻，主要研究领域为外显子拼接复合体的结构与功能，RNA解旋酶的分子调控机制。Molecular Cell、Cell、Nature Structural and Molecular Biology等SCI刊物发表论文40余篇💇🏽‍♀️。

报告摘要🤸🏽：Packed into RNP particles, nascent mRNAs are covered with a myriad of RNA binding proteins that specify their functional outcome. The identity of these proteins is not only dictated by mRNA primary sequences but also echoes its processing history. The Exon Junction Complex (EJC) nicely exemplifies the impact of nuclear history on mRNA lifecycle. This multiprotein complex tags mRNA exon junctions as a consequence of splicing and travels with mRNAs to the cytoplasm, during which it influences mRNA cellular localization, translation and stability by nonsense-mediated mRNA decay (NMD). At the center of the EJC resides the DEAD-box RNA helicase eIF4A3 that ensures the tight and sequence-independent binding of the complex to RNA. I will present the mechanism by which eIF4A3 is recruited by the splicing machinery to promote EJC assembly. In addition, CLIP-seq of eIF4A3 RNA targets revealed that EJC assembly is more complicated than previously suspected. Finally, I will present how the manipulation of single RNA molecules with magnetic tweezers revealed remarkable biophysical characteristics of the helicase Upf1, whose enzymatic activities are essential for mRNA surveillance by NMD.