Lebeda Dennis, Fierenz Adrian, Werfel Lina, Rosin-Arbesfeld Rina, Hofhuis Julia, Thoms Sven
Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany.
Department of Child and Adolescent Health, University Medical Center Göttingen, Göttingen, Germany.
J Mol Med (Berl). 2024 May;102(5):641-653. doi: 10.1007/s00109-024-02436-6. Epub 2024 Mar 2.
Rett syndrome (RTT) is a neurodevelopmental disorder resulting from genetic mutations in the methyl CpG binding protein 2 (MeCP2) gene. Specifically, around 35% of RTT patients harbor premature termination codons (PTCs) within the MeCP2 gene due to nonsense mutations. A promising therapeutic avenue for these individuals involves the use of aminoglycosides, which stimulate translational readthrough (TR) by causing stop codons to be interpreted as sense codons. However, the effectiveness of this treatment depends on several factors, including the type of stop codon and the surrounding nucleotides, collectively referred to as the stop codon context (SCC). Here, we develop a high-content reporter system to precisely measure TR efficiency at different SCCs, assess the recovery of the full-length MeCP2 protein, and evaluate its subcellular localization. We have conducted a comprehensive investigation into the intricate relationship between SCC characteristics and TR induction, examining a total of 14 pathogenic MeCP2 nonsense mutations with the aim to advance the prospects of personalized therapy for individuals with RTT. Our results demonstrate that TR induction can successfully restore full-length MeCP2 protein, albeit to varying degrees, contingent upon the SCC and the specific position of the PTC within the MeCP2 mRNA. TR induction can lead to the re-establishment of nuclear localization of MeCP2, indicating the potential restoration of protein functionality. In summary, our findings underscore the significance of SCC-specific approaches in the development of tailored therapies for RTT. By unraveling the relationship between SCC and TR therapy, we pave the way for personalized, individualized treatment strategies that hold promise for improving the lives of individuals affected by this debilitating neurodevelopmental disorder. KEY MESSAGES: The efficiency of readthrough induction at MeCP2 premature termination codons strongly depends on the stop codon context. The position of the premature termination codon on the transcript influences the readthrough inducibility. A new high-content dual reporter assay facilitates the measurement and prediction of readthrough efficiency of specific nucleotide stop contexts. Readthrough induction results in the recovery of full-length MeCP2 and its re-localization to the nucleus. MeCP2 requires only one of its annotated nuclear localization signals.
雷特综合征(RTT)是一种神经发育障碍疾病,由甲基CpG结合蛋白2(MeCP2)基因的基因突变引起。具体而言,约35%的RTT患者由于无义突变,在MeCP2基因内存在提前终止密码子(PTC)。对于这些患者,一种有前景的治疗途径是使用氨基糖苷类药物,这类药物通过使终止密码子被解读为有义密码子来刺激翻译通读(TR)。然而,这种治疗的有效性取决于几个因素,包括终止密码子的类型和周围的核苷酸,统称为终止密码子上下文(SCC)。在这里,我们开发了一种高内涵报告系统,以精确测量不同SCC下的TR效率,评估全长MeCP2蛋白的恢复情况,并评估其亚细胞定位。我们对SCC特征与TR诱导之间的复杂关系进行了全面研究,共检测了14个致病性MeCP2无义突变,旨在推进针对RTT患者的个性化治疗前景。我们的结果表明,TR诱导能够成功恢复全长MeCP2蛋白,尽管程度不同,这取决于SCC以及PTC在MeCP2 mRNA中的具体位置。TR诱导可导致MeCP2重新定位于细胞核,表明蛋白功能可能恢复。总之,我们的研究结果强调了SCC特异性方法在开发针对RTT的定制疗法中的重要性。通过揭示SCC与TR治疗之间的关系,我们为个性化、个体化的治疗策略铺平了道路,这些策略有望改善受这种使人衰弱的神经发育障碍影响的个体的生活。关键信息:MeCP2提前终止密码子处的通读诱导效率强烈依赖于终止密码子上下文。转录本上提前终止密码子的位置影响通读诱导性。一种新的高内涵双报告检测方法有助于测量和预测特定核苷酸终止上下文的通读效率。通读诱导导致全长MeCP2的恢复及其重新定位于细胞核。MeCP2仅需要其注释的核定位信号之一。