Abstract：
The well-known hepatotoxicity mechanism resulting from alpha-amanitin (α-AMA) exposure arises from RNA polymerase II (RNAP II) inhibition. RNAP Ⅱ inhibition occurs through the dysregulation of mRNA synthesis. However, the signaling pathways in hepatocytes that arise from α-AMA have not yet been fully elucidated. Here, we identified that the RAS/RAF/ERK signaling pathway was activated through quantitative phosphoproteomic and molecular biological analyses in Huh-7 cells. Bioinformatics analysis showed that α-AMA exposure increased protein phosphorylation in a time-dependent α-AMA exposure. In addition, phosphorylation increased not only the components of the ERK signaling pathway but also U2AF65 and SPF45, known splicing factors. Therefore, we propose a novel mechanism of α-AMA as follows. The RAS/RAF/ERK signaling pathway involved in aberrant splicing events is activated by α-AMA exposure followed by aberrant splicing events leading to cell death in Huh-7 cells.
摘要：
由α-amanitin（α-AMA）暴露引起的众所周知的肝毒性机制源于RNA聚合酶II（RNAPII）抑制。RNAPⅡ的抑制是通过mRNA合成的失调而发生的。然而,α-AMA引起的肝细胞信号通路尚未完全阐明。这里,在Huh-7细胞中,通过定量磷酸化蛋白质组和分子生物学分析,我们发现RAS/RAF/ERK信号通路被激活.生物信息学分析表明，在时间依赖性的α-AMA暴露中，α-AMA暴露会增加蛋白质磷酸化。此外,磷酸化不仅增加了ERK信号通路的组成部分，而且增加了已知剪接因子U2AF65和SPF45。因此,我们提出了一种新的α-AMA机制如下。参与异常剪接事件的RAS/RAF/ERK信号通路被α-AMA暴露激活,随后是导致Huh-7细胞中细胞死亡的异常剪接事件。
