Wilson Maxwell Z, Ravindran Pavithran T, Lim Wendell A, Toettcher Jared E
Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
Mol Cell. 2017 Sep 7;67(5):757-769.e5. doi: 10.1016/j.molcel.2017.07.016. Epub 2017 Aug 17.
Cell signaling networks coordinate specific patterns of protein expression in response to external cues, yet the logic by which signaling pathway activity determines the eventual abundance of target proteins is complex and poorly understood. Here, we describe an approach for simultaneously controlling the Ras/Erk pathway and monitoring a target gene's transcription and protein accumulation in single live cells. We apply our approach to dissect how Erk activity is decoded by immediate early genes (IEGs). We find that IEG transcription decodes Erk dynamics through a shared band-pass filtering circuit; repeated Erk pulses transcribe IEGs more efficiently than sustained Erk inputs. However, despite highly similar transcriptional responses, each IEG exhibits dramatically different protein-level accumulation, demonstrating a high degree of post-transcriptional regulation by combinations of multiple pathways. Our results demonstrate that the Ras/Erk pathway is decoded by both dynamic filters and logic gates to shape target gene responses in a context-specific manner.
细胞信号网络响应外部信号协调特定的蛋白质表达模式，然而信号通路活性决定靶蛋白最终丰度的逻辑复杂且鲜为人知。在此，我们描述了一种在单个活细胞中同时控制Ras/Erk通路并监测靶基因转录和蛋白质积累的方法。我们应用该方法剖析即刻早期基因（IEGs）如何解码Erk活性。我们发现IEG转录通过共享的带通滤波电路解码Erk动态变化；重复的Erk脉冲比持续的Erk输入更有效地转录IEGs。然而，尽管转录反应高度相似，但每个IEG的蛋白质水平积累却表现出显著差异，这表明多种通路组合进行了高度的转录后调控。我们的结果表明，Ras/Erk通路通过动态滤波器和逻辑门进行解码，以特定背景的方式塑造靶基因反应。
