MRC Laboratory of Molecular Biology, Cambridge, UK.
Mol Cell. 2023 Aug 17;83(16):2840-2855. doi: 10.1016/j.molcel.2023.07.014.
Cells tightly regulate mRNA processing, localization, and stability to ensure accurate gene expression in diverse cellular states and conditions. Most of these regulatory steps have traditionally been thought to occur before translation by the action of RNA-binding proteins. Several recent discoveries highlight multiple co-translational mechanisms that modulate mRNA translation, localization, processing, and stability. These mechanisms operate by recognition of the nascent protein, which is necessarily coupled to its encoding mRNA during translation. Hence, the distinctive sequence or structure of a particular nascent chain can recruit recognition factors with privileged access to the corresponding mRNA in an otherwise crowded cellular environment. Here, we draw on both well-established and recent examples to provide a conceptual framework for how cells exploit nascent protein recognition to direct mRNA fate. These mechanisms allow cells to dynamically and specifically regulate their transcriptomes in response to changes in cellular states to maintain protein homeostasis.
细胞严格调控 mRNA 的加工、定位和稳定性,以确保在不同的细胞状态和条件下实现基因表达的准确性。这些调控步骤中的大多数传统上被认为是在翻译之前通过 RNA 结合蛋白的作用发生的。最近的几项发现强调了多种共翻译机制,这些机制可以调节 mRNA 的翻译、定位、加工和稳定性。这些机制通过识别新生蛋白质来起作用,而新生蛋白质的编码 mRNA 在翻译过程中必然与其偶联。因此,特定新生链的独特序列或结构可以募集具有特权的识别因子,使其能够在细胞环境中拥挤的情况下,对相应的 mRNA 进行特异性识别。在这里,我们借鉴了成熟和最近的例子,为细胞如何利用新生蛋白质识别来指导 mRNA 命运提供了一个概念框架。这些机制允许细胞根据细胞状态的变化,动态而特异性地调节其转录组,以维持蛋白质的内稳态。