Xi Jiajia, Snieckute Goda, Asthana Abhishek, Gaughan Christina, Bekker-Jensen Simon, Silverman Robert H
Department Cancer Biology, Cleveland Clinic Foundation, Lerner Research Institute, Cleveland, OH, 44195, USA.
Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
bioRxiv. 2023 Oct 12:2023.10.12.562082. doi: 10.1101/2023.10.12.562082.
RNase L is a regulated endoribonuclease in higher vertebrates that functions in antiviral innate immunity. Interferons induce OAS enzymes that sense double-stranded RNA of viral origin leading to synthesis of 2',5'-oligoadenylate (2-5A) activators of RNase L. However, it is unknown precisely how RNase L inhibits viral infections. To isolate effects of RNase L from other effects of double-stranded RNA or virus, 2-5A was directly introduced into cells. Here we report that RNase L activation by 2-5A causes a ribotoxic stress response that requires the ribosome-associated MAP3K, ZAKα. Subsequently, the stress-activated protein kinases (SAPK) JNK and p38α are phosphorylated. RNase L activation profoundly altered the transcriptome by widespread depletion of mRNAs associated with different cellular functions, but also by SAPK-dependent induction of inflammatory genes. Our findings show that 2-5A is a ribotoxic stressor that causes RNA damage through RNase L triggering a ZAKα kinase cascade leading to proinflammatory signaling and apoptosis.
核糖核酸酶L是高等脊椎动物中一种受调控的内切核糖核酸酶，在抗病毒先天免疫中发挥作用。干扰素诱导寡腺苷酸合成酶（OAS），该酶可识别病毒来源的双链RNA，从而导致核糖核酸酶L的2',5'-寡腺苷酸（2-5A）激活剂的合成。然而，核糖核酸酶L究竟如何抑制病毒感染尚不清楚。为了将核糖核酸酶L的作用与双链RNA或病毒的其他作用区分开来，将2-5A直接导入细胞。在此我们报告，2-5A激活核糖核酸酶L会引发一种核糖体毒性应激反应，这需要与核糖体相关的丝裂原活化蛋白激酶3（MAP3K）ZAKα。随后，应激激活蛋白激酶（SAPK）JNK和p38α被磷酸化。核糖核酸酶L的激活通过广泛消耗与不同细胞功能相关的mRNA，以及通过SAPK依赖的炎症基因诱导，深刻改变了转录组。我们的研究结果表明，2-5A是一种核糖体毒性应激源，它通过核糖核酸酶L导致RNA损伤，触发ZAKα激酶级联反应，从而导致促炎信号传导和细胞凋亡。
