Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK.
Department of Biological Sciences, SRM University-AP, Amaravati, 522502, India.
EMBO J. 2024 Jul;43(14):2929-2953. doi: 10.1038/s44318-024-00126-0. Epub 2024 Jun 4.
PARP-catalysed ADP-ribosylation (ADPr) is important in regulating various cellular pathways. Until recently, PARP-dependent mono-ADP-ribosylation has been poorly understood due to the lack of sensitive detection methods. Here, we utilised an improved antibody to detect mono-ADP-ribosylation. We visualised endogenous interferon (IFN)-induced ADP-ribosylation and show that PARP14 is a major enzyme responsible for this modification. Fittingly, this signalling is reversed by the macrodomain from SARS-CoV-2 (Mac1), providing a possible mechanism by which Mac1 counteracts the activity of antiviral PARPs. Our data also elucidate a major role of PARP9 and its binding partner, the E3 ubiquitin ligase DTX3L, in regulating PARP14 activity through protein-protein interactions and by the hydrolytic activity of PARP9 macrodomain 1. Finally, we also present the first visualisation of ADPr-dependent ubiquitylation in the IFN response. These approaches should further advance our understanding of IFN-induced ADPr and ubiquitin signalling processes and could shed light on how different pathogens avoid such defence pathways.
聚腺苷二磷酸核糖聚合酶（PARP）催化的 ADP-核糖基化（ADPr）在调节各种细胞途径中很重要。直到最近，由于缺乏敏感的检测方法，PARP 依赖性单 ADP-核糖基化的理解还很不完善。在这里，我们利用一种改良的抗体来检测单 ADP-核糖基化。我们可视化了内源性干扰素（IFN）诱导的 ADP-核糖基化，并表明 PARP14 是负责这种修饰的主要酶。恰当地说，这种信号被来自 SARS-CoV-2 的宏结构域（Mac1）逆转，提供了一种可能的机制，即 Mac1 抵消抗病毒 PARPs 的活性。我们的数据还阐明了 PARP9 及其结合伴侣 E3 泛素连接酶 DTX3L 的主要作用，通过蛋白-蛋白相互作用和 PARP9 宏结构域 1 的水解活性来调节 PARP14 的活性。最后，我们还首次观察到 IFN 反应中 ADPr 依赖性泛素化。这些方法应该进一步推进我们对 IFN 诱导的 ADPr 和泛素信号转导过程的理解，并可能阐明不同病原体如何避免这种防御途径。
