Abstract:
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.
摘要:
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,PARP依赖性单-ADP-核糖基化由于缺乏灵敏的检测方法而知之甚少。这里,我们利用改进的抗体来检测单ADP核糖基化。我们观察了内源性干扰素(IFN)诱导的ADP-核糖基化,并表明PARP14是负责这种修饰的主要酶。恰到好处,这种信号被SARS-CoV-2(Mac1)的宏域逆转,提供Mac1抵消抗病毒PARP活性的可能机制。我们的数据还阐明了PARP9及其结合伴侣的主要作用,E3泛素连接酶DTX3L,通过蛋白质-蛋白质相互作用和PARP9巨域1的水解活性调节PARP14活性。最后,我们还介绍了IFN应答中ADPr依赖性泛素化的首次可视化。这些方法应进一步促进我们对IFN诱导的ADPr和泛素信号传导过程的理解,并可能阐明不同病原体如何避免此类防御途径。