The role of asymmetric protein dimethylation during the human papillomavirus lifecycle

人乳头瘤病毒（hpv）感染是美国最常见的性传播感染。除了导致子宫颈癌和其他肛门生殖器癌以及头颈癌发病率上升外，hpv还导致全球约5%的癌症。重要的是，持续感染，而不是急性感染是（子宫颈癌）发展的主要危险因素。因此，了解促进或限制病毒持久性的病毒-宿主相互作用对HPV生物学和人类癌症具有重要意义。直到最近，研究感染后HPV生命周期的直接早期事件以及这些事件如何促进建立阶段的初始基因组扩增和长期病毒持续存在一直具有挑战性。我们使用单细胞基因组学方法来确定参与病毒感染和持久性的细胞因素。我们的初步数据确定蛋白精氨酸n -甲基转移酶1 （PRMT1）是病毒感染原代人宫颈细胞的重要因素。PRMT1调节几种可能与HPV生命周期相关的细胞功能。我们证明PRMT1抑制导致病毒基因剪接模式高度失调。在机制上，我们发现病毒mRNA的m6A修饰显著增加，特别是在内含子中。这些数据与RBM15有关，RBM15是m6A甲基转移酶复合物的调节亚基。我们假设PRMT1调节RBM15控制的m6a沉积在病毒mRNA上，从而在病毒感染过程中暂时调节选择性剪接。我们将(1)确定不对称蛋白二甲基化在病毒生命周期中的重要性。(2)确定RBM15在PRMT1介导的病毒mRNA m6a甲基化调控中的作用。(3)确定m6a甲基化对病毒mRNA剪接的影响。PRMT1抑制导致病毒剪接失调。该建议解决了我们关于HPV剪接如何调节最佳感染，建立和长期持久性的知识中的关键空白。我们确定PRMT1是病毒剪接的调节因子，并假设这是通过靶向m6A沉积在病毒内含子上发生的。由于PRMT1是一个确定的可药物靶点，这些结果可能会导致hpv诱导癌症的新疗法。

Infections with human papillomaviruses (HPVs) are the most common sexually transmitted infection in the US. In addition to causing cervical and other anogenital cancers and a rising incidence of head and neck cancer, HPVs are responsible for an estimated 5% of cancers worldwide. Importantly, persistent infection, and not an acute infection is the primary risk factor for (cervical) cancer development. Thus, understanding the virus-host interplay that promotes or restrict viral persistence has important implications for HPV biology and human cancers. Until recently, it has been challenging to study the immediate early events of the HPV lifecycle following infection and how these events contribute to initial genome amplification during the establishment phase and long-term viral persistence. We used a single-cell genomics approach to identify cellular factors involved in viral infection and persistence. Our preliminary data identify protein arginine N-methyltransferase 1 (PRMT1) as an important factor upon viral infection of primary human cervical cells. PRMT1 regulates several cellular functions that may be relevant to the HPV lifecycle. We demonstrate that PRMT1 inhibition leads to a highly dysregulated splicing pattern of the viral genes. Mechanistically, we identify a dramatic increase in m6A modifications of viral mRNA, specifically in introns. These data implicate RBM15, a regulatory subunit of the m6A methyltransferase complex. We hypothesize that PRMT1 regulates RBM15 controlled m6a deposition on viral mRNA to temporally regulate alternative splicing throughout viral infection. We will (1) Determine the importance of asymmetric protein dimethylation throughout the viral lifecycle. (2) Determine the role for RBM15 in the PRMT1 mediated regulation of m6a methylation of viral mRNA. (3) Determine the effects of m6a methylation on viral mRNA splicing. PRMT1 inhibition leads to dysregulated viral splicing. This proposal addresses a critical gap in our knowledge relating to how HPV splicing is regulated for optimal infection, establishment, and long-term persistence. We identify PRMT1 as a regulator of viral splicing and hypothesize that this occurs through targeted m6A deposition on viral introns. Since PRMT1 is an established druggable target, these results may lead to novel therapeutics for HPV-induced cancers.