Mechanistic Analysis of Papillimavirus E2 Functions

乳头状瘤病毒（PVs）是一组小的DNA病毒，其在多种较高水平上诱导良性病变。 脊椎动物，包括人类。某些乳头瘤病毒，包括人乳头瘤病毒（HPV），如 如HPV 16和18，也与宫颈癌和其他人类肿瘤的发病机制有关。 乳头瘤病毒建立持续性感染，其中病毒基因组保持自主 在增殖宿主细胞的细胞核中以低拷贝数复制质粒。在牛乳头瘤病毒 （BPV 1）转化的小鼠细胞，病毒基因组也复制为多拷贝核质粒， 持续很长一段时间，以维持细胞的转化状态。为了确保持久性， 无论是感染的还是转化的细胞，复制的病毒基因组都必须被分配并维持在细胞中。 有丝分裂后的子细胞核。如果没有一种机制来确保病毒的定位 在核重组后，病毒基因组可能会留在核膜内， 细胞分裂后，由于降解或稀释而丢失。乳头瘤病毒E2 蛋白，其是在病毒转录和病毒DNA中起关键作用的重要调节蛋白 复制，也是分裂细胞中病毒基因组维持所必需的。E2，以及PV基因组， 与分裂细胞中的有丝分裂染色体密切相关。利用蛋白质组学方法 系统地表征了体内与E2相关细胞蛋白，我们最近鉴定了Brd 4 （含溴结构域蛋白4）作为E2相互作用蛋白，并表明它作为有丝分裂的蛋白发挥作用。 BPV 1 E2的染色体受体。这项研究资助的重点是扩展PV E2的这些研究 蛋白质，并检查E2与Brd 4相互作用的功能意义的其他方面， 病毒生命周期破坏E2与Brd 4的结合可以阻断BPV 1对细胞的转化， E2和病毒DNA与有丝分裂染色体的关联。将进行化学遗传筛查 鉴定E2/Brd 4结合的小分子抑制剂作为用于新型治疗的潜在先导分子， 抗病毒化合物。

The papillomaviruses (PVs) are a group of small DMAviruses that induce benign lesions in variety of higher vertebrates, including humans. Certain papillomaviruses, including the human papillomaviruses (HPVs) such as HPV16 and 18, are also associated with the pathogenesis of cervical cancer and other human tumors. Papillomaviruses establish persistent infections in which the viral genomes are maintained as autonomous replicating plasmids at a low copy number in the nuclei of proliferating host cells. In bovine papillomavirus (BPV1) transformed mouse cells, the viral genomes also replicate as multicopy nuclear plasmids that can persist over long periods of time to maintain the transformation status of the cells. To ensure persistence in both infected and transformed cells, the replicated viral genomes must be partitioned and maintained in the nuclei of daughter cells following mitosis. Without a mechanism to ensure the localization of the viral genome within the nuclear envelope following nuclear reassembly, the viral genome could be left behind in the cytoplasm and lost either through degradation or dilution after cell division. The papillomavirus E2 protein, which is an important regulatory protein that plays critical roles in viral transcriptional and viral DNA replication, is also required for viral genome maintenance in dividing cells. E2, as well as the PV genomes, are closely associated with mitotic chromosomes in dividing cells. Utilizing a proteomic approach to systematically characterize cellular proteins that associate with E2 in vivo, we recently identified Brd4 (bromodomain-containing protein 4) as an E2 interacting protein and showed that it functions as the mitotic chromosome receptor for BPV1 E2. The focus of this research grant is to extend these studies on the PV E2 proteins and to examine the functional significance of the interaction of E2 with Brd4 to other aspects of the viral life cycle. Disruption of the binding of E2 to Brd4 can block the transformation of cells by BPV1 and the association of E2 and the viral DNA with mitotic chromosomes. Chemical genetic screens will be conducted to identify small molecule inhibitors of E2/Brd4 binding as potential lead molecules for novel therapeutic antiviral compounds.