Josefsson A, Magnusson P, Gyllensten U
Department of Medical Genetics, Biomedical Center, Uppsala, Sweden.
Methods Mol Med. 1999;20:171-93. doi: 10.1385/0-89603-535-2:171.
The papillomaviruses form a nonenveloped virion with an icosahedral capsid structure and contain a double-stranded circular DNA genome of 7800-7900 bp. The HPV genome is organized into three major regions; two protein-coding regions (1) early and (2) late-expressing genes, and (3) a noncoding upstream regulatory region (URR) (Fig. 1). The early region is downstream of the URR and consist of six open reading frames (ORFs) (El, E2, E4, E5, E6, and E7). El encodes a DNA binding protein involved in the regulation of viral DNA replication. E2 regulates viral DNA replication and gene expression. E4 is only expressed during the viral infection phase, and important for the maturation and replication of the virus. The function of E5 is less well known and may involve a stimulation of cell proliferation in HPV-infected cells. E5 has also shown a weak transforming activity. The E6 and E7 are coding for two oncoproteins with a high transforming activity. Upon integration into the human genome, E2 and parts of the El gene are, in general, deleted. This is followed by high levels of E6 and E7 expression. The late region contains two ORFs termed LI and L2 that code for the viral capsid proteins (1). Finally, the URR, or LCR long control region, contains binding sites for different transcriptional repressors and activators, and along with E5-7, is highly variable among HPV types.
乳头瘤病毒形成一种具有二十面体衣壳结构的无包膜病毒粒子，其基因组为7800 - 7900碱基对的双链环状DNA。人乳头瘤病毒（HPV）基因组分为三个主要区域：两个蛋白质编码区，即（1）早期表达基因和（2）晚期表达基因，以及（3）一个非编码上游调控区（URR）（图1）。早期区域位于URR下游，由六个开放阅读框（ORF）组成（E1、E2、E4、E5、E6和E7）。E1编码一种参与病毒DNA复制调控的DNA结合蛋白。E2调控病毒DNA复制和基因表达。E4仅在病毒感染阶段表达，对病毒的成熟和复制很重要。E5的功能尚不太清楚，可能涉及刺激HPV感染细胞中的细胞增殖。E5也显示出较弱的转化活性。E6和E7编码两种具有高转化活性的癌蛋白。整合到人类基因组后，E2和部分E1基因通常会缺失。随后E6和E7会高水平表达。晚期区域包含两个称为L1和L2的ORF，它们编码病毒衣壳蛋白（1）。最后，URR或长控制区（LCR）包含不同转录抑制因子和激活因子的结合位点，并且与E5 - 7一起，在HPV各型之间高度可变。
