Mechanisms regulating expression of the HPV 31 L1 and L2 capsid proteins and pseudovirion entry.
Mechanisms regulating expression of the HPV 31 L1 and L2 capsid proteins and pseudovirion entry.
复制标题
调节HPV 31 L1和L2衣壳蛋白的表达的机制和伪卵形进入。
DOI：
10.1186/1743-422x-4-19
复制
发表时间：
2007-02-26
期刊：
影响因子：
4.8
通讯作者：
Laimins, Laimonis A.
中科院分区：
文献类型：
--
作者：
Hindmarsh, Patrick L.;Laimins, Laimonis A.
人乳头瘤病毒（HPV）感染复层上皮细胞，并限制晚期衣壳基因的表达，高度分化的细胞。为了开始了解调节HPV 31感染的过程，我们使用异源表达系统检测了HPV 31衣壳蛋白L1和L2的合成。与HPV 16中的研究类似，从异源启动子表达野生型HPV 31 L1和L2导致非常低的合成水平。相反，将衣壳基因中的密码子修改为细胞基因中更常用的密码子，导致高水平的合成。通过使用将野生型L1的片段融合到绿色荧光蛋白（GFP）编码序列的嵌合蛋白，鉴定了足以抑制高水平合成的短区域，并且在L2中检测到类似元件。一个元件定位于L1基因的3'端，而一系列元件定位于L2编码序列的3'端。这些观察结果与控制L1和L2合成水平的负RNA调控元件最一致，这与HPV 16中鉴定的那些不同。然后将密码子修饰的HPV 31衣壳蛋白的表达载体与GFP报告质粒一起转染以产生HPV 31假病毒。在存在抑制剂氯丙嗪、制霉菌素或甲基-β-环糊精的情况下，用HPV 31假病毒感染细胞，证明HPV 31与HPV 16一样，通过网格蛋白介导的途径进入人类和猴细胞，而不是通过先前报道的小窝。这表明高危HPV类型可能通过共同机制进入细胞。
Human papillomaviruses (HPV) infect stratified epithelia and restrict expression of late capsid genes to highly differentiated cells. In order to begin to understand the processes regulating HPV 31 infection we examined the synthesis of the HPV 31 capsid proteins, L1 and L2, using heterologous expression systems. Similar to studies in HPV 16, expression of wild type HPV 31 L1 and L2 from heterologous promoters resulted in very low levels of synthesis. In contrast, modification of the codons in the capsid genes to ones more commonly used in cellular genes resulted in high-level synthesis. Through the use of chimeric proteins that fused fragments of wild type L1 to Green Fluorescent Protein (GFP) coding sequences, a short region was identified that was sufficient to inhibit high level synthesis and similar elements were detected in L2. One element was localized to the 3' end of the L1 gene while a series of elements were localized at the 3' end of the L2 coding sequences. These observations are most consistent with negative RNA regulatory elements controlling the levels of L1 and L2 synthesis that are distinct from those identified in HPV 16. Expression vectors for the codon modified HPV 31 capsid proteins were then transfected together with GFP reporter plasmids to generate HPV 31 pseudoviruses. Infection of cells with HPV 31 pseudoviruses in the presence of the inhibitors, chlorpromazine, nystatin or methyl-beta-cyclodextrin, demonstrated that HPV 31, like HPV 16, enters human and monkey cells through a clathrin-mediated pathway rather than through caveolae as previously reported. This suggests that high-risk HPV types may enter cells through common mechanisms.