Human papillomaviruses (HPVs) produce a large number of alternatively spliced mRNAs, including a number of differently spliced mRNAs with the potential to produce E2 protein. To identify the alternatively spliced HPV16 mRNA with the highest ability to produce E2 protein, we have generated E2 cDNA expression plasmids representing the most common, alternatively spliced E2 mRNAs, and assessed their translational potential. Our results revealed that an mRNA initiated at the HPV16 late promoter p670 and spliced from the HPV16 5'-splice site SD880 to the HPV16 3'-splice site SA2709, located immediately upstream of the E2 ATG, produced higher levels of E2 than any of the other alternatively spliced, E2-encoding mRNAs. Utilization of a known, alternative 3'-splice site located upstream of the E2 ATG named SA2582, generated mRNAs with lower ability to produce E2 than mRNAs spliced to SA2709. Finally, analysis of HPV16 mRNA splicing demonstrated that SA2709 was more efficiently spliced to the upstream 5'-splice site SD880 than to the upstream 5'-splice site SD226. In conclusion, the HPV16 mRNA with the greatest ability to produce E2 protein is generated from the HPV16 late promoter and is spliced between HPV16 5'-splice site SD880 and HPV16 3'-splice site SA2709.

中文翻译：

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从从 SD880 拼接到 SA2709 的 HPV16 晚期 mRNA 中高效生产 HPV16 E2 蛋白。

人乳头瘤病毒 (HPV) 产生大量可变剪接 mRNA，包括许多具有产生 E2 蛋白潜力的不同剪接 mRNA。为了鉴定具有最高产生 E2 蛋白能力的可变剪接 HPV16 mRNA，我们生成了代表最常见的可变剪接 E2 mRNA 的 E2 cDNA 表达质粒，并评估了它们的翻译潜力。我们的结果显示，在 HPV16 晚期启动子 p670 处启动并从 HPV16 5'-剪接位点 SD880 剪接至位于 E2 ATG 上游的 HPV16 3'-剪接位点 SA2709 的 mRNA 产生的 E2 水平高于任何一种另一个选择性剪​​接的 E2 编码 mRNA。利用位于 E2 ATG 上游名为 SA2582 的已知替代 3'-剪接位点，产生的 mRNA 产生 E2 的能力低于剪接到 SA2709 的 mRNA。最后，对 HPV16 mRNA 剪接的分析表明，与上游 5'-剪接位点 SD226 相比，SA2709 与上游 5'-剪接位点 SD880 的剪接效率更高。总之，具有最大产生E2蛋白能力的HPV16 mRNA由HPV16晚期启动子产生，并在HPV16 5'-剪接位点SD880和HPV16 3'-剪接位点SA2709之间剪接。