The E2 protein of human papillomavirus type 16 is translated from a variety of differentially spliced polycistronic mRNAs
The E2 protein of human papillomavirus type 16 is translated from a variety of differentially spliced polycistronic mRNAs
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DOI：
10.1099/0022-1317-80-1-29
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发表时间：
1999-01-01
影响因子：
3.8
通讯作者：
Sherman, L
中科院分区：
文献类型：
--
作者：
Alloul, N;Sherman, L
人乳头瘤病毒 (HPV) 转录的主要调节蛋白是病毒 E2 蛋白。先前的研究已鉴定出多种选择性剪接的 mRNA，其中含有编码 HPV 16 型 E2 蛋白的多个开放阅读框 (ORF)。在这些 mRNA 中，E2 ORF 作为内部 ORF 包含在内。在本研究中，研究了从p97启动子开始并包含E2 ORF上游的880/2581、880/2708和226/2708剪接点的三种mRNA种类的翻译能力。合成了跨越 E2 ORF 和相关上游 ORF 的部分 cDNA，并评估了体内、COS 细胞和体外无细胞系统中的 E2 蛋白翻译。这些分析的结果表明，E2 蛋白是从所有三种 mRNA 翻译的，来自天然多顺反子模板的 E2 翻译效率低于来自合成单顺反子对照的翻译效率。 d 型双顺反子模板 (226/2708) 的翻译比 a 型 (880/2708) 和 a' 型 (880/2561) 多顺反子模板的翻译更有效。进一步研究由之前的 ORF 编码的蛋白质的翻译； E2 ORF显示a型和a'型模板主要用于E7的翻译，但也用于E61的翻译，而d型模板用于E6IV的翻译。总体而言，翻译数据支持相应的 mRNA 可能作为多顺反子转录物发挥作用的建议。
The major regulation protein of human papillomavirus (HPV) transcription is the viral E2 protein. Previous studies have identified a variety of alternatively spliced mRNAs containing multiple open reading frames (ORFs) encoding the E2 protein of HPV type 16. In these mRNAs the E2 ORF is contained as an internal ORF. In the present study, the translational capacities of three mRNA species starting at the p97 promoter and containing the 880/2581, 880/2708 and 226/2708 splice junctions upstream of the E2 ORF were investigated. Partial cDNAs spanning the E2 ORF and the related upstream ORFs were synthesized and assessed for E2 protein translation in vivo, in COS cells, and in vitro, in cell-free systems. Results of these analyses indicated that E2 protein was translated from all three mRNAs, Translation efficiency of E2 from the natural polycistronic templates was lower compared with that from a synthetic monocistronic control. Translation from the d-type bicistronic template (226/2708) was more efficient than that from the a-type (880/2708) and a'-type (880/2561) polycistronic templates. Further investigation of the translation of proteins encoded by the ORFs preceding the; E2 ORF showed that a- and a'-type templates served for translation mainly of E7 but also of E61, while the d-type template served for translation of E6IV. Overall, the translation data support the suggestion that the corresponding mRNAs may function as polycistronic transcripts.