Klimkait T, Doerfler W
Institute of Genetics, University of Cologne, Federal Republic of Germany.
Virology. 1987 Nov;161(1):109-20. doi: 10.1016/0042-6822(87)90176-0.
Adenovirus type 12 (Ad12) DNA cannot replicate in hamster cells and the late Ad12 genes cannot be expressed. It has been demonstrated previously that these defects can be at least partly overcome by coinfection of hamster cells with Ad12 and wild-type adenovirus type 2 (Ad2) or type 5 (Ad5) or by superinfection of Ad2- or Ad5-transformed cells with Ad12. These transformed cell lines carry in an integrated form and constitutively express the E1 region of Ad2 or Ad5. The compensation in Ad12 DNA replication and late gene transcription does not, however, lead to the assembly of intact Ad12 virions. In the present study, it has been demonstrated that the complementing functions in the Ad5 genome, which can effect Ad12 DNA replication and late transcription in hamster cells, reside predominantly but not exclusively in the E1B region. A supporting role in the E1A region is likely. These conclusions have been adduced from the results of double infection experiments using Ad12 and deletion mutants of Ad5. Inside the E1B region of Ad5 DNA, the complementing functions have not yet been precisely located. Although late Ad12 messenger RNAs are synthesized in Ad12 and Ad5-coinfected hamster cells, most of the late structural Ad12 proteins are not made or are made in minimal amounts, and consequently virions are not assembled. It is necessary to investigate whether hamster cells also exhibit a translational block vis à vis the expression of late Ad12-specific mRNAs. The data presented here also demonstrate that Ad12 functions can effectively complement E1A or to a lesser extent E1B deletions in the Ad5 genome in hamster cells. Upon coinfection with Ad12 and deletion mutants of Ad5 in either the E1A or the E1B region, Ad5 DNA and late proteins are synthesized, although Ad5 E1A or E1B functions cannot complement the deficient late Ad12 protein synthesis in hamster cells.
12型腺病毒（Ad12）DNA无法在仓鼠细胞中复制，且Ad12晚期基因无法表达。此前已证明，通过将Ad12与野生型2型腺病毒（Ad2）或5型腺病毒（Ad5）共同感染仓鼠细胞，或用Ad12对Ad2或Ad5转化的细胞进行超感染，这些缺陷至少可以部分得到克服。这些转化细胞系以整合形式携带并组成性表达Ad2或Ad5的E1区。然而，Ad12 DNA复制和晚期基因转录中的补偿作用并未导致完整Ad12病毒粒子的组装。在本研究中，已证明Ad5基因组中的互补功能可影响仓鼠细胞中Ad12 DNA复制和晚期转录，这些功能主要但并非完全位于E1B区。E1A区可能起辅助作用。这些结论是从使用Ad12和Ad5缺失突变体的双重感染实验结果得出的。在Ad5 DNA的E1B区内，互补功能尚未精确定位。尽管在Ad12和Ad5共同感染的仓鼠细胞中合成了Ad12晚期信使RNA，但大多数Ad12晚期结构蛋白并未产生或产生量极少，因此无法组装病毒粒子。有必要研究仓鼠细胞对于Ad12晚期特异性mRNA的表达是否也存在翻译障碍。此处呈现的数据还表明，Ad12功能可有效补偿仓鼠细胞中Ad5基因组E1A或程度较轻的E1B缺失。当Ad12与Ad5在E1A或E1B区的缺失突变体共同感染时，会合成Ad5 DNA和晚期蛋白，尽管Ad5 E1A或E1B功能无法补偿仓鼠细胞中Ad12晚期蛋白合成缺陷。
