Schaack J, Ho W Y, Freimuth P, Shenk T
Howard Hughes Medical Institute, Department of Biology, Princeton University, New Jersey 08544.
Genes Dev. 1990 Jul;4(7):1197-208. doi: 10.1101/gad.4.7.1197.
Adenovirus DNA is tightly bound to the nuclear matrix throughout the course of infection. Analysis of adenovirus DNA from infected HeLa cell nuclei after extraction with lithium diiodosalicylate and digestion with restriction enzymes demonstrated that the sites of tightest attachment occur in the terminal fragments of the linear viral chromosome. Analysis of viruses mutated in the precursor terminal protein coding sequence demonstrated that the terminal protein, which is covalently attached to the 5' end of each DNA strand, mediates the tight binding. Virions containing chromosomes with mutant terminal proteins were unpackaged and viral DNA accumulated in the nucleus at a normal rate and competed for the limiting component during transcription complex formation, but their early genes were transcribed at reduced efficiency by both RNA polymerases II and III. The transcriptional defects were not complemented by coinfection with a wild-type virus. We propose that the adenovirus chromosome may exist as a single chromatin domain during infection and that binding of DNA to the nuclear matrix may play a critical role in adenovirus transcription.
在整个感染过程中，腺病毒DNA与核基质紧密结合。用二碘水杨酸锂提取并经限制性内切酶消化后，对来自受感染HeLa细胞核的腺病毒DNA进行分析，结果表明，最紧密附着的位点位于线性病毒染色体的末端片段。对在前体末端蛋白编码序列中发生突变的病毒进行分析表明，共价连接到每条DNA链5'端的末端蛋白介导了这种紧密结合。含有突变末端蛋白染色体的病毒粒子被解包，病毒DNA以正常速率在细胞核中积累，并在转录复合物形成过程中竞争有限的成分，但其早期基因被RNA聚合酶II和III转录的效率均降低。野生型病毒共感染不能弥补转录缺陷。我们提出，腺病毒染色体在感染期间可能作为单个染色质结构域存在，并且DNA与核基质的结合可能在腺病毒转录中起关键作用。
