Thompson J, Doniger J, Rosenthal L J
Department of Microbiology, Georgetown University Medical Center, Washington.
Arch Virol. 1994;136(1-2):161-72. doi: 10.1007/BF01538825.
Human cytomegalovirus (HCMV) morphological transforming region (mtr)II is the only HCMV mtr that was retained and expressed in transformed mouse or rat cells. The minimal transforming region has previously been shown to be within a 980-bp BanII/XhoI subfragment which encodes three open reading frames (ORF) of 34, 79, and 83 amino acids. This report provides definitive evidence that the 79-aa ORF is responsible for mtrII mediated tumorigenic transformation. The 79-aa ORF, subcloned into a mammalian expression vector, pCHC79orf, induced morphologic transformation of NIH 3T3 cells. These transformed cells expressed 79-aa ORF specific transcripts and were tumorigenic when injected into nude mice. A construct containing a triple termination linker inserted after codon 24 failed to transform NIH 3T3 cells to tumorigenicity even though 79-aa ORF specific transcripts were expressed. Furthermore, when the triple termination linker was inserted after codon 49, tumorigenic transformation still occurred. These results demonstrate that the 79-aa ORF is the oncogene within HCMV mtrII and that the first 49-aa are sufficient.
人巨细胞病毒（HCMV）形态转化区（mtr）II是唯一在转化的小鼠或大鼠细胞中保留并表达的HCMV mtr。先前已证明最小转化区位于一个980 bp的BanII/XhoI亚片段内，该亚片段编码三个分别含34、79和83个氨基酸的开放阅读框（ORF）。本报告提供了确凿证据，表明79个氨基酸的ORF负责mtrII介导的致瘤转化。将79个氨基酸的ORF亚克隆到哺乳动物表达载体pCHC79orf中，可诱导NIH 3T3细胞发生形态转化。这些转化细胞表达79个氨基酸的ORF特异性转录本，注射到裸鼠体内时具有致瘤性。一个在第24个密码子后插入三重终止接头的构建体，即使表达了79个氨基酸的ORF特异性转录本，也未能将NIH 3T3细胞转化为具有致瘤性。此外，当在第49个密码子后插入三重终止接头时，仍会发生致瘤转化。这些结果表明，79个氨基酸的ORF是HCMV mtrII中的癌基因，前49个氨基酸就足够了。
