Zhu W, Kriajevskaia M, Chou W G
Department of Radiation Oncology, University of Rochester Medical Center, New York 14642.
Oncogene. 1992 Oct;7(10):2081-3.
A partial cDNA (B52) molecule with the characteristics of retroviral sequences was isolated from the Chinese hamster ovary (CHO) K1 cell line. The B52 cDNA contains 1184 nucleotides. The first 452 nucleotides (nt) are 71% homologous to the env gene of Moloney murine leukemia virus (MMLV) and murine endogenous retroviruses. The 139 amino acids predicted from the 452 nt have 82% homology with the carboxy-terminal amino acids of the env protein of MMLV. The remaining 732 nt have several features of a typical retroviral long terminal repeat (LTR). For example, the first 14 nt are identical to the 5' inverted repeat of the retroviral LTRs. The 41-nt sequence at the 3' end is common to the R region of retroviral LTRs. The 732-nt sequence was shown to have promoter activity. The activity is approximately twofold higher than that of the Rous sarcoma virus LTR, and 1.5-fold lower than that of the early promoter of SV40 virus. Two species of mRNA of 5.2 and 2.7 kb in size were readily detected by B52 cDNA in the CHO K1 cells.
从中国仓鼠卵巢（CHO）K1细胞系中分离出一个具有逆转录病毒序列特征的部分cDNA（B52）分子。B52 cDNA包含1184个核苷酸。前452个核苷酸（nt）与莫洛尼鼠白血病病毒（MMLV）和鼠内源性逆转录病毒的env基因有71%的同源性。从这452个nt预测的139个氨基酸与MMLV的env蛋白的羧基末端氨基酸有82%的同源性。其余732个nt具有典型逆转录病毒长末端重复序列（LTR）的几个特征。例如，前14个nt与逆转录病毒LTR的5'反向重复序列相同。3'端的41个nt序列是逆转录病毒LTR的R区域共有的。732个nt序列显示具有启动子活性。该活性比劳氏肉瘤病毒LTR高约两倍，比SV40病毒的早期启动子低1.5倍。在CHO K1细胞中，B52 cDNA很容易检测到大小为5.2和2.7 kb的两种mRNA。
