FUNCTIONAL ACTIVATION OF THE LONG TERMINAL REPEAT OF HUMAN T-CELL LEUKEMIA-VIRUS TYPE-I BY A TRANS-ACTING FACTOR
FUNCTIONAL ACTIVATION OF THE LONG TERMINAL REPEAT OF HUMAN T-CELL LEUKEMIA-VIRUS TYPE-I BY A TRANS-ACTING FACTOR
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DOI：
10.1073/pnas.82.8.2277
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发表时间：
1985-01-01
影响因子：
11.1
通讯作者：
YOSHIDA, M
中科院分区：
文献类型：
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作者：
FUJISAWA, J;SEIKI, M;YOSHIDA, M
通过构建含人T细胞白血病病毒I型(HTLV-I)长末端重复序列(LTR)的重组表达载体，研究其对HTLV-I基因表达的启动子作用。将编码氯霉素乙酰转移酶(CATase)的基因与HTLV-I LTR序列(pLTR-CAT)连接，将pSV2-CAT中的SV 40启动子替换为LTR序列。比较了瞬时CATase活性。HTLV LTR即使在上皮细胞系中也是活性的，其效率与SV 40启动子相似。在HTLV-I感染的人T细胞系MT-2和HUT-102以及HTLV-I感染的大鼠细胞系中，pLTR-CAT表达的CATase活性是pSV1-CAT的40-200倍。这种LTR活性的增强似乎与HTLV基因的表达有关，因为在HTLV感染的MT-1细胞中只观察到低活性的pLTR-CAT，其中只有一小部分细胞表达病毒抗原。在HTLV感染的大鼠细胞系中，Px编码蛋白p40x是唯一检测到的病毒蛋白。因此，我们认为p40x是与LTR活性增强直接或间接相关的因子。
Promoter function for gene expression of the long terminal repeat (LTR) of human T-cell leukemia virus type I (HTLV-I) was studied by constructing plasmids containing the LTR sequence. The gene encoding chloramphenicol acetyltransferase (CATase) was linked to an HTLV-I LTR sequence (pLTR-CAT) by replacing the sv 40 promoter in plasmid pSV2-CAT with the LTR sequence. The transient CATase activities of cells transfected with the plasmids were compared. The HTLV LTR was active even in an epithelial cell line, with efficiency similar to that of the sv 40 promoter. pLTR-CAT expressed high CATase activity, 40-200 times that expressed by pSV1-CAT, in HTLV-I-infected T-cell lines, such as the human cell lines MT-2 and HUT-102, or in HTLV-I-infected rat cell lines. This enhanced activity of the LTR seems to be associated with HTLV gene expression, since only low activity of pLTR-CAT was observed in the HTLV-infected cell line MT-1, in which only a small pervent of cells express viral antigens. In HTLV-infected rat cell lines, the pX-encoded protein p40x was the only viral protein detected. Thus, it is suggested that p40x it the factor associated directly or indirectly with the enhanced activity of the LTR.