Asano M, Murakami Y, Furukawa K, Yamaguchi-Iwai Y, Satake M, Ito Y
Department of Viral Oncology, Kyoto University, Japan.
J Virol. 1990 Dec;64(12):5927-38. doi: 10.1128/JVI.64.12.5927-5938.1990.
Element I, homologous to the adenovirus type 5 E1A enhancer core, is a 10-bp sequence in the A core of the polyomavirus enhancer and was shown previously to be responsive to 12-O-tetradecanoylphorbol-13-acetate (TPA). We found that element I by itself was capable of activating polyomavirus DNA replication in COP-5 cells which express the polyomavirus large T antigen. A nuclear factor, polyomavirus enhancer-binding protein 5 (PEBP5), which bound to the entire sequence of element I and was responsive to TPA was identified by an in vitro binding assay. Although the binding site of PEBP5 partly overlaps with that of PEBP1 (PEA1), a member of the AP-1 family, PEBP5 appears to be a distinct factor. Since we previously showed that element I alone was able to activate transcription, our present results suggest that PEBP5 is involved in the regulation of both transcription and replication of DNA. The amount of PEBP5 increased after F9 cells were induced to differentiate by retinoic acid. A relatively large amount of PEBP5 was detected in lymphoid and trophoblast cells.
元件I与腺病毒5型E1A增强子核心同源，是多瘤病毒增强子A核心中的一个10碱基对序列，先前已证明其对12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯（TPA）有反应。我们发现元件I自身能够在表达多瘤病毒大T抗原的COP - 5细胞中激活多瘤病毒DNA复制。通过体外结合试验鉴定出一种核因子，多瘤病毒增强子结合蛋白5（PEBP5），它能结合元件I的整个序列并对TPA有反应。尽管PEBP5的结合位点部分与AP - 1家族成员PEBP1（PEA1）的结合位点重叠，但PEBP5似乎是一个独特的因子。由于我们先前表明单独的元件I能够激活转录，我们目前的结果表明PEBP5参与DNA转录和复制的调控。用视黄酸诱导F9细胞分化后，PEBP5的量增加。在淋巴细胞和滋养层细胞中检测到相对大量的PEBP5。
