Repression of the IgH enhancer in teratocarcinoma cells associated with a novel octamer factor.
Repression of the IgH enhancer in teratocarcinoma cells associated with a novel octamer factor.
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DOI：
10.1126/science.2536195
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发表时间：
1989-01
期刊：
影响因子：
56.9
通讯作者：
M. Lenardo;L. Staudt;P. Robbins;A. Kuang;R. Mulligan;D. Baltimore
中科院分区：
文献类型：
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作者：
M. Lenardo;L. Staudt;P. Robbins;A. Kuang;R. Mulligan;D. Baltimore
胚胎癌（EC）细胞系是小鼠胚胎发生中早期细胞的模型。重链增强子的300个碱基对片段在F9 EC细胞中无活性，不像在其他非淋巴细胞中具有显著活性。八聚体基序的改变增加增强子活性。F9细胞的核提取物含有EC细胞特有的八聚体结合蛋白（NF-A3）; NF-A3的量在分化后下降。有人提出，NF-A3抑制特定的调控序列，包含八聚体基序。因此，相同的DNA序列介导负或正转录效应，这取决于细胞类型。
Embryonal carcinoma (EC) cell lines are models for early cells in mouse embryogenesis. A 300-base pair fragment of the heavy chain enhancer was inactive in F9 EC cells, unlike in other nonlymphoid cells where it has significant activity. Alterations of the octamer motif increased enhancer activity. Nuclear extracts from F9 cells contained an octamer binding protein (NF-A3) that was unique to EC cells; the amount of NF-A3 decreased upon differentiation. It is proposed that NF-A3 represses specific regulatory sequences that contain the octamer motif. Thus, the same DNA sequence mediates either negative or positive transcriptional effects, depending on the cell type.