Feng J L, Villeponteau B
Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-2007.
Mol Cell Biol. 1990 Mar;10(3):1126-33. doi: 10.1128/mcb.10.3.1126-1133.1990.
Transcription of the proto-oncogene c-fos is known to be activated by growth factors in serum and subsequently repressed by the Fos protein. We show that generalized DNase I sensitivity of c-fos chromatin correlates closely with enhancer activity during induction, repression, and superinduction of the c-fos gene. Within 90 s of serum stimulation, proximal DNA sequences on both sides of the enhancer exhibit increased DNase I sensitivity. Within 5 min, elevated DNase I sensitivity spreads to chromatin at the distal 3' end of the c-fos gene. These results suggest that an open state of chromatin is propagated in both directions from the enhancer. The induced alterations in chromatin structure precede the increased transcriptional activity of the c-fos gene, suggesting that these changes in chromatin structure potentiate transcription.
已知原癌基因c-fos的转录可被血清中的生长因子激活，随后被Fos蛋白抑制。我们发现，在c-fos基因的诱导、抑制和超诱导过程中，c-fos染色质的普遍DNase I敏感性与增强子活性密切相关。在血清刺激后90秒内，增强子两侧的近端DNA序列表现出DNase I敏感性增加。5分钟内，升高的DNase I敏感性扩散到c-fos基因远端3'端的染色质。这些结果表明，染色质的开放状态从增强子向两个方向传播。染色质结构的诱导性改变先于c-fos基因转录活性的增加，表明染色质结构的这些变化增强了转录。
