Dean Ann
Laboratory of Cellular and Developmental Biology, NIDDK, NIH, Bethesda, MD 20892, USA.
Trends Genet. 2006 Jan;22(1):38-45. doi: 10.1016/j.tig.2005.11.001. Epub 2005 Nov 23.
Transcription activation of a gene involves the ordered recruitment of components of the basal transcription machinery in concert with alterations in chromatin structure, including nucleosome remodeling and post-translational modification of histones. Enhancers and locus control regions (LCRs) that are remote from the genes they activate, recruit the complexes that carry out these alterations and, sometimes, recruit RNA polymerase II. The question of how these distant activators interact with their target genes has been of long-standing interest. Recent data indicate that LCRs mediate contact with their coordinate genes through the formation of domains of histone modification and of intra- and inter-chromosomal loops and that they might localize genes within nuclear regions that favor transcription.
基因转录激活涉及基础转录机制各组分的有序募集，同时伴随着染色质结构的改变，包括核小体重塑和组蛋白的翻译后修饰。增强子和基因座控制区（LCR）距离它们所激活的基因较远，可募集执行这些改变的复合物，有时还能募集RNA聚合酶II。这些远距离激活因子如何与其靶基因相互作用的问题一直备受关注。最近的数据表明，LCR通过形成组蛋白修饰结构域以及染色体内和染色体间环来介导与其协同基因的接触，并且它们可能将基因定位在有利于转录的核区域内。
