The proper activities of enhancers and gene promoters are essential for coordinated transcription within a cell. Although diverse methodologies have been developed to identify enhancers and promoters, most have tacitly assumed that these elements are distinct. However, studies have unexpectedly shown that regulatory elements may have both enhancer and promoter functions. Here we review these results, focusing on the factors that determine the promoter and/or enhancer activity of regulatory elements. We discuss emerging models that define regulatory elements by accessible DNA and their non-mutually-exclusive abilities to drive transcription initiation (promoter activity) and/or to enhance transcription at other such regions (enhancer activity).

中文翻译：

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调节元件的增强子和启动子活性的决定因素。

增强子和基因启动子的适当活性对于细胞内的协调转录是必不可少的。尽管已开发出多种方法来鉴定增强子和启动子，但大多数已默认假定这些元件是不同的。但是，研究出乎意料地表明，调控元件可能同时具有增强子和启动子功能。在这里，我们回顾这些结果，重点关注确定调控元件启动子和/或增强子活性的因素。我们讨论了新兴的模型，这些模型通过可访问的DNA及其非互斥能力来定义调控元件，以驱动转录起始（启动子活性）和/或增强其他此类区域的转录（增强子活性）。