Arnold Preston R, Wells Andrew D, Li Xian C
Texas A&M Health Science Center, College of Medicine, Bryan, TX, United States.
Immunobiology and Transplant Sciences, Department of Surgery, Houston Methodist Hospital, Houston, TX, United States.
Front Cell Dev Biol. 2020 Jan 14;7:377. doi: 10.3389/fcell.2019.00377. eCollection 2019.
Enhancers are -regulatory elements in the genome that cooperate with promoters to control target gene transcription. Unlike promoters, enhancers are not necessarily adjacent to target genes and can exert their functions regardless of enhancer orientations, positions and spatial segregations from target genes. Thus, for a long time, the question as to how enhancers act in a temporal and spatial manner attracted considerable attention. The recent discovery that enhancers are also abundantly transcribed raises interesting questions about the exact roles of enhancer RNA (eRNA) in gene regulation. In this review, we highlight the process of enhancer transcription and the diverse features of eRNA. We review eRNA functions, which include enhancer-promoter looping, chromatin modifying, and transcription regulating. As eRNA are transcribed from active enhancers, they exhibit tissue and lineage specificity, and serve as markers of cell state and function. Finally, we discuss the unique relationship between eRNA and super enhancers in phase separation wherein eRNA may contribute significantly to cell fate decisions.
增强子是基因组中的调控元件，与启动子协同作用以控制靶基因转录。与启动子不同，增强子不一定与靶基因相邻，并且无论增强子的方向、位置以及与靶基因的空间分隔如何，都能发挥其功能。因此，长期以来，增强子如何在时间和空间上发挥作用的问题引起了广泛关注。最近发现增强子也大量转录，这引发了关于增强子RNA（eRNA）在基因调控中确切作用的有趣问题。在本综述中，我们重点介绍增强子转录过程以及eRNA的多种特征。我们回顾了eRNA的功能，包括增强子-启动子环化、染色质修饰和转录调控。由于eRNA是从活跃的增强子转录而来，它们表现出组织和谱系特异性，并作为细胞状态和功能的标志物。最后，我们讨论了eRNA与超级增强子在相分离中的独特关系，其中eRNA可能对细胞命运决定有重大贡献。
