Figure 1.

Schematic diagram showing a network for NamiRNAs, enhancers, and gene activation

Active enhancers have some features, including H3K4me1, H3K27ac, p300/CBP co-activator binding, DNase I hypersensitivity, and production of eRNAs. NamiRNAs could interact with and activate the enhancers. Meanwhile, enhancers could also activate the expression of endogenous NamiRNAs and proximal genes. Thus, enhancers and NamiRNAs form a positive feedback network. Tissue-specific transcription factors may sometimes regulate the expression of miRNAs by targeting their promoters, or participate in the process of enhancer activation. In the figure, the thin green arrow indicates that the encoded transcription factors could regulate the expression of miRNAs or the activation of enhancer; the thick green arrow indicates that enhancer and NamiRNA could regulate the expression of target genes mutually or individually. RNAPII, RNA polymerase II.