FIGURE 1.

Examples of lncRNA-mediated epigenetic regulation of gene expression. (A) By forming an RNA-DNA triplex structure on target promoters (Foxf1, Pitx2, and Irx3), lncRNA Fendrr acts as a scaffold that promotes the binding of PRC2-inducing H3K27me3 deposition (left panel). Fendrr loss of function results in decreased PRC2 occupancy and increased TRX/MLL-mediated deposition of H3K4me3. The resulting altered epigenetic profile is responsible for severe impairment in heart and body wall development and, ultimately, in embryonic lethality around E13.75 (right panel). (B) In muscle, upon oxidative stress, MALAT1 promotes PRC2 assembly and guides it on the late myogenic genes, inducing their silencing by H3K27me3 deposition.