positive and negative, nuclear and cytoplasmic, epigenetic and post-transcriptional regulatory modalities. Documented lncRNA functions include: positive regulation of sense mRNA translation by an antisense lncRNA [8], trans-repression of mRNAs by repeat-containing lncRNAs through the Stauffen-1 mRNA decay pathway [9]; epigenetic regulation of protein-coding targets by lncRNAs that recruit PRC2 to gene promoters [10], and direct RNA-protein interactions between lncRNAs and TFs: the Evf-2 lncRNA directly interacts with distal-less homeobox proteins to regulate mouse hippocampal development [11]. The Gas5 lncRNA contains a precise ribomimic of the genomic DNA binding site of the human glucocorticoid receptor, therefore titrating out bioavailable glucocorticoid receptor molecules and preventing them from binding their cognate sites in gene promoters along genomic DNA [12]. More generally, endogenous riboregulation of DNA-binding NHRs through direct interactions with lncRNAs [2], [12], [13] is an emerging leitmotif of post-genomic lncRNA biology.
