FIGURE 2.

LncRNA regulation of transcription and translation by acting as scaffolds to facilitate interactions between macromolecules. Schematic examples of how lncRNAs participate in RNA–DNA, RNA–RNA, and RNA–protein interactions to facilitate the regulated expression of protein coding genes. (A) LncRNAs like Six3OS interact with chromatin-modifying complexes to regulate gene transcription. Additionally, lncRNAs can interact with transcription factors to facilitate target gene expression. (B) Complementary sequence on lncRNAs with enhancer sequences is proposed to enable chromatin looping to regulate gene transcription. (C) Expression of lncRNAs that contain repeat sequences for protein binding help facilitate co-regulated transcription of multiple targets, including transcription across different chromosomes. (D) LncRNAs are implicated in the formation and maintenance of nuclear paraspeckles that facilitate alternative splicing events of nascent transcripts. (E) Through homologous base-pairing with mRNA transcripts and interactions with ribosomal proteins and/or RNAs, lncRNAs are able to target mRNAs to the ribosomes. (F) Containing complementary target sequences, lncRNAs also serve as miRNA decoys to prevent interactions of miRNAs with protein-coding transcripts.