Scientists Unearth Long ncRNA Chromosomal Interactions
Thousands of long non-coding RNAs (ncRNAs) are encoded in the genome, fulfilling regulatory functions in development and disease. Long ncRNAs are often enriched in the nucleus and in some cases tethered to chromatin suggesting an involvement in epigenetic regulation.
Long ncRNAs are emerging as key players in transcription regulation, exerting both positive and negative activity; through currently emerging sequence-structure motifs, some long ncRNAs have been shown to target promoters or interact with chromatin, while others mediate transcriptional interference of antisense overlapping genes without leaving the site of transcription.
Now, scientists have now demonstrated that not only the where and when of long non-coding RNA expression is important for their function but also the how. The results can have a big impact on our understanding of dynamic regulation of gene expression in biological processes.
The research team has paid particular attention to long non-coding RNAs that can enhance the production of specific mRNAs, and hence proteins, in breast cancer cells. They show that the expression of long non-coding RNAs can result in particularly high expression levels of specific proteins with involvement in cancer.
The study found that the non-coding RNA called A-ROD (Activating Regulator Of DKK1 expression) is only functional the moment it is released from chromatin into the nucleoplasm. At this phase, it can bring transcription factors to specific sites in DNA to enhance gene expression. After its complete release from chromatin, A-ROD is no longer active as an enhancing long non-coding RNA. In a way, A-ROD functions as a lasso that can be thrown from DNA to catch proteins.
This study bears interesting results and the team believes that these differences can be exploited to optimize the approaches for targeting RNA-dependent processes in disease. A future scientific goal is to identify more of the non-coding RNA lassoes to fully understand their potential and application in regulation of gene expression.