How RNA regulates activation, inhibition of genes

London, July 7 : Experts at UT Southwestern Medical Center have gained insights into how RNA - a chemical cousin of DNA - regulates activation and inhibition of genes.

The researchers have found that RNA can interact with a non-gene region of DNA, known as the promoter region, which must be activated before a gene can be turned on.

The finding is significant because scientists to date have not achieved any big success in discerning how RNA strands might regulate activation and inhibition of genes.

"Our findings about the underlying mechanisms of RNA-activated gene expression reveal a new and unexpected target for potential drug development," Nature magazine quoted Dr. David Corey, professor of pharmacology and biochemistry and one of the senior authors of the study, as saying.

The study was carried out in cancer cell cultures, and unveiled an unexpected target for the RNA manufactured in lab.

The research team discovered the RNA did not home in on the gene itself, but rather on another type of RNA produced by the cell, a so-called non-coding RNA transcript.

This type of RNA is found in association with the promoter regions that occur in front of the gene, and act essentially as a "start" command for turning on genes when activated.

The researchers found that their man-made RNA strand bound to the RNA transcript, which then recruited certain proteins to form an RNA-protein complex. The whole complex then bound to the promoter region, an action that could then either activate or inhibit gene expression.

"Involvement of RNA at a gene promoter is a new concept, potentially a big new concept. Interactions at gene promoters are critical for understanding disease, and our results bring a new dimension to understanding how genes can be regulated," Dr. Janowski said.

The new findings suggest that the assumption that proteins alone control gene expression at promoters is not necessarily true.

"By demonstrating how small RNAs can be used to recruit proteins to gene promoters, we have provided further evidence that this phenomenon should be in the mainstream of science," Dr. Corey said.

Since the type of man-made RNA molecules employed in this study are already being used in human clinical trials, the researchers hope that progress toward the development of gene-regulating drugs could move quickly.

ANI