RNA Changes Guide the Nervous System

Release Date:
NIGMS Communications Office

The four chemical building blocks of DNA connect in various orders, or sequences, to form genes. Our genes carry the instructions for making proteins, which perform thousands of different tasks in our bodies. In reading a particular gene's instructions and making the protein it specifies, a cell creates an intermediate molecule called messenger RNA (mRNA). This molecule's sequence usually exactly reflects the gene's sequence. But in certain cases, cellular enzymes can "retype" a portion of an mRNA's sequence. This "edited" mRNA template causes the cell to produce a completely different protein than the original gene specified. The new protein often has a different function.

Geneticist Robert Reenan, Ph.D., of the University of Connecticut Health Center in Farmington has developed a new approach to search for edited genes. In doing so, he discovered that the process is not as rare as was once believed. Reenan compared the sequences of an edited gene in 18 species of experimental fruit flies. He noticed a preserved pattern, or signature, in all of the versions of the gene. Reenan suspects that the signature translates into a common RNA shape that is easily recognized by RNA editing machinery in the cell. Looking for other fly genes that may contain the editing signature, he evaluated the spellings of more than 900 genes in just two fruit fly species and discovered 16 additional genes that undergo editing. He found that all of the newly discovered editable genes spell out proteins used for super-quick electrical or chemical transmission by the fruit fly nervous system.

Reenan's discovery may help explain how the nervous system can adapt rapidly to changes in our surroundings by permitting cells to make quick edits to gene copies (in the form of mRNA) rather than to the original DNA. A more thorough interpretation of the language scripted in genes central to nervous system function may help researchers find new ways to diagnose and treat a variety of neurological diseases known to have a genetic component, such as Parkinson's disease, Alzheimer's disease, epilepsy, and many others.

Writer: Alison Davis, Science Writing Contractor