Scientists have identified an RNA molecule with broad powers to regulate the body’s inflammatory response to infection and injury. Called lincRNA-Cox2, it belongs to a recently discovered, highly abundant class of RNAs whose functions are only beginning to be understood.
The sequencing of the human genome revealed that only a small fraction of the DNA in our chromosomes comprises genes that encode instructions for making proteins. Those genes are transcribed into messenger RNA, which directs the synthesis of proteins that carry out various functions in the cell. The rest of the genome, about 98 percent of it, was sometimes referred to as the “dark matter” of the genome or dismissed as “junk DNA.”
In the past decade, however, new RNA sequencing technologies have revealed that much of the genome is transcribed into noncoding RNA molecules of various types. Long intergenic noncoding RNA (lincRNA) is the largest class of these RNAs.
“We now know of about 16,000 long noncoding RNAs, about as many as there are protein-coding genes, but we know the functions of less than one percent of them,” said Susan Carpenter, an assistant professor of molecular, cell and developmental biology at UC Santa Cruz.
Carpenter’s lab is interested in how lincRNAs control the processes involved in inflammation. The new study, published November 6 in Cell Reports, shows that lincRNA-Cox2 functions in several different ways to regulate the activity of genes involved in inflammation and other immune system responses.