Imagine a huge spool of film containing thousands of sequences of random scenes. Without a talented editor, a screening would have no meaning.
The RNA “spools” that make up DNA in our genes need careful editing, too. Genes are composed of meaningful sequences, called exons, separated by meaningless junk sections called introns. In order for cells to produce RNA — the material that is required to create proteins that are vital for life — they must precisely remove meaningless introns and bind meaningful exons together, a process called “splicing.”
How cells differentiate between what’s useful and what’s garbage in our complicated and messy genetic code is a fundamental biology question — one with extremely important implications. Now, Prof. Gil Ast and his doctoral student Schraga Schwartz at the Sackler School of Medicine at Tel Aviv University are successfully finding answers.
Their groundbreaking findings, recently published in Nature Structural and Molecular Biology, reveal a new mechanism to explain how splicing works. They’ve discovered that the structure of DNA itself affects the ways RNA is spliced. “These findings,” says Prof. Ast, “will bring us closer to understanding diseases like cystic fibrosis and certain forms of cancer that result from our cells’ failure to edit sequences properly.”
Rewriting textbook science on DNA
Until now, how RNA was “edited” to fit together has been a mystery. The TAU revelations provide important information about creating proteins, and give new clues to drug developers to better understand how diseases such as cancer and genetic disorders operate at the gene level. That insight can offer significant new cellular mechanisms to create innovative drug therapies.
“We’ve found something previously unknown,” Prof. Ast explains. “At the DNA level, exons are packaged differently than introns. This fact is significant, telling us a process of gene expression is taking place at an earlier step than previously believed.” …