Chemist Creates Tool for Gene Editing

Since 2013, scientists have used the gene editing tool CRISPR/Cas9, to excise a gene, alter its function, or introduce desired mutations. The method employs a bacterially derived protein (Cas9) and a synthetic guide RNA to induce a double-strand break at a specific location in the genome. The CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats of DNA base sequences) method has shown tremendous promise to enable researchers to treat cystic fibrosis and sickle-cell anaemia, create laboratory animals that mimic human disease, and create a strain of wheat resistant to powdery mildew.

Alexander Deiters, chemistry professor at the University of Pittsburgh, together with colleagues at the University of North Carolina at Chapel Hill, have found a lysine residue in Cas9 that can be replaced with a light-activated analog. The approach, developed by Deiters, generates a Cas9 protein that is functionally inactive, so called "caged," until the cage is removed through light exposure, activating the enzyme and thereby activating gene editing.

"This method may allow people to engineer genes in cells or animals with better spatial and temporal control than ever before," says Deiters. "Engineering a light switch into Cas9 provides a more precise editing tool. You can say, ‘In this cell, at this time point, is where I want to modify the genome.'"

More details about this research are available at the University of Pittsburgh website.