Every cell in the body has the same genes, yet many of them—for example, nerve cells and skin cells—have very different jobs. This specialization is due in part to a cell’s ability to turn genes on and off using short stretches of DNA known as enhancers. David Stern, a lab head at Janelia Farm Research Campus, has found a way to learn more about these regions by targeting them with particular DNA-binding proteins.
Stern and Justin Crocker, a researcher in his lab, used a group of proteins called transcription activator-like effectors, or TALEs. Originally isolated from bacteria, TALEs can be altered to bind to a specific sequence of DNA. Stern and Crocker created TALEs that bound to the enhancer for a gene called eve. They then attached part of a protein known to stop gene expression to those TALEs. As they reported in the August 2013 issue of Nature Methods, their engineered TALEs were able to halt eve expression in developing fly embryos.
Scientists will be able to use the technique to engineer their own TALEs and to learn more about enhancer function and gene expression. “Not only does this let us understand enhancers in their native context,” says Crocker, “but it also lets us take the next step forward to controlling them.”