Want to turn a specific gene or protein off or on in one particular area of an organism? Then let there be light! UV light, to be specific. Chemistry professor Dr. Alex Deiters specializes in creating light-activated biological switches that can help scientists control and study the function of specific genes and proteins in localized areas of cells and organisms.
Scientists have a wide range of tools to activate genes and express proteins in cells and organisms. However, those tools don’t allow scientists to control cellular processes in specific locations or at certain times. Light, in combination with light-regulated gene and protein switches, gives scientists the ability to precisely control these cellular mechanisms.
Deiters has helped create switches with “photocaged“ molecules that only become activewhen exposed to UV light. The light “frees” the molecule to initiate the process it was designed to–whether it’s activating a particular gene or causing a certain protein to be functional. In close collaboration with the laboratory of professor Klaus Hahn at the University of North Carolina-Chapel Hill, Deiters’ lab engineered an important enzyme, a kinase, that is activated when exposed to UV light.
Want to see this in action? Here’s a link to a short movie from their most recent paper (hint: the first .avi movie on that page is awesome!). A photocaged molecule – specifically, a photocaged version of the immunosuppressive drug rapamycin – is introduced into a cell, exposed to UV light, and voila! It binds to a particular kinase (in this case a protein involved in cell movement) known as focal adhesion kinase, or FAK, leading to the formation of dorsal protrusions and ruffles on the cell surface.
According to Deiters, this light-activation technology doesn’t just let them control the activity of kinases, but it can also be used to trigger a wide range of protein-protein interactions. Thanks to this work, maybe one day we’ll be able to turn cancer cells off with the flick of a light switch.