Researchers from the University of Seville, in collaboration with colleagues from the Universities of Murcia and Marburg (Germany) have identified a new protein that makes it possible to repair DNA. The protein in question, called cryptochrome, has evolved to acquire this and other functions within the cell.

Ultraviolet radiation can damage the DNA, leading to mutations that disrupt cell function and can allow cancer cells to grow out of control. Our cells have DNA repair systems to defend themselves against this sort of damage. One of these systems is based on a protein, photolyase, which uses blue light to repair DNA damage before it leads to mutations.

Over the course of evolution, the genes for photolyase duplicated and became specialized, creating new proteins, cryptochromes, which have honed their ability to perceive blue light and now perform other functions in cells. For example, cryptochromes use blue light as a signal to regulate plant growth and the rhythm that controls daily activity (the circadian rhythm) in fungi and animals.