Scientists discover that genes switches do more than turn on and off

Scientists have known for decades that genes are turned ‘on’ and ‘off’ by proteins known as transcription factors. They were thought to be like a switch -- either bound to DNA or not. Now scientists led by the University of North Carolina have demonstrated that transcription factors don’t act like an on-off switch, but are more complex. Working with yeast, the team learned that in addition to a stable binding state, transcription factors exist in a state deemed ‘treadmilling,’ where no forward transcription process is occurring. “This discovery is exciting because we developed a new way to measure and calculate how long a protein is associated with all of the different genes it regulates,” Jason Lieb, the study’s senior author, said. “This is important because it represents a new step in the process of how genes are regulated. And with every new step, there are opportunities for new mechanisms of regulation.”