Scientists engineer new tools to electronically control gene expression

Researchers, led by experts at Imperial College London, have developed a new method that allows gene expression to be precisely altered by supplying and removing electrons.

This could help control biomedical implants in the body or reactions in large 'bioreactors' that produce drugs and other useful compounds. Current stimuli used to initiate such reactions are often unable to penetrate materials or pose risk of toxicity – electricity holds the solution.

Gene expression is the process by which genes are 'activated' to produce new molecules and other downstream effects in cells. In organisms, it is regulated by regions of the DNA called promoters. Some promoters, called inducible promoters, can respond to different stimuli, such as light, chemicals and temperature.

Using electricity to control gene expression has opened a new field of research and while such electrogenetic systems have been previously identified they have lacked precision during the presence or absence of electrical signals, limiting their applications. The newly proposed system, with engineered promoters, allows such accuracy to be obtained for the first time using electrical stimulus in bacteria.

In this research, the PsoxS promoter was redesigned to respond more strongly to electrical stimuli, provided by the delivery of electrons. The newly engineered PsoxS promoters were able not only to activate gene expression but also repress it.