More Than a Feeling

Much of what scientists know about how cells function is the result of directly observing their inner workings using fluorescent reporter proteins, originally discovered in jellyfish. A reporter protein is used as a marker and attached to another protein or gene of interest, allowing the function or location of the target to be tracked and monitored.

However, standard fluorescent proteins are limited because they depend on oxygen to emit light. And they cannot be used to study research animals, since light cannot penetrate opaque biological tissue. As a result, fluorescent reporters do not work deep in anaerobic systems, such as gut microbes, or inside living animals. This leaves two fascinating and medically important biological systems outside the purview of existing biomolecular imaging techniques.

Arnab Mukherjee, an assistant professor in UC Santa Barbara’s Department of Chemical Engineering, has focused his research on developing new reporter proteins that tackle these challenges. He wants to illuminate what he refers to as the “invisible dark matter” of biology by engineering new genetic reporters that will fluoresce in anaerobic environments and can be seen in living animals using magnetic resonance imaging (MRI).