A flash of light changes cell activity — and understanding of disease

With a milliseconds-long flash of blue light, Yale University researchers regulated a critical type of signalling molecule within cell membranes, another illustration of the power of light-based techniques to manipulate cell functions and thus to study mechanisms of disease.

One of the most exciting new research approaches of recent years is called optogenetics or the use of genetically encoded probes to make cell functions sensitive to light.

The new study, published the week of 30 July in the journal Proceedings of the National Academy of Sciences, is one of the first to use light to regulate metabolic activity in the membranes of cells.

''The cell outer membrane is the part of the cell that communicates with the environment,'' said Olof Idevall-Hagren, post-doctoral researcher and lead author of the paper. ''Many cellular processes start at the cell outer membrane.''

The team combined a plant protein that is sensitive to blue light with enzymes that catalyse the metabolism of signalling lipids within the cell membranes. When the complex was expressed in animal cells, scientists changed properties of cells such as their shape or ability to move simply by using blue light.

By turning off the light, the researchers were able to rapidly reverse the changes they induced. They were also able to regulate activities within a region of a cell by illuminating the area.