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Optogenetics: Using the power of light to understand and manipulate cell behaviour

21 June 2019
Congratulations Dr Harald Janovjak and PhD candidate Alexandra-Madelaine Tichy, on your recent review paper. Optogenetics has revolutionized the field of neuroscience and is starting to have a big impact on cell and developmental biology. It is a key area of interest for Dr Harald Janovjak, a researcher at the Australian Regenerative Medicine Institute at Monash University.

Optogenetics is a recently developed technology that uses light to control the function of genetically modified cells, usually through acting on cell membrane proteins. Optogenetics is used in research to learn the function of specific cells or proteins, as well as understand and change their behaviour. 

Using light offers several advantages to using chemicals or hormones to activate a cell, as light can be focused on a very specific area. It can also be turned on and off again very quickly, and from a distance, similar to flicking a switch.

Harald is interested in using optogenetics to understand and manipulate cell signalling (how cells talk to each other) and cell behaviour, in tissues affected by degenerative diseases, including Type 1 Diabetes and Parkinson’s.

A recent review, titled “Light-activated chimeric GPCRs: limitations and opportunities”, led by Alexandra-Madelaine Tichy, a PhD student in the Janovjak Lab, evaluated the different studies on genetically modified, light sensing G-protein coupled receptors, called Opto-GPCRs. G-protein coupled receptors are important receptor proteins found throughout the body and are the drug target for many diseases. The review also discussed the opportunities and limitations of Opto-GPCRs as a research tool. One limitation is that the engineered Opto-GPCRs are likely to not fully behave like their  non-genetically modified counterpart. 

However, there are several opportunities for future Opto-GPCRs. New structural information and different light-sensitive parts can be used to improve the design strategy of Opto-GPCRs. Because light can also act on proteins inside the cell, not just on the outside, Opto-GPCRs could be targeted to specific cellular compartments and activated there. This will assist in studying the effect of GPCR localisation on cell behaviour.

Looking forward, optogenetics might help researchers identify new small-molecule drugs for new treatments. Optogenetics can also help researchers such as Harald and Alexandra-Madelaine understand how cells behave during cell death and cell growth processes, and might one day control potentially fatal disorders, such as cancer (where excessive cell growth is a hallmark) and degenerative diseases (in which cell death features an important role).

Dr Harald Janovjak is a Chief Investigator at Stem Cells Australia.