Australian researchers have made a huge breakthrough in the fight against Parkinson’s disease after solving a decades-long mystery.

Scientists at the Walter and Eliza Hall Institute of Medical Research (WEHI) have for the first time been able to observe a key protein directly linked to the awful disease, and determine what it looks like.

The protein, PINK1, supports cell survival by detecting damaged mitochondria and tagging them for removal.

In a healthy person, when mitochondria are damaged, PINK1 gathers on mitochondrial membranes and signals through a small protein called ubiquitin, that the broken mitochondria need to be removed.

The PINK1 ubiquitin signal is unique to damaged mitochondria, and when PINK1 is mutated in patients, broken mitochondria accumulate in cells.

In a person with Parkinson’s and a PINK1 mutation, the mitophagy process no longer functions correctly and toxins accumulate in the cell, eventually killing it.

Brain cells need a lot of energy and are especially sensitive to this damage.

Although PINK1 has been linked to Parkinson’s, and in particular Young Onset Parkinson’s Disease, researchers had been unable to visualise it and did not understand how it attaches to mitochondria and is switched on.

The idea of using PINK1 as a target for potential drug therapies has long been touted but not yet achieved because of the unknowns.

The research team hope to use this new breakthrough to find a drug to slow or stop Parkinson’s in people with a PINK1 mutation.

Parkinson’s disease is insidious, often taking years, sometimes decades to diagnose.

Often associated with tremors, there are close to 40 symptoms including cognitive impairment, speech issues, body temperature regulation and vision problems.

In Australia, over 200,000 people live with Parkinson’s and between 10 per cent and 20 per cent have Young Onset Parkinson’s Disease – meaning they are diagnosed under the age of fifty.

The impact of Parkinson’s on the Australian economy and healthcare systems is estimated to be over $10 billion each year.

“This is a significant milestone for research into Parkinson’s. It is incredible to finally see PINK1 and understand how it binds to mitochondria,” corresponding author on the study Professor David Komander said.

“Our structure reveals many new ways to change PINK1, essentially switching it on, which will be life-changing for people with Parkinson’s.”