A MOLECULAR "switch" that could explain how certain genes protect the brain from Parkinson's disease has been discovered by Scottish scientists.

A team from Dundee University said they have mapped the molecular pathway between the Pink1 enzyme, produced by the Pink1 gene, and a protein called Parkin.

Mapping the link means they now know the Pink1 gene works to control the Parkin gene, paving the way for a potential treatment for the disease.

Parkin's main job is to keep cells healthy by removing damaged proteins. Mutations in the gene that makes it can also cause inherited forms of Parkinson's in younger patients.

Around 127,000 people in the UK have Parkinson's, a progressive neurological condition for which there is no cure.

Scientists have already discovered 20 genes, including Parkin and Pink1, that cause Parkinson's disease – but they did not know what the role of the genes was or why the mutations caused the disease.

They looked at the way the Pink1 enzyme reacted with the Parkin and 18 other known genes. A "staggering" result took place between Pink1 and Parkin but nothing happened with the 18 other tests.

Scientists now hope that a drug can be developed that mimics Pink1 in switching on the Parkin gene.

The team was led jointly by Dr Miratul Muqit and Professor Dario Alessi at the Medical Research Council protein phosphorylation unit at the University of Dundee.

Dr Muqit said: "Parkinson's is a devastating degenerative brain disorder and currently we have no drugs in the clinic that can cure or slow the disease down.

"Over the last decade many genes have been linked to Parkinson's but a major roadblock has been determining the function of these genes in the brain and how the mutations lead to brain degeneration."