Scientists have found that broken protein recycling system in nerve cells may be a common cause behind different forms of motor neuron disease (MND). A team of US researchers has discovered that a malfunctioning protein recycling system in the neurons of the brain and spinal cord is the possible cause of many fatal neuron diseases, including Amyotrophic lateral sclerosis or ALS. ALS, also known as Lou Gehrig's disease, is the most common form of motor neuron disease that causes progressive paralysis and eventually death. ALS affects about 350,000 people around the world, with many of them losing their life within three years due to complications caused by breathing and swallowing difficulties. To find a treatment, scientists have been trying for a long time to find a clue or underlying condition behind the disease. Now, Northwestern University researchers say dysfunction of protein recycling system in nerve cells disrupts their ability of self repair that leads to severe damages. The study also involved a search for potential gene mutations in families with members in five generations that suffered from ALS. The results suggested that a mutation in a UBQLN2 gene that controls the production of a protein named ubiquilin 2. The key protein plays a crucial role in recycling damaged or misshapen proteins in motor nerves, Teepu Siddique and colleagues wrote in the journal Nature. "The exact function of ubiquilin 2 is not well understood," the researchers added. "However, there is increasing evidence that ubiquilins, together with their interactions with other proteins, may be involved in neurodegenerative disorders." The Scientists expressed hope that in the future their findings may pave the way for effective treatments and medications for motor neuron disease. "These data provide robust evidence for an impairment of protein turnover in the pathogenesis of ALS and ALS/dementia, and possibly other neurodegenerative disorders, as well," said the report. "These pathways should provide novel molecular targets for the design of rational therapies for these disorders." "We can now test for drugs that would regulate this protein pathway or optimize it, so it functions as it should in a normal state," the authors said. They also suggested that the discovered mechanism could have a role in other neurodegenerative diseases, including dementia and Parkinson's disease.