Protein VPS35 Helps In Sorting

Recently, by means of a new research it has been discovered that a molecule named as VPS35, performs the task of detecting and removing defective proteins from the neurons just as a sorting machine in an assembly line. The researchers have stated that the VPS35 system goes a long way in protecting health. The VPS35 plays a very important role. It clears the harmful protein tau from the brain. Tau usually accumulates and leads to neurodegenerative disorders, such as Alzheimer's disease. An important function performed by the VPS35 is sorting out and then transporting the dysfunctional proteins to degradation sites. Those people who suffer from Alzheimer disease often have neurons containing defective proteins. Similar is the case/ condition in diseases such as Parkinson's disease and other neurodegenerative diseases. The Tau protein is extremely harmful. It collects in the brain and causes huge harm and damage leading to a condition called tauopathy. As per the previous researchers that have been so far conducted on the same subject, it was noticed that the activity of the VPS35 is reduced in the brains of the Alzheimers patients. The relationship between VPS35 activity and tau accumulation was highly unknown. A team of researchers examined the brain tissue of patients suffering either from progressive supra-nuclear palsy (PSP) or Picks' disease. Various analysis have shown that the PSP and Pick's disease patients had VPS35 levels that were 50 percent lesser as compared to those of the control subjects. When the researchers intentionally changed the VPS35 levels in individual tauopathy-affected neurons in vitro, they observed that they could directly keep a control over tau accumulation, for the first time implicating VPS35 in tauopathy. The VPS35-dependent effect on tau was mediated by the activity of cathepsin D. Cathepsin D is an enzyme that specializes in the phenomenon of protein degradation. Dr. Praticò's team also performed experiments in mice along with tau accumulation. It was found that VPS35 reduction lead to a loss of synaptic integrity between neurons in the animals' brains, significantly damaging neural communication. When tau flows across cells, it is very harmful for synapses, the places where neurons meet and exchange signals. The animals in which the study was carried out,, there was a 40 to 50 percent loss in synaptic connectivity when VPS35 activity was reduced, which caused cognitive and motor deterioration, including losses in memory and learning ability, that is commonly seen in human tauopathy patients."

By: Preeti Narula
Content: https://www.sciencedaily.com/releases/2019/07/190709110222.htm