American researchers have discovered a molecular switch to prevent Huntington's disease from developing in mice.
The study carried out by scientists from UCLA has appeared in the December 24 edition of the journal Neuron.
The neurodegenerative genetic disorder impairs the ability of patients to walk, speak, think clearly and swallow. Parents often pass on the disease to their offspring.
Huntington's is triggered off by a mutation in the polyglutamine (polyQ) region of huge protein called huntingtin.
Since huntingtin is everywhere in the body, it is extremely difficult to to analyse the mechanism of the mutant protein.
Senior author X. William Yang, associate professor of psychiatry and biobehavioral sciences at the Semel Institute of Neuroscience and Human Behavior at UCLA, said: "It's unclear how the mutant protein causes age-related and progressive loss of brain cells in patients with Huntington's disease.
"We explored whether regions of the protein besides the polyQ mutation play a role in the development of the disorder."
Collaborators Joan Steffan and Leslie Thompson, of the University of California, Irvine, proved that two amino acids near the beginning of the huntingtin protein can be chemically modified by phosphorylation by which cells control protein function after the proteins are formed.
To find if phosphorylation could affect Huntington's disease in a living animal, Yang's lab experimented on mice to carry the polyQ HD mutation and modified the two amino acids in two different ways. First to mimic phosphorylation and the other to prevent it.
Yang said: "Our study identified a critical molecular switch which lies next to the polyQ mutation in the huntingtin protein.
"We were surprised to find that subtle modification of only two amino acids in this very large protein can prevent the onset of disease."