WEST LAFAYETTE – A Purdue University biochemist has determined the function of a gene that when mutated leads to a genetic variation of amyotrophic lateral sclerosis, or Lou Gehrig's disease.
James Clemens, an assistant professor of biochemistry, found that a gene called VAPB is responsible for transporting certain proteins to their proper places along neurons. When the gene is mutated or deleted, these proteins are unable to make it to locations in neurons where their function is critically required.
ALS causes neurons to die, slowly eliminating voluntary muscle control and eventually causing death in about five out of 100,000 people worldwide, according to the National Institutes of Health.
Clemens studied the VAPB gene, which, when mutated, causes a portion of the disease’s genetic versions. Using the fruit fly as a model, his laboratory determined that VAPB is critical to delivering a cell surface receptor called Dscam – Down syndrome cell adhesion molecule – to the neuron’s axons.
Dscam is important for proper neural function. When communication between neurons is disrupted, they undergo programmed cell death. If a neuron dies, it disrupts the signaling chain from the brain to muscles, which results in neurodegenerative diseases, Clemens said.
In experiments using the fruit fly, the loss of the gene eliminated the amount of Dscam found around the axons of neural cells. “We hope that our discovery in fruit flies will ultimately lead to the development of new clinical strategies to detect, treat or prevent ALS,” said Clemens.
His work was funded by the Klingenstein Foundation, the ALS Association and the Canadian Institutes of Health Research.
