Clues About Protein
Promising for SMA
Recent reports shed more light on the functions of the survival of motor neuron (SMN) protein and lend support to increasing production from the SMN2 gene as a potential treatment for spinal muscular atrophy (SMA).
A team led by Kay Davies at the University of Oxford (England) found that the protein Brunol3, which belongs to a group of “RNA binding proteins,” is found in the same places in nerve and muscle cells as is SMN, the protein needed but deficient in SMA.
The researchers, who published their findings in the November issue of Neuromuscular Disorders, speculate that the two proteins may work together to help process RNA, the genetic message made from DNA. They also hypothesize that their actions could play a role both in development of the nervous system and in maintaining the connections among cells.
“An understanding of why motor neurons are vulnerable to the lack of SMN in patients will help us devise ways to target an effective treatment for the disease in the future,” Davies says.
In another study, MDA grantees found that people with five copies of the SMN2 gene apparently withstand a total loss of the gene known as SMN1. Until now, researchers thought at least one intact SMN1 gene was necessary to prevent the development of SMA.
MDA grantees Thomas Prior at Ohio State University in Columbus and Kathryn Swoboda at the University of Utah in Salt Lake City report in the Oct. 15 issue of the American Journal of Medical Genetics that even a complete lack of the SMN1 gene doesn’t necessarily lead to SMA if a person has several SMN2 genes.
Previously, it’s been found that people lacking a functioning SMN1 gene but with three or four copies of SMN2 usually develop relatively mild (type 3) SMA, while those with one or two copies develop more severe (type 1 or 2) SMA.
These findings provide additional support for current research that aims to treat SMA by increasing protein production from the SMN2 gene, Prior says. “Now we know how much SMN2 we need -- about five genes’ worth.”
