Gary Bassell, professor of cell biology and neurology at the Emory University School of Medicine in Atlanta, Ga., was awarded an MDA research grant totaling $405,000 over a period of three years to discover new functions of the SMN protein in spinal muscular atrophy (SMA).
SMA occurs when the gene for SMN (survival motor neuron) is mutated, leaving too little SMN protein to perform its normal functions. While some of those functions are known, Bassell expects there are others that have yet to be described.
SMN binds to a molecule in cells called messenger RNA (mRNA), which carries genetic instructions from the nucleus, where they are stored, to the cytoplasm, where they are used to build proteins. Researchers know that SMN interacts with mRNA in the nucleus, but there is also evidence that the two pair up outside the nucleus, in the cytoplasm, as well. Exactly how SMN functions in this role, and exactly where in the cell the pair are located, is unknown.
“Our central hypothesis is that SMN protein plays a critical role in facilitating regulation of mRNA transport in motor neurons,” Bassell says, particularly the long extensions of these cells called axons, which carry nerve impulses to the muscles.
Bassell will use a mouse model of SMA to study the movements of SMN in cells. Using high-resolution fluorescence microscopy and imaging, he will directly visualize those movements within live nerve axons. His goal is to understand the adverse consequences for mRNA regulation when SMN protein is lost.
“We also will use these state-of-the-art methods to investigate whether specific compounds can correct defects in mRNA regulation in motor neurons from SMA mice,” he says, potentially pointing the way for development of new therapies.
Funding for this MDA grant began Feb. 1, 2013.