AUGUSTA, Ga., Nov. 28 (UPI) -- Without the connection between brain and muscle, humans wouldn't be alive. The ability to walk, talk and breathe relies upon the ability of the human brain to deliver instructions to every muscle in the body.
New research suggests the protein rapsyn is vital to the brain-muscle connection. The revelation promises to shed light on brain-body communication and help scientists understand how diseases like muscular dystrophy come to wreak havoc on muscle control.
According to the new research, rapsyn plays a key role in creating and maintaining a colony of receptors on human muscles -- receptors that field orders form the brain via a neurotransmitter called acetylcholine.
"For precise, efficient synapse function, the receptors have to be extremely highly concentrated at exactly the right place," Lin Mei, a neuroscientist at the Medical College of Georgia at Augusta University, said in a news release.
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Scientists had a general understanding of how neurons from the spinal cord and muscle cells forge biochemical connections during embryonic development. The latest study -- detailed in the journal Neuron -- revealed the unique importance of rapsyn.
In addition to anchoring receptors on muscle cells, rapsyn also encourages the production of additional receptors through a process called neddylation. The protein is an anchor and a catalyst. Neddylation is enabled by a part of rapsyn's structure called RING.
Scientists were surprised when they discovered the activity of RING. Multitalented anchor proteins are rare.
Previous studies have suggested defects in the RING portion of rapsyn's structure result in stillborn babies.
"Fundamentally, it provides a novel mechanism for synapse formation," Mei said. "Translationally, by identifying this novel enzymatic activity, presumably, you could develop a therapeutic way to make it more active."
There are other portions of rapsyn that are still a mystery. Researchers hope additional tests will explain how these substructures influence the protein's functionality.
