Innovative Review Highlights the Role of Rapsyn in Neuromuscular Junction and Congenital Myasthenic Syndrome

A recent review article titled "The Role of Rapsyn in Neuromuscular Junction and Congenital Myasthenic Syndrome" has been published by researchers from Nanchang University in China. Led by first author Xufeng Liao and senior author Shunqi Wang, the article provides a comprehensive overview of the critical role of Rapsyn in neuromuscular junction (NMJ) and congenital myasthenic syndrome (CMS), with a focus on its essential function in nicotinic acetylcholine receptor (nAChR) clustering.

The neuromuscular junction is a specialized synapse connecting motor neurons and skeletal muscle fibers, facilitating the transmission of action potentials and subsequent muscle contraction. Congenital myasthenic syndrome is a rare genetic disorder that affects the neuromuscular junction, leading to muscle weakness and fatigue. Symptoms can vary from mild to severe, often impacting respiratory muscles.

CMS is associated with mutations in genes involved in NMJ formation and maintenance, including Rapsyn. Rapsyn is an intracellular scaffolding protein crucial for the clustering and maintenance of nicotinic acetylcholine receptors, essential for muscle contractions. Initially isolated from the Torpedo electric organ and named Torpedo43K protein, it has been found to have a broader role beyond skeletal muscle-derived cells and nAChR clustering, potentially impacting GABAA receptors or AchR.

The review highlights a significant finding that Rapsyn is expressed not only in muscle cells but also in non-muscle cells, tightly associated with cytoplasmic membranes. This suggests that the protein's function extends beyond its role in NMJ and nAChR clustering, potentially influencing other receptors.

Furthermore, the authors discuss the implications of Rapsyn mutations for CMS patients, as well as the potential function of Rapsyn in the central nervous system (CNS). Notably, patients with CMS due to Rapsyn mutations have shown remarkable responses to anticholinesterase drugs, such as pyridostigmine, and sometimes additional treatments have led to significant clinical improvement. The review also explores potential functions of Rapsyn in the peripheral nervous system (PNS), offering new avenues for future research on Rapsyn's role in various neurological conditions.

This innovative review expands our understanding of Rapsyn's role in the nervous system and its implications for neuromuscular and neurological disorders. As research continues to unravel the complexity of Rapsyn's functions, it holds the promise of contributing to the development of more effective treatments for a wide range of neuromuscular and neurological conditions.

More information:
Liao X, Wang Y, Lai X, Wang S. The role of Rapsyn in neuromuscular junction and congenital myasthenic syndrome. Biomol Biomed [Internet]. 2023Feb.20 [cited 2023May19];. Available from: www.bjbms.org/ojs/index.php/bj … ms/article/view/8641

Provided by Association of Basic Medical Sciences of FBIH