Researchers from Nanchang University in China have published a review article titled “The Role of Rapsyn in Neuromuscular Junction and Congenital Myasthenic Syndrome” in the Biomolecules and Biomedicine. This review article, led by first author Xufeng Liao and senior author Shunqi Wang, provides a comprehensive overview of the critical role of Rapsyn in neuromuscular junction (NMJ) and congenital myasthenic syndrome (CMS), focusing on its essential function in nicotinic acetylcholine receptor (nAChR) clustering.
The neuromuscular junction (NMJ) is a specialized synapse connecting the motor neuron and skeletal muscle fiber, allowing for the transmission of action potentials and subsequent muscle contraction. Congenital myasthenic syndrome (CMS) is a rare genetic disorder that affects the NMJ and leads to muscle weakness and fatigue. The disorder can occur at any age and symptoms can vary from mild to severe, often affecting the respiratory muscles.
CMS is caused by mutations in several genes involved in the formation and maintenance of NMJ. These include Rapsyn – an intracellular scaffolding protein that plays a critical role in the clustering and maintenance of nicotinic acetylcholine receptors, which are essential for muscle contractions. It was first isolated from the Torpedo electric organ and named Torpedo43K protein because of its molecular weight.
A key finding of the review is that Rapsyn is not only expressed in muscle cells but also in non-muscle cells, and is tightly associated with cytoplasmic membranes. This indicates that the protein’s function extends beyond skeletal muscle-derived cells and nAChR clustering, potentially affecting GABAA receptor or AchR.
In addition to its role in NMJ formation and maintenance, the authors discuss the implications of Rapsyn mutations for CMS patients. The researchers also discuss the possible function of Rapsyn in the central nervous system (CNS), as patients with CMS due to the Rapsyn mutation respond remarkably to anticholinesterase drugs such as pyridostigmine, and sometimes the addition of 3,4 DAP, ephedrine or albuterol leads to significant clinical improvement. The review also delves into the potential functions of Rapsyn in the peripheral nervous system (PNS). This opens up new avenues for future research on Rapsyn’s role in various neurological conditions, and as our understanding of Rapsyn’s role in the nervous system expands, it will undoubtedly contribute to the development of more effective treatments for a range of neuromuscular and neurological disorders.
For more information on this innovative review, visit the Biomolecules and Biomedicine website.
先天性肌无力综合症是由多种参与神经肌肉连接形成和维护的基因突变引起的。其中包括Rapsyn – 一种细胞内支架蛋白，在尼古丁乙酰胆碱受体的聚集和维护中发挥关键作用，这些受体对于肌肉收缩至关重要。它最初是从电鳐电器官中分离出来的，并因其分子量而被命名为“Torpedo43K蛋白”。