An emerging picture of synapse formation: a balance of two opposing pathways.
The neuromuscular junction (NMJ) is a well-studied chemical synapse and has served as a tractable model system to clarify how synapse formation occurs. Proteins on both the presynaptic and postsynaptic sides collaborate to induce the high-density accumulation of acetylcholine receptors (AChRs) at the NMJ. Two opposing pathways work in this process: A dispersing pathway works through acetylcholine and the AChR, and a clustering pathway works through agrin and the transmembrane tyrosine kinase MuSK. The molecular mechanisms underlying these two signaling cascades are beginning to be understood.
Ono
Fumihito
F
Laboratory of Molecular Physiology, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892, USA. onof@mail.nih.gov
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D006801:Humans; D008954:Models, Biological; D009469:Neuromuscular Junction / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D011950:Receptors, Cholinergic / Q000378:metabolism*; D017978:Receptors, Growth Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
D011950:Receptors, Cholinergic; D017978:Receptors, Growth Factor; C080030:agrin receptor; D020794:Receptor Protein-Tyrosine Kinases; D000109:Acetylcholine