Agrin released by motor neurons induces the aggregation of acetylcholine receptors at neuromuscular junctions

• Published in: Neuron (Cambridge, Mass.) Vol. 8; no. 5; pp. 865 - 868
• Main Authors: Reist, Noreen E., Werle, Michael J., McMahan, U.J.
• Format: Journal Article
• Language: English
• Published: Cambridge, MA Elsevier Inc 01.05.1992; Cell Press
• Subjects: Agrin; Animals; Antibodies; Biological and medical sciences; Cells, Cultured; Chickens; Fundamental and applied biological sciences. Psychology; Macromolecular Substances; Motor Neurons - metabolism; Nerve Tissue Proteins - immunology; Nerve Tissue Proteins - metabolism; Nerve Tissue Proteins - pharmacology; Neuromuscular Junction - drug effects; Neuromuscular Junction - metabolism; Peripheral nervous system. Autonomic nervous system. Neuromuscular transmission. Ganglionic transmission. Electric organ; Rats; Receptors, Cholinergic - metabolism; Vertebrates: nervous system and sense organs; Vertebrata; Mixed cell culture; Cholinergic receptor; Mammalia; Rat; Rodentia; Molecular interaction; Motor neuron; Chicken; Myotube; Aves; Neuromuscular junction
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/0896-6273(92)90200-W

To test the hypothesis that agrin mediates motor neuron-induced aggregation of acetylcholine receptors (AChRs) in skeletal muscle fibers and to determine whether the agrin active in this process is released by motor neurons, we raised polyclonal antibodies to purified ray agrin that blocked its receptor aggregating activity. When the antibodies were applied to chick motor neuron-chick myotube cocultures, they inhibited the formation of AChR aggregates at and near neuromuscular contacts, demonstrating that agrin plays a role in the induction of the aggregates. Rat motor neurons, like chick motor neurons, induce AChR aggregates on chick myotubes. This effect was not inhibited by our antibodies, indicating that, although the antibodies inhibited the activity of chick agrin, they did not have a similar effect on rat agrin. We conclude that agrin released by rat motor neurons induced the chick myotubes to aggregate AChRs.