title: A mechanism for acetylcholine receptor clustering distinct from agrin signaling.
abstract: Acetylcholine receptors (AChRs) and other postsynaptic molecules cluster spontaneously on cultured C2 myotubes. The frequency of clustering is enhanced by neural agrin, neuraminidase, or calcium through a signaling pathway which includes tyrosine phosphorylation of a muscle-specific kinase (MuSK) and the AChR beta-subunit. Vicia villosa agglutinin (VVA) lectin, previously shown to potentiate agrin-induced clustering on C2 myotubes, is shown here to also potentiate neuraminidase- and calcium-induced clustering of AChRs, while having no effect on the level of tyrosine phosphorylation of MuSK or the AChR beta-subunit. We propose that VVA lectin increases the frequency of AChR clustering through a mechanism that is distinct from agrin signaling, and that may involve alpha-dystroglycan.
authors.affiliation: Department of Cell Biology and Anatomy, College of Medicine, University of Arizona, Tucson, AZ, USA. wgrow@online.emich.edu
authors.forename: W A
authors.initials: WA
authors.lastname: Grow
authors.forename: M
authors.initials: M
authors.lastname: Ferns
authors.forename: H
authors.initials: H
authors.lastname: Gordon
mesh_terms: D018171:Agrin / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000378:metabolism; D049030:Dystroglycans; D007797:Laminin / Q000378:metabolism; D037102:Lectins / Q000378:metabolism / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000737:chemistry / Q000166:cytology / Q000201:enzymology; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D009439:Neuraminidase / Q000494:pharmacology; D009469:Neuromuscular Junction / Q000737:chemistry* / Q000166:cytology / Q000201:enzymology; D010766:Phosphorylation; D037121:Plant Lectins; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000032:analysis* / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D014443:Tyrosine / Q000378:metabolism
chemical_list: D018171:Agrin; D003598:Cytoskeletal Proteins; C483081:DAG1 protein, human; D007797:Laminin; D037102:Lectins; D008562:Membrane Glycoproteins; D037121:Plant Lectins; D011950:Receptors, Cholinergic; C042242:Vicia lectins; D049030:Dystroglycans; D014443:Tyrosine; C095714:MUSK protein, human; D020794:Receptor Protein-Tyrosine Kinases; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid; D002118:Calcium