title: Beta-catenin regulates acetylcholine receptor clustering in muscle cells through interaction with rapsyn.
abstract: Agrin is believed to be a factor used by motoneurons to direct acetylcholine receptor (AChR) clustering at the neuromuscular junction. However, exactly how agrin mediates this effect remains unclear. Here we demonstrate that the beta-catenin interacts with rapsyn, a molecule key for AChR clustering. Agrin stimulation increases the association of beta-catenin with surface AChRs. Suppression of beta-catenin expression inhibited agrin-induced AChR clustering, suggesting a necessary role of beta-catenin in this event. The beta-catenin action did not appear to require the function of T-cell factors (TCFs), suggesting a mechanism independent of TCF-mediated transcription. In contrast, prevention of beta-catenin from interacting with alpha-catenin attenuated agrin-induced AChR clustering. These results suggest that beta-catenin may serve as a link between AChRs and alpha-catenin-associated cytoskeleton, revealing a novel function of beta-catenin in synaptogenesis.
authors.affiliation: Program of Developmental Neurobiology and Department of Neurology, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia 30912, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Shiwen
authors.initials: S
authors.lastname: Luo
authors.forename: Xian-Ping
authors.initials: XP
authors.lastname: Dong
authors.forename: Xian
authors.initials: X
authors.lastname: Zhang
authors.forename: Chunming
authors.initials: C
authors.lastname: Liu
authors.forename: Zhenge
authors.initials: Z
authors.lastname: Luo
authors.forename: Wen-Cheng
authors.initials: WC
authors.lastname: Xiong
authors.forename: Lin
authors.initials: L
authors.lastname: Mei
mesh_terms: D000818:Animals; D002460:Cell Line; D002642:Chick Embryo; D051379:Mice; D009046:Motor Neurons / Q000378:metabolism / Q000502:physiology; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D032446:Myoblasts / Q000166:cytology / Q000502:physiology*; D009469:Neuromuscular Junction / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D011940:Receptor Aggregation / Q000502:physiology; D011950:Receptors, Cholinergic / Q000502:physiology*; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
chemical_list: D009124:Muscle Proteins; D011950:Receptors, Cholinergic; D051176:beta Catenin; C051609:peripheral membrane protein 43K