Beta-catenin regulates acetylcholine receptor clustering in muscle cells through interaction with rapsyn.
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.
Zhang
Bin
B
Program of Developmental Neurobiology and Department of Neurology, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia 30912, USA.
Luo
Shiwen
S
Dong
Xian-Ping
XP
Zhang
Xian
X
Liu
Chunming
C
Luo
Zhenge
Z
Xiong
Wen-Cheng
WC
Mei
Lin
L
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*
D009124:Muscle Proteins; D011950:Receptors, Cholinergic; D051176:beta Catenin; C051609:peripheral membrane protein 43K