alpha-Actinin interacts with rapsyn in agrin-stimulated AChR clustering

Mol Brain. 2008 Dec 3;1:18. doi: 10.1186/1756-6606-1-18.


AChR is concentrated at the postjunctional membrane at the neuromuscular junction. However, the underlying mechanism is unclear. We show that α-actinin, a protein known to cross-link F-actin, interacts with rapsyn, a scaffold protein essential for neuromuscular junction formation. α-Actinin, rapsyn, and surface AChR form a ternary complex. Moreover, the rapsyn-α-actinin interaction is increased by agrin, a factor known to stimulate AChR clustering. Downregulation of α-actinin expression inhibits agrin-mediated AChR clustering. Furthermore, the rapsyn-α-actinin interaction can be disrupted by inhibiting Abl and by cholinergic stimulation. Together these results indicate a role for α-actinin in AChR clustering.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinin / metabolism*
  • Agrin / pharmacology*
  • Animals
  • Cluster Analysis
  • HEK293 Cells
  • Humans
  • Mice
  • Muscle Proteins / metabolism*
  • Protein Binding / drug effects
  • Protein Transport / drug effects
  • Receptors, Cholinergic / metabolism*


  • Actn2 protein, mouse
  • Agrin
  • Muscle Proteins
  • Receptors, Cholinergic
  • peripheral membrane protein 43K
  • Actinin