Format

Send to

Choose Destination
Curr Biol. 2008 Jan 22;18(2):109-15. doi: 10.1016/j.cub.2007.12.029.

Acetylcholine receptor clustering is required for the accumulation and maintenance of scaffolding proteins.

Author information

1
Department of Molecular, Cellular, and Developmental Biology and Program in Neuroscience, University of Michigan, Ann Arbor, Michigan 48109, USA.

Abstract

The maintenance of a high density of postsynaptic receptors is essential for proper synaptic function. At the neuromuscular junction, acetylcholine receptor (AChR) aggregation is induced by nerve-clustering factors and mediated by scaffolding proteins. Although the mechanisms underlying AChR clustering have been extensively studied, the role that the receptors themselves play in the clustering process and how they are organized with scaffolding proteins is not well understood. Here, we report that the exposure of AChRs labeled with Alexa 594 conjugates to relatively low-powered laser light caused an effect similar to chromaphore-assisted light inactivation (CALI) , which resulted in the unexpected dissipation of the illuminated AChRs from clusters on cultured myotubes. This technique enabled us to demonstrate that AChR removal from illuminated regions induced the removal of scaffolding proteins and prevented the accumulation of new AChRs and associated scaffolding proteins. Further, the dissipation of clustered AChRs and scaffold was spatially restricted to the illuminated region and had no effect on neighboring nonilluminated AChRs. These results provide direct evidence that AChRs are essential for the local maintenance and accumulation of intracellular scaffolding proteins and suggest that the scaffold is organized into distinct modular units at AChR clusters.

PMID:
18207744
DOI:
10.1016/j.cub.2007.12.029
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center