The Actin-Driven Movement and Formation of Acetylcholine Receptor Clusters

• DOI: 10.1083/jcb.150.6.1321
• Publication Date: 2002-07-26T16:45:41Z
• Authors: Zhengshan Dai; Xiaoyan Luo; Hongbo Xie; H. Benjamin Peng
• Keywords: Agrin; Actin remodeling; Actin-binding protein

A new method was devised to visualize actin polymerization induced by postsynaptic differentiation signals in cultured muscle cells. This entails masking myofibrillar filamentous (F)-actin with jasplakinolide, a cell-permeant F-actin–binding toxin, before synaptogenic stimulation, and then probing assembly fluorescent phalloidin. With this procedure, associated newly acetylcholine receptor (AChR) clustering heparin-binding growth-associated molecule–coated beads agrin observed. The local F-actin that colocalized AChR clusters at bead–muscle contacts, whereas both the cytoskeleton bath application were diffuse. By expressing green protein–coupled version of cortactin, protein binds active F-actin, dynamic nature revealed. In fact, motive force generated propelled entire bead-induced cluster its attached bead move plane membrane. addition, is also necessary for formation agrin-induced as well phosphotyrosine accumulation, shown their blockage latrunculin A, toxin sequesters globular (G)-actin prevents assembly. These results show movement implicate role scaffold structural signaling molecules neuromuscular junction formation.