Organization of the Arp2/3 complex in hippocampal spines.
Changes in the morphology of a dendritic spine require remodeling of its actin-based cytoskeleton. Biochemical mechanisms underlying actin remodeling have been studied extensively, but little is known about the physical organization of the actin-binding proteins that mediate remodeling in spines. Long-term potentiation-inducing stimuli trigger expansion of the spine head, suggesting local extension and branching of actin filaments. Because filament branching requires the Arp2/3 complex, we used quantitative immunoelectron microscopy to elucidate the organization of ARPC-2 (Arp2/3 complex subunit 2), an essential component of the complex. Our data from CA1 hippocampus indicate that Arp2/3 concentrates within spines in a previously unrecognized torroidal domain, apparently specialized to mediate actin filament branching.
Department of Anatomy and Histology, Faculty of Veterinary Science, Szent István University, 1078 Budapest, Hungary. racz.bence@aotk.szie.hu
Bence
B
Rácz
Richard J
RJ
Weinberg
D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism*; D000818:Animals; D049229:Dendritic Spines / Q000378:metabolism* / Q000648:ultrastructure*; D006624:Hippocampus / Q000648:ultrastructure*; D008856:Microscopy, Fluorescence / Q000379:methods; D008959:Models, Neurological; D051381:Rats; D017207:Rats, Sprague-Dawley
D051376:Actin-Related Protein 2-3 Complex