Electron microscopy and 3D reconstruction reveals filamin Ig domain binding to F-actin.

ABSTRACT: Filamin A (FLNa) is an actin-binding protein that cross-links F-actin into networks of orthogonally branched filaments. FLNa also directs the networks to integrins while responding to mechanochemical signaling pathways. Flexible, 160-nm-long FLNa molecules are tail-to-tail dimers, each subunit of which contains an N-terminal calponin homology (CH)/actin-binding domain connected by a series of 24 immunoglobulin (Ig) repeats to a dimerization site at their C-terminal end. Whereas the contribution of the CH domains to F-actin affinity is weak (apparent K(a)~10(5)), the binding of the intact protein to F-actin is strong (apparent K(a)~10(8)), suggesting involvement of additional parts of the molecule in this association. Indeed, previous results indicate that Ig repeats along FLNa contribute s

SUBMITTER: Suphamungmee W 

PROVIDER: S-EPMC3502691 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature