Filamins are a family of high molecular mass cytoskeletal proteins that organize filamentous actin in networks and stress fibers. Recently it has become clear that filamins anchor various transmembrane proteins to the actin cytoskeleton and provide a scaffold for a wide range of cytoplasmic signaling proteins (1). Actin-binding protein (Filamin A) is a ubiquitous dimeric actin cross-linking phosphoprotein of peripheral cytoplasm, where it promotes orthogonal branching of actin filaments and links actin filaments to membrane glycoproteins (2). The actin-binding domain is near the amino-terminus of the subunit where the amino acid sequence is similar to other actin filament binding proteins, including alpha-actinin, beta-spectrin, dystrophin, and Dictyostelium abp-120. Detection of Filamin A /Fh1 proteins suggests that these presenilin-interacting proteins may be involved in the development of Alzheimer’s disease and that interactions between presenilins and Filamin A /Fh1 may be functionally significant (3).

WB, IHC, ICC