Filamin-B

Filamin-B (FLNB) is a cytoskeletal linker protein of 2602 amino acids that connects cell membrane constituents to the actin cytoskeleton, promotes orthogonal branching of actin filaments, and anchors transmembrane proteins (UniProt: O75369). It plays roles in neuronal migration through interaction with Filamin-A and influences myotube morphology and myogenesis through various isoforms. The protein is primarily associated with skeletal dysplasias including Atelosteogenesis, Larsen syndrome, and Boomerang dysplasia, reflecting its structural importance in bone and cartilage development.

Filamin-B has been identified as upregulated in Alzheimer's Disease brain tissue (Chaparral AD proteomics). Analysis of post-mortem AD brain versus age-matched controls using quantitative proteomics detected increased Filamin-B levels with a mean log₂ fold-change of 0.89 across one measured subcellular fraction. This elevation suggests potential involvement in cytoskeletal reorganization or compensatory mechanisms accompanying neurodegeneration in AD pathology, though the functional significance of increased Filamin-B in disease progression requires further investigation.