Alternative Names
ABP 278; ABP 280 homolog; ABP-278; ABP-280 homolog; ABP278; Actin binding like protein; Actin binding protein 278; Actin-binding-like protein; AOI; Beta filamin; Beta-filamin; DKFZp686A1668; DKFZp686O033; Fh1; Filamin 1 actin binding protein 280 like; Filamin 3; Filamin B; Filamin B beta actin binding protein 278; Filamin homolog 1; Filamin-3; Filamin-B; FLN B; FLN-B; FLN1L; FLN3; FLNB; FLNB_HUMAN; LRS1; SCT; TABP; TAP; Thyroid autoantigen; Truncated ABP; Truncated actin binding protein; Truncated actin-binding protein
Protein Function
Connects cell membrane constituents to the actin cytoskeleton. May promote orthogonal branching of actin filaments and links actin filaments to membrane glycoproteins. Anchors various transmembrane proteins to the actin cytoskeleton. Interaction with FLNA may allow neuroblast migration from the ventricular zone into the cortical plate. Various interactions and localizations of isoforms affect myotube morphology and myogenesis. Isoform 6 accelerates muscle differentiation in vitro.
Tissue Specificity
Ubiquitous. Isoform 1 and isoform 2 are expressed in placenta, bone marrow, brain, umbilical vein endothelial cells (HUVEC), retina and skeletal muscle. Isoform 1 is predominantly expressed in prostate, uterus, liver, thyroid, stomach, lymph node, small intestine, spleen, skeletal muscle, kidney, placenta, pancreas, heart, lung, platelets, endothelial cells, megakaryocytic and erythroleukemic cell lines. Isoform 2 is predominantly expressed in spinal cord, platelet and Daudi cells. Also expressed in thyroid adenoma, neurofibrillary tangles (NFT), senile plaques in the hippocampus and cerebral cortex in Alzheimer disease (AD). Isoform 3 and isoform 6 are expressed predominantly in lung, heart, skeletal muscle, testis, spleen, thymus and leukocytes. Isoform 4 and isoform 5 are expressed in heart.
Involvement in Disease
Interaction with FLNA may compensate for dysfunctional FLNA homodimer in the periventricular nodular heterotopia (PVNH) disorder. Defects in FLNB are the cause of atelosteogenesis type 1 (AO1), atelosteogenesis type 3 (AO3), boomerang dysplasia (BOOMD), Larsen syndrome (LRS), spondylocarpotarsal synostosis syndrome (SCT).
