Actin binding protein that promotes orthogonal branching of actin filaments and links actin filaments to membrane glycoproteins. Anchors various transmembrane proteins to the actin cytoskeleton and serves as a scaffold for a wide range of cytoplasmic signaling proteins (By similarity). Interaction with FLNB may allow neuroblast migration from the ventricular zone into the cortical plate. Tethers cell surface-localized furin, modulates its rate of internalization and directs its intracellular trafficking. Involved in ciliogenesis. Plays a role in cell-cell contacts and adherens junctions during the development of blood vessels, heart and brain organs (PubMed:17172441). Plays a role in platelets morphology through interaction with SYK that regulates ITAM- and ITAM-like-containing receptor signaling, resulting in by platelet cytoskeleton organization maintenance (PubMed:20713593). During the axon guidance process, required for growth cone collapse induced by SEMA3A-mediated stimulation of neurons (PubMed:25358863). Homodimer. Interacts with FCGR1A, FLNB, FURIN, HSPB7, KCND2, INPPL1, MYOT, MYOZ1, PDLIM2, ARHGAP24, PSEN1, PSEN2 and ECSCR. Interacts also with various other binding partners in addition to filamentous actin. Interacts (via N-terminus) with TAF1B. Interacts (via N-terminus) with MIS18BP1 (via N-terminus) (By similarity). Interacts with TMEM67 (via C-terminus) and MKS1 (By similarity). Interacts (via actin-binding domain) with MICALL2 (via calponin-homology (CH) domain). Interacts with RFLNA and RFLNB (PubMed:24436304, PubMed:21709252). Interacts (via filamin repeat 5) with SYK; docks SYK to the plasma membrane. Interacts (via filamin repeats 19 and 21) with DRD3; increased PKA-mediated phosphorylation at Ser-2152. Interacts (via filamin repeat 21) with MAS1, AGTR1 and ADRA1D; increases PKA-mediated phosphorylation of FLNA at Ser-2152. Interacts (via filamin repeats 4, 9, 12, 17, 19, 21, and 23) with GP1BA (high affinity), ITGB7, ITGB2 and FBLIM1 (By similarity). Interacts with CEACAM1 (via cytoplasmic domain); inhibits cell migration and cell scattering by interfering with the interaction between FLNA and RALA (By similarity). Interacts with FOXC1 (By similarity). Interacts (via calponin-homology (CH) domain 1 and filamin repeat 24) with CRMP1; the interaction alters FLNA ternary structure and thus promotes FLNA dissociation from F-actin (By similarity). Interacts with DPYSL3/CRMP3 and DPYSL4/CRMP4 (By similarity). Colocalizes with CPMR1 in the central region of DRG neuron growth cone (PubMed:25358863). Following SEMA3A stimulation of DRG neurons, colocalizes with F-actin (PubMed:25358863). Widely expressed. Highly expressed in Purkinje cells. Widely distributed (PubMed:11807098). Expressed at 12.5 dpc in the ventricular and subventricular zones. Highly expressed at 16 dpc in blood vessels, renal cortices, respiratory and alimentary tracts, olfactory epithelium, presumed isles of hematopoiesis within the liver; lower expression in the cerebral cortex and choroid plexus (PubMed:11807098). In 12 dpc embryos, expressed in DRG neurons, motoneurons and the neuroepithelial cell layer around the central canal in spinal cord (PubMed:25358863). Comprised of a NH2-terminal actin-binding domain, 24 immunoglobulin-like internally homologous repeats and two hinge regions. Repeat 24 and the second hinge domain are important for dimer formation. Filamin repeat 20 interacts with filamin repeat 21 masking the ligand binding site on filamin repeat 21, resulting in an autoinhibited conformation. The autoinhibition can be relieved by ligands like ITGB7 or FBLIM1. Filamin repeats 19 and 21 can simultaneously engage ligands. Phosphorylation at Ser-2152 is negatively regulated by the autoinhibited conformation of filamin repeats 19-21. Ligand binding induces a conformational switch triggering phosphorylation at Ser-2152 by PKA. Polyubiquitination in the CH1 domain by a SCF-like complex containing ASB2 leads to proteasomal degradation. Prior dissociation from actin may be required to expose the target lysines. Ubiquitinated in endothelial cells by RNF213 downstream of the non-canonical Wnt signaling pathway, leading to its degradation by the proteasome. Female heterozygous knockout mice show normal development, but 20% die in the first 3-4 months with many anomalies, including lung edema and emphysema, liver thrombi and necrosis, leukocytosis, and heart dilation. Some females die after birth; only about 50% of expected female heterozygous mice are observed at weaning. Male hemizygous knockout mice die by embryonic day 14.5 dpc with vascular defects; their blood vessels are coarse and dilated and extend aberrant branches and sprouts into somitic tissues. Male hemizygous knockout mice display severe cardiac structural defects involving ventricles, atria, and outflow tracts. Conditional Flna knockout males, in the neural crest, survive until birth but die on the first postnatal day with cyanosis; all males show abnormal cardiac outflow tracts (PubMed:17172441). Female heterozygous knockout mice present a mild thrombocytopenia and conditional Flna knockout males, in platelets display a macrothrombocytopenia (PubMed:20713593). May be due to an intron retention. Belongs to the filamin family. Truncated N-terminus. Truncated N-terminus.