Filamin A, alpha (FLNA) is a protein that in humans is encoded by the FLNA gene. Function Actin-binding protein, or filamin, is a 280-kD protein that crosslinks actin filaments into orthogonal networks in cortical cytoplasm and participates in the anchoring of membrane proteins for the actin cytoskeleton. Remodeling of the cytoskeleton is central to the modulation of cell shape and migration. Filamin A, encoded by the FLNA gene, is a widely expressed filamin that regulates the reorganization of the actin cytoskeleton by interacting with integrins, transmembrane receptor complexes, and secondary messengers. At least 31 disease-causing mutations in this gene have been discovered. Structure The protein structure includes an actin binding N terminal domain, 24 internal repeats and 2 hinge regions. Interactions Filamin has been shown to interact with: BRCA2, CD29 CASR, FBLIM1, FILIP1, FLNB, NPHP1, RALA, SH2B3, TRIO, and VHL. RNA editing The edited residue was previously recorded as a single nucleotide polymorphism(SNP) in dbSNP. Type A to I RNA editing is catalyzed by a family of adenosine deaminases acting on RNA (ADARs) that specifically recognize adenosines within double-stranded regions of pre-mRNAs and deaminate them to inosine. Inosines are recognised as guanosine by the cells translational machinery. There are three members of the ADAR family ADARs 1-3 with ADAR 1 and ADAR 2 being the only enzymatically active members.ADAR3 is thought to have a regulatory role in the brain. ADAR1 and ADAR 2 are widely expressed in tissues while ADAR 3 is restricted to the brain. The double stranded regions of RNA are formed by base-pairing between residues in a region complementary to the region of the editing site. This complementary region is usually found in a neighbouring intron but can also be located in an exonic sequence. The region that base pairs with the editing region is known as an Editing Complentary Sequence (ECS). Site The one editing site of FLNA pre-mRNA is located within amino acid 2341 of the final protein. The Glutamine (Q) codon is altered due to a site specific deamination of an adenosine at the editing site to an Arginine (R) codon. The editing region is predicted to form a double stranded region of 32 base pairs in length with a complementary sequence about 200 nucleotides downstream of the editing site. This ECS is found in an intronic sequence. Editing at the Q/R site is likely to involve both ADAR1 and ADAR2.Mice ADAR2 knockouts show