L1 dimer:Ankyrin:Spectrin:F-actin spectrin based actin L1 trans-homodimer:Ankyrin L1 linked to actin cytoskeleton by ankyrin Ankyrins are bifunctional linker proteins that tether L1 to the membrane associated, spectrin based actin cytoskeleton. Spectrin is a tetramer of two alpha- and two beta-chains. The spectrin alpha chain has 21 and the beta chain has 16 (conventional beta) or 30 (heavy beta) successive triple helix repeats. At the N-terminus of beta spectrin, there is a pair of CH (calponin homology) domains which together form an actin binding domain, while the triple helical repeats 14-15 bind ankyrin. <br>Interaction with spectrin bound F-actin blocks the mobility of L1 and this immobilization mediates adjacent neuron adhesions. Authored: Garapati, P V, 2008-07-30 10:22:58 Edited: Garapati, P V, 2008-07-30 10:22:58 Pubmed11222639 Pubmed16904324 Pubmed17223356 Reactome Database ID Release 43392751 Reactome, http://www.reactome.org ReactomeREACT_22148 Reviewed: Maness, PF, 2010-02-16