Troponin T is capable of binding dystrophin via a leucine zipper

Abstract
Using genetic and physical assays for protein—protein interactions, we identified a fast isoform of troponin T that binds to dystrophin. Troponin T specifically bound to the first of two highly conserved leucine zipper motifs in the carboxy terminus of dystrophin [1,2]. Single amino acid changes in the zipper predicted to disrupt α‐helix formation or cause steric hindrance abolished this binding. These data support the hypothesis that dystrophin couples the contractile apparatus to the sarcolemma and indicate that leucine zipper mediated protein—protein interactions are functionally important in the cytoskeleton as well as the nucleus.