Here, we aimed to elucidate the mechanisms underlying the interplay and possible synergy between these two cytoskeletal components in cardiomyopathy caused by mutations in LMNA. We show that cofilin-1 phosphorylated on T25 binds to MRTF-A in the cytoplasm in muscle cells expressing LMNA mutations. Here, LMNA is linked to cardiomyopathy.