“…Synemin is present in two alternatively spliced forms, ␣ and . Previous studies revealed synemin at different subcellular locations in cardiac and skeletal muscle, neurons, and glial cells (18,21,25,28,31) and showed that synemin interacts with several other proteins, including desmin, vimentin, ␣-actinin, and vinculin (14,20,21,25), which all bind to the  isoform, with additional binding sites for vinculin and talin on ␣-synemin (26,27). Here we test the hypothesis that both isoforms of synemin are expressed in the developing heart and that each isoform associates with and differentially stabilizes distinct structures in cardiomyocytes.…”