MmuEX0030525 @ mm9

Microexon B constitutes an essential part of the DYNLL2 binding site. A brain-specific isoform in which exon B is skipped can no longer interact with DYNLL2. These data show that alternative splicing of the myosin Va heavy chain controls DYNLL2-myosin Va interaction and that DYNLL2 binding alters the structure of a portion of the myosin's coiled-coil domain. These results suggest that exon B could have a significant impact on the conformation and regulatory folding of native myosin Va, as well as on its interaction with certain cargos.

DLC2 was found to bind as a homodimer to a approximately 15 residue segment (Ile1280-Ile1294) localized between the medial and distal coiled-coil domains of the tail of MYO5A. The binding region contains the three residues coded by the alternatively spliced microexon B (Asp1284-Lys1286). Removal of microexon B eliminates DLC2 binding. Co-localization experiments in a transfected mammalian cell line confirm the finding that exon B is essential for DLC2 binding.