MyTH4-FERM myosins have an ancient and conserved role in filopod formation

Significance

Filopodia are actin-based structures used by cells to sense chemical stimuli and promote adhesion to the extracellular environment during the development of multicellular organisms. Filopod formation in evolutionarily distant organisms requires MyTH4-FERM (myosin tail homology 4-band 4.1, ezrin, radixin, moesin; MF) myosins that consist of a motor domain paired with a tail domain that binds cytoskeletal and membrane proteins. Mutational analysis identified the minimal requirements for MF myosin function in filopod formation and revealed that the key features are conserved between amoebozoan and metazoan MF myosins. These findings have implications for understanding the fundamental principles of how filopodia form and how MF myosins function in phylogenetically distant organisms.