Bar diagrams showing the overall architectures of human myosins discussed in this review. All the myosins have conserved motor heads (blue), different numbers of IQ motifs (gray) followed by a distinct tails with various functional domains. Colored boxes represent different regions predicted by sequence homology: PH, pleckstrin homology domain; TH1, TH2, and TH3, tail homology region 1, 2, and 3; CC, coiled-coil domains; GTD, globular tail domain; CBD, cargo binding domain; SH3, Src-homology 3 domain. Myosin-Va, and myosin-X exist as constitutive dimers and myosin-VI may exist in both monomeric and dimeric forms.