Motor protein that may participate in process critical to neuronal development and function such as cell migration, neurite outgrowth and vesicular transport. Prominent expression is seen in the brain, lung and liver. It is also expressed in the heart and testis. A high level expression is seen in virtually all neurons (but not glia) in the postnatal and adult mouse brain and in neuroblasts of the cerebellar external granular layer. Belongs to the TRAFAC class myosin-kinesin ATPase superfamily. Myosin family. Represents an unconventional myosin. This protein should not be confused with the conventional myosin-1 (MYH1).