One of the most abundant Myosin proteins in human cells. Myosin one is found in the form of a monomer because its heavy chain lacks Myosin II and Myosin 5's alpha-helical sequences) with a head that binds actin. The light chains (in the neck region) of Myosin I and Myosin 5 are known as calmodulin which allows myosin I, like all other Myosins, to be calcium regulated. Function of mysoin I is similar to that of Myosin 5.

A test called filament sliding is often performed with Myosin I.
