Myosin II is a motor protein found in the cytoskeleton in the cytoplasm of cells. It is responsible for enpowering actin to contract.
In "A quantitative analysis of contractility in active cytoskeletal protein networks" by Weitz et al. Show the role of myosin in actin contraction. It was shown that without appropriate amounts of <math>alpha</math>-actinin, myosin cannot produce contraction.