MYL2 regulatory light chain is associated with cardiac myosin beta （or slow） heavy chain. Ca+ activates the phosphorylation of regulatory light chain that in turn activates contraction. Mutations in this MYL2 gene are related with mid-left ventricular chamber type hypertrophic cardiomyopathy. MYL2 is an essential protein that plays a role in the regulation of myosin ATPase activity in smooth muscle. MYL2 phosphorylation is regulated by ROCK and MLC kinase and is involved in platelet biogenesis by controlling proplatelet formation and fragmentation.
