Myosin Light Chain 6B （MYL6B） is a heavy chain regulator located in smooth muscle and non-muscle Myosin complexes. Contractile activity in the smooth muscle is regulated by the calcium/calmodulin-dependent phosphorylation of Myosin light chain by Myosin light chain kinase. MYL6B doesn’t bind calcium during contraction. MYL6B is mostly found as a hexamer consisting of 4 light chains and 2 heavy chains. MYL6B usually interacts with Myosin Va， an Actin based motor which moves in large steps. MYL6B is expressed in the majority of tissues with neurons， while smooth muscle tissue having the highest expression.
