Regulation of calmodulin-binding myosins.

Myosins constitute a diverse superfamily of actin-based mechanoenzymes that are involved in many essential cellular motilities. In addition to conventional muscle myosin II, ten other classes of unconventional myosins are known. Many unconventional myosins bind multiple calmodulin light chains and Ca2+, which can dramatically alter their mechanochemical and enzymatic activity. Calmodulin-binding myosins can also be regulated by phospholipid binding, phosphorylation of the heavy chain and actin-binding proteins. The molecular details linking unconventional-myosin regulation and function are just beginning to emerge.