Kinetic Analysis Reveals Differences in the Binding Mechanism of Calmodulin and Calmodulin-Like Protein to the 3 IQ Motifs in Myosin-10

Abstract

Myosin-10 (Myo10) is an unconventional myosin associated with dynamic actin remodeling implicated in a multitude of cellular functions. Like most unconventional myosins, Myo10 binds calmodulin (CaM) as the principal light chain. In epithelial cells Myo10 also binds calmodulin-like protein (CLP) as a tissue-specific light chain, resulting in increased Myo10 levels and Myo10-dependent cell motility. This raises questions as to how CaM and CLP compete for the individual IQ sites on Myo10. Indeed, there is little information on the kinetics of light chain binding to any unconventional myosin.