May function as a specific light chain of unconventional myosin-10 (MYO10), also enhances MYO10 translation, possibly by acting as a chaperone for the emerging MYO10 heavy chain protein. May compete with calmodulin by binding, with different affinities, to cellular substrates (By similarity). Interacts with MYO10, the interaction is calcium-dependent and essential for MYO10 function in filopodial extension. Binds four calcium ions. Belongs to the calmodulin family.