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. Interacts with MYO10, the interaction is calcium-dependent and essential for MYO10 function in filopodial extension. Expressed in normal mammary, prostate, cervical, and epidermal tissues. It is greatly reduced or undetectable in transformed cells. By TGFB1. Binds four calcium ions. Belongs to the calmodulin family.