Enables cytoskeletal protein binding activity and small GTPase binding activity. Acts upstream of or within melanocyte differentiation; melanosome localization; and protein targeting. Located in cytoskeleton and melanosome. Part of unconventional myosin complex. Is expressed in several structures, including genitourinary system; gut; liver; lung; and spleen. Human ortholog(s) of this gene implicated in Griscelli syndrome type 3. Orthologous to human MLPH (melanophilin). [provided by Alliance of Genome Resources, Apr 2022]