Predicted to enable SH3 domain binding activity and actin filament binding activity. Involved in negative regulation of cytoskeleton organization. Acts upstream of or within locomotory behavior; parallel actin filament bundle assembly; and positive regulation of filopodium assembly. Located in actin cytoskeleton; brush border; and stereocilium. Is active in stereocilium tip. Is expressed in organ of Corti; seminiferous tubule; and seminiferous tubule epithelium. Human ortholog(s) of this gene implicated in autosomal recessive nonsyndromic deafness 36. Orthologous to human ESPN (espin). [provided by Alliance of Genome Resources, Apr 2022]