Enables actin filament binding activity. Involved in several processes, including bicellular tight junction assembly; positive regulation of pinocytosis; and protein localization to bicellular tight junction. Located in several cellular components, including Z disc; cytoskeleton; and pseudopodium. Is expressed in early conceptus and heart. Used to study focal segmental glomerulosclerosis 1. Human ortholog(s) of this gene implicated in focal segmental glomerulosclerosis and focal segmental glomerulosclerosis 1. Orthologous to human ACTN4 (actinin alpha 4). [provided by Alliance of Genome Resources, Apr 2022]