Contributes to actin filament binding activity. Acts upstream of or within barbed-end actin filament capping. Located in several cellular components, including brush border; cell-cell junction; and cortical cytoskeleton. Part of F-actin capping protein complex. Is expressed in early conceptus; head mesenchyme; and lung. Orthologous to human CAPZA1 (capping actin protein of muscle Z-line subunit alpha 1). [provided by Alliance of Genome Resources, Apr 2022]