F-actin-capping proteins bind in a Ca(2+)-independent manner to the fast growing ends of actin filaments (barbed end) thereby blocking the exchange of subunits at these ends. Unlike other capping proteins (such as gelsolin and severin), these proteins do not sever actin filaments (PubMed:2689884). May play a role in the formation of epithelial cell junctions (By similarity). Heterodimer of an alpha and a beta subunit. Component of the WASH complex (By similarity). Belongs to the F-actin-capping protein alpha subunit family.