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. Plays a role in the regulation of cell morphology and cytoskeletal organization (By similarity). Heterodimer of an alpha and a beta subunit. Interacts with ARHGAP17 and RCSD1/CAPZIP. Component of the WASH complex, composed of F-actin-capping protein subunit alpha (CAPZA1, CAPZA2 or CAPZA3), F-actin-capping protein subunit beta (CAPZB), WASH (WASHC1, WASH2P, WASH3P, WASH4P, WASH5P or WASH6P), WASHC2 (WASHC2A or WASHC2C), WASHC3, WASHC4 and WASHC5. Interacts with ACTG1. Directly interacts with CRACD; this interaction decreases binding to actin (By similarity). Belongs to the F-actin-capping protein beta subunit family.