Cell membrane-cytoskeleton-associated protein that plays a role in the regulation of actin polymerization at the barbed end of actin filaments. Prevents F-actin heterodimeric capping protein (CP) activity at the leading edges of migrating cells, and hence generates uncapped barbed ends and enhances actin polymerization, however, seems unable to nucleate filaments (PubMed:16054028). Plays a role in lamellipodial protrusion formations and cell migration (PubMed:19846667). Homodimer (PubMed:19846667). Interacts (via C-terminus) with heterodimer capping protein (CP); this interaction uncaps barbed ends capped by CP, enhances barbed-end actin polymerization and promotes lamellipodial formation and cell migration (By similarity). Interacts with heterodimer capping protein (CP) (PubMed:19846667). Interacts with MYO1E (PubMed:19846667). Interacts with TRIO (PubMed:19846667). Found on macropinosomes (PubMed:19846667). Colocalized with heterodimeric capping protein (CP) and F-actin in lamellipodia but not with F-actin in stress fibers (PubMed:19846667). Expressed in lung, placenta, small intestine, liver, thymus, colon, skeletal muscle, heart and brain. Higher expression in kidney. The C-terminus is necessary for localization to the cell membrane (PubMed:26578515). Belongs to the CARMIL family.