Ca(2+)-regulated actin-binding protein (By similarity). Binds actin microfilaments (MFs). Involved in actin filament bundling, severing and capping. Caps the barbed end of actin filaments and is able to sever them in a calcium-dependent manner. May regulate cell expansion in developing organs. Required for the regulation of plant architecture via the modulation of polar auxin transport and root gravitropism (PubMed:26486445). Mostly expressed in growing tissues. Malformed organs, including twisted roots and shoots at the seedling stage, mainly caused by asymmetrical expansion of cells on the opposite sides of an organ. Increased dynamic actin cytoskeleton network. Hypersensitive gravitropic response, faster recycling of PIN2, and altered auxin distribution. Belongs to the villin/gelsolin family.