Calcium-sensitive protein which reversibly blocks the barbed ends of actin filaments but does not sever preformed actin filaments. May play an important role in macrophage function. May play a role in regulating cytoplasmic and/or nuclear structures through potential interactions with actin. May bind DNA. Interacts with NUP62 (PubMed:18266911). Interacts with NUTF2 and RAN; involved in CAPG nuclear import (PubMed:18266911). In macrophages, may be predominantly cytoplasmic. Nuclear localization was observed in fibroblasts. In macrophages, present at the membrane-cytoplasm interface. In activated macrophages, concentrated in the ruffles of the leading lamellipodia. Macrophages and macrophage-like cells. The N-terminus is blocked. Belongs to the villin/gelsolin family. This protein was originally thought to be a DNA-binding protein with a helix-loop-helix domain.