Ca(2+)-dependent actin filament-severing protein that has a regulatory function in exocytosis by affecting the organization of the microfilament network underneath the plasma membrane. In vitro, also has barbed end capping and nucleating activities in the presence of Ca(2+). Severing activity is inhibited by phosphatidylinositol 4,5-bis-phosphate (PIP2) (By similarity). Required for megakaryocyte differentiation, maturation, polyploidization and apoptosis with the release of platelet-like particles (By similarity). Plays a role in osteoclastogenesis (OCG) and actin cytoskeletal organization in osteoclasts (By similarity). Regulates chondrocyte proliferation and differentiation (PubMed:17097081). Inhibits cell proliferation and tumorigenesis. Signaling is mediated by MAPK, p38 and JNK pathways (By similarity). Expressed in the pre-hypertrophic and hypertrophic cartilage of the embryonic growth plate. Up-regulated in pre-hypertrophic and hypertrophic chondrocytes during the embryonic development of long bones. Belongs to the villin/gelsolin family. Truncated C-terminus.