TWF2 (Twinfilin 2) was identified by its interaction with the catalytic domain of protein kinase C zeta. It contains an actin binding site and an ATP binding site and is most closely related to twinfilin (PTK9), a conserved actin monomer binding protein. TWF2 is an actin binding protein involved in motile and morphological processes. It inhibits actin polymerization, likely by sequestering G actin. By capping the barbed ends of filaments, it also regulates motility. It seems to play an important role in clathrin mediated endocytosis and distribution of endocytic organelles.