Plays a role in the cell cycle. Involved in cytokinesis. Component of the cell division ring. In the absence of profilin, caps the barbed end of actin filaments, thus preventing subunit addition and dissociation. In the presence of profilin, nucleates actin filaments that grow rapidly from their barbed ends. Interacts with profilin and actin at the FH1 and FH2 domains respectively. Nuclear, and septum. Belongs to the formin homology family. BNI1 subfamily.