Plays a role in the regulation of cell morphology and cytoskeletal organization. Required in the control of cell shape and migration. Required for developmental angiogenesis (By similarity). In this process, required for microtubule reorganization and for efficient endothelial cell elongation. In quiescent endothelial cells, triggers rearrangement of the actin cytoskeleton, but does not alter microtubule alignement. Interacts with SRGAP2 (via SH3 domain). Enriched in lamellipodia. Expressed in endothelial cells. The DAD domain regulates activation via by an autoinhibitory interaction with the GBD/FH3 domain. This autoinhibition is released upon competitive binding of an activated GTPase. The release of DAD allows the FH2 domain to then nucleate and elongate nonbranched actin filaments (By similarity). Belongs to the formin homology family.