Formin homology family, Cappuccino subfamily (IPR001265)

Short name: Formin_Cappuccino_subfam

Overlapping homologous superfamilies


Family relationships



Formins (formin homology proteins) proteins play a crucial role in the reorganisation of the actin cytoskeleton and associate with the fast-growing end (barbed end) of actin filaments [PMID: 12775772, PMID: 10631086]. This entry represents the formin homologues from animals (and some fungi), including protein cappuccino from Drosophila melanogaster and formins from human and mouse. Protein cappuccino acts as an actin nucleation factor and promotes assembly of actin filaments together with spir. It may play a role in intracellular vesicle transport along actin fibres, providing a novel link between actin cytoskeleton dynamics and intracellular transport [PMID: 19633175].

Formins are characterised by the presence of three FH domains (FH1, FH2 and FH3), although members of the formin family do not necessarily contain all three domains [PMID: 12538772]. The proline-rich FH1 domain mediates interactions with a variety of proteins, including the actin-binding protein profilin, SH3 (Src homology 3) domain proteins, and WW domain proteins. The FH2 domain is required for the self-association of formin proteins through the ability of FH2 domains to directly bind each other [PMID: 14576350], and may also act to inhibit actin polymerisation [PMID: 14992721]. The FH3 domain (IPR010472) is less well conserved and may be important for determining intracellular localisation of formin family proteins. In addition, some formins can contain a GTPase-binding domain (GBD) (IPR010473) required for binding to Rho small GTPases, and a C-terminal conserved Dia-autoregulatory domain (DAD).

GO terms

Biological Process

GO:0045010 actin nucleation

Molecular Function

GO:0008017 microtubule binding

Cellular Component

GO:0005884 actin filament

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.