Ezrin, moesin, and radixin are highly related proteins (ERM protein family), but the other proteins in which the FERM domain is found do not share any region of similarity outside of this domain. ERM proteins are made of three domains, the FERM domain, a central helical domain and a C-terminal tail domain, which binds F-actin. The amino-acid sequence of the FERM domain is highly conserved among ERM proteins and is responsible for membrane association by direct binding to the cytoplasmic domain or tail of integral membrane proteins. ERM proteins are regulated by an intramolecular association of the FERM and C-terminal tail domains that masks their binding sites for other molecules. For cytoskeleton-membrane cross-linking, the dormant molecules becomes activated and the FERM domain attaches to the membrane by binding specific membrane proteins, while the last 34 residues of the tail bind actin filaments. Aside from binding to membranes, the activated FERM domain of ERM proteins can also bind the guaninenucleotide dissociation inhibitor of Rho GTPase (RhoDGI), which suggests that in addition to functioning as a cross-linker, ERM proteins may influence Rho signalling pathways. The crystal structure of the FERM domain reveals that it is composed of three structural modules (F1, F2, and F3) that together form a compact clover-shaped structure.[3] The N-terminal module is ubiquitin-like. The C-terminal module is a PH-like domain.
The FERM domain has also been called the amino-terminal domain, the 30kDa domain, 4.1N30, the membrane-cytoskeletal-linking domain, the ERM-like domain, the ezrin-like domain of the band 4.1 superfamily, the conserved N-terminal region, and the membrane attachment domain.[1]
Ezrin, a component of the undercoat of the microvilli plasma membrane.
Moesin, which is probably involved in binding major cytoskeletal structures to the plasma membrane.
Radixin, which is involved in the binding of the barbed end of actin filaments to the plasma membrane in the undercoat of the cell-to-cell Adherens junction.
Talin, a cytoskeletal protein concentrated in regions of cell-substratum contact and, in lymphocytes, of cell-cell contacts.
^ abcChishti AH, Kim AC, Marfatia SM, Lutchman M, Hanspal M, Jindal H, Liu SC, Low PS, Rouleau GA, Mohandas N, Chasis JA, Conboy JG, Gascard P, Takakuwa Y, Huang SC, Benz EJ, Bretscher A, Fehon RG, Gusella JF, Ramesh V, Solomon F, Marchesi VT, Tsukita S, Tsukita S, Hoover KB (August 1998). "The FERM domain: a unique module involved in the linkage of cytoplasmic proteins to the membrane". Trends Biochem. Sci. 23 (8): 281–2. doi:10.1016/S0968-0004(98)01237-7. PMID9757824.
