FERM domain C-lobe of FERM domain containing 1 and 6 proteins
FRMD6 (also called willin and hEx/human expanded) is localized throughout the cytoplasm or along the plasma membrane. The Drosophilla protein Ex is a regulator of the Hippo/SWH (Sav/Wts/Hpo) signaling pathway, a signaling pathway that plays a pivotal role in organ size control and is tumor suppression by restricting proliferation and promoting apoptosis. Surprisingly, hEx is thought to function independently of the Hippo pathway. Instead it is hypothesized that hEx inhibits progression through the S phase of the cell cycle by upregulating p21(Cip1) and downregulating Cyclin A. It is also implicated in the progression of Alzheimer disease. Not much is known about FRMD1 to date. Both FRMD1 and FRMD6 contains a single FERM domain which has a cloverleaf tripart structure composed of: (1) FERM_N (A-lobe or F1); (2) FERM_M (B-lobe, or F2); and (3) FERM_C (C-lobe or F3). The C-lobe is a member of the PH superfamily. The FERM domain is found in the cytoskeletal-associated proteins such as ezrin, moesin, radixin, 4.1R, and merlin. These proteins provide a link between the membrane and cytoskeleton and are involved in signal transduction pathways. The FERM domain is also found in protein tyrosine phosphatases (PTPs) , the tyrosine kinases FAK and JAK, in addition to other proteins involved in signaling. This domain is structurally similar to the PH and PTB domains and consequently is capable of binding to both peptides and phospholipids at different sites.
Feature 1:putative actin binding site 2 [polypeptide binding site]
Evidence:
Comment:ERM and merlin proteins might utilize interaction of the second masking motif with the FERM domain to compete with and suppress the binding of this region to actin