?
mu-homology domain (MHD) of F-BAR domain-containing Fer/Cip4 homology domain-only protein 1 (FCH domain only 1 or FCHo1, also known as KIAA0290) and similar proteins This family corresponds to the MHD found in ubiquitously expressed mammalian membrane-sculpting FCHo1 and similar proteins. FCHo1 represents a key initial protein that ultimately controls cellular nutrient uptake, receptor regulation, and synaptic vesicle retrieval. It is required for plasma membrane clathrin-coated vesicle (CCV) budding and marks sites of CCV formation. It binds specifically to the plasma membrane and recruits the scaffold proteins eps15 and intersectin, which subsequently engage the adaptor complex AP2 and clathrin, leading to coated vesicle formation. FCHo1 contains an N-terminal EFC/F-BAR domain, a proline-rich domain (PRD) in the middle region, and a C-terminal MHD. The crescent-shaped EFC/F-BAR domain can form an antiparallel dimer structure that binds PtdIns(4,5)P2-enriched membranes and can polymerize into rings to generate membrane tubules. The MHD is structurally related to the cargo-binding mu2 subunit of adaptor complex 2 (AP-2) and is responsible for the binding of eps15 and intersectin. Unlike other F-BAR domain containing proteins, FCHo1 has neither the Src homology 3 (SH3) domain nor any other known domain for interaction with dynamin and actin cytoskeleton. However, it can periodically accumulate at the budding site of clathrin. FCHo1 may utilize a unique action mode for vesicle formation as compared with other F-BAR proteins. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",