ANTH (AP180 N-Terminal Homology) domain, N-terminal region, of Huntingtin-interacting protein 1
Huntingtin-interacting protein 1 (HIP1) was identified in 1997 as an interactor of huntingtin; when mutated, it is involved in the neurodegenerative disorder Huntington's disease. HIP1 promotes clathrin assembly in vitro. Together with its interacting partner HIPPI, it regulates apoptosis and gene expression. HIP1 contains an N-terminal ANTH, a central clathrin-binding colied-coil, and a C-terminal actin-binding talin-like (also called I/LWEQ) domain. ANTH domains bind both inositol phospholipids and proteins, and contribute to the nucleation and formation of clathrin coats on membranes. The ANTH domain is a unique module whose N-terminal half is structurally similar to the Epsin N-Terminal Homology (ENTH) and Vps27/Hrs/STAM (VHS) domains, containing a superhelix of eight alpha helices. In addition, it contains a coiled-coil C-terminal half with strutural similarity to spectrin repeats. It binds phosphoinositide PtdIns(4,5)P2 at a short conserved motif K[X]9[K/R][H/Y] between helices 1 and 2. The ANTH domain of mammalian HIP1 was found to preferentially bind PtdIns(3,4)P2 instead of PtdIns(4,5)P2, which is considered to be an interaction hub in the clathrin interactome. This model describes the N-terminal region of ANTH domain of Huntingtin-interacting protein 1.
Jiyao W et al.(2023). "The conserved domain database in 2023.",